OCTOBER 1990 Enimmcs TECHNOLOGY - VIDEi mwM mm. Digital readout gives a second-by-second playback Df your rocket's flight ii[i(Q)^v mm Add up to 4 megabytes to your LaserJet for a ycaction of HP's price TEREO - COMPUTERS - SERVICE Stretch your counter's performance to 1.6 GHz! Display standard video on your computer monitor ©(0)iWl^TES3 How magnetrons work gcaioa^iSi^ 71896 48783' 1 $2.50 U.S. $2.95 CAN \ GERHSBACK jTi I?*- A iTi tT- nTij^D J'j Ij^^" t^ i . ... T i. X : ffi i T :"5!rt FLUKE AND PHILIPS - THE GLOBAL ALLIANCE IN TEST & MEASUREMEN FLUKI PHILIP: High Resolution Digital Meter ^000 counl digital readout; 20,000 cojnt mode (Fluke 87) lor 4V2 digit resolutioA Backlit display: Makes it easy to read Itie DMM in iwK crampect quartets. Automatically stiuis olf alter 68 seconds to save the battery. Analog Meter: Hlgti-speed analog display updates 40 times/ second-asfastasttieeyeMn follow; X10 Zoom baigtaph mode (Fluks 83 and 85) makes high resoiiilion oflsel measurements a snap! HotslBt with Fleii Stand": Protects rnete.' and provides lest lead storage. Fiexitiie leg allows meter lo be hung from peg, bent around a pipe, or used almost atiywtiere. FLUKE 83 FLUKE 85 VQlls.oNrr«.^mps.di(Ml«1es1.3Ljdbble£dneifiui1y.iTequEc;cyanddti1ycyct^ capacirana. Touch rtjld* reialive. proticlivetol^er wilhFlflt-sland'* ^ S199' t225- t}.3% bastcticaecurac y aTftbaaJcdcaHuracy 5 kH; acV Analog btarQi^ androAni AnatoQ bargraph and zoom T^reeyearwajranry Three yaafwarranly 'Sug{i«s^uS iisrprKv HecorilflnreMfasrhinimuiTisand maximums, plus true aritinnetic atyerage; audit)le Min Max Alert; selBciable response limes — 1 second and 100 ms (all models) plus 1 rrs Peak Min Mm (Fluke 87) Frequency counter: Accurate down lo (3.5 Hz; also measures duly cytJe Capacitance meter: Autorangirtg, witti manual ranging at the toudi of a button Meet the meter that brings an entire test bench to your job. The versatile F!uke 80 Series do-just-aiiout' everything "!«ulti" Meter. it offers everything you'd expect from an advartced handheid MM, plus a lot you'd find only in dedicated instruments. Plus Fluke-exclusive features you can't buy any- where else. Ail built witti the most advanced surface mount design and single-chip ASIC technology for a thinner, tougtier, more reli- able paclage. There's a fully annunciated display for clear operation. Duty cycle lunclion. High-speed analog indicator, A protective holster with innovative Flex-Stand'" for easy adaptable operation. Audible Input Alert'" to reduce the risk of damage to the meter, the user, and the unit being tested. Plus the strcmgest warranty in the business. All good reasons to move up to the truly- multi Fluke 80 Series today. You'll find 80 Series \MMs, at your Fluke distributor. For immediate, off-ttie-shelf delivery Cal! CIRCLE 121 ON FREE INFORMATION CARD 1-800-44-FLUKE, ext. 33 for the name of your nearest distributor. J*n Fluke Ml[!. Cn.. lit P.O Bw 509QI*S Z50C. Evenki. WA 9S2Q6 U.£: (206) »r-S4l» CANAEA: 4tB.39a-76C(] tm€R COINTWES: (206) 356-S5O0 ©Copyriiht t389. JoMi Fhjte Mlg Co, Bit All iiglits raswl Piitm ant ifeaha^am, sub^ lo ctiange yiiltm nottg. M no (Jt(2-F60 FROM THE WORLD LEADER IN DlGiTAL MULTIMETERS. FLUK October 1990 Ei^tmrit^s. 37 ROCKET ALTiiVIETER Follow the flights of model rockets with a second-by-second electronic playback, John Fleischer 47 1.6-GHz COUNTER PRESCALER Update your old frequency counter with this low-cost, high- performance amplifier/prescaler. Fred J. Hum 55 LASER JET IVI EMORY CARD Build a 4-megabyte memory expansion board for your LaserJet IIP or III printer. Bill Green 59 NTSC-TO-RGB CONVERTER This inexpensive circuit lets your VGA monitor work as a TV. Jim Harrigfeld 67 TV SERVICE CASE HISTORIES Servicing tips and tricks gleaned from real-life cases. Cleo Zymarie 71 INTRODUCTION TO MICROWAVE TECHNOLOGY A look at the principles of magnetron tubes. Joseph J. Carr ■^'l-'^IJI^J^:^- Vol. 61 No. 10 BUILD THIS USER JET MEMORY CARD\. PAGE 55 TV SERVICE CASE HISTORIES PAGE 67 86 COMPUTER CONNECTIONS Create MIDI-compatible music scores with Audio F/X and use EHjnii^^ UltraViston to control your monitor's display. Jeff Holtzman 98 Advertising and Sales Offices 10 VIDEO NEWS 77 HARDWARE HACKER What's new in this fast- A variety of fitters, and a changing field. unique digital thermometer. David Lachenbruch Don Lancaster 20 EQUIPMENT REPORTS 84 AUDIO UPDATE Optoelectronics Handi- An Audio Engineering Society Counter LITC3000 and the conference report. Analyx Powercard PC- Larry Klein controlled power supply. 98 Advertising Index 1 2 Ask R-E 97 Free Information Card 14 Letters 89 Market Center q 30 New Lit 3 22 New Products 3 8 What's News | For those who already enjoy model rocketry — and for anyone who'sthinking of trying it — our cover project offers a whole new dimen- sion to the hobby. The Rocket Al- timeter charts the flight path of rockets with an accuracy and ease unheard of with visual tracking meth- ods. The device consists of an on- board flight recorder and an LCD module that's used to display the data back on the ground. The flight recorder takes four pressure sam- ples during every second of flight time. When it's connected to the LCD module back on earth, it dis- plays the rocket's peak altitude and gives a 'A-speed playback of the en- tire flight. If you'd like to create your own small-scale space program, check out the Rocket Altimeter on page 37. tn o z o CE m O Q < a: THE NOVEMBER ISSUE GOES ON SALE OCTOBER 2. BUILD A SOLID-STATE LASER Use the new visible-light laser diode to build a hand-held, battery-powered visible-light laser. PHONE-CALL SCREENING SYSTEM Build a system that puts an end to junk calls by requiring a special code. BUILD A PORTABLE QUAD ANTENNA Our 2-meter quad antenna is ideal for hill-top DX'ing. AUDIO SWEEP/MARKER GENERATOR Build this test gear designed for audio applications. As a service to readers. RADIO-ELECTRONICS publishes available plans Dr infDnnatiori relating to newsworthy prodgcts, techniques and scientific and teciinalagical developmonts. Because of possible variances in the quality and CDnditinn of materials and workmanship used by readers, RADIO-ELECTROhJIGS disclaims any responsibility ror the sate and proper functioning of reader-built projects based upon or from plans or Information published In tills magazine. Since some of the equipment and circuitry described In RAt^lO. ELECTRONICS may relate tc or be covered by U.S. patents. RADIO.ELECTRONIGS disclaims any liability for the infrinoement of such patents by the mailing, using, or seliing of any such equipment cr circuitry, and suggests that anyone interested in such prugec^ consult a patent attorney. RADIO. ELECTRONICS, (ISSN I»33-7862) October1990, Publlslied monliily by Gernsback Publications, Inc., 500-B Bl -County Boulevard. Farminodale. MY 1 1 73 5 Second-Class Postage paid at Famningdale. W and additional mailing offices. Second. Class mall raglstration f^c. 9242 authorized at Toronto, Canada- One-year subscription rate U.S.A. and possessions $17.97, Canada S23.97. all other countries $26.97. All subscription orders payable in U.S.A. funds only, via international postal money order or cfieck drawn ort a U.S.A. bank. Single copies $2 .50. '^.- 19^ byGemsback Publications, Inc. All rights reserved. Printed in U.S.A. POSTMASTER; Please sand address changes to RAOIO-ELECTfK^NICS. Subscription Dept.. Box 55115, Boulder, CO 80321-S11S. A stamped self-addressed envelope must accompany all submitted manuscripts and/or artworkor photographs If their return is desired should they be rejected. We disclaim any responsibility for the loss or damage of menuscripts and/or artwork or photographs while in our possession or o^erwise. Hugo Gernsback (1884-1967) founder M. Harvey Gernsback, editor-m-chlef. emeritus Larry Steckfer, EHF. CET. editor-in-chief and pubiisher EDITORIAL DEPARTMENT Brian C. Fenton. editor Marc Spiwak, aesooijite editor Daniel Goodman, technical editor Ktm Dunleavy, assistant technical editor Teri Scaduto. assistant editor Jeffrey K. Holtzman computer editor RobertGrossblatt, circuits editor Larry Klein, audio editor David Lachenbruch contributing editor Don Lancaster contributing editor Richard D. Fitch contributing editor Kathy Campbell, editorial assistant ART DEPARTMENT Andre Duzant, art director Injae Le«, illustrafor Russell C. Truelson, illustrator PRODUCTION DEPARTMENT Ruby M. Yea, production director Janice Box, editorial production Karen S. Tucker advertising production Marcetta Amoroso productionassistant CIRCULATION DEPARTMENT Jacqueline P> Cheeseboro circulation director Wendy Aianko circuEatlon analyst Theresa Lombardo circulation assistant Michele Torrillo, reprint bookstore Typography by Mates Graphics Ccver photo by Diversified Photo Services Radio-Electronics is indexed in Applied Science & Technology Index and Readers Guide to Periodical Liter- ature. Microfilm & Microfiche editions are available. Contact circulation depart- ment for details. Advertising Sales Offices listed on page 98- Radto-Electronjcs Executive and Administrative Offices: 1-516-293-3000. SubscriberCustonter Service: 1-800-288-0652- Order Entry for New Subscribers; 1-800-099-7139, Jf^\ Audil V_^ Bureau ol Circulation 5 WAYS TO STOP WASTING TIME IN ELECTRONICS. Stop wasting your time soldering. Save ■ hours of soldering, desoldering, resoldering Willi Quick Test'" sockets and bus strips. Connect/ disconnect resistors, capac- itors, transistors, ICs, etc. as fast as you can push in/pull out leads. Interlock for limit- less expandability. Priced as ; low as $1.60, you'll wonder / how you've done without them! 2 Stop wasting your time breadboard- H Ing. Here are three popular PROTO BOARD* Brand solderless' breadboarding systems that meet any budget or time schedule. First the diminutive PB-10's 840 contact points and 3-color binding posts. PB-102has 1,240 tie points, accepting up to 12 16-pin ICs Finally, PB-103, with 2,250 contact points, and up to 24 16-pin capacity. They're affordable, American-made lifetime guaranteed. You'll soon see why PROTO BOARD Brand is Today's Standard for Quality in Breadboarding. Stop wasting your time jury-rigging large numbers of circuits. Here are two oversized PROTO BOARDS Brand, with expanded area, tie points, and more to keep your ideas together. PB- 104 features 3,060 tie points, which can handle to 32 16-pin ICs with ease. Four color coded binding posts, and roomy 9.2" x 8" metai panel make it big. ..but simple. The humungous PB-105 lets you load up to 48 16-pin ICs, and much more onto its 5-color coded binding posts and 17 sockets, for over 4,560 contact points. Lifetime guarantee. American made. Affordably priced 4 Stop wasting your timeplugglng- in external power. We've added the power to the breadboard. And, what power! Up to triple voltage power. +5V, +12V, -12V, reg- ulated/current limited and DC. Up to 2,250 tie points, with 24 10 capacity and 14 pin DIPs. Now you can create, test and modify TTL, CMOS, Op-Amps and even microprocessor circuits. Plus, there is the standard Global Lifetime Guarantee on the sockets. And, wait 'til you see the modest prices! ,RD Brand is 3. PROTO BRAND 5 Stop wasting time designing computer circuits. Now you can use your solderless breadboard concepts for designing accessory ' circuits. PROTOCARD® is a PROTO BOARD Brand which fits any standard slot in your IBM. PC/XT or PC/AT computer. Some modules even include built-in basic decoder circuits for memory and I/O addressing. Breadboard areas up to 3,360 contact points. Buffered versions eliminate loading of pc buses. Call toll-free for details CyLOBAL 1-800-572-1028 SPECIALTIES Global Specialties, An Interplex Electronics Company. 70 Fulton Terrace. New Haven, CT 06512 Telephone: (2031 624-3103. t Interplex Electronics 1989. All Global Specialties breadboarding products made In USA. CD m 3 (O CD O CIRCLE 193 ON FREE INFORMATION CARD A0011 No other training— anywhere— sliows you service computers Only NRI walks you through the step-by-step assembly of a powerful AT-compatible computer system yoiJ keep— ■giving you the hands-on experience you need to work with, troubleshoot, and sen/ice all of today': most widely used computer systems. With NRI at-home training, you get everything you need to start a money-making career, even a computer sen/ice business of your own. NEW! Now includes AT-compatible computer with 1 meg RAM and 20 meg hard drive! No tioiibt about it. The best way to learn to service computers is to actually ftrnTrf a state-of-the-art computer from the keyboard on lip. As you put the machine togpther, performing key tests and (jemonstrations at each stage of assembly, you see for yourself how each part of it works, what can go wrong, and how you can fix it. Only NRI, the leader in career- building electronics training for more than 75 years, gives you such practical, real-world computer servicing experience. Indeed, no other training — in school, on the job, anytvhere — shows you how to troubleshoot and service computers like NRI. You get in-demand computer skills as you train with your own AT-compatible computer system— now with 20 meg hard drive and 1 meg RAM With NRI's exclusive hands-on training, you actually build and keep the powerful new AT- compatible West Coast 1010 ES computer, complete with 1 meg RAM and 20 meg hard disk drive. You start by assembling and testing the "intelligent" keyboard, move on to test the circuitry on the main logic board, install the power supply and 5- !4 " floppy disk drive, then interface your high- resolution monitor. But that's not all. Only NRI gives you a top-rated micro with complete training built into the assembly process HARD DISK DRIVE 20 megahyie hard disk drive you install internally for greater disk storage capacity and data access speed AT-COIWMTIBLE COMPUTEn 80286 CPU (12 MHz clock, wail slates), 1 itlcE RAM (expandable to 4 meg), 1,2 meg higji-dcnsity floppy disk drive. DIGITAL MULTIMETER Professional test instrument for quick and circuit measurements. Your NTU hands-on training continues as you install the powerful 20 megabyte hard disk drive— today's most- wanted computer peripheral — included in your course to dramatically increase your computer's data storage capacity while giving you lightning-quick data access. Having hilly assembled your West Coast 1010 ES, you take it through a complete series of diag- nostic tests, mastering professional computer servicing techniques as you take command of the foil power of your computer's high- speed 80286 microprocessor. In no time at all, you have the confidence and the know-how to work with, troubleshoot, and service every computer on the market today. Indeed, you have what it takes to step into a full-time. LESSONS Clearcut, illustrated iext.5 build your understanding of computers step by step. SOFTWARE Including MS-DOS, GW-BASIC, word processing, database, and spreadsheet programs. ^ money-making career as an industry technician, even start a computer service business of your own Voice synthesis training adds an exciting new dimension to your computer sicilis Now NRI even includes innovative hands-on training in voice syn- thesis, one of today's most exciting and widely applied new develop- ments in computer technology. You now train with and keep a full-featured 8-bit D/A converter that attaches in-line with your computer's parallel printer port. in school, on the job, how to troubleshoot and like NRI MONITOH High -resolution, nonglare^ 12'^ TTL monochrome moiitlor with Lilt and swivel base. TECHNICAL MANUALS You get "inside"' your Packard Bell computer system with exclusive NKi Training Kit Manuals plus technical specs direct from Ehe manufaciurer. DISCOVERY LAB Comi^lete breadboarding sysietm to let you design and modify circuits, diagnose and repair faults. DIOITAL LOGIC PHOBE Gives you first-hand experience anal)^ng digital circuit operation. Using your D/A converter along with the exclusive text-to-speech software also included, you explore the fascinating technology behind both digitized and synthesized computer speech. Ytju discover how you can use your computer to access and play back a variety of prerecorded sounds . . . you see how to add speech and sound effects to programs written in BASIC, C, Pascal, and others . . . you even learn how to produce high-qualiry speech directly from your own original printed text. NRI's exclusive new hands-on training in voice synthesis is just r I I I I I I I one more way NRI gives you the confidence- building experience you need to feel at home with the latest advaiices in computer technology. No experience needed, NRI builds it in You need no previous experience in computers or electronics to succeed with NRI. You start with the basics, following easy-to-read instructions and diagrams, movuig step by step from the fundamentals of elec- tronics to sophisticated computer servicing techniques. With NRI's unique Discovery Learning Method, you're sure to get tlie kind of practical hands-on experience that will make you fully prepared to take advantage of every opportunity in today's top-growth field of computer service. With NRI, you learn at your own pace in your own home. No classroom pressures, no night school, no need to quit your present job until you're ready to make your move. And all throughout your training, you have the full support of your personal NRI instructor and the NRI technical staff. Your FREE NRI catalog tells more Send today for your free full-color catalog describing every aspect of NRI's innovative computer training, as well as hands-on training in robotics, video /audio servicing, telecommunications, electronic music technology, and other growing high-tech career fields. If the coupon is missing, write to NRI School of Electronics, McGraw-Hill Continuing Education Center, 4401 Connecticut Avenue, NW, Washington, DC 20008. AT is a rcgistctKl trjdcmarb of Intemnional Business Machines Corporation School of Electronics McGraw-Hill Continuing Education Center 4401 CoiMccticut Avenue, N W Vfeshington, DC 20008 B CHECK ONE FREE CATALOG ONLY D Computers and Microprocessors D Robotics n TVA'ideo/Audio Servicing n Computer Programming tim For career courses approved under GI Bill D check for details D Secutit)' Electronics D Electronic Music Technology D Basic Electronics D Telecommunications I I I I I illL Nimc (Pieise Prim) Age g Address ■ CiLy/SESlc/Zip - Accredited Member, National Home Study Council - - 3-tOO ■ WHAT'S NEWS A review of the latest happenings in electronics. o z o tr t- o LLI _l UJ 6 < Progress in handwriting recognition IBM researchers in Yorktown Heights, NY, have reported the first accurate, real-time computer recog- nition of run-on, hand-printed charac- ters — even those that run together touch, or overlap. Previous handwrit- ing-recognition systems could recog- nize only hand-printed characters that were spatially separated or con- fined to boxed areas. The research effort, centered on the experimental IBM computer sys- tem called the Paperlike Interface, has as its ultimate goal computer rec- ognition of natural, cursive writing. The recognition of run-on characters is considered a significant step to- ward that goal. With the Paperiike Interface, a user "writes" with a stylus on a trans- parent digitizing tablet that is placed over a flat LCD. The tablet has a layer that allows the computer to sense the position of the stylus on the pa- per. The path of the stylus appears as "electronic ink" on the flat display directly below it. In the traditional, "segment-then- recognize" approach, a group of strokes — a stroke is the stylus mo- tion from the point where it first touches the tablet until it is lifted — is held in the computer's memory until the group forms a discrete character that the computer can recognize. In the IBM approach, called "recognize- then-segment," character samples are broken down into stroke tem- plates that the computer can recog- nize. Written strokes are matched against the stroke templates and la- beled to describe the possible character parts they might represent, and sequences of labels are exam- ined to see if they correspond to the components of particular characters. There are several advantages to the "recognize-then-segment" ap- proach. Because a single template can represent a stroke common to several letters, the number of tem- plate-matching steps can be signifi- cantly smaller. In addition, the recognition process can begin as bOXtD DISCRETE CHARACTLJ?5 Spaced Discre+e Characfers TRun-CTL di-screttly uJn" -Hen cliaraciers IBM'S PAPERLIKE INTERFACE computer system can recognize run-on characters, com- pared to existing tiandwriting recognition systems whicti are limited to boxed or spaced discrete characters. IBM hopes eventually to achieve real-time computer recognition of cursive script writing. soon as a stroke is complete, rather than waiting for the completion of a character. Stroke labeling also allows built-in constraint functions — diction- aries, for example — so that irrelevant characters or words can be pruned at early stages of the recognition pro- cess. Finally with stroke matching it is possible for the system to adapt to a particular writer, through an optional training process involving custom- ized templates. In addition to hand-printed letters, the recognizable writing could include hand-drawn "gestures" such as lines, proofreader's marks, mathematical symbols, and musical notes. Ges- tures could be used as computer commands, and the stylus could be used to perform mouse-like func- tions. It is possible that handwriting and gesture analysis could become as popular as the use of keyboards and mice, providing a more natural and convenient way to use and con- trol computers. R-E Consumer electronics trials CHRIS OSTERLOH (LEFT) AND CHARLES (TOMMY) WOOD (RIGHT) WON THEIR SEMI- final rour>ds in the consumer-electronics trials held in Washington, DC during a three>day competition hosted tiy the Electronic Industries Association (EIA) and the Vocational Industrial Clubs of America (VICA). Competitors were required to assemtile a stereo receiver, take a written theory exam, and troubles hoot 15 different pieces of consumer- electronic equipment. The 19-year-old semifinal Ists started the year-long industry train- ing programs in June — Osterloh with Matsushita and Wood with Sony — and will receive additional training from EIA instructors. One oj the two will be selected in May, 1991 to represent the United States In the International Youth Skill Olympics In Amsterdam next summer. Radio Shack Parts Place YOUR SOURCE FOR PROJECT AND REPAIR ELECTRONICS TTY Our Special-Order "Hotline" ICs, Crystals, Tubes, Much More Your Radio Shack store manager can special -order a wide variety of parts and ac- cessories from our main warefiouse. Over 200,000 ilems are available including va- cuum lubes, iCs, microprocessors, plioro cartridges and styli, crystais for scanners and computers, even SAMS Pholofacts* manuals. Best of alt, there are no handling cfiarges or minimum order requirements. Your order is sent directly to the Radio Shack near you and we notify you when it arrives. Delivery time lor most items is about a weel<. Battery Special-Order Service Hundreds of Types Available In addition to our large in-store stock, Radio Shack can now supply almost any currently manufactured consumer-type battery — for cordless phones, computer memory, camcorders, walkie-talkies, pagers and more Batteries are sent from our main warehouse to the Radio Shack near you. We notify you when they arrive and there's no postage or handling charge. Infrared Module Neater Wiring Tantalum caps "Snap" RFi Choke Complete, Easy-to-Use IR Detector III! Heart of a remote-control project! Combines detector, limiter, band- bass, demod, integrator and com- parator In a compact 3-lead module. #276-137 3.*9 (1) Heat-Shrink Tubing. V.6 to Vz" sijes #276-1627 . Pkg. of 7/1.79 (2) CableTi^yMarkera.Farcablesupto %■' dia. f27S-!648 Pkg. of 10/2.49 (3) Wire Markers. 630 "peel and slic1<" characters. #278-1650 Set '1.79 High capacilance in a liny size. tlF VWDC Cat No Each 0.1 35 272-1432 .69 0.47 35 272-1433 .59 1.0 36 272-1434 .59 2.2 35 272-1435 .69 10 16 272-1436 .79 22 16 272-1437 1.19 \ Snap'TogetherToroid Cores, Effeclive "roadWock" to radio -fiequency interfei- ence. Just wind on AC, phone, compuler, coax or audio cable, ihen snap choke togesher. #273-104 Set o1 Z/7.95 Resistance items Shielded D>sub Hoods "Ding-Dong" Chime Rod Antennas (1) ^W (3) (1) 1S-Turn Trimmers, Ik, * 271 -342 10k. (STl-atS. 20k. ('271-340. Each 1.49 ^2) Precision Thermistor, Resistance changes in proper lien le temperature. -50 10 +110° C. H27M10 1.99 [Z] Cplor-Code Decoder. #271-1210 79e (1) Fig. Description Cat. No. Each 1 2 9-PosiLion Metal 25-Posiiion Metal 9-Pos. Metaliied 25- Pes. Metalized 276-1508 276-1510 276-1513 276-1536 2.19 2.79 1.49 1.99 TNC and Mini-UHF Connectors S (1) (2) (3) 0, (4) (1) TNC Twlst-On Male for R6-58 Ca- ble. I'27e-140 1,99 (S) TNC Double -Female, #278-142, 1.99 Fig. Accepts Fits TNC Cat No Each 3 4 PL-2S9 BNC Male Female Female 278-119 278-145 349 4.99 t(5) (6) (7) (5) MInl-UHF Double-Female. Joins two mal9 mini-UHFs »278.172 . . 2.49 ($) Mini-UHF T Adapter. Female-malG. female power divider. #278-173 . . . 3.99 (7) UHF Adapter. Accspis Pl.-a59. Fits female Mini-UHF #278-174 3.99 Great Entry Alerter n This IC and mini-speaker combo has a pleasant chime output and it's ideal tor a customer-entry alert, doorbell or event indicator. Oper- ates from 6 to 18 VDC, ProduceseO dB sound pressure at 12 VDC. 5" leads. #273-071 8.99 Ftjr projects Or raplacmg damaged an- tennas on cordless handsets and bases. waikio- talkies and radios. We have over a doifln styles in stock. For example: Seoiions Emended Cai. No. Each 5 6 4 13" i7!y," 34:*." 270-1407 270-1409 270-1402 279 2.59 3.79 Soiderless IDC-Type connectors (1) (2) (3) W (5) Fig. Description Cat. No, Each 1 2 3 4 5 25-Posilion D-Sub Male 25 -Position D-Sub Female 34-Po5ilion Header 3S-Posilion Mala Printer Connector 34-Position Card-Edge Connector 276-1559 276-1565 276-1525 276-1533 276-1564 3.99 3.99 2.49 4.99 1.99 Electronic counter Module Prewired! Great tor a traffic or event counter. Counts up to 99,999. Advanced {Or reset) by external switch closure or digital circuit Ac- cepts count rate up to 7 Hz. Has Vi" liquid crystal display. Requires "AA" battery. With data. S277-302 16,95 Foldup Autoranging DVM Select the function and this precision Micronta* meter sets the range. Has automatic power-off when shut, detented hinge for best viewing angle. Mea- sures to 1000 VDC, bOO VAC, tOA AC/DC, 2 meg- ohms resistance. Re- quires 2 "AA" batteries #22-193 69.95 Dual-Power Soldering iron since 1921 Radio Shack has been the place to obtain up-to-date electronic parts as well as quality tools, test equipment and accessories. Today, with our big In-store selection and convenient special-order service, Radio Shack continues Its tradition of supplying high-tech products at com- petitive prices. We're America's Technology Store with over 7000 locations— NOBODY COMPARES Prices apply at participaling Rattio Shack stores anil dealers, f^adio Shack is a dlvisian tit Tandy Corporation Go from IS to 30 watts with the flick of a switch. Has replaceable tip, 6V4" long. UL listed AC, 364-2055 9.49 Replacement Tip. #64-2065 1.18 Chisel Tip, #64-2056 t,19 MMEmCA'S TECHNOLOGY o i tn m J] CO 10 o CIRCLE 78 ON FREE INFORMATION CARD VIDEO NEWS What's new in the fast-changing video industry. DAVID LACHENBRUCH o o H o o < EC • Instant VCR programming. Several proposals to make program- ming a VCR "as simple as pushing a button" have cropped up recently — and at least two are close to reaching the public. Widespread attention — in- cluding a reference by President Bush and jokes by stand-up com- ics — has been focused on the diffi- culty of programming VCR's. Is help finally on the way? Three systems are described below. VCR Plus. Several major news- papers and magazines, including The New York Times, the Los Angeles Times, the San Francisco Chronicle. and some editions of TV Guide will soon begin programming their read- ers' VCR's for them. That will be done by printing special six- or seven -digit code numbers along with the pro- gram listings. Viewers can punch those codes into a wireless remote gadget that will automatically set up VCR's and cable boxes to record the programs. The $59.95 gadget, VCR Plus, which is being marketed in selected areas by Gemstar Development Corp. , Monterey Park, CA, contains a 14-event timer that substitutes for the VCR's timer. The numerical code printed in the TV program listing con- tains all the information needed to set up the VCR (and cable box, if any) to record the specific program. The de- vice operates both VCR's and cable boxes, so it can be used to record cable programs on different channels (including premium channels) without any extra equipment. It can also "re- member" cable channels. For exam- ple, if HBO is on cable Channel 33 on one system and Channel 11 on an- other, the same code number may be used for both systems. The key is in the initial setup of the home unit. It comes supplied with special num- bers to correspond to the IR remote- control frequencies of various brands of VCR and cable boxes. Another part of the setup consists of inform- ing VCR Plus of the channel numbers occupied by various cable networks. Thus the code numbers printed in the program listings automatically switch the user's VCR or cable box to the proper channel. The system's propo- nents hope to go nationwide with VCR Plus next year Instant Guide. Gemstar's VCR Plus is just one approach to solving the VCR-programming problem. Something much more elaborate is in the wind. InSight Telecast of Palo Alto, CA, which is partly owned by the Japanese trading company Sumitomo, is cooperating with Public Broadcasting Service CPBS) on an on-screen program guide to be trans- mitted during the TV picture's vertical blanking interval. Using a VCR with a special adaptor, the viewer merely can select the program to record from the program listings without worrying about the time or channel. Pushing a button on the remote con- trol automatically sets up the VCR to record the program. The "Instant Guide" program ser- vice will be by subscription and will cost viewers about $5 a month, VCR adaptors are expected to cost around $100, but should be much less when built into a new VCR. The service is scheduled to start next year in the United States, with Sumitomo esti- mating that adaptors and adaptor- equipped decks will sell at the rate of one million per year SuperGuide. But Instant Guide also has some competition. Would you believe "SuperGuide? " The sys- tem, developed by a North Carolina company, was the subject of a paper at this year's International Con- ference on Consumer Electronics in Chicago, SuperGuide is described as "a low-cost, home-oriented, interac- tive, electronic, on-screen program- ming guide," designed to be "integrated with the TV tuner remote control, and other devices." The TV set receives a broadcast database of "programming for only those ser- vices to which a viewer subscribes." The hardware is described as costing less than $40. "Operation of the menus, as weW as the Guide itself, requires six buttons on the handheld remote: cursor keys up and down, page forward and page back keys, a select key, and a return key , , . Super- Guide takes a show you want to rec- ord and passes the information to a standard event timer in a VCR or sat- ellite receiver" Eventually, the sys- tem's proponents say, "SuperGuide will be ready to make recording on your VCR truly as simple as finding the show you want to record and pressing a single button." • Widescreen VCR. A VCR that will play both widescreen (16:9 as- pect ratio) and pictures of standard (4:3) TV proportions is under de- velopment by the VMS group. It al- ready has been demonstrated in Europe by Thomson Consumer Elec- tronics. In its normal mode, the VCR records conventional TV pictures. In the widescreen mode, tapes of 16:9 pictures are stored on the tape in horizontally squeezed form, A special signal on the sync track will automat- ically adjust future TV sets to display a "letterbox" picture, or on future widescreen sets the picture will fill the screen automatically. Letterbox pictures may be accommodated by many conventional sets without the automatic-adjustment facility by man- ual adjustment of the height control to obtain the proper picture propor- tion. TV sets that come equipped with widescreen picture tubes are ex- pected to be on the European market some time this fail, • Duat-deck VCR's. Go Video, which filed lawsuits against several Japanese manufacturers, claiming that they refused to make double- deck VCR's for it, is finally marketing its two-slot VCR. The unit, made for Go- Video by Samsung of Korea, will copy tapes (except for those using Macrovision anti-copy encoding), play back one tape while another is being recorded, or record tvro tapes sequentially. The suggested list price is $995. In Europe, Amstrad has an- nounced its own similar unit, which it calls the "Double Decker," for about $695, but says it has no plans to make one for sale in the American market, R-E 10 ELENCO & HITACHI PRODUCTS AT DISCOUNT PRICES ^^^ ^»i^ RSOs (Real-Time & Storage Oscilloscopes) From HITACHI The RSO ■ its the new solution View, Acquire, Test, Tfonster and Document Your Wovelorm Data >V5fj th Compact Series Scopes 4-Ctionnel, lOOMS/s Model Inttoductory Piice lOOMS/s (25MS/S on 4 channels sinulsaneously), lOOMHi, 4kwx Icti., 2to» x 2ch., Ikw x 4cti. VC-6145 i 4,695.00 Compacl, Full Feature Models 40MS/S, lOOMHi, 4kw K Ich., 2kw x 2cH. VC-6045 $ 3,049.00 20MS/S, SOMHz, 2kw x 2ch. VC-602S t 2,295.00 Low Cost/High Value Models 2QUS/S. SmHz. 2kw k 2ch VC-6024 $ 2.049.00 20MS/S, 20MHI. 2kw x 2ch. VC-6023 $ 1 ,749.00 RSOs from Hi1ac^t feature such functions as rail mode, averagcng, save memory, smoothing^ tnlerpolalion, pretr^gering, cursor measurements, pbtter irtterfaco, and RS-232C interface. Wrth the comfort of analog ar>d the power of digital. ^■^■•2 Hitachi Portable Scopes $435 DC to 50MHI, 2-Channel, DC offset ocio2DMHz function. Alternate magnifier function DualChannal V-525 CRT Readoul. Cursor Maas. 1 1,025 V-523 Delayed Sweep $995 V-522 Bask: Modal S8% V422 4aMHz Dual Trace $795 20MHz Elenco Oscilloscope $375 Oe1a/ed Sw^p Lighlwaighttt3lbs) 2mV Sens 3 Yr Warranty Model V-106S Shown This seties provides many new functions such as CRT Readout, Cursor measurements (V-1 085/1 06S/SS5), Frequency Ctr (V-1085), Sweeplime Autoranging and Trigger Locl< using a 6-incti CRT. You don't teel the compaclfiess in terms of performance and operatran. V-660 60MHz Dual Trace $1 ,195 V-665 60MHz Dual Trace w/Cursor $1 ,345 V-1060 100MHz Dual Trace $1,425 V-1 065 1 0OMHz Dual Trace w/Cursor $1 ,695 V-1085 100MHz Quad Trace w/Cursor $2,045 V-1 1 0CA 100MHz Quad Trace w/Cursor $2,295 V-1150 150MHz Quad Trace w/Cursor $2,775 MO-1251 • Dual Traca > Componant Tester • 6- CRT • X-Y Operation • TV Sjnc • 2 p-1 Pfotws FREE DMM with purcfiase of ANY SCOPE SCOPE PROBES P-l 65tYIHz. Ix, lOx SI9,95 P-2 ICOMHz. Ix, lOx S23.95 Elenco 35MHz Dual Trace tAoc MO- 1252 • High luminance 6* CFtT • 1mV Sensitivity • 6KV Acceleration VolEage • 10ns Rise Time • X'Y Operation • Z Axis • Delayed Triggering Sweep • Includes 2 P-t Profces Xr-^i^^f?: All scopes include probes, schematics, operators manual, and 3 year (2 yrs for Elenco scopes) world wide warranty on parts & labor. Many accessories available tor all Hitachi scopes. Call or write for complete specifications on tiiese and many other tine oscilloscopes. WE NOW CARRY COMI>LETE LINE OF FLUKE MULTIMETERS Models 21 F 83 85 87 23F 25F 27F 73 75 77F &050A M60A 8062A + More CALL FOR SPECIAL PRICING s True RMS 4 1/2 CHgit MutflfTteter M-7000 $135 .05% DC Accuracy .1% Resistance wHtt Freq. Counter and deluxe case Function Generator Blox #9600 fvi„# $28,95 Provides sine, Iriarote, square wavft from \Hz lo 1 MHz AM or FM capabJIily um 10 Function Multimeter CM -365 $65 AC + DC Voyage i Ainps Resistance lo 20aaUa Diode, Logic. & Trans lesl Capacitance to 200 uF Digital Capacitance Meter CM -1550 $58.95 9Ran9fls .1pl-20.O0OuId .5% basic accy Zero control Hithcase Triple Power Supply XP-62a Assembled $6S Kit $45 2to1SVal1A. -2 to -15V at 1A (or 4 to 30V at 1 A) and 5V at 3A Contains all the desired features for doing eKperiment^. Fealures short circuil pralaclion. all supptie$. LU * « Digital LCR Meter ^ LC-1S01 - $125 @ Measures: Coils 1uH-2(X)H Caps .1pf-200m i i. c|i Decode 6lox ^T#%10 or «9620 $18.95 t96ta Resistor Blox 47otinilo1US lOOKpol 19620 Capacrter Blox 4Tpl to 10 MFD Quad Power Supply XP.580 $59.95 Fully regulaled an3 shott circuil piplecte 292-7711 (708) 541-0710 WRITE FOR FREE CATALOG CIRCLE 109 ON FREE INFORMATION CAFID O 11 iii ASK RE Write to Ask R-E, Radio-Electronics, 500-8 Bi-County Blvd., Farmingdale, NY 11735 EGA TO CGA CONVERSION I'm trying to build a circuit that would slow down the sync of EGA video to CGA speed. The reason I want to do this is so I can use a cheaper com- posite monitor or RF modu- lator/TV combination. I have a circuit that will allow me to convert an RGB signal into composite video but it doesn't work when I try it with an EGA signal. Would I be on the right track if I used the 5321 Video Sync Generator IC or some kind of video buffer? Any help would be appreciated. — J. Ayala, Fort Lee, NJ Whenever someone upgrades their computer from CGA to EGA or VGA, they're faced with the same problem and, so it would appear, the same thoughts cross their minds. Since they already have a CGA monitor, there must be something that can be done to convert it for use with EGA or VGA. \Wiile it's certainly not impossible, converting a CGA monitor for use with a higher video standard is far from being a trivial task. You're cor- rect in assuming that the sync rates are very different for the two video standards, but this difference is a lot more than a simple obstacle. The chart in Fig. 1 lists the scan rates for several popular IBM video standards. As you can see, the CGA horizontal sync rate is a rather famil- iar number — 15.75 kHz. This is exact- ly the same as NTSC video so it's possible to use a standard NTSC monitor along with the computer Things are quite different when you switch to EGA or VGA and there's more involved than just worrying about the horizontal sync signal. Since your EGA card is putting out video with a horizontal sync rate of 21.8 kHz, it's about 38% higher than the rate for which the NTSC-compati- ble CGA monitor was designed. If you were absolutely determined to use the CGA monitor for EGA, there are three approaches you could take. We'll look at them in the order of decreasing complexity. Assuming that there's nothing you can do to your EGA card to make it work with a CGA monitor (some cards can be configured that way), the first way to solve the problem would be the one you're trying to take — convert the EGA signal to something compatible with CGA, Even though it is possible, it's going to be a lot of wori<, and the resulting image will probably be terrible. Your first step would be to build an NTSC sync generator (using a chip like the 5321 or discrete compo- nents), and then you'd have to design a circuit that would detect the hori- zontal sync on the EGA signal and gen lock it to the sync from the NTSC generator You'd need a phase lock- ed loop to keep both of the signals in phase. Of course you have to strip the sync from the EGA signal as well. The stuff I've described so far is a major undertaking in itself, and we're not even near the end. Since EGA video is being generated much faster than can be handled by a CGA monitor, you're going to need a bunch of memory to store the lines of EGA video until they can be sent out to the monitor at CGA speed. I haven't done the arithmetic but you'll need a lot of memory for the job. The good news is that there's probably enough time in the EGA vertical interval to finish sending out the stored video before the next frame begins. Since ISM v/P£o srA^£>A^os ]///}£ o ry/^£. ACJ^OM^ COi-O/?. SCA/^i^TEL A^OUOCNROME D/£,Pl^y AOAPT£R. A4€>A 3^/r /8^^3. //^ //^/ZCi/^BS Gy^AP'V-^CS /H^A/T.^^ Ar'GA S^i/V /Si^-3^ ^^ COLO A G^^PM/C^ ^j:>APT^^ CGA 8 /S7SO //^ BA!U^NC£i:} G^/'WCS A^^r^/?. £GA /e zmoa p^ /5€0^ GJ^P/i/CS Ji:>APT£/? PGC Z5B 30-/S0 //^ y/DEO GRAP^/CS APMAV VGA 2.-S6 3/^00 Pz both EGA and CGA operate at a ver- tical sync rate of 60 Hz, that's one less thing to worry about. The second approach to the prob- lem would be to look at the CGA monitor rather than the video being fed to it. If you're lucky enough to have the schematic of the monitor, it might be possible to increase the sweep speed of the flyback so the monitor's horizontal circuitry can lock to the EGA sync. Chances are you'll have to rebuild a good part of the monitor circuitry since the flyback transformer might not be able to han- dle the increased frequency. Even if you managed to overcome all this, you'll have to make sure that the per- sistence in the picture tube is up to EGA and that the dot pitch of the tube is at least 0.28 mm, since any larger pitch will create a really fuzzy image. The third approach to the problem is to donate the CGA monitor to a worthy charity and spend the bucks for an EGA monitor That's the quick- est, easiest, and probably feast cost- ly way to solve the problem (depend- ing on how you value your time and eyesight). What you'd like to do isn't impossi- ble, but the chances of getting a re- sulting image that's worth the time and money that it takes to work through all the design problems is about the same as finding intelligent life on Pluto. A NOISY SOLUTION Do you have a circuit for a simple analog noise gener- ator? I'd like to use the output to generate random clocking edges for a circuit based around a 7474 flip-flop. — D. Gates, Wichita, KS Since you didn't specify the kind of noise your were looking for (pink or white), I'm guessing that it doesn't matter And from what little you did mention about the application you have in mind indicates that all you're looking for is random-frequency sound. There are two ways you can easily generate the random pulses you're looking for. The first is to use a MM5837N noise generator chip, and the second is to use the old trick of reverse biasing any small-signal tran- sistor. Neither of those methods will produce true analog signals but, since you're feeding them to a digital circuit, you're probably better off with square waves anyway. Both methods are shown in Fig, 2. The component values aren't very critical and, as long as you stay within ten percent or so of the values shown, you won't have any problems with either circuit. The circuits are both self-starting and will pnoduce the kind of random pulses you're looking for, but you'll more than likely need some buffering circuitiy between them and the flip-flop. MJtiS8l7N "X" -OA/O/SE. N/C ZfJZS.S.Z OA AN^ ^f -0-Vl^/5i SURROUND SOUND VCR I recently purchased an LXI TV from Sears with Dolby Sur- round Sound. Do I have to buy a VCR with Surround Sound to get the most out of my TV, or will a regular stereo VCR de- code the Surround signals from my pre-recorded tapes? Also, is anyone manufacturing VCR's that include Dolby Sur- round Sound? — George Fos- ter, Detroit, Ml In answer to yourfirst question, the Surround signals are encoded in the standard left- and right-channel audio signals. As long as you are able to feed the left and right signals into a Surround-Sound decoder, the de- coder will be able to do its job, re- gardless of where it is located. As for your second question, there are no Surround-Sound VCR's that I know of, but that doesn't mean that they don't exist. And, considering Sur- round Sound's increasing popularity, I'm sure you'll see it incorporated into VCR's in the near future. R-E Extend Your Frequency Counter Range To I.3GH2 Without Extending Your Budget. FCI3OA Frequency Counter U .OlHz to 1.3GHz Frequency Range ■ 8-Digit LED Display Measures Frequency Period and Rale per itaiute (RPM) lOmV Sensitivity (lypical) ,£t3nn CHLMCi ■ r* D O i-i ri A tVUSrVHO-Mtm^i LriBTIP *Tt CftF "wm lwr>tT FTttQ nri r^-^ nnl ^ Dk hX K jlb^^k A Beckman Industrial " An Afflli3!e :>' Ei^^e^'i^or £,'ecrr.L Co R>r more infomation and tlie loc^on of your nearest authorized Beckman Industrial dfialer caU 1-800-854-2708 (in California 1-800-227-9781). InsUnmentation Products Division, 3883 Ruffln Road, San Diego, CA 92123-1898 © IS^ Beckman Industrial Corponuion. Specifications are subjen to diange wilhout notice. CIRCLE 163 ON FREE INFORMATION CARD JN1S1-0M0M Cable TV Descrambter Article Parts We stock the exact Parts for several articles putilished in Radio-Electronics magazine on building your own Cable TV Descrambler. February 1984 SB-3 Type 701 Parts Pkg 519.00 InctudBS all original parts. 702 PC Board 7.9S Original 3X4 etched, drilled and Silk-Screen pc board. 704 AC Adaptor 7.95 12 to IB Volt DC ® 200ma. 701, 702 & 704 29.00 All three tor special saving. February 1987 Tri-Wlode 301 Parts Pkg 29.00 Inclutles all original parti. 302 PC Board 7.95 Original 5X8 etched, drilled and Silk- Screen pc board. 304 AC Adaptor 7.95 12to1SVol!DCI§!200ma. 301, 302 & 304 39.00 Ail three for tpecial savings. Tri-Mode Tutor!al..7.95 2B pages ol in-depih Into, May 1990 Universal 901 Parts Pkg $49.00 Includes ail original parts. 902 PC Board 9.9S Original 4X7 etched, drilled and Silk-Screened pc board. 904 AC Adaptor S.95 12 Volts AC @ aSOma. 90T, 902 & 904 59.00 All three for speciai savings. CD22402E 12.95 Video sync IC (IC-9) Snooper Stopper.. .$39. 00 prevent Descfambier detection with snooper ^opp&f/data hiocker and protect your privacy, fnciiides free article on Cable Snooping. Macrovision Kit.. .$29.00 Macfovlslon now you sea IL, now you don't with our macro- scrubbef kit Originafly Published in Radio-ElectTontcs , 58 Channel Cable TV Converter with infra-red remote $69.95 Re-Manufacturer^ Jerroid 400 with new remote. Ctiannel 3 output. Compatible witti all External Descramblers. CALL TOLL FREE 1-800-332-3557 Outside USA Call t- 508-699-6935 Visa, MasterCard and COD, Free Catalog. Add $4.00 S&H, $6.50 Outside USA. D & D Electronics. Inc. PO Box 3310. VISA MC N. Attleboro, Ma. 02761 CIRCLE 201 ON FREE INFORMATION CARD O O CD m ID to o 13 SL Which symbol represents a variable inductor? CO O ■z. o EC H o LU _J 111 6 < EC 14 What is ttie principle disadvantage Of neon lights? What are aut-of-phase signals? Heath Video Courses speed your learning curve! Learn basic electronics at home at your own pace with lour, 60-minute video tapes. Know the variable inductor symbol. Recognije a PN junction. Understand osciilator fundamentais. Clearly SEE what most basic electronic books can oniy describe. DCBfCTROUCS. Covers electron movement to troubleshooting and repairing a simple electronic circuit. EV-31Q1-A. ACBfCTROnCS. Follow-up to DC Electronics. Covers the principles of AC, voltage and electrical measurement. Includes motors, generators and test instrument meter movements. EV-3102-A, SBVRCOnDUCTQfiS. Complete the DC/AC videos and you're ready to learn how semi- conductor devices are made, plus the principles ot discrete devices, integrated circuits & optoelectronic devices. EV-3103-A. BfCTnOMCCKCUITS. Completethe basic course with amplifier configurations, biasing, coupling, audio amplifiers, closed-loop vs. open-loop operation and more. EV-31D4-A. An activity-filled workbook and explanation ot how to solve each problem comes with each tape so you learn three ways — video . workbook and hands-on ! Order* today! C^l Toll free, 24-liouns a day. 1-800-253-0570. We accept VISA, MasterCard, American Express and Heath Revolving^ Charge card. Use Order Code 601 -023 Heath Benton Harbor, Ml CaUfor a FflEcatalog 1 -80044llEAm S199D, Healti Company Subsrdiarv of Bull Data S/slerqs, Inc. 'PficedDes not include shipfinfland tendling, or spplicabje sales lax. CIRCLE 86 ON FREE INFORMATION CARD LETTERS W\le to Letters, Radio-Electronics, 500-B Bi-County Blvd., Farmmgdale, NY 11735 BELLS A'RINGING I had the same problena as the au- thor of "Ring My Phone" iAsk R-E, Radio-Electronics, July 1990), due to the old-style phones with bell ringers. The newer phones with elec- tronic ringers use very little current. At first, I shut off the ringers, or disconnected sonne of them. I found that Motorola made an excellent "Telephone Tone Ringer," so I decid- ed to either make one for each phone or run another phone line and place it in a central location so that it could be heard throughout the house. I turned off all of my old phones and I discon- nected one wire to the ringer, I ran the ringer line down to the front doorbell box and installed my electronic ringer in it. If you want you can run another line to the garage workshop and an- other to the back patio. My phone rings loud enough now to be heard all over the house. Motorola has an excellent book en- titled "Telecommunications Device Data" (#DL136, Rev 1). See pages 2-201 and 2-241. Everything is in the IC and outside requires 3 resistors, four capacitors, and one piezo sound element. The cost is only about $4.80. Figure 1 shows a complete tele- phone-bell replacement circuit with minimum external components, on- chip diode bridge and transient pro- tection, direct drive for piezoelectric transducers. It rejects rotary dial tran- sients and has an input impedance signature that meets Bell and EIA standards. Three versions of MC34012 C-1 , -2, and -3) are available. Motorola's other options are the MC34017-1, MC34017-2, and MC34017-3. I hope that will be of interest to everyone. That's a much simpler cir- cuit than the one in Ask R-E. LLOYD F. THOMAS Oxnard, CA SERVICING VCR'S After reading Larry Klein's Audio Update in the July issue of Radio- Electronics, I was very disturbed that he would extrapolate his unique experience with head cleaners in his older VCR to recommend them as safe "... if used precisely according to instructions ..." I am a Certified Electronic Techni- cian CISCET) with over 20 years of experience, with 11 years servicing video tape recorders. The shop where I am employed services about 250 VCR's a week. Since January, I personally have removed more than 25 head cleaners from customers' machines. More than half of those machines required head replacement and straightening or aligning some part of the transport or basket as- sembly. Not one of the machines was over five years old. To refute some of Mr. Klein's state- ments: Our shop is not "Factory Au- thorized" anything, The price we charge for a cleaning is $9.95, For a complete mechanical overhaul — re- place belts, clutched idler, resurface pinch roller, and complete lubrica- tions — we charge $79.95. That comes with a one-year warranty, which is void if a head cleaner is used. Based on Mr Klein's recommenda- tions on protecting the cassettes, I assume he also covers his VCR and lives in a sterile, dust-free environ- ment. I am sorryto say that the major- ity of VCR's passing through our +4-^ 8 MCSMO/^ 1 ■sci. tt^ ■^l /■O^/:, /aV J Fig. 1. shop are so full of dust, fur, and as- sorted debris that we wear face masks to clean them. To generalize from my experience, if your VCR weighs over 40 pounds and is more than six years old, you can probably follow Mr. Klein's advice without endangering more than the video heads. Those machines were very tough and could withstand abuse. My own advice is to buy the very best high-grade tape, and, if the head clogs from a rented movie or cheap tape, put the new tape in and record for 15 minutes.. The chemicals the tape manufacturer puts on the tape do a good job of cleaning. JO ANNE ABBOT GET Poiitand, OR Is Ms. Abbott implying that head- cleaner cassettes tend to jam in ma- chines? That doesn't seem to hap- pen in my neck of the woods. (Of course, cassettes of any type will sometimes jam.) Perhaps things are cheaper iri Oregon than New York, but the cheapest price I've found a head-cleaning locally is $35. 00. The complete overhaul sounds like a great deal — it would cost a fortune in New York. I don 't cover my VCR or live in a "stehle, dust- free environ- ment and my consultants don 't think that the new machines are more frag- ile than the old. although they are lighter The cleaning method Ms. Ab- bott recommends is news to me. — Larry Klein, Audio Editor INGENUITY PAYS OFF I have a Sabtronics multimeter sim- ilar to the one illustrated in the "Ca- pacitance Adapter" article in the April issue of Radio-Electronics. A couple of years ago the high-current range indicated a malfunction while the meter was monitoring a battery- charging circuit that was supplying less than 4 amps. The 0.1 -ohm power resistor was open. I couldn't find a resistor of that val- ue and tolerance, so the high-current range was useless. Then, recently, I stumbled onto a somewhat unlikely remedy — wind a coil! I'd like to pass the procedure along for any other readers who might encounter the same problem. A few days ago, when I was check- ing an AWG table, I noticed that #18 wire has a resistance of one ohm-per 1 56 feet. It occurred to me that about 15.6 feet of #18 wire would give me More Features Give This lOOMHz Counter Universal Appeal At '339- UQOA Universal Counter ■ 5Hz to lOOMHz Frequency Range ■ 8-Digit LED Display Measures Frequency Period, Frequency Ratio, Time Interval and Unit Count 4 Selectable Gate Times Beckman Industrial " An AiUhale ot Emerson Etectric Co. For more information and ttie location of your nearest authorized Beckman Industrial dealer call 1-800-854-2708 (in Califomia 1-800-227-9781). Instrumentation Products Division, 3883 Ruffin Road, San Di«go, CA 92123-1898 © 1989 Beckman Industrial Corporation Specificaiions are subject to change wiihout notice. CIRCLE 1S4 ON FREE INFORMATION CARD JN162-0MDSa Be an FCC LICENSED ELECTRONIC TECHNICIAN! No costly school. No commuting to class. 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STATE ZIP AFTER YEAR MfeVe Become Better For You with • MODERN FACltreS * LOW Pff/CES • HIGH QUALITY • PROMPT 5EBWCE For Telecommunicattms • Industry • Two -Way • Amateur- Marine • Mictoprocessw • Radio Control • Satellite Let Us Solve Your Crystal Needs "A CUT ABOVE THE REST" JAN CRYSTALS P,0. Box 06017 ^^^1 Ft. Myers, FL 33906 Q " ^ -MPJ (813) 936-2397 TOLL FREE 1-800-526-9825 FAX ORDERS 1-813-936-3750 CIRCLE 104 ON FREE INFORMATION CARD O O m 33 CD CO o 15 my 0.1 -ohm resistor, and it would monitor 4 amps all day without heat- ing up. I had some #18 magnet wire on hand (from the good old days of audio-crossover projects), so I cut off about 17 feet, stripped the ends, cut the high-current leads of the dual-pur- pose resistor, and connected the magnet wire. Sure enough, it worked! The reading was high because of the excess margin I had allowed in cutting the wire, but it was easily trimmed down to the optimum resistance. My Sabtronics multimeter which has been checked against a lab-stan- dard meter, was accurate on voltage and resistance but not on high cur- rent, which violated Ohm's law in rela- tion to its other readings on the same circuit. Careful trimming of the mag- net wire corrected that condition. A lantern battery and a resistor make a good test circuit for Ohm's law eval- uation. Of course, you can't use clip leads in calibrating the magnet-wire length; you have to solder both ends in place, take a reading, unsolder, trim, and resolderoneendof thewire 16 .^^'^s^V, A: Pinott^* In one volume, NEW IC Pinout Guide: The compact, low-cost solution to your repair and maintenance headaches. Do you repair TVs, radios, computers.. anything containing ICs? Now you can open one book and find all the info you need to help you do your repair jobs quickly. • IC circuit connection data— pinouts— for over 170,000 ICs currently in use worldwide • Package style drawings " [C descriptions • Manufacturer information We guarantee the new IC Pinout Guide will pay for itself within two weeks. 30-day money-back guarantee. If you're not satisfied with the book, just contact us within 30 days. We'll refund your purchase price (less shipping and handling). Call today toll-free 800-854-71 79 to order your copy at the introductory price of only $99! You'll save $50 off the list price. The NEW IC Pinout Guide: Put the world of ICs in your hands. Global Engineering 2805 McGaw Ave., Irvine, CA 92714 Telephone 714-261-1455 800-854-7279 until your reading conforms to Ohm's law. Then you unsolder both ends and start winding your coil. A light applica- tion of five-minute epoxy will keep the coil compact. My calibrated wire came close to the 15.6 feet predicted on the AWG table, and wound into a neat two- layer coil on a piece of '/s-inch dowel. It sits atop the four-lead, dual-pur- pose power resistor, which still serves the 200- mA range. The meter has been upgraded in both accuracy and durability, and 1 doubt if the 0.1- ohm coil would heat up any faster on a 10-amp current reading than the test leads. R.R. DALLING San Diego, CA PHONE LINE CORRECTIONS In last month's article, "Build R-E's Telephone-Line Controller," the schematic diagram might cause some confusion. The 9-pin D con- nector, J2, was shown as a 10-pin connector. Pins 1-9 are correct as shown; pin 10 should be ignored. On the 62- pin card edge connector, the labels A1 -A31 should also be ignored . The metal PC mounting bracket that is available from AC&C includes cut- outs for all connectors. R-E CLEARER RESOLUTION I would like to clarif/ the answer given in/\sfc R-E to the "Lines of Res- olution" question (Radio-Elec- tronics, June 1990). First, the conventional definition of lines of res- olution in the horizontal direction is actually equal to the number of visible lines per unit picture height. That defi- nition allows proper comparison for resolution in horizontal and vertical directions. For example, on a 4-by-3 aspect ratio display. 440 visible lines would correspond to 330 "lines of resolution." Second, for a color CRT television, the electrical bandwidth is not the only limiting factor for resolution. The spacing of the color phosphors Cor pitch) is a limiting factor, especially for higher performance sets. In fact, an artifact similar to digital sampling aliasing can occur if the electrical sig- nal driving the tube has a bandwidth higher than the tube pitch can display. Finally, for the vertical direction, an NTSC display will not show 525 lines even though there are 525 lines of video available. Limiting factors in- clude 42 lines used for vertical timing and blanking, the CRT pitch, and the Kell scanning factor (which defines how much detail from a real scene can be encoded into a scanned for- mat. In NTSC format, vertical resolu- tion generally works out to 330 lines, which is equal to the 330 horizontal "lines of resolution" that are possible for a broadcast NTSC signal. KARL FRIEDLINE Liverpool. NY SPEAKING OUT ABOUT CABLE TV First, let me express my sincere appreciation for Robert Grossblatt's Drsw/ng Board columns on PC-board fabrication and video systems. Both series were timely informative, and entertaining, I'm writing about cable-TV signal "piracy." I wholeheartedly agree with Mr Grossblatt's concept that the ca- ble-TV service should not put the sig- nal on the line in the first place, if they won't permit you to intercept it. In some areas of the country, the pre- mium channel signals are blocked at the pole, preventing the signal from entering the customer's premises if not subscribing. I've been preaching Mr. Grossblatt's message — that the ca- ble companies have to catch up with the phone company in the area of "open access" — for some time now A mid- 1 960 's federal-court decision opened up the phone-company mo- nopoly; we need an equivalent federal -government- level decision for the cable-TV systems. What I find to be the most unnerv- ing condition is that the fed's are reg- ulating the EMF spectrum. It's as basic to our democracy as mom. ap- ple pie. and the flag, that each and every individual could do with the EMF in the air what he pleased, as long as he didn't hurt anybody with iti Once it's propagating through the ether, it's free— -or should be! Regula- tion of the signal on a wire is bad enough, but regulation of what we can do with what's not even on a conductor is unconscionable. Finally 1 want to thank you for con- tinuing to publish such fine technical The Only 5-Digit Sweep AM/FM Function Generator At A 3-Digit Price. FG3A Stveep/Ftinction Generator ■ 7 Frequency Ranges from 0.2H2 to 2MHz ■ Sine, Square, Triangle, Ramp, TXl and CMOS Outputs Linear or Logarithmic Sweep Internal/External AM or FM Modulation Beckman Industrial " An Atliliaie ol Emerson Eiecinc Co For more information and the location of your nearest authorized Bedtman Industrial dealer caU 1-800-854-2708 (in California 1-800-227-9781). Instrumentation Products Division. 5883 Ruffin Road, San Diego, CA 92123-1898 © 19S9 Beckman Indusirial Corporaiion. Specificaiinns ^ siib^ lo change without notice. CIRCLE 184 ON FREE INFORMATION CARD jNiB4.oi.ro90 with over 24,000 tndustf iai electronic corrjponents artd will. , . $htp your ofdertociaYM (800) 992-99431 ' ■ ■■■"■ ■^■^:%: ^mHmwm MOUS ELECTRONICS Stocking Loccations Across America CIRCLE 117 ON FREE INFORMATION CARD EARN YOUR B.S.E.E. DEGREE THROUGH HOME STUDY Our New and Highly Effective Advanced- Place- merif Program for experienced Electronic Tech- nicians grants credit for previous Scfiooling and Professional Experience, and can greatly re- duce the time required to comptele Program and reach graduation. No residence schooling re- quired for qualified Electronic Technicians. Througfi this Special Program you can puH all of the bose ends of your electronics background together and earn your B.S. E.E, Degree, Up- grade your status and pay to the Engineering Level. Advance Rapidly! Many finish in 12 months or less. Students and graduates in all 50 States and throughout the World. Established Over 40 Years f Write for free Desonptive Lit- erature, COOK'S INSTITUTE OF ELECTRONICS ENGINEERING m 42St CYPRESS DRIVE E JACKSON. MISSISSIPPI 3921 2 CIRCLE 58 ON FREE INFORMATION CARD O n CD to CO 17 Put Professional Knowledge and a COLLEGE DEGREE In your Technical Career through HOME STUDY w o z o (r h- o UJ _l LU 6 o < Add prestige and earning power to your technical career by earning your Associate or Bachelor degree through directed home study. Grantham College of Engineering awards accredited degrees in electronics and computers. An important part of being pre- pared to move up is holding the right college degree, and the abso- lutely necessary part is knowing your field. Grantham can help you both ways — to learn more and to earn your degree in the process. Grantham offers two degree pro- grams — one with major emphasis in electronics, the other with major emphasis in compyters. Associate and bachelor degrees are awarded in each program, and both pro- grams are available completely by correspondence. No commuting to class. Study at your own pace, while continuing on your present job. Learn from easy-to-understand lessons, with help from your Grantham instruc- tors when you need it. Write for our free catalog (see address below), or phone u.s at toll-free 1-800-955-2527 (for catalog requests only) and ask for our "degree catalog," * Accredited by the Accrediting Commission of the National Home Study Council GRANTHAM College of Engineering 250 Frontage Road Slidell, LA 70460 articles and continually sticking your necks out. Keep up the good work. RAYMOND C. MINICH Bradford. PA FREE CABLE TV I enjoy reading Drawing Board in Radio-Electronics, especially Robert Grossblatt's editorializing in the July issue, 1 agree that once the signal is inside your television set, you should be free to modify the TV for your own personal reasons in any manner you choose. 1 also feel that signals should not be scrambled. Subscriptions to cable should be on a pay-one-price basis, similar to admission to amusement parks (unlimited rides for one price), subway fares (unlimited rides for one token), and the cost of a postage stamp (25 cents to send a letter across the country or across the street). After the cable enters your home, you should be responsible for running the cable to all of your cable- ready TVs The responsibility of the cable company should end at an inter- face box on the side of your home, which would prevent a problem on your end from loading down the line. t8 Use KLOCKIT's Quick-Mount Inserts To Complete Your Electronics Project Turn Projects Into Profit! FREE 64-page 1990 Fall Catalog KLOCKIT is your best source for com- plementing electronic projects witti hygrometers, ttiermometers, barometers and mini clock inserts. Our catalog features quartz clock movements and exclusive clock kits. Build a clock for yourself or to give as a gift! Call for large volume pricing. Call tDll-free: -l-BOO-KLOCKIT (Dial's S5G-2548) P.O. Box &42, Dept. RE1090 ^^ LakB CBTitita, Wl 531 47 CIRCLE 200 ON FREE INFORMATION CARD Another gripe of mine is not know- ing the channel allocations on my friends' cable systems. I propose that all channels be assigned a 3-digit identifier For example. Showtime might be "347." Then, wherever i am, I could enter 347 in the cable box to receive Showtime. Cable boxes could even be configured to map channels in two modes — the current two-digit randomly assigned channel and a three-digit universal identiher — by pressing a selector button. ROBERT ELBURN Hicksville. NY DIGITAL DISPLAYS 1 have used the LCD display mod- ule mentioned in "Add a Digital Dis- play to Your Project" in the June and July issues of Radio-Electronics in a Morse-code translator based on an 8085 microprocessor I have found that, while it will respond to a 1 -micro- second (minimum) write pulse on the E pin, it requires a minimum delay of 1 millisecond between data entries; that is, individual ASCII letter entries must be spaced 1-millisecond apart, even though they will write into the module with a 1 -microsecond pulse on the E pin. The standard 6,144-MHz clock crystal was replaced to length- en the T states. Everything is done with software rather than hardware, as is done in other display devices. For example, if one wants to enter new data at the right of the display and push the old data off to the left, the shifting must be done by software addressing indi- vidual locations in the LCD. That gives flexibility, but with the limitation that the slow speed of the device is not compatible with normal Z80 or 8085 systems, ADELBERT KELLEY Tampa. FL THROWING CAUTION TO THE WIND In practically every article on using CMOS integrated circuits, repeated warnings are given on how to avoid static-charge damage and overheat- ing. As a matter of fact, one is always advised to use sockets, rather than direct soldering. Recently, I bought a kit to assemble a "Radalert" Geiger counter (Ra- dio-Electronics, June 1988, up- dated June 1989). Pfiesumablydueto space limitations, the 16 IC's had to be soldered directly to the PC board. with no sockets. The instructions outlined many items to avoid, es- pecially overheating, and said to use a temperature-controlled iron (if not available, then a 25-watt iron) and to allow a short period of time between soldering the pins to prevent heat buildup. In spite of all those warnings, I somehow managed to solder one IC in backward. That error was not dis- covered until all the chips, and most of the other components, were in- stalled. Of course, I was dismayed to realize it. There seemed to be three options; start over, with a new board and new components; remove the IC and buy a new one, or try to salvage the old one. It was obvious that to remove the chip, all 16 pins had to be un- soldered at the same time — impossi- ble to do. Since it was Sunday. I couldn't get any new parts, and waiting seemed intolerable, so I decided to throw cau- tion to the wind. By jamming a small screwdriver under the offending IC, while using the soldering iron up and down over the rows of pins, I pried and jerked the thing out. It took about a half hour; all the pins were bent and one was broken about half way up. By that time, all the remaining pin holes were filled with solder, and I had to use a very small drill to remove it. I straightened the pins and put the chip back in, but I made sure that I did it properly this time. Much to my amazement and relief, the IC worked beautifully. (It was the one that provides the pulse for the Radalert to measure the counts per minute.) That experience leads me to be- lieve that the extreme caution urged in handling IC's is overplayed and, quite often, unnecessary. There were also a few diodes that got in back- wards, but they caused no particular problems. In the end, the project worked very well, and the Radalert is now measuring counts in 12-hour pe- riods around the house to check the radon level. J.F, BURTON Downers Grove. IL It might have worked for you. but we'd hesitate to recommend your technique to others! By the way haven 't you heard of any of com- monly-used solder removal tech- niques ? They would have saved you a lot of grief.^Editor At ^215 This Function Generator Makes More Waves. FG2 A Function Generator ■ 7 Frequency Ranges from 0.2Hz to 2MHz ■ Sine, Square, Triangle, Ramp and TIL Pulse Output Duty Cycle Control \blt^e Controlled Frequency (VCF) Beckman Industrial ' An Atlthaie oi £mer.5c?rr Electee Co. For more infonnation and the loation of your nearest authorised Bedcman [ndustrial dealer call 1-800-854-2708 (in California 1-800-227-9781). Instmtnentation Produas Division, 3883 Ruffin Road, San Diego, CA 92123-1898 © 1989 Beckman Industrial Corporation. Spedfications are subfect lo change without nolia. CinCLE 1S1 ON FREE INFORMATION CARD JN163.0M090 Get A Complete Course In ELECTRONIC ENGINEERING 8 volumes, over 2000 pages, Including all necessary math and physics. 29 examinations to help you gauge your personal pro- gress. A truly great learning experience. Prepare novi/ to take advan- tage of ttie growing demand for people able to work at the eng in- ©ering level. Ask for our brochure giving complete details of content Use your free information card num- ber, or write us directly, $99,95, Postage Included. Satisfaction guaranteed or money refunded. >L rWV/ u Banner Technical Books, Inc. 1203 Grant Ave. Rockford. IL 61103 CIRCLE 67 ON FREE INFORMATION CARD <-<;v-,f^ CIRCLE 108 ON FREE INFORMATION CARD CO CO o 19 mnzEn optoelectronics Handi-Counter UTC3000 A 10 Hz-2.4 GHz universal CQunter that lives up to its name. CIRCLE 315 ON FREE INFORMATiON CARD Thanks to surface-mount tech- nology and MMIC's (mono- lithic microwave integrated circuits), handheld frequency coun- ters are rapidly approaching the ca- pabilities of benchtop models, A good illustration of that trend is the UTC3000 Handi-Counter from Op- toelectronics, Inc. (5821 N.E.. 14th Avenue. Fort Lauderdale, FL 33334). The UTC3000 is truly a handheld counter, measuring about 5'/3X4x 1'/2 inches. Even with its ex- truded-aluminum case and built-in Ni- Cd battery pack, the Handi-Counter weighs less than one pound. But don't let those statistics lead you to thinking that the counter is short on capabilities and features. The Handi-Counter has two input channels that provide a basic mea- sur-ement range from 10 Hz to 2.4 GHz, One channel, input a, has an input impedance of 50 ohms, and can be used to measure signals from 10 MHz to 2.4 GHz, A whip antenna is perfect as a probe for input a, and is a good choice for RF measurements. The second channel, input b, has a high input-impedance (1 megohm, 30 pF) and can be used to measure sig- nals from 10 Hz to 40 MHz, The input sensitivity of the 50-ohm input is <1 mV for signals with fre- quencies to 200 MHz, decreasing to <5 mV to 2 GHz, and to <10 mV to 2.4 GHz. Although outside the rated capabilities of the counter the Handi- Counter can typically measure sig- nals up to 3 GHz. but with reduced sensitivity. The rated sensitivity for the high- impedance input B is <10 mV to 20 MHz, and <20 mV to 40 MHz. Typical maximum readings extend up to 80 MHz. again with reduced sensitivity. The front panel of the counter fea- tures a 10-digit LCD readout. The dis- play features a built-in 16-segment Analyx Powercard PC-controlled Power Supply Transform your PC into a triple-output programmable power supply. CIRCLE 316 ON FREE INFORMATION CARD Although the IEEE-488 or Gen- eral-Purpose Interface Bus (GPIB) is in no danger of be- coming obsolete, test equipment controlled by the PC bus is becoming increasing popular That's great news for small test labs and even hobbyists g who are looking for a lower-cost way z to get automatic test and measure- cc ment capabilities. The latest example tS we've seen is the Powercard pro- y grammable power supply from Ana- 5 lyx. Inc. (P.O. Box 14644. Fremont. 5 CA 94539. cc The Powercard model PPS- W06 is an add-on board that turns any IBM PC or compatible computer into a tnple-output programmable instru- mentation power supply and multi- meter. It features one D-6-volt, 2-amp supply, and two -15.7--l-15.7-volt, 200-mA bipolar supplies. This "power supply on a board" is com- pletely contained within the PC; volt- ages are brought out to the user by a 26-pin ribbon cable and. if desired, into a convenient terminal box with 5- way binding posts. Installing the Powercard is easy. You simply plug the card into an emp- ty slot in the PC, and connect it to the computer's power supply, Clf you don't have any free power-supply ca- bles, there's no need to worry — a set of "Y" adapters is included.) Then you plug one end of the ribbon cable into the rear of the card, and the other end to the terminal box. If the Powercard conflicts with any other installed card, its base address can be changed by moving a set of jum- pers. The Powercard is controlled by an easy-to-use, intuitive program. The voltage and current output of each power supply is indicated numerically and with a bar graph. Voltage and current settings and limits can be en- tered numerically or they can be in- cremented using the cursor keys. Power-supply settings can be saved in files, and readings can be logged automatically. Our only complaint about the software is a minor one: The selected field is sometimes diffi- cult to find because it is made dim rather than being highlighted, in color, the selected field is much more ob- vious. 20 bargraph that indicates the relative strength of the input signal. That fea- ture makes the counter ideal for rela- tive field-strength measurements or even for locating hidden transmitters or bugs. While the Handi-Counter's basic specifications are impressive, its ad- ditional features, including period-, time-interval-, and ratio-measure- ment modes, are what make it ap- proach the capabilitiesof a bench-top unit. The additional modes are selected by using a function switch, which scrolls through the different options. When the power switch is turned on, the counter comes up in the frequen- cy mode. Successive presses of the function switch will select period, in- terval, and ratio functions; the se- lected mode is indicated by LCD annunciators. In the time-interval mode, the pulses that start and stop the timing must be applied to the a and b inputs respectively. In the ratio- measure- ment mode, the counter displays the ratio of the frequency of the signal at the A input to that of the b input. Aver- aging modes for time-interval and period measurements can increase the resolution of the display. Aver- ages of 10, 100, or 1000 measure- ments can be selected. The Handi-Counter'is supplied with a high-accuracy crystal timebase with a rated stability of 1 ppm Cpart-per- mtllion), A TCXO (temperature-com- pensated crystal oscillator) time- base, with a rated accuracy of 0.2 ppm is available as an option. With a base price of $375, the UTC3000 is a tough competitor that should come out a winner in most battles. The precision TCXO time- base will add $80 to the counter's cost, and an extra Ni-Cd battery pack (that doubles the operation time to more than two hours) will cost an additional $24. A custom-fit protec- tive vinyl carrying case is available for $15. If you've been thinking of a benchtop counter, we encourage you to look at Optoelectronics' handheld that seems to offer the best of two worlds. R-E While the software supplied with the Powercard is adequate for most purposes, complete instructions are provided for reading from and writing to on-board registers so that the board can be controlled by user-writ- ten software. We found the Powercard to per- form flawlessly and according to the manufacturer's specifications. We liked the fact that — because our computer is already on our test bench — the supply added virtually no clutter to our already-crowded work surface. We also liked that, unlike other computer-controlled supplies, the Powercard is self-contained. A separate host interface card Cas is required for GPiB equipment) isn't necessary. And since it's directly con- trolled from the PC bus, it's fast Of course, since the Powercard gets its power from the PC's supply, Its output power is limited. And even though most PC's have plenty of ex- cess power-supply capacity (the Powercard consumes a maximum of 30 watts), there is the possibility of overtaxing the computer's supply. Coax It Your Way Pomona's Universal Adapter Kit lets you make your own connections on the spot. You get two each of industry's most popular styles; BNC, INC, SMA, plus "N" males and females. Plus, a spedal Doubk'* Banana Plug and Double Binding Post. And, four inSermediate couplers to make it your way K!t.\-o. 5698 THIS SAMPLE SCREEN DISPLAY shows the settings at the three power supplies, and their readings as measured by the on- board 12-bit A,'D converter. The multimeter section in this example is set to Its resis- tance mode. You don't have to be vrorried about system crashes, however; the soft- ware continuously monitors the PC's supply voltage and displays a warning if the voltage drops below 4.75 volts. The Powercard will automatically shut down if the PC's supply voltage drops below 4.6 volts. Although it's sure to be copied, the Powercard is for the time being a one- of-a-kind instrument. It's priced at $995. R-E A Case For Reliable Connections. There's quality in every piece, with gold plated center pins and silver plated bodies. And everything's in a hinged, plastic case for years of dependable use. You'll find the best selection of coaxial adapters in the pages of the new Pomona Catalog. See your near- est Authorized Pomona Distributor. POMONA ELECTRONICS, 1500 E. Ninth St., P. a Box 2767, Pomona, CA 91769 (714)623-3463 FAX (714) 629-3317 . *'=«^ FREE 1990 CATALOG.' Tbottsatuis (^test solutions and accessories m thisfmii 138-page handbook (^qiialilyproclucia It 's Free! Call or write today ITT Pomona ^^- Use the Free Information Card for more details on these products. DIAGNOSTIC DISPLAY CARD. THE JDR POST Code display card provides system designers, engi- neers, integrators, and computer enthusiasts with a tool that locates the source of a system failure and displays a diagnostic code. Designed to alleviate the frustrating hours often spent trying to track down system failures, the card saves time, energy, and re- sources. In fact, the card can often solve problems in a matter of minutes, that would have taken hours. The easy-to-use POST Code card plugs into an available bus slot and uses LED indicators to display 'immunmmrmrK'fi CIRCLE 12 ON FREE INFORMATION CARD the code that corresponds to the problem. The mean- ing of the code can be found in the BIOS listings in the manual that comes with the card. That will help you to quickly locate almost any problem. The 80286- and 80386- compatibie card features switchless and jumperless design for easy installation and LED indicators for all power-supply voltages. Display LED's may be placed on-board, or on a back-panel bracket for easy readouts with a closed case. Because the circuit uses a dual GAL- chip design, it ensures ul- tra-low current operation and low noise. The POST Code diag- nostic card costs $49.95.— JDR Micro- devices. 2233 Branham Lane, San Jose, CA 95124; Tel: 408-559-1200; Fax: 408-559-0250. OPTOELECTRONIC IN- TERFACES. Dubbed the "Byte-to-Light" solution, the FOXI transmitter and receiver integrated circuits from Advanced Micro De- vices, Inc. (AMD) and BT&D Technologies con- vert light waves directly to computer-readable data, thus eliminating the tech- nical problems that once made optical connections difficult to use. The devices make it as easy for engi- neers to design optical links into electronic sys- tems as it is to install any other integrated circuit, AMD expects the "first in- telligent optoelectronic in- terface circuits" to dramat- ically increase the use of photonics in computing CO o z o cc H LLI 6 CC 22 MDdol UTCSOOO •^SOOH 22I0A I^IKIH'A Function Frijq, Period Hfltifl.Inlprtffll. Ave PrejiralE Frcquci^y Frequency Fiwii«^ RaiiEc lOlli- ■>AV,Hr. lUMHz- IOHe IMKz- 1 IKJHl Display lU Digit LCD w'.'FunctmTi Aiinuniriiitftrs in UtRit U'n K Digit LEI) liD.Bit KF Sismal SlronRth Indicator IG StfEment ,\djiiiitablp 1*3 St-ffmcnt Adjuiitablt. BaruTBpb • • Price $37E. «3S5. *J3». SITS. . SL'niiitlvlty; i;] to clDtnVtj'pjcnl. Timt^ HiniH-r ^ ],p])m,; ^.^ptiin, nrfrf S' E.^:i> MDiJial«, ^-3p^ni ttM &U0. - IjL'D MndtLv Sw.tti^ Sn AC chni^nt adapter includiKl. Carr,V Com-. AnU'nnn.-^ ami Urjfix* pxlra. 0Fn;,V4?Jirparij(& ]nbor \v.Lir.inL> m'l .»3I ptixluLj- i OPTOELECTRONICS The only name in HANDI- COUNTERS Check These Incredible Features On The All New UTC3000 dimply :j 111 axing! 10 Digit LCD Display. 1 H £ resr) lui ion to over 150 M H z di rect. Readable in bright sun Eight, • RF Signal Strength Bargraph. 6 Seamen U Zero^ & Full Stnlc adjust ment. SEE ihf input Hi^al) • Supersensitivity. EL cs-sies 60 HHl, 3 Channel, fi-Trace, Delayed S^eep. REB. tl09S-00 SALE MM. 95 tnOEL CS-?1S0 150 HHi, « Chinn^T, B- Trace, DeTftyed Sweep. REG. UiK.Oa MLE S14«B.95 MULOG OSCILLOSCOPES H/READDOT/CURSORS MOEl CS-SISO «0 MHz, Ousl Channel, 4-Trace, Delayed Sweep. REG. SIOSS.OO SALE teM.H /// |l^.^.^ & HODEL CS-4n25 20 llHz, Dual Channel Dscil loscope. REG. 1195.™ SALE $349.95 t|NT «OEL CS-5170 IDD mz. Dual Channel, *- Trace, Delayed Sweep. REG J1695.00 SALE tl3W.95 PDDEl CS-iOlD 100 NK! , ' Channel . 10-lr-ace, Delayed Sweep. REG. (1595. CO SALE $1699.95 MDEL CS-60ZO 150 ret;, 1 Channel , 10-1 race, Oe:ayed Sweep. REG i23S5.D,1 SALE $1999.95 Products International 8931 Brookv1ll« Rd. Silver Spring, HJ 20910 (800)638-2020 (301)5a7-78?4 FAX* 301-5B5-5402 EASY ORDER FAK LINE (800)545-0058 800-638-2020 CABLE - TV SIGNAL RE/H€VERS •FOR ELIMINATION OF SEVERE INTERFERENCE -FOR -CENSORING' OF ADULT BROADCASTS x-:iA ■ ATTENUATION - 45 dB TYPICAL ■ BANDWIDTH - 4 MH7 AT S (*B POINTS • INSERTION LOSS - 2 dB Hon EL TUMIKC FOR CMAMWELS PASSU HD PRICE JHIPPIMO 23H 50.6G MHz 2.3 \(n% mai»r himl ia-ym MHz lac NO SHIPPING or co.o CHARGES 40 FM 66-103 UHj 4.5 6 (or any FMI SMM MHz tut 1417 1M-14t UHr "4(A) 1S(B1 16(017(01 50.401) MHz »? 1622 H4-17J MH: U(E) 1SlF)2t)(G|!)(H12!(IJ sa.400 MHz no 713 174-216 MMz 7 8.9. 10.11. 12.13 504IH MHz iso 3 for $75 - 1 for $200 - mix or match CALLTOLLFREEFORCOD ORSENDCHECKTOOROER FAST DELIVERS 30 DAY MONEY BACK GUAR ANTeE{3 FILTERLIMIT) Star Circuits P.O. Box 94917 LasVegas, IJV 89193-4917 1-800-433-6319 CIRCLE 199 ON FREE INFORMATION CARD r quad flat-pack (PQFP) de- vices with 100 to 160 pins. The 5640 Series of clips fit EIAJ IC's of 100. 120, and 160 pins, spaced on 0,65- mm C0.025-inch5 and 0,80- mm CO. 031 5-inch) centers. Model 5643 fits the 120- pin (20 X 30), model 5644 fits the 120-pin (30 x 30), and model 5645 fits the 160-pin (40 X 40) devices. They "break out" each IC pin to a more accessible 0.64-mm (0.025-inch) square post. Tfie clips, which are cost effective compared to hand wiring or accessing diffi- cult-to-test leads, feature a press-on design to fit di- rectly over the surface- mounted IC's, keyed by a No. 1 pin locator. Contact with the IC's gull-wing leads is via specially con- figured, gold-plated, beryl- lium-copper pins. The clips' bodies are made of black, molded, liquid-crystal poly- mer Multiple rows of gold- CrRCLE 19 ON FREE INFORMATION CARD plated, phosphor-bronze square pins are positioned on a grid designed to match commercially avail- able headers. In single quantities, the list prices of the models 5643. 5644. and 5645 PQFP IC clips are $31 7,00, $353.00, and $425.00, re- spectively, — ITT Pomona Electronics, an ITT EMC Woddwide Company, 1500 East Ninth Street, Pomona, CA 91769; Tel: 714- 623-3463; Fax: 714- 629-3317, DIGITAL TROUBLE- SHOOTING KITS. For field-service and educa- tional applications. Global Specialties has introduced three digital-logic test kits that are TTL and CMOS compatible. The models LTC-6. LTC'7. and LTC-8 each feature a logic probe, a 16-channel logic monitor, a logic pulser, a tone-ohm- meter, and an accessory kit, all packaged in a rug- ged plastic carrying case. Each kit contains a logic probe to find pulses too fast for oscilloscopes: The LTC-6 contains a lO-MHz probe, the /.TC- 7 contains a 35-MHz probe, and the LTC-8 contains a 100-MHz probe. The static and dy- namic states of 16 logic in- puts are simultaneously displayed on the logic monitor The digital pulser is a pocket-size pulse gen- erator used to stimulate logic circuits with a single pulse or a continuous pulse CIRCLE 20 ON FREE INFORMATION CARD train. The tone-ohmmeter locates bad IC's and circuit shorts without unsoldering parls. The accessory kit in- cludes probe tips, ground clips, tip adapters, and quick hook cables, allowing "hands-free" testing. Prices for the LTC-6, LTC-7, and LTC-8 digital- logic test kits range from $299-00 to $379.00 each. — Global Spe- cialties, 70 Fulton Terrace, New Haven, CT 0651 2; Tel; 1-800-572-1028. R-E STANDARD FEATURES I FULL FUNCTION: Direct and prescaied Frequency, Periods (or averages), Time Intervals (or averages). Frequency Ratios, I WIDE FREQUENCY RANGE: 10 Hz to 2,4 GHz, useful 1 Hz to 3 GHz I HIGH RESOLUTION: 1 sec gate time displays 1 Hz in 200 MHz, I HIGH ACCURACY: TCXO ± 1 ppm standard 1 16 element signal strength meter 1 10 digit LCD readout I NBS traceable calibration ONLY 8579 OEt's mcKle! UTC 8030 is a full- featured Universal Counter-Timer with a Frequency Finder buiit in a unique bench, portable enclosure. Ttie Frequency Rnder's TO mV antenna sensitivity and NiCad batteries provide true off-the-air measurements at maximum distance from any transmitter up to 3 GHz, OPTOELECTRONICS, INC. 5821 NE 14TH AVENUE FORT LAUDERDALE, FL 33334 FLORIDA PHONE (305) 771-2050 CIRCLE 19S ON FREE INFORMATION CARD OPTIONS TCXO 80 S125 High precision 3 0.1 ppm sealed 10 MHz 20°-40°C temp controlled xtal oscillator NICAD 80 $75 Intemal rechargeable NiCad battery pack for >2 hours field use without recharging BL 80 $40 Display backlight for nighttime use ASK ABOUT USEFUL ACCESSORIES 1-800-3Z7-5912 FAX (305) 771-2052 o o UP m o 29 NEW LIT Use the Free Information Card for fast response 1990 INDUSTRIAL HANDBOOK AND AP- PLICATION GUIDE. Ac- culex, A MetraByte Company, 440 Myles Standish Blvd., Taunton, MA 02780; Tel: 508-880-3660; free. Newly expanded to 80 pages, this catalog con- tains full product specifica- tions and prices for a variety of Industrial monitoring and control products for instrument manufacturers, industrial OEM's, and end users. Also included are applica- tions, wiring diagrams, and 4-20-mA Process Loop accessories. Six sub-mini- ature thermocouple and RTD-input DPM's have CIRCLE 22 ON FREE INFORMATION CARD been added to the Acculex line of digital panel meters. Other new items include a full line of calibrators, sig- nal-conditioning modules, counters/timers, and the "Acupac" 4-20-mA Rack Mount Signal Conditioning System. The wide array of products described covers virtually all industrial ap- plications from tempera- ture, position, pressure, pH, high/low-level voltage input, dynamic watt mea- surements, level sensing, and resistance bridges. 1990 FULL LINE CATA- LOG. Sencore, Inc., 3200 Sencore Drive, Sioux Falls, SD 57107; Tel: 1-800-SENCORE; free. Sencore's entire line of products — all made in the U.S.A., and 93% pat- ented — is described in this catalog. Included are the latest in instruments for testing audio, video, and cable systems. Also fea- CIRCLE 24 ON FREE INFORMATION CARD tured are component and waveform analyzers, IEEE/ RS232 instruments, and a full line of accessories. Specifications and applica- tion information are also provided. B-E t/3 o z o tr o < EC 30 MARK V ELECTRONICS, INC. Competiti\e Pricing :i: Fast Shipping ORDER m CALIFORNIA 800-521-MARK ORDER OUTSIDE CA 800-423-3483 FREE CATALOG & INFORMATION (213)888-8988 FAX(213)8S8-6868 I nd icates the level of difttculty in the assembling of our P rod u cts . Amphljer TA-3600 TA-477 TA-802 TA-1000A ^ * vMelal Cabinet LG-1925 LG-1925 LG-1924 LG-1924 Tran$(ormer MOT #003 #001 #001 Kit Set Assmb. Sat $ 138.60 $ 160.20 $115.20 $130.50 $ 91.75 $104.15 $104.12 $122.32 A Beginner AA Intermediate AAA Advanced * SM-323 Fully Assembled S 139.00 $J5«Q5 Oue 10 (his spedal oWer&lowpfjce. wecanonlyexctian^eof repair any crillieae units jTA-36aO, JAA77. TA.aOZ £ TA.IOODA) wrchin 1 5 days at your rei^ipl. The above prices are lor 5he compiele sees. For soparaTe unil p^ice. please see betaw. AMPLIFIERS KIT MODEL TA-2eMKa ta-50a;b TA-SOC TA-120MK2 TA-300 TA-302 TA-3S3A TA-377A TA-dOO TA-477 TA-800 TA-802 TA-820A TA-10O0A TA.16O0 TA-220D TA-24O0A TA-2500 TA-28O0 TA-30O0 TA-3600 DESCRIPTION Digilal Voice Wemo AA ..$ 30,00 Muitl-Purpose Melody Generator A , 1 2 34 MulEi-Purpose Melody Generalor A 1 3.65 35WCIass-A''MajnF'owe/MonoAmp AA .-.,...,. 2B.50 3CW Muili- Purpose Single Channel Amp A 20.00 60W Slerco Power Boosler (w.'case) AA , „.. 30Wi;2 Stereo Pie-majn Amp A „ 29.50 Hi-Quallly FET Slereo Pre-Amp AAA ..._ , 59.95 40W Solid Slate Mono Amp A 28.00 120W Mosfcl Power Mono Amp.AA 63.00 80W<-3OW DC Pie-Main & Power Amp AA 60.92 80W+aOW DC Stereo Main Power Amp AA 45.94 60W<60W OCL DC Pre-Main Steieo Amp AA 40.39 1 0OW Dynamic Class '*A"Maln Power Mono Anyp AA 59.69 1 OOWkJ Class "A- DC Sleieo Pre-Main Amp AAA 73.70 FET Soper tjlass "A" DC Pre. Amp AAA 47.70 Elerllronic Ecno & Reverberation Amp AAA* , HO Pre-Amp. w.i'1 band graphic equalizer * m-FET IC Pre-Amp. w.'S way tone eonlrol AA 48.90 Stereo Simulator (mono TV .' any mono source) AA 27.0C 300W HQ Hi-Fi Power Mono Amp AAA. 79.00 17.20 1871 39.60 29.00 70.00 3B35 75.00 34.93 8500 79.20 69.72 49.37 SO. 58 95.61 68 24 96.00 68.80 63.57 38.50 103.00 MODEL TY-23B TY-25 Ty-35 TV-36 TY-38 TV-41MKV TY-42 TV-43 T^-45 TY-47 SM-222 SM-328 SM-333 SM-666 POWER SUPPLIES KIT ASSMB. Tfl-IOOA TF1-355A 0-1 5V 2A Regulated DC Power Supply (w.'casel AAA 0- 1 5V 5A Regulated DC Power SuppI/ A s 14 55 1 69.50 20 76 TR-365B 14.55 16.76 20.76 TR-503 O-50V3ARegu]atedDCPowarSupplyAA 22.66 ■" "iNSTftOMKOTS KIT ASSMB. MODEL L,G-1273 LG-16a4 LG-1924 LG-1925 Le-1933 DESCRIPTION 3 Ctiannel Color Lignt Controller AAA* S 51 .20 % 65.00 Stereo Loucispeaker Prolet:tDrA 13.85 13.65 FM W/ireless Microptione 10.22 ACVDC Quartz Digital Clock A 1 9.00 26 20 SourMtiToucti Conlrol SwitcJi A 12.00 Infared Remote Control Unilwycase AAA , 20.00 35.00 Ban'Dot Level Meier AA 24.15 3i/i Digilal Panel Meter A 89.00 38.00 20 Stops Bar.'Dol Audio Level Display AA 38.45 46.14 Superior Electronic Rouletle AA 19.46 27.24 7 Band HI-FI Graptilc Equalizer AAA 26.80 38.60 4 Ctiannel Protessional Color LIghl Conlrollar-*. 139.00 Audlo.'Video Surround Sound Processor AAA* 62.00 70,00 Dynamic Moise Reduclion A 26.00 34.00 MET.\?.gAbt!^ei^WmiAllMNUMi^AKEL W 1 12" 16- 19" 19- 19" tllri" 1115- MATCHING PRICE TA-28O0.TA-377A, TA-2E00 $ 22.16 TA-323A. TA-377A. TA.2200 26.64 TA-S02. TA-320A. TA- 1500. TA- 120MK 2. TA-BOO. TA-KMOA 32.00 TA-477,TA-e0O.TA-15O0.TA.1000A. TA.3600 36.00 TA-377A, TA-2800. TA-2200. TA-120MK 2 26.50 POWER TRANSFOR-MERS SM-43 SM-48 SM-4aA SM-49 SM-10O FC-1000A ■1 Mul1J'Fun[;tlonaJ Led D.P.M. {w/ABS plaslic case) AA $ 34.50 ; Hi-Precision 0. P.M. AAA 38.00 .• Hi-Presclsion D.P.M. {w/ABS plaslic easel AAA 41 20 3'A Mulli-Funt^ional LCD D.P.M, (w/liold (unciion) AA 36.00 150 MC Digital Freguency Counter AAA 79.00 1 GHi Freouency Counler * ^~ im.i.iwiiim.i.niii iliHifiiiHiiHiii MODEL #001 S 43.00 #002 48.00 62.00 44.50 90.00 179.00 #003 #004 #005 #006 #007 DESCRtPTtOI^ 56VCT.B0VCT6A 72VCT 3A 60VCT 6A 48VCT 6A 52VCT3A 36VCT 6A 112VCTSA MATCHING PRICE TA-SOO. TA-802. TA-320A. TA-1000A. TA-ISOO % 26.00 TR.603 TA323A TA 400 TA 300 21.00 TA.477 27.00 TA-120MK2 21.00 TR-355B 15 OO TR-3S6A 14.50 TA-3600 42.00 MARK V ELECTRONICS, INC. - 8019 E. Slauson Ave, Montebello, CA 90640;^ Q]^ CIRCLE 93 ON FREE INFORMATION CARD WITH CIE, THE WORLD OF ELECTRONICS CAN BE YOUR WORLD, TOO. Look at the world as it was 20 years ago and as it is today. Now, try to name onotlier field that's grown taster in those 20 years than electronics. Everywhere you look, you'O find electronics in action. In industry, aerospace, business, medicine, science, government, communications— you name it. And as high technology grows, electronics will grow. Which means few other fields, il any, offer more career opportunities, more job security, more room for advancement — if you have the right sidlis. SPECIALISTS NEED SPECIALIZED TRAINING. It stands to reason that you team anything best from a specialist, and CIE is the largest independent home study school specializing exclusively in electronics, with a record that speaks for itsell. According to a recent survey. 92% of CIE graduates are employed in electronics or a closely related Held. When you're investing your time and money, you deserve results like that. INDEPENDENT STUDY BACKED BY PERSONAL ATTENTION. We believe in independent study because it puts you in a classroom of one. So you can study where and when you want. At your pace, not somebody else's. And with over 50 yeais of experience, we've developed proven programs to give you the support such study demands. Programs that give you the theory you need backed with practical experience using some of the most sophisticated electronics tools avaOable anywhere, including our Microprocessor Training Laboratory with 4K of random access memory. Of couree, if you ever have a question or problem, our instructors are only a phone call away. START WHERE YOU WANT, GO AS FAR AS VOU WANT. ClE's broad range o! entry, intermediate, and advanced level courses in a variety of career areas gives you many options. Start with the Career Course that best suits your talents and interests and go as far as you want— all the way, if you wish, to your Associate in Applied Science Degree in Electronics Engineering Technology, But wherever you start, the time to start is now. Simply use the coupon below to send for your FREE CIE catalog and complete package of career infoimation. Or phone us, toU-fi-ee, at 1-800-321-2155 (in Ohio, 1-800-523-9109). Don't wait, ask for your tree catalog now. After all there's a whole world of electronics out there waiting for you. CIE Cleveland Institute of Electronics, Inc. 1776 East t7c}^ Scre^c, Oeveisnci, Ohio ^41,1^4 Mem]^I^FHSC Acoredlled MeirLbef National Home Studv Conjndl CIE Cleveland Institute of Electronics, Inc. 177B East I^Eh Screec, Cleveland, Ohio 4-4114 ARE-177 YESa** I want to learn from the specialists in electronics — CIE. Please send me my FREE CIE school catalog, including details about CIE's Associate Degree program, plus my FKEE package of home study information. Name (print): Address: Zip: City Age: Check box for G.l. Bill bulletin on educational benefits: MAIL D Veteran D Active Duty TODAY! Area Code/Phone No.: State: _ /_ Electronics Engineers & Designers! 95 Take any ^ books for only A •^ (Values to $168.40) ^ SHARPEN YOUR SKILLS— With Quality, Affordable Professional Books COMPUTER SCIENCE ENGINEERING MATH II GjmpiiErToob, Models and "fedrique 3059 S34.95 Master the art of modeling, ren- dering, and animating on your IBM® PC. J24 pp. Counts as 2. Nefworldng with Novell Netware *inogcr's handbook 3200 $32.95 Guidelines for enhancing software-driven project manage- ment in large or simll business- es. 320 pp. Counii as 2. 9321 $49.50 3429 $29.95 3241P tl6.95 This timt-saving handbook pro- vides problem-solving calcula- tions for engineering design, production and research, 4 1 6 j^. Counts as 2 Your source for well -developed, ready-to-use computer sUgoiithm codes. 180 pp. Get immediate access to infor- mation on calculations for all types of projects and phenome- na with this handy reference, 280 pp. f I i^^ 80336 IBM COMEUIBLE AMD SAVE A 8UNEIX p •W'-'/f ^H PERSONAL COMPUTERS 3283 S28.9S Covers all aspects of LAN plan- ning, installation, and operation. including standard and non- statKjard arrangements, 240 pp. 3197P S24.95 Provides all ihc information needed to begin programming with batch files. 400 pp. 3237P $24.95 This handy guide demonstrates such advanced features as debugging applications and Vir- nisl 8086 Mode. 432 pp. 3131 $26.95 Assemble your own powerful microcomputer system . . . it's easy and inexpensive. 224 pp. 2809 $29.95 This hands-on servicing manual covers IBM-PC/XT/AT and compatibles, MAC. Apple II series. C-64&I2S and more. 4 16 pp- ELECTRONIC CIRCUITS- o o 111 Q < THE KHCYtXOfEDl* OF ■ ELECTRONIC \ ciRCSirts SOUaNGHAMWOOK SURMa WXNTMC 325S 127.95 Stcp'by-stcp instructions for Eraublcshooting and repairing the ialcst in electrical equipment. 310 pp. 1938 $60.00 Over 1 .200 useful and versatile elecironic circuit designs. 768 pp. Coimts as 2 9244P $18,95 This revised and updated edition H both a comprehensive, industry-wide reference, and a valuable collection of project ideas. 3t2 pp. 9243P $12-95 This booli will eliminate Ehc guesswork in clioosing the best circuit or tracking down mal- functions in a completed circuit, 282 pp. 9825 $49.95 A comprehensive manual for soldering and cleaning printed circuit boards, 430 pp. 32 if) g z LU 6 ECONOMICAL SILICONE RUBBER TEST LEADS Best value in moderalely priced leads. High quality, soft, silicone rubber cable. Banana plug on measuring tip accepts push-on accessories; alligator clips included, Plugs have spring- loaded safely sleeves. Model TLIOOO $14.00 Satisfaction guaranteed. TEST PROBES, INC. Call toll-free for cata- log: 1-80O-368-5719 CIRCLE 225 ON FSEE INFORMATION CARD FREE PROBE REFERENCE GUIDE One -page chart lists TPI probes for most oscil- loscopes. Also cross references other probes to less expensive TPI equivalents. Performance and satisfaction guaranteed. TEST PROBES, INC. Call toll-free for guide and catalog. 1-800-368-3719 CIRCLE 22E ON FREE INFORMATION CARD DELUXE TEST LEAD KIT Users call TPI leads The Absolute BesL The TLS2000 features the highest quality cable in the industry - with spring- loaded safety-sleeved plugs. U.L. listed (file E79581). Kh:S30 Leads and probes only: S19 Satisfaction guaranteed, TEST PROBES, INC. Call toll-free for cata- log: 1-800-368-5719 CIRCLE 227 ON FREE INFORMATION CARD COAX ADAPTER KIT • Create any adapter in seconds • Make all combinations of BNC, TNC, SMA, N, UHF, Mini-UHF, F and RCA. The TPI 3000 A kit contain.5 male and female connectors of all 8 types, and 6 universal inter- faces. Simply screw any combination of 24 connectors to one of the interfaces to create the desired adapter. $150 TEST PROBES, INC. 9178 Brown EJeerRoad, San Diego. CA 92121, Call toll-free for catalog: 1-800-368-5719 CIRCLE 189 ON FREE INFORMATION CARD The World's Most Popular Probe Model SPIOO 100 MHz Switchable Ix-lOx '43 CIRCLE 226 ON FREE INFORMATION CARD More SPIOO Probes Have Been Sold Worldwide Than Any Other Probe Ever Made For Tektronix, Hewlett Packard, Philips, Leader, B&K, Kikusui, Hitachi, Beckman and other oscilloscopes Immediate delivery frotn distributor stock Economical - Substantial savings compared to OEM probes Durable - Unique cable is slim, very flexible and resists breakage 1 day return policy - Guaranteed performance and quality Free cross reference chart for all makes of scopes and probes. Call toll-free for chart and name of your local distribu- tor. PROBES. INC. 9178 Brown Deer Road San Diego, CA 92121 Toll Free 1-800-368-5719 36 CIRCLE 123 ON FREE INFORMATION CARD STATE-OF-THE-ART THE PROGMMmBU LOGIC BBmE HmBGOK I JHHlli I *773 $44.95 Examines Lhe significant ad- vances in comniunlcations tech- nology. 406 pp. 2962P SI 7. 95 Complete schematic diagrams, parts lists, and photos for build- ing a variety of projects. 296 pp. 9781 $68.95 Designed to help deal effective- ly with today's fast-paced EMC technology. 707 pp. 3098 $44.50 A comprehensive overview of CAD/CAM, CAE, and CIM concepts, c^pj^bililie^ and appli- cations. 43S pp. Counts as 2 ELECTRONIC COMPONENTS — i EXP BUMB ITSm AsnmoAL NEURAL NETWORKS 3140 M9.95 Includes detail.'! on PLD Icchnol- ogy: architectural characteris- tics, lech, tradeorfs, logic synthesis, software tools, dc- velopmcnl systems, and hard- ware. 480 pp. Counts as 2 POMGisuppiy H^NDBOOKHS. jiw S52.00 2672 $49.50 3199 SMT layout and design guidelines for effi- cient assembly processing, inspection and repair. I SO pp. Counti as 2 2672 Linear integrated circuits— speciflt:at]ons. prices & data. 614 pp. 3151 $39.95 3037 $24.95 9290 S36.0a 930S $59,50 3151 Frovid&s detailed insight Into every aspect of the engineering design process— fronrt tlie precor>cept phase thorough the life-cycle costs and commercial applications. 334 pp. Counts as 2 3037 Build your own neural networking breadboards— systems that can store and retrieve like ihe brain! 160 pp. 9290 Provides many ncvcr-before-published troubleshooting techniques and case histories. 315 pp. Counis as 2 9305 The solution-oriented handbook for practicing engineers at all levels. Contains hundreds of informative illustrations and diagrams demonstrating key principles. 600 pp. Counis as 3 How the Club Works: SEND NO MONEY NOW! YOUR BENEFITS: You get 3 books for $4.95 plus shipping & hand- ling when you join. Yoti keep on saving with discounts of tip to 50% as a member. 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This order is subject to acceptance b^ the Electronics Engineers & Designers Boat^ Oub- DRE1090 o e CD m XI — L CO CO o 35 liiiiiHillliiii ROCKET ALTIMETER Four... three,.. two.,.one... ignition! Mode! rocketry catches up with technology with this electronic altimeter. try allows hobbyists to man- age their own miniature space.^ program. Small-scale rockets! usually constructed from paper, plastic, and balsa wood, are rou- tinely launched with commercially made solid-fuel motors. Reaching al- titudes between 100 feel and several miles, model rockets are safely recovered by parachute to allow repeated flights and to reduce the risk of personal injur>'. [n NAR (National Association of Rocketry) contest events, a visual tracking system using triangulation is used to determine the peak al- titude of each model. The contestant who launches his rocket oiU-of-sight. or through the clouds, will receive a "track lost" rating instead of altitude points. Visual tracking, dependent upon weather conditions and operator skill, can often be difficult, and the spori flyer who wants to know how high his model went will rarely take the time to set up and operate visual trackers. Our rocket altimeter was developed to help contest and sport rocketeers determine their models altitude without tracking. This airborne ■'lltght-recorder"' is an all-CMOS microcomputer that is coupled lo an atmospheric pressure sensor via signal-con- ditioning circuitry. Powered by a 9-voit battery, the unit is small enough to be launched in a D-, E-. or F-motor powered model rocket. (The letters indicate the relative power of each engine: in aiphaheticai order, each engine Is twice as powerful as the previous one.) The unit takes a pressure sample eveiy '/i second and stores 1000 data values in memory during the flight. The completed system contains [wu sections: the flight-recorder section that goes up in the rocket, and an LCD module that's used to display flight data back on the ground. When the rocket returns to Earth, the LCD module is connected to the flight recorder and the peak altitude achieved can be displayed in 50-fool increments, along with a 'A-speed "playback" of the entire flight. Rocketeers now JOHN FLEISCHER 8 CD m J} S o CO o z o EC LU O D < have a reliable and accurate means to measure the altitude that a model reaches. The data obtained can then be used to cal- culate the speed and acceleration of the rocket. Figure 1 shows the con- struction and pinout of the SCX15AN pressure sensor used In the altimeter. The sensor, manufactured by Sensym (1255 Reamwood Ave., Sunnyvale, CA 94089). is a low-cost (about $42) plezoresistive IC In a strain- gauge bridge conflguration. The monolithic circuitry inside the sensor (see Fig. 2) is deposited on a silicon chip that has a cavity etched out to form a diaphragm. A port is on top, and a vacuum reference cavity is on the bottom. The result is a sensor that mea- sures absolute barometric pres- sure. Output voltage (VI -V2) ranges from 10-50 mV, and is proportional to atmospheric pressure — which, of course, var- ies with altitude. Although the entire unit is not temperature compensated, the sensor itself is, by means of two built-in ther- mistors. Best accuracy for the al- timeter is achieved in the 55-75°F range. Outside that range, a shift of 2% for every ICF will occur. Figure 3 shows the block di- agram of the system. The pres- sure sensor is buffered with an LM324 op-amp to feed an LM331 voltage-to-frequency (V/F) con- verter At ground level, a signal of about 3.7 kHz will be output by the V/F converter. As the at- mospheric pressure decreases (with increasing altitude), that frequency also decreases; at 15,000 feet, the signal is about 2.9 kHz. An RCA 1802 micro- processor calculates the altitude data from the frequency input. The entire system is made up from three separate PC boards, although only two ever leave the ground. The pressure sensor, the LM324 buffer, the V/F converter. and other support circuitry is lo- cated on an "analog" PC board, and the microprocessor and data-logging circuitry are on a "CPU" board. The two boards are held together with screws, and electrical connections are jum- pered between the two. The dis- play module is built on a separate PC board, and it stays on the ground; the module must be con- ftLUMINUM PLWl "^^^^^^^ fjYLOn SIGNAL WIRE BOND 3^^gQ,^.^p»TV SEAL HOUSING "^"Sr " ALUMINUM BASE PLATE SX SERIES SENSOR PACKAGE S)L GEL PROTECTIVE: COATING LEADS FOR ELECTRICAL CONNECTION PRESSURE MED!A(B) PRESSURE MEDIA(A1 FIG. 1— THE MONOLITHIC CIRCUITRY Inside the SCX15AN pressure sensor Is deposited on a silicon chip that has a cavity etched out to form a diaphragm. A port Is on top, and a vacuum reference cavity Is on the bottom. The result Is a sensor that measures absolute barometric pressure, which is then converted to altitude. SENSYM PIN DTEMPERATURE OUTPUT(+) PtN 2)Vs PIN310UTPUTf+5 PIN'IIGROUNO '(^PINSIOUTPUTHI " PIN 61TEMPERATURE OUTPUTH; 12 3 4 5 6 BOTTOM VIEW FIG. 2— THE SENSOR'S OUTPUT VOLTAGE (VI -V2) ranges from 10-50 mV, and Is proportional to atmospheric pressure. +5V DISPLAY MODULE MICRO- PROCESSOR CDP1S02 SAMPLE LED" FIG. 3— THE BLOCK DIAGRAM OF THE SYSTEM. The pressure sensor is buffered with an op-amp to feed a voltage-to-frequency (V/F) converter. At ground level, a signal of about 3.7 kHz will be output by the V/F converter; at 15,000 feet, the signal is about 2.9 kHz. nected to the other two boEirds via a ribbon cable to play back flight Information. Figure 4 shows the schematic of the CPU board ; i t gets i ts input from the analog board and logs the data every % second. The cir- cuit consists of the micro- processor which calculates the altitude, the EPROM containing the operating software, and the RAM where the altitude data is stored. Figure 5 shows the sche- matic of the analog board; the pressure sensor is located on this board. The output from the sen- sor is buffered and fed to the V/F converter, which provides the fre- quency input for the micro- processor. Figure 6 shows the schematic of the display module board. It is basically made up of the display driver and the display itself, but also contains the con- 36 06 V Q5 OE D7 IC8 G 06 74HC374 DO D5 D1 04 D2 Q4 D3 10 4 +5V IC3 A7 27C16 35' A6 CWIOSEPROM B6 B5 S4 B3 B2 B1 BO B7, J5 |3 11 |2 IB B1 9 BO 5 D !W-a Vz 4013 R Q S 1 - 3 6 1 4! 13 10_ (DATA J1-5 LOAD * J1-3 FIG. 4— THE SCHEMATIC OF THE CPU BOARD. It logs the data to be read back when the rocket returns to Earth. -^^ 9V OUTPUT mi IK O 1).F la |\ '■I \M32y '^ [^-^ \^ -If- ._s ^iri i» LM3I1H ni3 loot Tj FIG. 5— THE ANALOG BOARD outputs a trequcncy that's proportional to altitude. The sensor (IC1) is located on this board. trol switches. Power for the dis- play module comes from the other two boards via the ribbon cable. The software for the altimeter is available on the R-E BBS— 516-293-2283. (For those who prefer to type, the machine code for the EPROM is shown in List- ing 1.) The flowchart for the pro- gram is shown in Fig. 7, The software handles data logging (the sample LED flashes every Va second), mode switch input, and LCD interfacing. o o d m m — ^ CD CO O 39 as D ID □ u u u DSPl LtWW \'_A ip » n la ii 16 ii ^ a ;» 2ii ;c zb Ji 3i 3i y aa Ji 3b y 'a 4t <■ it 4c 4b y si ifw irlielis nl T3 IS 11 n\ t > I r U 5 4 'BeriNbl l>2 M M u W bT M tSbfDbllblZblsb' liTO ISf bl9 b20W1h22 bUsK-f bk b ^ SEjImomT SAMPU ji-i inci J5 .'-J _-S(>t«B«« I iia^4 it ZEBO f€M( MODE * .CI '1(if o z o QC H O LU O Q < EC FJG. 6— THE DISPLAY MODULE stays on the ground; when the rocket is retrieved, ttie data from the CPU board is displayed on this module. c START 3 INITIALIZE REGISTERS RESET MEMORY POINTER »y^^ STORE PEAK r .!- PTwratk — — .. YES, SET-UP DATA ^^MODE?. — NoT ^ CALCULATE SAMPLE DELAY ■ ' , STORE PEAK (F GREATER THAN UST «=: J,ASTSAMP^?:r>- N0| ■ INCREMENT CO JIfl" YES, BCD CONVERTER * it LCD DISPLAY DELAY RG. 7— THE SOFTWARE FOR THE ALTIMETER HANDLES data logging, mode switch tnput, and LCD interfacing. Construction Three printed-circuit boards are used. The pressure sensor and analog section are combined on a single-sided PC board. The CPU board is double-sided, as is the board for the display module. If the holes in either of the dou- ble-sided boards are not plated- through, feed-through wires must be used instead. All pads on the top and bottom of the boards must be soldered to the compo- nent lead or feed-through wire. {The boards available from the source mentioned in the parts list are plated- thro ugh.) To assemble the CPU board, fol- low the parts-placement diagram shown in Fig. 8. Install the re- sistors, capacitors, connector, switch, LED, and transistor. The crystal may be fastened to the board with foam tape or RTV sil- icone cement. IC sockets should be used to ease any future repairs All resistors are 'fy-watx, 5%, unless otherwise noted. R1 — 10 megohms R2 — 1 megohm R3— 100.000 ohms R4— 22,000 ohms R5 — 10 ohms R6— 2700 ohms, SIP resistor {cut to fit board) Capacitors C1-C3— 0.1 jjlF, monolithic C-l — 1 (iR 25 volts, tantalum C5— 100 M-F. 16 wits, electrolytic Semiconductors IC1— CDP1802CE microprocessor {GE/ RCA) iC2— HM6116LP-4 RAM IC3— 27C16 CMOS EPROM ICjI — 4013 dual D-type flip flop IC5— 4520 dual synchronous up counter IC6 — 4081 quad 2-input AND gate IC7— 4564 hex Schmitt trigger IC8— MM74HC374N octal trt-state D- type flip-ffop LED1 — red light-emitting diode Q1— 2N4401 NPN transistor Other components XTAL1— 2 MHz crystal 81— PC- mount slide switch J1— -10-pin header Miscellaneous: 10-conducfor ribbon ca- ble,3Vi-inch#6spaGers,3#6-32 x Vi- inch screws and nuts, PC board, IC sockets, wire, solder, etc. ANALOG BOARD All resistors are Vi-watt, 5%, unless otherwise noted. Rl — 50.000 ohms, 25-turn trimmer potentiometer R2 — not used R3, R4~4O.2O0 ohms, "/b-watt, 1%, meta!- film R5, R1&— 8060 ohms, i/S-watt, 1%, metal- fiim R6— 2000 ohms, Vl-watt, 1%, metal-fitm R7, Ra— 1 megohm. M-watt, 1%, metal- film R9. Rl 3— 100,000 ohms. 'A- wait, 1%, metal-fiim RIO— 20.000 ohms, Va-watt, 1%, metal- film Rl 1—100,000 ohms. 5% resistor, 1/4W R12— 47 ohms R14— 1000 ohms R15— 6800 ohms, !*-wa«, 1%, metal-film Capacitors CI, C5 — 4.7 jiF, 16 votts, tantalum C2-C4— 1 ia,F. 25 volts, tantalum C6— 0.01 M.F 50 volts, 5% film-type Semiconductor tC1~-SCX15AN pressure sensor iG2— LP2950CZ-5.0, 5-vott regulator !C3— LM324rM op-amp !C4 — LM331N vottage-to-frequency converter D1— 1N4002 diode Miscellaneous: 9-volt battery and clip, PC board. IC sockets, wire, solder, etc.. 40 GROUND FROM ANALOG BOARD FROM B1 L-^ + SV'FROM ANALOG BOARD FIG. S— WHEN ASSEMBLING THE CPU BOARD, the crystal should be fastened to the board with foam tape or RTV silicone cement to prevent damage due to vibration. + 9V +5V TO CPU BOARD TO +9V FROM CPU BOAflDf V ei 1'"n n' D] r I SOLDER LEADS i TO i BATTERY TERMINALS! tl MOUNT B1 ON FOIL Lj.-, iJSIDE OF BOARD WITH +yJ 'JDOUBLE-SIDED TAPE \l ) CPU BOARD n^ GROUND TO CPU BOARD 1R'4 , . MC2 o IC2 IC1 PORT B O _PORT, U A 1^.3 R5 (J BU K S _P0RTr' 1 , . Pa U R6Ft7s IC3 I ^ R12 Ria _ R1 J C6 ss. -TTTT ^ -RIO 1C4C FI15- +g-5^ FIG. 9— THE ANALOG-BOARD PARTS LAYOUT Carefully install the pressure sensor and, if you ever clean the PC board, do not allow any solvent or moisture to enter the sensor port. DISPLAY MODULE AM resistors are Vi-watt, 5%, unless otherwise noted. R1 — 1 megohm R2— 22,000 ohms R3— 10 ohms Capacitors CI ^70 pF, ceramic disc C2— 1 M-F, 25 volts, tantalum Semiconductors IC1— MM5483N display driver DSP1— LCD009 LCD module LED1 — red light-emitting diode Q1— 2N4401 NPN transistor Other components J 1— 10-pin header SI, S2^momentary pushbutton switch S3— SPST toggle switch Miscellaneous: 4 #6-32 x 1-inch screws and nuts. 8 Vt-mch #6 spacers, case, clear plastic sheet for display window, 40-pin wirewrap socket strip, PC board, wire, solder, etc.. Note: The following items are available from Transolve Corporation, 1336t Shady Lane, Chesterland, Ohio 44026 (216) 341-5970: Pressure sen- sor, S42; PC board set, S35; complete kit (except case), $13S; EPROM only, $15; machined case and custom EPROM's available on request. For large-scale rocket kits contact North Coast Rocketry, P.O. Box 2446B, Mayfield Heights, Ohio 44124. For more information on model rocketry in general, contact the National As- sociation of Rocketry, 2140 Colburn Drive, Shakopee, MM 55379. PLAYBACK MODE r^ --•^!.LED12i fl O -r- w .1 nr.r-^ m DSPl- 1* 1 It ■ ■J. ..-■ . '/ ' " : ! I J cLLi-^.^ ' ■ ■ ' ' t ' t ^ f ' IC1 MOUNTS UNDERNEATH DSPl 'J FIG. 10— DISPLAY BOARD parts-place- ment diagram. The LCD module is plugged into wire wrap socket strips above IC1, (Tl-ansolve Corp. will not service any non-socketed unit). Follow the analog-board parts layout shown in Fig. 9, and in- stall the resistors, jumper wire, diode, and capacitors. Note that C6 must be a film-type capaci- tor — a disc capacitor will cause excessive drift with temperature. Next install the trimmer potenti- ometer and the IC's. Carefully in- stall the pressure sensor as shown. If you ever clean the PC board, do not allow any solvent or moisture to enter the sensor port, or you'll damage it. You must test the analog board before attaching it to the CPU board. The display board parts-place- ment diagram is shown in Fig. 10. Install the resistors, capaci- tors, connector, LED, and ICl. The LCD module is plugged into wire-wrap socket strips above ICl. Space the top of the strips 'A- inch from the board. Make sure the LCD pins are perfectly straight, and press the display into the socket strips. The finished analog/CPU assembly is shown in Fig. 11. and the display module in Fig. 12. lasting and calibration Connect a 9-volt battery to the -I- and - battery input pads on the analog board. Connect your DVM and scope ground leads to battery - . The regulator output (1C3 pin 4) should measure 5 volts. Set Rl to midpoint. Con- nect scope probe to iC4 pin 3; this output signal should be a short, negative-going pulse, re- peating at about 3.7 kHz, Adjust Rl to obtain that value. Use a fre- quency counter if one is avail- able. Apply suction to sensor port A (draw a vacuum with your mouth) and verify that the signal frequency decreases slightly. If the analog board is function- ing, it can now be attached to the CPU board. The wire attachment points are designated in the three parts layouts. The 9-volt battery's positive lead connects to the CPU board, and the 9 volts from the CPU board is jumped over to the analog board. Also remember to connect ground, +5 volts, and the analog output between the two boards. A rocket is a very high vibration environment, so the 9-volt battery snap must be taped on, or the leads must be soldered to the battery. After the electrical connections are made between the two boards, the ana- log board is fastened to the CPU board with three screws, spacers, and nuts. Wire the pushbutton and tog- gle switches to the display PC board as shown in the display- module parts-placement di- agram. One of the normally open pushbuttons is used to select o o 03 m 3) (D CD O 41 PEAK, and the other zero. The to- ggle switch selects the playback mode (when closed). Install the header connectors on the ribbon cable that goes between the CPU and display boards, and connect the two boards together. Tlirn the power switch on and open the playback switch. The sample LED on the CPU and dis- play boards should be flashing four times per second. A value of several thousand feet should be displayed. Adjust Rl on the ana- log board for a reading of 100 feet, then 50 feet, and the unit will then be calibrated for ground level. Do not adjust past that threshold, or the altitude mea- MICROPROCESSOR EPROM POWER ON/OFF SAMPLE LED FIG. 11— THE FINISHED ANALOG/CPU ASSEMBLY. It fits in the pay load section of a rocket. LISTING 1 ] 000000 cO 00 c5 fS 00 b3 f8 fa a3 7a e3 65 7b 7a 7b 7a 000010 f8 20 b5 bl fS 06 35 f8 02 al fS 00 b2 f8 fO 32 000020 fS 02 55 el 82 f4 a2 e5 02 f2 32 31 fS fb a3 30 000030 34 f8 fa a3 7a e3 65 7b 73 05 fe 55 3a 27 11 81 000040 fb 06 3a la fS fb a3 7a e3 65 7b 7a 65 65 f8 00 000050 a9 b9 19 99 fb 10 3a 52 cO 00 db f8 00 a4 b4 3c 000060 5f 34 51 14 3c 63 f8 00 a5 f8 05 b5 cO 01 85 fb 000070 00 3a 5c cO 01 Oe f3 05 al f8 20 bl el fS 00 73 000080 73 73 51 c4 c4 fS 05 al 01 32 90 f8 00 51 30 95 000090 f8 05 51 30 bb 21 01 fb 09 32 al f8 01 f4 51 30 OOOOaO bb f8 00 73 01 fb 09 32 af f8 01 f4 51 30 bb f8 OOOObO 00 73 01 fb 09 32 bb fB 01 f4 51 24 94 3a 85 84 0000 cO 3a 85 CO 00 03 f8 00 a6 b6 a7 b? f8 20 ad bd cO OOOOdO 01 cO c4 c4 c4 c4 c4 c4 c4 c4 c4 35 g7 37 e4 36 OOOOeO ea cO 01 45 cO 01 07 cO 01 00 cO 01 78 c4 c4 c4 . OOOOfO fc 60 da f2 66 b6 be eO fe e6 00 01 02 00 c4 c4 . 000100 96 b4 86 a4 cO 00 76 fS 00 a7 b7 f8 20 ad bd CO : 000110 00 df c4 04 c4 C4 c4 c4 c4 c4 c4 C4 c4 c4 94 bf ; 000120 84 af 96 be 86 ae 9f 3a 2c 8f 32 36 2f 9e 3a 33 000130 8e 32 26 2e 30 26 9e 3a 3c 8e 32 3e 30 42 94 b6 000140 84 a6 cO 01 aO fS 00 a4 b4 3c 49 34 4b 14 3g 4d 000150 fS 00 a5 f8 05 b5 94 3a 61 84 fb 01 3a 61 cO 01 000160 70 24 25 95 3a 56 30 5e c4 c4 c4 c4 o4 c4 c4 c4 000170 94 5d Id 84 5d Id 30 le 4d b4 4d a4 f8 00 39 b9 000180 19 99 fb 30 3a 80 30 sO c4 c4 c4 c4 c4 o4 c4 c4 000190 c4 c4 c4 c4 c4 c4 c4 g4 c4 c4 c4 c4 c4 c4 c4 c4 OOOlaO 97 fb 03 3a af 87 fb fO 3a af 2d 2d cO 00 76 17 OOOlbO 30 ac o4 C4 c4 c4 c4 c4 c4 c4 g4 c4 C4 c4 c4 c4 0001 cO f8 20 a5 b5 fS 00 55 15 fS 01 55 15 95 fb 28 3a OOOldO c4 cO OO db c4 c4 c4 c4 c4 C4 c4 c4 c4 c4 c4 C4 OOOleO c4 c4 c4 c4 c4 c4 c4 c4 o4 c4 c4 c4 c4 c4 c4 C4 OOOlfO c4 c4 C4 c4 c4 c4 c4 c4 c4 c4 c4 c4 c4 c4 c4 C4 000200 c4 • • m jm ■1 Hi m ■^ FIG. 12— THE DISPLAY MODULE can be housed in any kind of project case you can find. C/3 O z o (r H O LU < B'AINCHES- THE ANALOG BOARD USES THIS FOIL PATTERN. 42 surements may be inaccurate. If not cycle. If a 50-foot reading can- the potentiometer adjustment is not be achieved, your altitude far off, the microprocessor may above sea level may be excessive. CDMP. THE COMPONENT SIDE OF THE CPU BOARD. THE SOLDER SIDE OF THE CPU BOARD. -4V< INCHES- e a B a e e e e a aajoe a 9 ajaVe In that case, simply adjust the value of R16 on the analog board: increase it by IK to decrease the reading by 1000 feet, or decrease it by IK to increase the reading by 1000 feet. Note that the potenti- ometer has enough range to al- low for "simulated flights" of thousands of feet. If the unit doesn't run, check for correct parts placement, sol- der bridges, and other defects. Verify that a 2-MH2 signal exists on ICl pin 1. The crystal circuit has a very high impedance. Any moisture or contamination may prevent oscillation (rosin flux won't hurt). Touching pins 1 or 39 of the microprocessor can cause the program to crash! Spraying the crystal area with clear lacquer is recommended. To reset the program, turn the power off for 5 seconds, then turn it back on. Removing the battery power will erase data. Switching the playback switch to off will resume data logging at whatever sample was last dis- played. The unit must be reset (turn off for 5 seconds, then on) before the next flight. Prepare for launch Mount the flight-recorder in the rocket payload section. Pack it securely with foam or some other support so that it will not rattle during flight. Punch sev- eral '/4-inch holes in the body tube near the sensor. An access port may be cut out to allow the ribbon cable to be attached. -3Vi INCHES- DISPLAY MODULE COMPONENT SIDE. DISPLAY MODULE SOLDER SIDE. 45 Oecrmnics® DtrDDDUD CO o o UJ 6 < DC 46 SIMPLY SNAP THE WAT-50 MINIATURE FM TRANSMITTER on top of a 9v battery and hear every sound in an entire house up to 1 mile away! Adjustable from 70-130 MHZ. Use with any FM radio. Complete kit $29,95 + $1.50 S + H. Free shipping on 2 or more! COD add $4. Call or send VISA. MC, MO. DECO INDUSTRIES, Box 607, Bedford Hills, NY 10507. (914) 232-3878. CIRCLE 127 ON FREE INFORMATION CARD FREE CATALOG OF HARD-TO-FIND TOOLS is packed with more than 2000 quality items. Your single source for precision tools used by electronic technicians, engi- neers, instrument mechanics, schools, labo- ratories and government agencies. Also contains Jensen's line of more than 40 tool kits. Send for your free copy today! JENSEN TOOLS INC., 7815 46th SL, Phoenix, AZ 85044. (602) 968-6231. CIRCLE 115 ON FREE INFORMATION CARD CABLE TV CONVERTERS AND DE- SCRAMBLERS SB-3 $79.00 TRI-BI $95.00 MLD-$79.00 M35B $69.00 DRZ-DIC $149.00. Special combos available. We ship COD. Quantity discounts. Call for pricing on other products. Dealers wanted. FREE CATA- LOG, We stand behind our products where others fail. One year warranty ACE PROD- UCTS. P.O. Box 582, Saco, ME 04072 1 (800) 234-0726. CIRCLE 75 ON FREE INFORMATION CARD LOW COST PC LOGIC ANALYZER. De- signed for students and hobbyists working with 5V TTI/CMOS signals in the Khz range. 36" data cable — eight channels, external clock, ground. Selectable trigger & clock edge, internal clock (1Hz-lOOKhz). Full-fea- tured software, state table graphics, file/print utilities, etc. Over 100,000 samples/sec on 12 Mhz AT LA1— $99.95. PHOTRONtCS, INC. 109 Camille St., Amite, LA 70422 (504) 222-4146. CIRCLE 179 ON FREE INFORMATION CARD CALL NOW AND RESERVE YOUR SPACE • 6 X rate $940.00 per each insertion. • Fast reader service cycle, • Short lead time for the placement of ads. • We typeset and layout the ad at no additional charge. Call 516-293-3000 to reserve space. Ask for Arline Fishman. Limited number of pages available. Mail materials to: mini-ADS, RADIO-ELECTRONICS, 500- B Bi-County Blvd.. Farmingdale, NY 11735. FAX: 516-293-3315 THE MODEL WTT-20 IS ONLY THE SIZE OF A DIME, yet transmits both sides of a tele- phone conversation to any FM radio with crystal clarity Telephone line powered - never needs a batteryl Up to Vt mile range. Adjusta- ble from 70-130 MHZ. Complete kit $29.95 -t-$1.50 S + H. Free Shipping on 2 or more! COD add $4. Call or send VISA, MC, MO. DECO INDUSTRIES, Box 607, Bedford Hilts, NY 10507. (914) 232-3878. CIRCLE 127 ON FREE INFORMATION CARD Activate the unit with the dis- play connected and verify ground cahbratlon (a 50-foot reading). Unplug the display, verify that the sample LED is flashing, and secure the hatch. Before launching, however, it is important to observe certain safety precautions in order to avoid unnecessary injury or property damage. First of all, al- ways use properly constructed rockets, launchers, and factory- loaded NAR-certified rocket en- gines. A model rocket should al- ways have a parachute recovery system. Never launch a rocket with a flammable, explosive, or live payload. Make sure that the launch area is free of obstruc- tions such as trees, power lines, and low-flying planes. Also avoid launching rockets on windy days or when clouds will obstruct your view of the rocket. To avoid fire hazards, never launch a rocket from ground covered with dry grass or shrubs. Always make sure that nobody is near the launch site, especially children. Launch the rocket using a re- mote ignition system. About four minutes of data will be stored, including the time on launch pad. When you recover the rock- et, plug in the display, press the PEAK button, and the peak al- titude achieved will be displayed. Next, switch the playback tog- gle to the closed position. Press the ZERO button (hold it for two sample LED flashes) and release. This will start playback from lo- cation zero at '/i speed (one sam- ple per second). The flight can be played back as many times as de- sired by pushing zero. The zero button may be pushed at any time to restart. Conclusion The collected data may be used to determine the performance of a model rocket. Many modelers are flying high-performance com- posite motors in their "birds" al- lowing altitudes of thousands of feet to be reached. Use of the al- timeter can help optimize rocket designs to get maximum altitude for a given engine size. Non-rocket uses of the system might include kites, hot-air bal- loons, hang-gliders, skydivers, and mountain climbers. What- ever your application, be care- ful... and have fun! R-E (Z. BUILD THIS 1.6-GHZ COUNTER PRESCALER Buifd this low'costf high-performance^ LS-GHz ampllfier/prescaler. You may want to keep that old frequency counter a while longer. ENGINEERS. TECHNICIANS, AND EX- perimenters who work with state-of-the-art electronics have an almost continuous need to update their test equipment in this rapidly changing field. High- er-frequency, less expensive cir- cuits have brought forth a new generation of inexpensive fre- quency counters with improved sensitivity that can measure into tlie microwave region. With the increased usage of higher frequencies, many quali- ty-built counters are being dis- carded mainly due to Inadequate range. Many of these instru- ments may only work up to 50-100 MHz. but have valuable features, including ultra-stable time bases that might yield much greater accuracy than could be found in newer, less expensive models. Enter our solution, a two-stage amplifier and dtvide-by-10 or -100 prescaler, with 10-segment LED signal strength indicator. Its inexpensive, compact, and can fit into a much larger instru- ment, like the Hewlett-Packard (HP) Corp. 5245L counter shown in Fig. 1. It has a typical sen- sitivity of 5 millivolts RMS from 50 MHz-1.6 GHz, and used with such a high-quality, low- range counter, is a practical way to up- date your gear. Many high-quality, major brand, low-range counters are available as surplus for $50-200. They're worth at least that much, if only for the time base, while a newer comparable counter may cost several times as much. The prescaler isn't just for old coun- ters; it's forany counter you'd like to extend the range or sensitivity of, or provide with an LED bar- graph indicator. Several divider schemes were considered for the prescaler. trading off bandwidth against cost; the original goal was 50 MHz— 1.5 GHz performance with excellent sensitivity. The pre- scaler divides (prescales) by 10 from 30-500 MHz, and by 100 from 300 MHz-1.6 GHz, for op- timal resolution from a basic counter. If you want to use a direct 50- MHz counter with 1-Hz resolu- tion and a one-second gate to measure up to 450 MHz. you'd have to prescale by 10 for a 7-digit resolution in one second, com- pared with 6-digit resolution if you prescaled by 100. To max- imize display resolution requires that the prescaler be able to di- vide by 10 to reach 500 MHz. Bin- ary dividers are cheaper and more common than decimal ver- sions, and prescaling by 256, 512 or 1024 is easier than by 100 or 1000, but decimal division lets you move a decimal point men- tally, and easily understand the reading. Circuit description Figure 2 shows the block di- agram of the prescaler, and Fig. 3 shows its schematic. IC5 has both -^ 2 and -^ 5 outputs, the one in use being selected using S2. With S2 set to -^ 100, IC3 is a ^ 4, and IC4 and IC5 are -h 5's. for a ^ 100. With 82 set to ^ 10. the input is routed around IC3 to 1C4 by PIN diode D4 (acting as a bandswitch). 1C4 is a -^5 coun- ter, and IC5 is a 4-2 counter, creating a -^10 counter overall. ICl and IC2 are broadband Mono- lithic Microwave IC (MMIC) am- plifiers used on both ranges. The output of ICl drives LED bar- graph DSPl. the RF signal strength indicator. It's very useful as a relative field strength meter, for peaking the output of a cir- cuit, or just as a convenient in- dication of signal presence. In the prescaler, D4 is used for bandswitching. When reverse-bi- ased. It's capacitance is almost constant from 0.65-0.75 pF. When forward-biased, it's capaci- tance rises rapidly to 6 pF or more. Its cathode is kept at about -I- 2.5 volts DC by voltage divider R7-R8; the drop across L4 is neg- o o m CO g 47 ligible. S2-a and S2-b switch the anode of D4 between + 5 volts DC and ground, so there's ± 2.5 volts DC across D4, relative to the cathode. With S2 set to ^ 10, D4 is for- ward-biased, so its capacitance increases as noted above, and the total impedance looking into the anode of D4 goes down, routing the output of IC2 through D4 and C9 to IC4. When S2 is set to ^ 10, 1C3 is off, since pin 1 (Vcc) is con- nected to +5 volts DC through R5. The R5-IC3 voltage divider reduces the potential at pin 1 to about 1.25 volts DC, turning IC3 off However you might wonder: Why not just turn off IC3 al- together? The reason is that CIO still looks into pin 7 (out 2), and would see too low an impedance if IC3 were totally off, and too much of IC2's output would be diverted away from 1C4. The val- ue of R5 was found by trial-and- error, to maximize the imped- ance looking into pin 7 (out 2), while keeping 1C3 off. Conversely, when S2 is on -^ 100, IC3 is now on, since it's now connected to + 5 volts DC through R5 and R6. and their parallel value is under 1.5 ohms. The cathode of D4 is still at 4-2.5 volts DC, but the anode is effectively grounded, so D4 is reverse-biased. The capacitance of D4 is now about 10% of its forward-biased value. Increasing capacitive reac- tance by about a factor of 10. The impedance looking into the anode of D4 thus increases, and almost no output from IC2 reaches 1C4 directly. The output of 1C2 enters IC3, is divided, and passed to IC4. lb avoid splitting the output of 1C3 between IC4 and the path along C9, trial-and-error again resulted in a high -Impedance path looking into the top of 09. In other words, the high impedance of a reverse-biased D4 works both ways. It keeps the output of 1C2 from being diverted to 1C4, while keeping the output of 1C3 from being diverted backward. The loss of output of 1C3 through C9-L4-R8 is minimal. The input enters through Jl and is AC-coupled through ICl and 1C2, Avantek MSA0104 MMIC amplifiers. They have dou- ble grounds and indirect biasing, through R1-LI-C26 for ICl, and FIG. 1— THE PANEL-MOUNTED VERSION of the prescaler, in an HP 5245L frequency counter. The HP5245L is often available as surplus for about $200, and the prescaler is a good way to update it. R2-L2-C15 for 1C2. Carbon-com- position resistors Rl and R2 tem- perature-compensate collector current in ICl and 102. LI and L2 prevent Rl and R2 from affecting the load impedance, which would reduce amplifier gain. IC3 is an NEC UPB582 -^ 4 MMIC pre- scaler, with R3, C8, C9, and D4 as its bypass for the -^ 10. D4 is a Motorola MPN3401 PIN diode, while R7 and R8 produce a -I- 2.5- voit DC bias at the cathode (the output) of D4 via L4. D4 is biased on or off by the or 5 volts DC switched through L3 at its anode. Device 1C4 is a Motorola MC 12009 emitter-coupled logic [ECL) -^5 prescaler, with a built- in ECL-to-TTL output level con- verter R9 keeps the circuit stable with no signal input. 1C5 is a TI 74S196 presettable binary/de- + 7.2V SIGOUT (AUX OUT ON AP-90-H) J2 1N40a7 ^- 10-1Z I VAC/VDC 1 (D5-D7ANDPL1F0R RANEL-MOUNT VERSION ONLY] FIG. 2— THE BLOCK DIAGRAM OF THE prescaler. ICl and 102 are MMIC amplifiers, 103 is a -^ 4 counter, IC4 is a ^ 5 counter, and IC5 lias ^ 2 and -. 5 outputs selected by S2. With S2 on -s-100, the input passes through IC3 and 1C4, and 105 is a ^ 5 counter. With S 2 on ^10, the input goes around 103, through PIN diode D4 to IC4, and ICS is a 2 counter. ICl drives DSP1, the RF signal indicator. PL1 is for the panel-mounted version only. 48 13VDC FOR AP-90>H (TEST ONLY) FIG. 3— THE SCHEMATIC DIAGRAM OF THE PRESCALER. DSP1 is a TSM3915 10-seg- ment LED bar-graph displsY; FlIS 3^^ R17 adjust zero and fulE-scate. 04 performs band- switching; it's reverse-biased capacitance is 0.65-0.75 pF, and over 6 pF forward-biased. With S2 on -^10, D4 is forward-biased, so its impedance goes down, and it passes tiie signal to 104. 103 is off, but pin 1 (Vcc) is at 1.25 volts DC to raise the impedance on pin 7 (out 2). With S2 on -s- 100, D4 blocks the signal, and it's now passed to 103. cade counter. It has separate ^ 2 and ^5 sections; the prescaler drives both, and you select the desired output using S2, R14 and R15 shape and pull up the output; the output will be 1—2 volts peak-to-peak into a load of 50 ohms or more. Display DSPl Is the Three-Five Systems, Inc. TSM3915 (formerly the National Semiconductor NSM3915) 10-segment LED bar- graph display; Fig. 4 shows the block diagram. It has an on- board monolithic IC with an ad- justable internal voltage refer- ence, high-impedance input buffer, accurate 10-step voltage divider, and 10 comparators. Rll and R22 bias D3 as an RF level detector coupled by C26 from ICl. D2 is directly connected to the high impedance input buffer at pin 6. Within DSPl, the signal is applied to 10 comparators, each biased differently by the pre- cision voltage divider, and driv- ing one LED. A low-voltage reference signal from R21-D2-R16 is applied to pin 5, to offset the input bias volt- age making RI6 the zero adjust- ment. R17 sets full-scale sen- sitivity by varying the internal reference voltage across the com- parators. The current from ref OUT (pin 8) deteriTiines the dis- play current and brightness. About 10 times this current is drawn through a lit segment, and is fairly constant despite voltage and temperature changes. The display is logarithmic, with segment thresholds at 3-dB intervals. If you remove V,-,,^ from MODE (pin 10} and join mode (pin 10) and LED 9 [pin 11), the display changes from a bar graph to a dot graph, with only the top LED of a reading lit. That saves current, but the bar graph is easier to read. The power supply provides reg- ulated -t- 7. 2 voits DC from 1C6 for ICl, IC2, and DSPl, and -i- 5 volts DC from IC7 for all else. IC6 is an LM317T adjustable regulator set by R18 and R19. The input is po- larity protected by Dl. Capacitor C23 bypasses high-frequencies avoid instability, and C24 filters 60-Hz ripples. Power jack J3 needs a center-positive, 2.1— 2.5- millimeter coaxial plug. The maximum current through DSPl with all segments lit is about 400 milliamps. An o o CD CD CD a 49 TupwriB "'^ g z o IT I- O UU _l LU O Q < I \l)- 10 COMfWWORS 10LEDS ( ^'^^ REF Will *.69K ! : 3.31 K 1CT soun«£ 'J FROM i,17K;; ,_n. >-^ FiG. 4— THE BLOCK DIAGRAM OF THE TSM391S 10-segment LED bar-graph dis- play. The on-board IC has an adjustable voltage reference, high-impedance input buffer, 10-step voltage divider, and 10 com- parators. The display is logarithmic; each segment represents another 3 dB. Max- imum current with all segments tit is about 400 mi 1 1 lamps. AC-to-DC adaptor should provide -I- 10- -I- 12 volts DC under load at J3, but be careful, since excess voltage will burn out 1C6. Such adaptors aren't regulated, so their voltage may vary greatly with load. The prescaler works fine with an adaptor rated at + 9 volts DC and 500 milliamps, that actually delivers -(- 10.5-+ 11.5 volts DC. Diodes D5-D7 provide an additional 1.8-2.1 volt DC drop, to avoid overheating 1C6. Construction Build the PC board for the pre- scaler exactly as shown. Don't drill any additional holes, or modify the microstrip foils. If you do, you'll ruin the ground plane needed to achieve the 1.6-GHz bandwidth and excellent sen- sitivity. The cabinet-mounted and panel-mounted versions were designed for a 3.8x3. 35- inch, double-sided, plated- through PC board, with solder masks and component screens on each side. The PC board was laid out with tape 4x actual size, using 50- ohm microstrip signal paths. size calculated for a 0.062-inch glass-epoxy FR4 PC board. The 29 surface-mount devices (SMD's) improve RF performance by reducing size, component lead inductance, impedance mis- match, and poor grounding com- mon in larger parts. MMlC's like ICl and 1C2 are mandatory for microwave circuits, and can be handled manually with practice; the prototypes shown here were built with no special tools. The parts are very small, so be careful. At bare minimum, you'll need a magnifier lamp, small-tip solder- ing iron, tweezers, miniature long-nose pliers, and a sharp knife with a small, pointed blade. There are small vacuum tools with different tip sizes available for about $10; a complete kit of solder creme dispenser gun with cartridges (called caplettes), and vacuum tools, is $75 (see the parts list). The PC board is avail- able, or you can use the foil pat- terns provided here. The parts-placement diagram for side A is shown in Fig. 5, and for side B in Fig. 6. Install Jl and J2 first, modified as shown in Fig. 7. with a '/le-inch wide (FOR PANEL-MOUNT VERSION ONLYj FIG. 5— PARTS PLACEMENT DIAGRAM FOR side A of the PC board. CIS has a hole for the negative lead; the positive lead is soldered to the foil where R3 meets L2. On IC1 and IC2, the dots are the outputs (pin 3); the input (pin 1) is opposite, and pins 2 and 4 are the grounds. D4 Is black, rectangular, and has a brown ridge on the cathode end. SO FIG. 6— PARTS PLACEMENT DIAGRAM FOR side B of the PC board. In the cabinet- mounted version, the header pins protrude from side A to holes 1-10 of DSP1 on side B; ttie separator is on side A. In tlie panel-mounted version, tiie header pins are inserted into side B; tlieir otiier ends go to holes 1-10 on DSP1, with the separator on side B. groove. Use a medium iron for them, and the small iron elsewhere. The kit in the parts list has IC socket pins for IC3 and IC4, to shorten the leads and get them closer to the ground plane for better frequency response. For IC5. use a regular 14-pin DIP socket, since it operates over a lower frequency range. Install the SMD's next; note the polarity of amplifiers ICl and IC2, tantalums C4. C5, C7. and C16, and LEDl and LED2, and install all parts from smallest to largest. ICl and IC2 should both have dots indicating their outputs (pin 3); the input (pin I) is op- posite this, and pins 2 and 4 are the grounds. With the dot on pin 3 pointing toward the bottom as in Fig. 5. pin 1 points upward, pin 2 points left, and pin 4 points right. For the SMD tantalums, C4, C5, and C16 are the same size. while C7 is much larger. In the prototypes and the kit in the parts list, C4, C5, and C16 are orange in the center and silver on each end. They have a small tip on the positive end, and a green dot on the top side, C7 is yellow, with a brown band on tlie top of the positive end. Capacitor C15, at the middle right, will partially block IC2 and L2, so install them first. There's a hole for the nega- tive lead of C15, but the positive lead is tack soldered to the foil where R3 meets L2. insert the negative lead into its proper hole, and bend the positive lead out- ward at right angles. Diode D4 is black, rectangular, and has a brown ridge on the cathode end; the brown ridge faces to the right. Install LEDl and LED2 last in the prescaler. For the case- mounted version, insert the LED's into their PC board holes FIG. 7— BNC SOCKET MODIFICATION for the cabinet-mounted version. In (a) a side view is shown of a female BNC panel- mount socket. In (d), a slot is cut in the threads with a hacksaw or file. In (c), the slot fits snugly over its PC board notch. Solder it on both sides of the PC board; the center pin goes on side A, without soldering. Hold them in place with your lingers and pull the leads through the holes, until they both almost touch the sur- face of side B. Fold the leads over slightly, so they can't fall out. In- sert the PC board into the case, with side A facing out. Bend the LED leads back to vertical so they slide freely, maneuver the LED's so they protrude through their holes in front, then solder and trim. If you remove the PC board from the case, the LED's should slide out freely. When you put the PC board back in the case, the LED's should slide back into their holes. For the panel-mounted ver- sion, don't install the LED's until you attach Jl and J2 to the face- plate, and are ready to attach the PC board. Pull the LED's through their holes in the PC board, and bend the leads to hold them in place. Insert the center pins and ground lugs of Jl and J2 into the holes next to the notches, and bolt the bottom of the PC board to o e m O 51 LBK CIS (SEETKT: UUNDERNEmfl FIG. 8— PROTOTYPE OF THE CABINET-MOUNTED version; side A appears in (a), side B appears in {b). The header pins protrude through trom side A, and are soldered to DSP1 using the bottom 10 pin holes on the display PC board. KOGND LUQ USED J3 (USED FOR TESTiNS) POWER HEADER PINS PIN 13 {+ 13VDC) 1N4007 (REPLACED BYD5-D7; SEE TEXT) Plt4 3 (GNDi PIN1 (OUTPUn FIG. 9— PROTOTYPE OF THE PANEL-MOUNTED version, showing side A. The header pins are inserted into side B; the separator is on the same side. PL1 connects two twisted pairs; the output to the HP 5245L is from the header pins at upper left, and the -i 13 volts DC from the HP 5245L to those at tower right The 1N4007 on pin 13 of PLl has been replaced by D5-D7 at Si's location (see text), to avoid damaging tC6. Use heatshrink tubing with all four wires to avoid shorts. SENsmvrrY.mVRMs CO o z o cr H O LU _J lU o D < DC ^100 1.2 I.") 1.6 FIG. 10— SENSITIVITY CURVES FOR BOTH the -^ 10 and ^100 ranges. The -^ 10 range covers 3Q-ABQ MHz, and the ^ 100 range covers 330 MHz-1.6 GHz. the faceplate with nylon washers and a nonconductive spacer. Sol- der the center pins and lugs for Jl and J2; use two lugs for Jl, and one for J2. When the PC board is attached to the face- plate, maneuver the LED's as be- fore, solder and trim. If you have no SMD tools, hold the SMD in place with a small, sharp knife, a pencil, or a probe. Tkck solder one side to hold it in place so you can solder the re- mainder with both hands; then, resolder the first side. There are kits of SMD tools available that can make working with the de- vices easier. Solder creme is powdered sol- der mixed with flux. With a gun dispenser, place a very tiny spot on each SMD solder pad, and po- sition the SMD with a vacuum tool; it should stick to the solder creme. Heat the foil, and the sol- der creme should melt; never heat the solder creme directly. Figure 8-a shows side A of the cabinet-mounted prototype, and Fig. 8-b shows side B. In Fig. 8-a, IC7 has been folded over to lie on its heatsink pad. You can't bolt the heatsink to the PC board in the prescaler, since DSPl is in the way, but even if you could, it's unnecessary. The center pins of Jl and J2 are on side A: both the threads and center pins were sep- arately soldered. In Fig. 8-b, 1C6 has been folded over like IC7, but also needn't be bolted down. The header pins protrude through from side A, and are soldered to holes 1-10 on DSPl on side B; the plastic separator is on side A. Figure 9 shows side A of the 52 UJ resistors are vS^watl, 5%, car- bon-composition or film, unless otherwise noted. R1, R2— 150 ohms carbon-composi- tion R3— 30 ohms, SMD R4— unused R5— 470 ohms, SMD R6— 1.5 ohms R7, R8. RIO—IIOO ohms, SMD R9~120,000 ohms, SMD R11,R12— 2000ohms, 1% R13— 470 ohms R14— 150 ohms, 10% R15— 91 ohms, 10% R16~R18— 5000-ohm, 4-tijfn, sub- miniature, PC-mounted potentiometer R19 — 240 ohms R20— 10 ohms R21— 2700 ohms R22— 2700 ohms, SMD Capacitors C1.C2— 820pF, SMD C3— 12 pR SMD C4, C5, C16— 1 p.¥, tantalum, SMD C6, C11, C20— 0.0033 |xF. SMD C7— 10 M-F, tantalum, SMD C&-C10, C13, C14~560 pR SMD C12, CI 7— 10 (xR tantalum, axial leads CI 5 — 100 p.f, electrolytic, axial leads 018, C21-C23, C28-C30— 0.1 jj.R monolithic ceramic, axial leads 019—0.0018 M.R SMD 024—330 jjlR 25-vo!t, electrolytic 025—1000 M-F, 10-volt, electfotytic C26— 4.3 pR SMD C27— 1 ilF, 16-w>it, tantalum inductors L1,L2— 6.5|a.H, SMD L3, L4— 18 M-H, SMD Semiconductors m, D5-D7— 1N4007 silicon diode D2, U3— RH-1100 diode D4~-Motorola MPN3401 PIN diode DSP1 — Three-Five Systems TSM3915 10-segment LED bar- _.- graph display panel-mounted prototype. PLl is connected to the PC board by two twisted pairs and two pairs of header pins. The output fed back into the HP 5245L comes from the header pins at upper left. The upper pin is the output, the lower pin is ground. Power goes into the header pins at lower left; the left one goes to the + 13 volts DC from the HP 5245L, and the right one is ground. The prototype was built before using D5— D7; the anode of a PARTS LIST D1 , LED2 — subminiatufe red LED IC1. IC2— Awantek MSA-0104 MMiC amplifier 103— NEC UPB582C MMIC divide- by-4 prescaler IC4— Motorola MC12009P ECL two- mode prescafer 105— Tl 74S196 presettable binary/ decade counter [C6—LM317T adjustable 1.25-37- volt DC regulator 107— LM340T-5 or 7805 fixed 5-vol1 DC regulator Other components 81- SPOT PC-mount slide switch (used in the cabinet-mounted ver- sion) S2— 4PDT right-angle PC-mount slide switch (used in the cabinet- mounted version) 82- 4PDT PO-mount slide switch (for the panel-mounted version} PLl — Centronics 50-ptn male ptug with hood J1, J2— UG1094-U female BNC socket (see text) J3— 2, 1 -millimeter coaxial power jack Miscellaneous: Case for the cab inet-mounted version (two- piece anodized aluminum, four machine screws, with specially punched and printed front), red lens for DSP1 (0.03x1x3- inches), front panel (optional tor the panel-mounted version), three BNC socket solder lugs, 4-40 X 0.2S-inch black Phillips pan head screws (for the cab- inet-mounted version en- closure), two 6-32 X 0.5-inch black Phillips pan head screws, two 8-32 X 0.5-inch black Phillips pan head screws, 4-40 nylon locknut, 4-40 X 0,3-inch threaded spacer, nylon washer, 2 feet of #22 stranded twisted-pair wire, two BNC socket lock- washers, one 10-pJn header pin with plastic separator (for both 1N4007 was soldered to pin 13 of PLl, and the cathode to the positive power wire (blocked by the black heatshrink tubing). PLl is a standard male Cen- tronics plug. Cover both ends of all four wires with heatshrink tubing to avoid shorts. However, one 1N4007 didn't provide a suf- ficient drop, so D5-D7 were used thereafter. Figures 2, 3, and 6 all show D5— D7; in the panel- mounted version they replace SI, to pro- -mounted version and the panel-mounted version), two 2-pin header pins with plas- tic separators (for the panel- mounted version), heatshrink tubing, AC power adapter with an output of 10-12 volts DC at 400 mA. NOTE: The following items are available from STARTEK Inter- national, Inc., 5200 N Federal Hwy„ Suite #2-1181, Rt. Lauder- dale, FL 33308, (305) 783-0008 or (800) 638-8050. A complete set of all parts (#AP-90K) for the cabinet-mounted version is $99.95, an enclosure (#CAB-90) is $25.00, and the AC adaptor (#AC-90) is $9.00. A factory-as- sembled and tested version with the aforementioned items (#AP-90) is $179.00. The tele- scoping antenna with BNC plug (#TA-90) is $12.00, and the PC board (#PCB-90) only is $25,00. All seven tC's (#ICS-90), includ- ing voltage regulators and DSP1, is $55.00. A complete kit of parts for custom installation of the panel-mounted version into the HP 5245L (#AP-90-HK) is $159.00, and an assembled and factory-tested version (#AP-90- H) is $199.95. A partially as- sembled kit (SMD components installed) is available. Call Star- tek or send SASE for informa- tion. For SMD tools, a Vac TWeezer pick-and-place tool kit (#VT-1) is $9.50, and a Dot.Maker solder creme dispenser kit con- taining the Vac TWeezer kit and an assortment of about 20 sol- der creme caplettes (#DMK-1) is $75.00. Add 5% (a minimum of S4.00 to a maximum of $10,00) for shipping/handling. Visa, MasterCard, C,0,D,, cash, or money orders accepted; allow three weeks for personal checks. vide an additional 1,8-2. 1-volt DC drop, as mentioned above, to reduce the + 13 volts DC from the HP 5245L, IC6 doesn't overheat to the point of exceeding specifi- cation. The drops across Dl and D5-D7 reduce the + 13 volts DC from the HP 5245L to -I- 10.2-10.6 volts DC, enough to o run IC6 with minimum heat dis- h sipation. § To install D5-D7, wrap the 3 cathode of D5 around the anode ^ of D6, and the anode of D7 8 53 COMPONENT SIDE OF THE PRESCALER, SOLDER SIDE OF THE PRESCALER. around the cathode of D6, solder and trim. Insert the anode of D5 and the cathode of D7 into their PC board holes, and leave enough lead length on side B to bend D5-D7 flat to the PC board. In the panel-mount version, in- stall the DSPl header pins with the plastic separator on side B (the separator is on side A for cabinet installation) to hold DSPl off the PC board and flush with the red lens and panel. The PC board and red lens is a precise fit inside the case and shouldn't move around. In the panel-mounted version, the lens is sandwiched between DSPl and the rear of the faceplate, and has a hole drilled in its bottom for the screw that attaches the PC board to the bottom of the faceplate. CO o z o CL 1- O LU _J UJ O D < EC IF YOU WANT SMD TOOLS, (a) shows a kit mentioned in the parts list. Solder creme is powdered solder mixed with llux. With the gun in {b), place a spot on each pad, and positiontheSUD with the vacuum tool in (c); it should stick to the solder creme. Heat the foil, and the solder creme should melt. In (d) a close-up of the gun and three caplettes is shown. The lens goes between the rear of the faceplate and the nylon wash- er at the base of the nonconduct- ing spacer. Power-on checkout Tbrn the power on. and check for proper voltages: • At J3, -h 10- -Hi 2 volts DC. in- put power. • At the output of 1C6. -1-7.1- + 7.3 volts DC (adjust R18). • At the output of IC7, -1-4.9—1-5.1 volts DC. • At the outputs of ICl and IC2. a bias of 4.6-4.7 volts DC (with no input signal). For the panel-mounted ver- sion, J3 is included to let you test it without connecting it to the HP 5245L. If all voltages are right, adjust R16 to zero the bar graph, and RI7 for full scale. The two potentiometers interact, but you should get a good setting with a signal generator and some ex- perimenting. The bar graph var- ies with frequency, but is a convenient relative RF signal strength indicator. With careful assembly, sensitivity should be 1-9 millivolts RMS from 50 MHz- 1.6 GHz, consistent with the curves shown in Fig. 10. R-E 54 m BUILD THIS LASER JET MEMORY CARD Build this 4-megabyte memory expansion board for your LaserJet Model IIP/IN printer. BILL GREEN LASER PRINTERS i-IAVE BKEN AROUND for some time but, until recently, they have been expensive. About a year ago Hewlett Packard intro- duced their LaserJet IIR the first low-priced entry in the market. It lists for $1495 but can be pur- chased through mail-order out- lets for under $1000, making it a truly "personal" laser printer. The Model IIP has many of the features of HP's newest and sub- stantially more expensive entry, the Model 111. The Model IIP falls short of the Model 111 in that it is half as fast and has half the built- in memory. The Model HP has 512K of memory built in, but that amount won't even allow you to print a full page of graphics at 300 dpi (300 dots-per-inch) reso- lution, let alone store a couple of softfonts (downloadable type- faces) in the printer. The fact is, laser printers are powerful in such applications as desktop publishing and for printing the output of CAD and CAM software (the PC board foil patterns for this project were printed on a LaserJet IIP), as well as for every- day printing. But having only 512K of memoiy severely limits the power. You can, of course, expand the memory in the printer, but the cost to purchase 4 -megabytes of memory from Hewlett Packard will set you back a cool $2000. The prices of laser printers have come down, and they now fit into the personal-computer market, but the price of expansion memo- ry has kept the cost of laser print- ing well above what it should be. The memory-board con- struction project which we will detail here can add up to 4-mega- bytes of additional memory to your LaserJet IIP, and also works with Hewlett Packard's newest laser printer, the Model III. A kit is available to build it (see parts list) for under $100. Memory is not included at that price, but is available for around $56 per megabyte through a number of mail-order sources. You can now add up to 4-megabytes to your o CD m 3) C5j [Va] ^» * r^ — ' r ^-rS"^ IN* ^ * » , »*^x y ^ ««*? .«>«*-rrn^ ^ %■ ^ ' »— ^ * I • \ / -v ,___^^^^^^^^_ *^ ~^> * • • • ¥T 'jr^ ^» • • • • • • alt • • • ^2 ►^ '^ "-sj -7 INCHES- COMPONENT SIDE OF THE MEMORY CARD. CO O z o cr I- o _i LU 6 Q < IT 58 SOLDER SIDE OF THE MEMORY CARD. Put a TV in your VGA monitor. JIM HARRIGFELD AT BOTTOM. A TV AND A COMPUTER monitor are more alike than they are different. As a matter of fact, a •' monitor is really just a TV in dis- guise less a few circuit boards and knobs. At one time, when computers used teletypewriters for display, television pictures were consid- ered high-resolution. Today, even the best TV sets cannot compare with the latest breed of computer monitors in terms of resolution, stability, convergence, and fidelity. So wouldn't it be nice if you could simply connect a VCR or camcorder to your monitor and enjoy some of that extra fidelity? This article will show you how to build a simple decoder that will take any standard NTSC video signal (from a VCR. camera, tuner, or what have you), and convert it into the analog RGB signals that computer monitors work with. The circuit costs well under SlOO to build, and re- quires no fancy test equipment to align. In addition, if you would like to build one, partial and com- plete kits are available. Some basics A color monitor has a simple interface. It generally requires four separate signals to operate: red, green, blue, and sync. Sync tells the monitor where and when to start each scan line, and the RGB signals determine how much red, green, or blue to dis- play in the picture at any instant in time. The composite video signal used in a television is more com- plicated, because it combines all the RGB signals, as well as other timing information, into a single high-frequency signal. In the United States, this signal is based on the NTSC/RS-170A vid- eo standard. The disadvantage of composite video is that a great amount of processing is required to com- bine and encode the separate sig- nals into one composite signal. The advantage of composite vid- eo, of course, is that the signal may be broadcast over the air or sent down a single piece of coax- ial cable. But to be displayed, eventually the signal must be broken down into its individual red, green, blue, and sync compo- nents. By contrast, the advan- tage of the RGB system is that no decoding circuitry is required, so circuit designs are simpler and cheaper. The disadvantage of the RGB system is that several wires and multi-pin connectors are re- quired to make connections. Given the similarity between a television and a monitor, what exactly is required to display NTSC video on an RGB monitor? First and foremost, we need an analog monitor that is capable of scanning at standard NTSC vid- eo rates (60 Hz vertical, 15.750 Hz horizontal). That requirement immediately eliminates most fixed-frequency (digital) monitors — i.e., most CGA and EGA types. However, most multi- frequency t3rpe monitors work beautifully. We also need a video source. You can choose any VCR, video camera, camcorder, or compo- nent tuner that has a video out- put in the NTSC/RS-170A for- mat. Those devices usually have some kind of audio output that you can use to drive a pair of headphones or your home stereo system. Of course, there's still one thing missing: a gadget that can be used to convert the composite video from your source device into the separate RGB signals that your monitor understands. About the circuit Figure 1 shows a block diagram of the circuit, and Fig. 2 shows the complete schematic. The heart of the circuit is 1C2, a TDA3330. That highly integrated Motorola IC is specifically de- signed to break a composite video signal down into its individual components. The TDA3330 re- quires three inputs to operate: chroma (color information), lu- minance (brightness informa- tion), and burst flag (timing in- formation). The other major component is ICl, an LM1881 video-sync sepa- rator made by National Semicon- ductor. It extracts most of the important timing information 59 CHROMA INPUT CHROMA IF IC1 LM1881 SYNC EXTRACTOR o- -COMPOSITE ' SYNC Q1 CHROMA TRAP 15 ACC 400ns DELAY BURST ; GATt INPUT 17 LUMINANCE (Y) INPUT OUTPUT MATRIX APC 8-Y DEMOD 90° PHASE SHIFT R-Y DEMOD VCO IC2 TDM330 j^^%^ — Jhdh B-Y R-Y C27 XTAL1 3.58MHI FIG. 1 — BLOCK DIAGRAM. IC1 derives the sync signal and timing information. IC2 uses the latter to decode the red, green, and blue outputs. T2 04 BLUE 13 14 * Q5^> O - Q^> O GREEN o o DC u LU o a < from a standard video signal, and it needs only three external (pas- sive) components to operate. Our circuit uses two of its three out- puts: composite sync, which after buffering becomes one of our outputs; and the burst flag, which is inverted by Ql to fur- nish the necessary timing infor- mation to 1C2. The other signals that are needed by IC2 are derived from the composite video input signal by means of several passive fil- ters. The chroma bandpass filter consists of R2. L2, Cll, and C12. That circuit works by allowing only 3.58-MHz signals to pass into pin 22 of 1C2, while blocking all others. The luminance input (pin 17) is just the opposite, in that the 3.58-MHz component must be blocked and all other frequencies allowed to pass through. That is accomplished with the chroma trap consisting of LI, R3, R4, C2, and C3. Basically, the output of the chro- ma trap is monochrome video, lb meet NTSC timing require- ments, that signal must also be delayed (by R5, R14. and L3) be- fore entering 1C2. With proper input signals, IC2 requires only a few more passive components to enable it to lock on to the incoming signals. Once locked, the IC performs all I/Q de- modulation, quadrature decod- ing, R-Y, and B-Y processing, and it then delivers red, green, and blue signals at pins 14, 13, and 12, respectively. Those sig- nals are buffered in turn by Q4, Q5, and Q6, which are set up as emitter followers designed to drive 75-ohm loads. The circuit has four controls for setting operational charac- teristics. The brightness control (R35) sets the black level of the RGB outputs; for most applica- tions, it should be set at mini- mum. The three other controls (hue, R37; saturation, R38: and contrast, R36) work much like their counterparts on a standard TV. After they have been properly adjusted, none of those controls should require operator interven- tion. The brightness control shifts the black level without af- fecting the overall peak-to-peak amplitude of the signal. On the other hand, the contrast control varies the peak-to-peak ampli- tude without affecting the black level. Figure 3 shows several wave- forms and timing relationships for a color-bar input signal at sev- eral points in the circuit: (a) The 60 J mm; I 1* ,- r: C16. .1 ' C11 lOOpF -9h" L2 39|iH nnnF *T^ . r lOOpF ■ 1.8MEG C17_L R16 1K -AVV- i POWER ■« — w— Dl o 1H4tlOJ C7 .1 CIS J. lOOpF C19 16V • CM. .1 ■ C29 .1 24 23 ZZ 21 + 12V 20 19 18 R13 IK . C15 .01 17 16 — .-+5V R35 tOK BRIGHTNESS 15 14 IK 06 2N4401 ■AW- + W 13 C30 t 22pF R25 33£2 -VvV- R31 15011 R30 75fi L5 22tiF IC2 TDfl3330 TT -v^ IC3 7SLD5 ? +]_ C8 I1(iF 35V 1 -•-+5V R1T Z20K C9 + 5V C22 .1 -1^ 023 .1 ' C21 35V' — VW R38 10K C25 A. .001 10 11 1 12 HDh XTALl 3,5eMHl C27 40pF R24 tK ' VW f ■^f C31 - IjiF 35V + 12V C26 22pF R21 33(1 R27 150n R26 75a L4 22iiH R20 IK f-C) < ZM4401.,- -^f- C28 ■=■ IfiF 35V -wv- R19 18K — 1 C24 + L IHF JP 35V R22 75fi R23 laOil RED GREEN BLUE FIG. 2— COMPLETE SCHEMATIC. The circuit accepts a 1-volt peak-to-peak composite input, and detivers RGB and sync outputs, also with a swing of 1 volt peak-to-peak. CO o 2 o DC I- O o Q < DC 1 HORIZONTAL LINE [L — WHITE BLACK WHITE BLACK WHITE BLftCK — WHITE BLACK WHITE UJ , ■ BLACK WHITE BLACK RG. 3 — SAMPLE WAVEFORMS. At (a) is a color- bar input; the text describes the remain- ing signals. color-bar input, (b) Composite video across one scan line, (c) The luminance input (pin 17) of IC2. (d) The chroma input (pin 22) of 1C2. (e) The composite sync output. (/) The burst-flag input (pin 15) of IC2. (g) The green out- put (Q5). (h) The red output (Q6). (i) The blue output (Q4). (j) All outputs with the saturation con- trol (R38) at minimum, [k) The blue output with the saturation control (R38) too high. (J) The blue output with the hue control (R37) improperly adjusted. Building the circuit With the high frequencies that are involved, stray capacitance and crosstalk will ahnost cer- tainly cause problems with most breadboarding and wirewrap techniques. Therefore, we recom- mend that you use a PC board for the project. Patterns for the board are provided if you wish to make your own; boards are also available commercially, as dis- cussed in the parts list. If you use our board. Fig. 4 shows the parts layout. All parts except possibly IC2 {the TDA3330) are readily avail- able from the mail-order houses advertising in Radio-Blec- tronics. If you purchase a partial kit, be careful in selecting capaci- tors. Only tantaluiTi or mono- lithic DIP types are suitable, as electrolytic. Mylar, or ceramic disc types may not fit in the allot- ted space on the printed circuit board. Also note that resistors and inductors are mounted ver- tically. Bend one of the leads back parallel to the body of the part and mount the body of the part in the hole with the circle around it, and then pass the bent lead through the other hole. Mount the inductors (except L3) in the same manner. This method saves space and also furnishes you with good debug/ test points. We also strongly recommend the use of IC sockets. If you are unable to locate a 24-pin socket for IC2, you can use 16- and 8-pin sockets mounted end-to-end. The pads around the trimmer po- tentiometers have been laid out so that several types of trimmers may be installed. Just be sure to mount the trimmers wiper arm in the correct pad. The board was designed to ac- cept PC-mounted connectors for Jl (input), J2 (output), and J3 (power). However, you may not want or need these types. Our prototype uses a BNC connector for Jl. but a simple RCA jack may suffice. Likewise, J2 and J3 may be eliminated entirely or changed depending on what your par- ticular application involves. Switch SI maybe replaced with a simple jumper/header combina- tion for most setups. For best operation, the board should be installed in a shielded enclosure. The template in Fig. 5 shows hole locations for mount- ing the board in the project box that is mentioned in the parts list. The board is held in place in the box by the connector hard- ware (J 1^3). Hooking it up Regardless of the type of con- J2 OUTPUT J3 POWER FIG. 4— PARTS LAYOUT. All parts, mount on the board. including the variable resistors and the I/O jacks, 64 -FOLD ALONG DOTTED LINE -ALIGN FOLD ON TOP OF BOX A^DCE^fTER-■^^PEON -PUNCH CENTERS CENTER CENTER LINE CENTtRLINE CUTx2 CLTTOUT DRILL Vz" DRILL Vl" DRILL Vs" 1 SCALE 1:1 COUNTERSINK ^^ W/'/3z"BIT J FIG, 5— DRILLING TEMPLATE. If you use our board and the box mentioned in the parts list, drill the box as shown here. PARTS LIST All resistors are Vi-watt, 5%, unless otherwise noted. R1, R22, R26, R30, R33— 75 ohms R2— 1500 ohms R3— 2700 ohms R^l — 15,000 ohms R5, R14— 1200 ohms R6~not used R7— 680,000 ohms R8, R10, R13, R16, R20, R24, R28— 1000 ohms R9_i68o ohms R11, R1 8— 33,000 ohms Rt2— 100,000 ohms R15 — 1.8 megohms R17— 220,000 ohms R19 — 18,000 ohms R21, R25, R29, R34— 33 ohms R23, R27, R31, R32— 150 ohms R35-R38— 10,000 ohms, cermet potentiometer, Panasonic #S0GA01B1 Capacitors 01 — 33 ^lF, 10 volts, tantalum C2, C3— 330 pf, 50 volts, monolithic C4, C5, C7, C9, CI 6, C20, C22, C23, Semiconductors 1C1— LM1881N video sync separator (National) IC2— TDA3330 NTSC to RGB decoder (Motorola) iC3— 78L05 low-power 5-vott neguiator Q1,Q2, Q4-Q6— 2N4401 Q3 — not used D1— 1N4002 rectifier diode Other components J1— PC-mount BNC connector (AMP #226978-1) J2--9-pin D connector, female, PC mount J3 — 3.5mm mono phone jack LI— 12 (xH variable inductor (Toko #A119ANS-T1034) L2— 47 >jlH fixed induetor{Toko #348LS-470K) L3 — 400 ns delay line (Toko #H321LNP-1436P) L4-L6— 22 jiH fixed inductor (Toko #348LS-220K) SI— SPST, PC board right-angle moun! XTAL1— 3.579-MHz crystal Miscellaneous: Metal case— (Hammond #15906), 12-voit regulated wall trans- former, soider, etc.. C29 — 0.1 nF, 50 volts, monolithic Note: The following items are available C6 — not used from Harmonic Research, Inc., 193 C8, CIO, C21, C24, C28. C31, C33— 1 ^F, Villanova Drive, Paramus, NJ 07652 35 volts, tantalum (201) 652-3277: Complete kit includ- C11, CI 2, CIS— 100 pF, 50 volts, ing PC board and all parts except monolithic wall transformer, $95.95; Partial kit C13~C15— 0.01 M.R 50 volts, monolithic including all parts except box, S1 C17— 0.47 jiF, 50 volts, monolithic and J1, S81.50; Etched, drilled, and C19— 10 M-F 16 volts, tantalum silk-screened PC board, $20; C25— 0.001 jxF, 50 volts, monolithic TDA3330 (IC2), S4.75. All orders add C26, C30, 032—22 pf, 50 volts. $2.50 for shipping and handling. monolithic New Jersey residents add appropri- C27— -5-30 pF, trimmer ate sales tax. nee tors that you use, the input should be wired using high-qual- ity coaxial cable for best results. Your VCR or camera may have come horn the factory with a ca- ble of this type. Otherwise you can buy or build an input cable with RG59U coax and either BNC or RCA connectors. The output cable depends on your application and use. Refer to your monitors manual to de- termine its input wiring require- ments. The decoder's output (J3J is a DB-9 connector that con- forms to the PC standard. Many multi-frequency monitors ad- here to ttiat standard; but it's a good idea to check the manual just to be sure. With a little luck, you should be able to unplug the cable from the display adapter in your PC and plug it directly into the decoder. If you're not so lucky, you'll have to wire up a cable or an adapter. In addition, we left a row of pads Just behind J2 on the PC board; you might find it easier to simply cut the traces between the two rows and add jumpers to rec- onfigure the pin out of J2. That could save you from having to modify a cable. The power supply for the NTSC converter can be any well-regu- lated 12-volt supply that is capa- ble of furnishing 250 mA of current on a continuous basis. Apply power to J3 through a Vs" phono plug with positive tip and grounded shield. Testing and adjustment Before applying power, check the PC board for solder splashes, bad or shorted connections, etc.. Do not install the IC's in their sockets yet: rather first apply power to the circuit and check for smoke and overheated compo- nents. Using a DMM, verify that pins I and 20 of IC2. and pin 8 of ICl, are all about -hl2 volts. In addition, verify that the positive side of C8 is -i-5 volts. After eveiything checks out, re- move power from the board, in- stall the IC's in their sockets, and make the external connections. A color-bar generator is nice for making the adjustments, but if o you don't have access to one. any j stable video signal will do. Use a ra camera or an off-the-air signal; u don't try to set up from a tape. ^ Turn the saturation, hue, and o 65 CO o z o n: in 6 Q < HERE'S THE COMPONENT SIDE OF THE NTSC/RGB CONVERTER HERE'S THE SOLDER SIDE OF THE NTSC/RGB CONVERTER. contrast controls (R36-R38) to maximum, and the brightness control (R35) to minimum. Adjusting without test equip- ment. With everything liooked up and the monitor on, plug in the power supply. You should im- mediately see some kind of pic- ture, although it will probably be black and white and possibly flashing on and off. Adjust C27 with a small screwdriver for the most stable picture and the best color You may find two spots where performance seems equal: either will do. Next, adjust LI for the deepest, richest color Then adjust the saturation, hue, and contrast controls for the most natural look, just as you would on a normal television. You should leave the brightness con- trol set at minimum unless you have a specific reason for want- ing the black level set higher than it already is. That's all it takes to adjust the unit, and you will probably be very close to the op- timum settings. Adjustment with color-bar generator and oscilloscope. With SI closed, verify with the scope that you have a 1-volt peak- to-peak signal similar to that shown in Fig. 3-a at the input connector Next, verify that a bur- st-flag pulse is present at pin 15 of IC2. That signal should look like the waveform shown in Fig. 3-f, and must be at least eight ■ — »\ 63.511S |-" — OUT OF LOCK IN LOCK lOOmV T FIG. 6— VCO LOCK AT PIN 7 OF IC2. In (a) Is an incorrectly adjusted signal; (b) shows the correct waveshape. volts in amplitude. Also, verify that you have a chroma signal similar to that shown in Fig. 3-d at pin 22 of IC2, If you examine pin 17 with a scope, it will proba- bly resemble something halfway between Fig. 3-b and Fig. 3-c. Ad- just LI for minimum subcarrier by making the signal look like in Fig. 3-c as much as possible. Continue adjustments by con- necting the scope probe to pin 7 of IC2 and referring to Fig. 6. An out-of-lock waveform is shown in Fig. 6-a; adjust CI until you ob- tain a stable waveform as shown in Fig. 6-b. There will probably be two spots in the adjustment range where lock occurs; either is OK. That signal is the VCO lock, and once set, you should be able to see nice, stable signals at the RGB outputs (pins 12-14 of 102). Refer to the output waveforms in Fig. 3 and watch your monitor while adjusting the saturation, hue, and contrast controls to your liking. Outputs should be set an3rwhere from 0.7 to 1.0 volt peak-to-peak. I want my MTV/2! After making all of the adjust- ments to the unit itself, leave them alone; instead use the brightness and contrast controls on your monitor to compensate for ambient lighting. The de- coder should be able to lock on to anything that comes anywhere close to NTSC video, but it can't deal with some of the copy-pro- tection schemes that many pre- recorded tapes use. However you may be able to compensate by running the composite video sig- nal through a descrambler or sta- bilizer first. You may notice that some video looks better on your monitor than on a TV, whereas other video looks worse. The reason is that a high-resolution display cannot improve a low-resolution input, and in some cases the high reso- lution might even bring out some unwanted artifact that a low- res- olution display would cover up. Some day, with all the hoopla over HDTV and multimedia, vid- eo and graphics displays will most likely merge. We will be run- ning our CAD program on the same screen that we sit back and watch STAR WARS 15 on. Until then, projects like this will inch us a little closer R-E 66 Here are a few tricks of the trade that may help you with your next TV repair. cteo ,^f^J^^p^s TV SERVICE CASE HISTORIES TV SERVICING CAN BE A PRECARIOUS business, but with a little intu- ition — and a firm background in TV repair fun darn en tats — your Job can be made easier. We'O dis- cuss a few examples of some com- mon problems a service techni- cian might come across, and how that intuition and background can lead to a solution. An AFT probtem Many TV repairs are fairly ob- vious examples of cause-and- effect; sometimes the cause is created by the customer! A cus- tomer came into the shop with a Samsung model CT-510AL, com- plaining that several channels were distorted, with un- synchronized video and an an- noying audio buzz. Luckily, raster, sound, and video were present. Those symptoms indi- cated a tuning problem, perhaps a malfunction of the fine tuning circuit or simply a misadjust- ment. The receiver had a preset button that .set the tint, contrast and colon In addition, another button energized the automatic fine tuning fAFF) circuit. The customer was probably unaware that he misadjusted the preset and AFT buttons. If the fine-tuning control was adjusted with the AFT activated, no change would occur in the pic- ture until the frequency was so far from its correct value that the AFT lost control and the set tuned off-channel. A common characteristic of an AFT circuit is that the hold-in range is greater than the pull-in range. A fine ttin- Ing adjustment, with the AFT on, would initially produce no change to the picture because of the hold-in characteristic. If the channel was changed, however, and then returned to the original channel, the picture might be completely detuned because the pull- in capability had been ex- ceeded. In the case of the Sam- sung model, that was indeed what happened. The customer wanted to modi- fy the tint Lo his hking. Because the preset button had been ener- gized, the set controls were in- operative. With the AFT acti- vated, he proceeded to rotate the only control available to him (other than volume) which was the fine tuning. As each channel was detuned he proceeded to the next. The icing on the cake was his fiddling around with a few control shafts on the back of the set. The repair was obvious. First. 1 disabled the AFT, then each channel was adjusted properly for good color. The automatic gain control (AGC) was adjusted for minimum snow and no over- load on any channel. 1 touched up the vertical controls that had been disturbed and sprayed clean the front panel controls that were acting erratic. Finally, the preset color, tint, and con- trast controls were adjusted for good fiesh tones. I ran the set for a few hours to make sure there was no front end drift. When the set was picked up, the owner was instructed to ad- just the fine tuning only with the preset button de-energized. Do you think he remembered? Since we are on the subject of AFT, let's look a little deeper into its operation. All AFT circuits are basically liiuiter-discriminators. The discriminator is tuned to the video intermediate frequency (IF) at 45.75 MHz. If the set is tuned properly, the discriminator will produce zero volts with respect to a reference. Tuning too high or too low produces a more positive or more negative output from the discriminator, U should be noted that the polarity depends on cir- cuit wiring and the maximum amplitude depends on the tuned o z o 68 circuit bandpass, circuit gain, and saturation level. Figure 1 shows the discrimi- nator curve with an IF of 45.75 MHz. The discriminator output is routed to a varactor, or a tran- sistor acting like a varactor, in the local oscillator (LO) tuning circuit. With proper polarities chosen, any detuning of the set would result in an error signal from the AFT circuit that would change the varactor's capaci- tance to properly tune the LO. VIDEO PIXIF 45.75MHz 45.7^MHz FIG. 1— DISCRIMINATOR OUTPUT TUNED to video IF at 45.75 MHz and zero volts with respect to reference. RG. 2— INTERMEDIATE FREQUENCY RE- SPONSE as the local oscMlator (LO) fre- quency is varied; (a) is the LO properly tuned, (d) Is the LO tuned high and (c) Is the LO tuned low. Figure 2 shows the IF response as the LO frequency varies. For proper tuning, the video IF car- rier at 45.75 MHz and the color subcarrier at 42.17 MHz (45,75 MHz minus 3.58 MHz) should ap- pear at the proper amplitude points on the IF response curve. Figure 2-a is a graph of ampli- tude versus frequency of a cor- rectly tuned LO. In this receiver, the video IF carrier and color sub- carrier frequencies are located at 50% of the mid-range amplitude. In addition, the sound carrier, which operates at 41.25 MHz, is located at a low amplitude point. If the local oscillator was tuned too high, the color subcarrier and the sound carrier would both increase in amplitude, as shown in Fig. 2-b. That would result in a 920-kHz beat which would be very noticeable on the screen. Figure 2-c shows the LO tuned too low — the amplitude of the color subcarrier is reduced, re- sulting in a loss of color. The Samsung model discussed here used an IC to perform the AFT function. Figure 3 shows that portion of the circuit. An IF sample is fed to pin U of the IC, a TA7070, The IF is amplified and the level stabilized by the first section of the IC and is output to pin 4. The amplified IF is passed through a discriminator trans- former tuned to the video carrier at 45.75 MHz, The transformer feeds into pins 3 and 5 of the IC, where differential DC voltages are produced that are propor- tional to the tuning error. The DC differential voltages are amplified and appear as differential out- puts on pins 7 and 8. Variable resistor VR 158 sets the quiescent level, and a single ended output from pin 8 is finally routed to the tuner's varactor. It is interesting to note that the AFT circuit adds to, or subtracts from the varactor bias, which is always reverse-, and never for- ward- biased. Another aspect of the AFT circuit is that the operat- ing voltages for the IC's are sta- bilized by an internal shunt regulator, in conjunction with an external dropping resistor R173. An orphan TV When a set comes into the shop for repair, it's comforting to go to the file cabinet and pull out its service information. Even before getting too deeply involved in the problem at hand, it can be helpful to identify major components and controls from the layout drawing. Take a look at the sche- matic and try to spot some clues for the repair. Is the power supply connected directly to the line? What form of voltage regulation is being used? How are the major components accessible? Are there plug-in modules? The owner of a Supre-Macy model 20MK came into the shop with a complaint of no operation. I had no Supre-Macy service in- I RG. 3— THE AUTOMATIC FINE TUNING (AFT) IC and associated circuitry. The discrimi- nator transformer Is tuned to the video carrier at 45.75 MHz. formation on file. Sams Pho- tofacts index, the serviceman's bible, was of no help either. Macy's was a local department store and that was their private label. 1 was sure that by con- tacting the store, I would even- tually find a source for service in- formation. For the time being, however, this was an orphan TV. Here's how I attempted to repair the set without the security of a schematic to fall back on. The back was removed cmd re- vealed a neat printed circuit board onto which several mod- ules were plugged. The main board had a fuse wired directly on the PCB, with a smoky look indi- cating a blown fuse. Tracing a few lands on the bottom of the board showed the fuse in series with the AC line. A single rectifier and 200 volt filter capacitor indicated half-wave rectification. The back of the set conve- niently identified the modules In English and French. On the reg- ulator/audio module, a TO-3 transistor Ql and a TO-220 tran- sistor Q3 were mounted on heat sinks. The module was unplug- ged and some lands were traced. The collector of Ql was connected to the unregulated B-l- source, shown in Fig, 4, The base was connected to a small plastic tran- sistor Q2 with the emitter wired on the board. That was the reg- ulator section, A little more trac- ing showed that Q3 operated as a single ended or class-A audio out- put amplifier, in conjunction with a main board transformer. The three transistors were check- ed for shorts with an ohmmeter and found to be normal. The regulator/audio module was plugged in and a few con- tinuity measurements were made to check for AC or DC short circuits. The load side of the blown AC fuse showed a resis- tance of approximately 350 ohms with reference to ground — a little low, but not a short. Disconnect- ing the degaussing coil increased that value to a more reasonable yalue in the range of tens of kilo- hms. Of course! The degaussing coil was in series with a thermal resistor, as it heated up its resis- tance increased, degaussing only on turn-on. Those measure- ments were made with a cold re- sistor. Continuity measurements with respect to ground were made at the cathode of the rec- tifier diode, and at the collector of the horizontal output transistor. No shorts were revcEiled. Access into the set was diffi- cult, so I decided to make life easier by mounting the fuse onto a stiff fuseholder on the PCB. Fuse replacement would be much quicker using a clip-type fuseholder. The set was connected to a Variac and an isolation trans- former. 1 adjusted the variac to produce a low value of about 30 volts DC at the rectifier cathode. The presense of B -I- voltages were checked at the regulator output, the audio output transistor, and at the horizontal output tran- sistor. I carefully increased the voltage gradually until audio noise was heard. The set seemed ready to work. The aroma of burning plastic was becoming noticeable and a wisp of smoke was seen coming from the PCB attached to the CRT socket. Shut off the power! Inspection of the PCB showed charring around the connector pins leading off the board, which indicated a dielectric breakdown between the PCB land patterns. Unplugging the connector showed burning between pins 3 and 4, Pin 4 had continuity to ground, pin 3 was on the high side of the screen control. Typically, a set with an in-line CRT has a circuit similar to that shown in Figure 5, where the connector details have been add- ed. The high side of the screen PLl 115 VAC ^< SI OH/OF j-mopv, *T«.C1 (T "^ I .01 T1 LINE — iJLliL/ — FILTER X DEGAUSSING COIL SPEAKER AF SOURCE FIG. 4— POWER SUPPLY CIRCUIT. O e CD m :eo, and, The permittivity of free space is Ep = 10-9/(36 X ;r) farads/m = 8.85 pF/m, and the permeab iltty of free space is fig = 4 X ji X 1 0-^ henry/m = 1 ,26 fM/m. FIG. 1— A BASIC CONVENTIONAL cylin- drical or conventional magnetron. The in- dividual chambers between tlie spokes are the reentrant cavities, and connected to the gaps betw^een the walls of the cav- ities. They're cavity resonators, metallic enclosures that confine RF energy. The M-type mjignetron A conventional cylindrical magnetron is shown in Fig. 1. The chambers are reentrant cav- ity resonators — metallic en- closures confining RF energy, connected at the gaps between their walls. They have an infinite number of oscillating modes, the lowest-frequency one being dom- inant. At resonance, a standing wave is generated, and the peak electric and magnetic field ener- gies are equal. There's a DC operating poten- tial Vq between cathode and anode, while magnetic flux den- sity is in the +z-direction, into the page. The anode is grounded, and the cathode is highly nega- tive. If the anode were positive. FIG. 2— ELECTRON PATHS IN A conven- tional magnetron. If an electron is injected into the electric field E^, between cathode and anode, it accelerates linearly. If the lines of magnetic flux density Bq is pres- ent into the page, and both £„ and B^ are properly adjusted, the electron moves cycioidally. both it and the output waveguide would need insulation, and be dangerous to service. Figure 2 shows electron paths in a conventional magnetron: when electrons are injected into the electric field between cathode and anode, they're linearly accel- erated. If the magnetic field is Into the page, and both the elec- tric and magnetic fields are prop- erly adjusted, the electron moves cycioidally. The Hull cutoff condition Figure 3 shows three views of a simple conventional magnetron. The electric field lines go from anode to cathode, and the mag- netic field lines are into the page. For a constant magnetic field, op- eration is governed by the Hull magnetic cutoff criterion. The first form gives the Hull cutoff po- tential in terms of magnetic Ilux density. The second form gives the Hull cutoff magnetic flux den- sity in terms of operating poten- tial. The first form is The second form is In the above expressions Vq is the operating potential, Vqp is the Hull cutoff potential in volts, SUBCRITICAL VV„ OPERATING VOLTAfiE AT HULL POTENTIAL OPERAnPJG VOLTAGE ABOVE HULL POTENTIAL CRITICAL THRESHOLD IZ. 0, a MAGNETIC FIELD FIG. 3— THE THREE ELECTRON TRAJECTORIES in conventional magnetrons. The lines of electric field Eq goes from anode to cathode, while those of magnetic flux density B^ are into the page. The subcritical case (a) yields true anode current. In the critical case (b), electrons graze the anode, and in the supercritical (cutoff) case (c), they never reach it. A plot of anode current I as a function of B^. is shown in (d). 72 a is the cathode radius in meters, b is the anode radius in meters, e = 1.6 X 10-1^ coulombs, the electron charge, m = 9.11xlO-3J kilograms, the electron mass, B(j is the magnetic flux density in webers per square meter (Wb/ Boo is the Hull cutoff magnetic flux density in webers per square meter (Wb/m^). The relative values of operating potential and magnetic flux den- sity govern magnetron opera- tion. For the first form, if mag- netic flux density is above cutoff for a given operating potential, the electrons don't reach the anode. The reverse holds true for the second form; if the operating voltage is under the Hull cutoff potential for a given magnetic flux density, the electrons again don't reach the anode. Figure 4 shows the three condi- tions for the second form of the Hull cutoff criterion. Figure 3 -a shows the subcritical case, where the operating potential is below cutoff, with a true anode current. Figure 3-fa shows the critical case, where the operating potential is at cutoff, and the electrons graze the anode before returning. Figure 3-c shows the supercritical case, where the op- erating potential is above cutoff, and the electrons are deflected back before hitting the anode. Figure 3-d shows anode current I as a function of magnetic flux density B„. Magnetron anodes The circular anodes in Fig. 3 have an infinite number of modes, and are useless. Real magnetrons use cavity reso- nators like those in Fig, 1: each is FIG. 4— THE CAVITY RESONATORS IN Fig. 2 act like a resonant L-C tank. The cavity walls primarily contribute to cavity inductance, while the spacing between the walls of ttie gap at the base of the cavity primarily contributes to cavity ca- pacitance. HOLE-AND-SLOT BLOCK a REGULAR TRAPEZOID! AL BLOCK t) m«;netic FIELD /\ . RISING SUN BLOCK B„ B, B, B. 9, B, B. B„ B, B. 11 1 CflTHOOE' -*r ANODE A 'CAVrriES AND SLOTS HEATER d FIG. 5— SEVERAL DIFFERENT MAGNETRON ANODES; a hole-and-slot block (a), a reg- ular trapezoidal block {b), and a rising sun block {c). In each, the cavities and anode are made from a single metal block; B^ is arranged as in (d). a resonant L-C tank as in Fig. 4; the cavity walls fix inductance, the wall conductivity fixes resis- tance (not shown). Several ver- sions are shown in Fig. 5; each is a single metal block, and B^^ ap- pears in Fig. 5-d. Consider the hole-and-slot block in Fig. 5-a; the others are similar. For unstrapped (un- shorted) anodes, the tanks are in series, as in Fig. 6-a. However, if alternate cavities are strapped (shorted) as in Fig. 6-b. the anode is an array of parallel L-C tanks, as in Fig. 6-c. That's normal for most magnetrons; due to the strapping of alternate cavities, adjacent resonators are 180° out of phase. Pi-mode operation Most magnetrons work in ji- mode, where the phase shift be- tween adjacent resonators is ji ra- dians, or 180°. The radian is an alternate unit of angle, where 1 radian = 57.3°. When a magne- tron is turned on, the electron cloud shock-excites (rings] the cavities, setting up a spatially- and time-varying electric field in the cathode-anode interaction space, adding to that due to the FIG. 6-EACH HOLE AND SLOT CAVITY IS A parallel -resonant L-C tank. In unstrap- ped (unshorted) anode, the tanks are in series, as in {a}. If alternate cavities are strapped (shorted) as in (b), the magne- tron becomes an array of parallel L-C tanks, as in (c). Magnetrons are normally strapped, so adjacent resonators are 180° out of phase. operating potential, it varies the acceleration of the electrons due to the operating potential V^,, modulating their velocity and V„ density, creating a "bunched up" pattern. Figure 7-a shows the electric field due to the operating poten- tial for a hole-and-slot block, and o o m CO CD O 73 to o z o IT 1- O UJ D < for a trapezoidal block in Fig. 7-5, both in ^T-mode. For oscillation to occur, the electron velocity must equal the phase velocity of the RF wave, so resonance can transfer kinetic energy into RF energy. If that occurs, the electron cloud keeps ringing the cavities, gener- ating RF waves. The electron ve- locity is the ratio of the electric field from the operating po ten tia! to the magnetic flux density, or Vo=Ec/Bo. At that speed, the electrons lose energy to the RF wave, slow down, and return. During os- cillation, there's no anode cur- rent, as shown in Fig. 3-d. Since the magnetic field is perpen- dicular to the electron motion, the centripetal acceleration in- ward from the magnetic field equals that radially outward from the electric field, A reentrant cavity resonator is a "slow- wave" structure; its pur- pose is to slow down the phase FIG. 7— THE SHOCK-EXCITED, spatially- varying .-T-mode Eo for a hole-and-slot block in (a), and a trapezoidal block In (d), both with N ^ 8. They cause nonuniform electron acceleration resulting In velocity and density modulation, and "bunching up" of electrons. velocity of an RF wave (more be- low), so it interacts with an elec- tron beam. The cavity is designed so oscillations occur only if the total phase shift around the anode is a multiple of 360° or 2xji radians, creating a stand- ing wave. For an N-cavity anode, the phase shift between adjacent resonators is Boi, oscillation occurs; if not, the RF energy is cutoff. density to the cathode-anode spacing and the operating poten- tial is the Hartree criterion. For the conventional magnetron V„K = 2nfB„ No -(b2 - aS). In this expression V^h is the Hartree potential in volts, B^ is the magnetic flux density in webers per square meter (Wb/ m2), f is the frequency in Hz, N is the number of resonators, b is the anode radius in meters, continued on page 76 74 MEMORY CARD continued from page 58 strobe) enable signals for the RAM. In order to keep the board size small, a PEEL programma- ble logic device was used for IC2. For those interested in program- ming their own device, or for those simply interested in how the decoding works, the truth ta- ble for IC2 is shown in Tkble 1. The address and control sig- nals to the RAM are buffered by IC3 and IC4. A four-position jumper, Jl, is used to select the amount of on-board memory you will use and whether the printer is a IIP or III. The 8048 micro- controller is programed to com- municate to the printer such information as "I am here," and"l have 1 megabyte of memory in- stalled," etc., and its hex code is shown in Listing L Assembly Although the circuit is simple, the need to accommodate up to 4- megabytes of memory (32 IC's) makes the PC board rather com- plex. The foil patterns are pro- vided for the board, but you will have to drill 945 holes if you wish to make your own. Referring to the parts-place- ment diagram in Fig. 2, install the parts in the following order. Start by installing and soldering all of the IC sockets. The 20-pin sockets should have built-in 0. 1 \xF decoupling capacitors. (The finished board is shown in Fig. 3, where you can see the IC sockets with the built-in decoupling ca- pacitors.) Orientation of these sockets is important, as the ca- pacitor must go to pins 10 and 20 of the pads on the board. How- ever, you can use regular sockets and mount the capacitors on the bottom side of the board or un- derneath the sockets. Because you dont have to install the full 4 megabytes of memory on the board, you might want to install only as many sockets as needed. Install 8 sockets per row per megabyte, starting in the row next to ICl. Install capacitors CI through C5. Make sure you properly ori- ent the polarized capacitors, CI and C5. Jumper block Jl may be either an 8-pin dual-row male header IC5" 'K Tf- rrr IC13"F5i!:F nc2^ c IG29 c IC6 C IC14 ( 1C22 C IC30 IC7 C ICI5 ( iC23 tC31 C I tC8 C IC16 3 IC24 C IC32 C IC9 ( IC17 '4 ICIO c tC18 C IC11 ( iC19 ( ij iiil '■ tC12 di I (C£0 3i IC25 ( IC33 C s IC26 ( iC34 £ ■s IC27 C (C35- i, ...i?28..^ ...,,'e36i;,£ FIG. 2— ALTHOUGH THE CIRCUIT IS QUITE SIMPLE, the PC board is rather complex, In order to accommodate up to 32 dynamic RAM IC's. FIG. 3— THE PROTOTYPE BOARD uses IC sockets with built-in decoupling capacitors. Orientation of these sockets Is important, as the capacitor must go to pins 10 and 20. You can also use regular sockets and mount the capacitor under the socket or on the solder side o1 the board. TABLE 1 TRUTH TABLE FOR 011273 DECODER Inputs Outputs 1 2 3 4 12 13 14 15 16 17 18 19 1 X X X H H H H H H H H L H H H H H H H 1 H L H H H H H H 1 H H L H H H H H 1 1 H H H L H H H H 1 H H H H L H H H 1 1 H H H H H L H H 1 1 H H H H H H L H 1 1 1 H H H H H H H L "X" = Don't Care o o CD m Jl tn CD o 75 O CL ts UJ _I LU < TABLE 2 MODEL IIP MODEL til PIN1 PIN2 PIN3 PIN4 PIN1 PIN2 PtN3 PIN4 1 MEG X 2 MEG X X X 3 MEG o 0X0 X X 4 MEG X X X X X LISTING 1 00 31 00 oe 06 oc 21 4a 01 4E 23 ED A3 ED A3 4E 23 ED A3 20 F4 CD DA 00 DD 21 35 01 CD E6 00 CD 24 01 FE 24 28 EF CD 7A 00 20 PI E5 CD OD 01 El E9 CD DA 00 DD 21 3E 01 CD E6 00 CD 24 01 FE 24 20 F6 OE 08 21 00 02 ED A3 DB 05 CB 7F 28 FA DB 05 CB 7F 20 FA ED A3 IS FO CD DA 00 DD 21 43 01 CD E6 00 CD 24 01 FE 24 20 F6 76 01 FF 07 21 00 OS 11 01 OB 36 oo ED BO 18 9B 06 03 OE 04 16 40 ED 51 DB 04 E6 OF 20 06 OB OA 10 F4 04 C9 CB 2F 4F 3E PB C6 05 10 FC 81 FE 03 FA 9F 00 D6 01 FE 07 FA A6 00 D6 01 FE OB FA AD 00 D6 01 S7 16 00 5F FD E5 FD 21 5C 01 FD 19 FD 6E 00 FD 66 01 PD El AF C9 CD E6 00 FE 24 20 F9 FD 7E 00 FD El F5 CD EC 00 CD OD 01 Fl CB 42 C9 OD 21 30 01 CD E6 00 FE 24 20 F9 C9 DD 7E 00 FE 24 C8 01 03 00 21 02 OS 11 03 08 ED B8 FE 2A 20 03 3A 03 08 12 DD 23 01 04 00 21 03 08 11 03 10 ED B8 C9 3E 70 D3 04 21 00 02 CD 27 01 DB 04 Ee OF 20 F4 21 00 02 CD 27 01 09 21 00 18 11 00 00 37 ED 52 20 FB C9 20 20 20 20 24 43 4F 4D 4D 41 4E 44 3F 24 52 45 44 59 24 44 4F 4E 45 24 OA CF 00 08 FF OB CF 00 09 00 06 CF OF 04 00 07 CF 80 05 3C 15 00 6B 00 15 00 15 00 15 00 15 00 15 00 15 00 IS 00 15 00 15 00 31 00 00 00 IS 00 31 00 00 00 00 00 00 00 FF FF FF FF FF FF FF PF 7F FF FF FF FF FF FF FF FF FF FF FF PF FP FF FF PF FF FF FF FF FF FF FF FF PF FF FF FF FF FF FF FF FF FF FF FF FF PF PF PF FF FF FF FF FF FF FF FF PP FP FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF PF FF FF FF FF FF FF FF PF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF PF PF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF PP FF FF FF FF FF FF FF FF FF FP FF FF FF FF FF FF FP FF FF FF FF FF 00 00 00 00 PF 00 00 00 00 00 00 00 00 PF FP FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 00 00 00 00 FF 00 00 00 00 FF 00 FF 00 FF FF FF FP FF PF FF PF FF FF FF FF FF FF FF FF FF 00 00 00 FF OF FP FF FF FF FF 00 00 EE EE FF 00 00 00 FF FF 00 FF FF FF 00 00 oo FF 00 FF OF OF OF FP FP OF FF OF FF FF OF OF EF IF FF FO FO FO FF FF FO FF FO FF FF FO FO FE Fl FF OF OF OF FF FF OF FF OF OF FF FF OF OF FF FF FO FO FO FF FF FO FF FO FO PF FF FO FO FF FF OF OF OF FF PP OF FF OF FF OF OP OF EF EF FF FO FO FO FF TT FO FF FO FF FO FO FO FE FE FF 3F 3F 3F FF FF 3F 3F 3F FF 3F 3F 3F 3F FT FF F3 F3 F3 FF FF F3 F3 F3 FF F3 F3 P3 F3 FF FF 3F 3F 3F 3F PF 3F 3F 3F 3F 3F 3P 3P 3P PF FF F3 F3 F3 F3 FF F3 F3 F3 F3 F3 F3 F3 F3 FF FF 3F 3F 3F 3F FF 3P 3P 3F 3F FF 3P FF FF 3F FF FO FO FO F3 FF FO FO F3 FO FO FO FC PC F3 FF 3C 30 FC 3C 3C FC FC FC PC FO 30 3C BO EC FC 30 30 FC 30 PC 3C PC FC FC 3C 30 30 FS 38 FC 30 30 FC 30 FC 30 FC 3C FC FO 30 30 BC 70 PC FC FC FC FC PC FC FC FC FC FO FC FC FO FC FC 30 30 FC 30 FC 30 FC 30 3C FC FO FO 33 34 FC DC CC CC CC CC CC CC CC CC CO CC CC CC CC CC 00 00 CC 00 CC 00 CC 00 CO OC 00 OC 80 SO CC CC CC CC 00 CO CC CC OC CC CC CC CC CC CC CC CO CO CC CO CC CO CC CO 00 00 CO CO C8 C8 CC CC CC CC CC GC CC CC CC CC CC CC 00 CC CO CO CC CC CC CC CC CC OC CO CO CC CC CC CC GC CC CC CC CC CC CC CC CC oc CO CC 00 00 CC CC CC CC CC CO CO CO CO CC CC CC CC CC CC CC CC CC CC CC CC CC CO 00 CC CC CC CC CC CC CC CC CC CO CO CC CO CC CO CO CC CO CO CO CO CO CC CC CO oo 00 CO 00 CO CO CO CO CO CO CO CO CO CO 00 00 00 CO CO 00 00 CO 00 00 00 00 00 CO CO 00 CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO oo 00 CO CO CO CO CO CO CO CO CO CO CO CO CO CO 00 CO CO 00 CO CO CO CO CO CO CO CO CO CO 00 CO CO CO CO CO CO CO CO CO CO 00 00 00 00 00 00 00 00 00 00 00 00 oo 00 00 00 connector with shorting blocks ora4-positionDIPswitch; install it now. Also install and solder J2. a 48-pin double-row straight male header Make or purchase a cable to plug the memory board into the printer. The cable must be a 48- conductor ribbon cable, about 2 inches long, with a 48-pin female IDC (insulation displacement) connector on each end. Install the 6-MHz crystal (XTALl) so that it lays on top of C3 and C4. parallel to the PC board. A dab of epoxy will keep it from getting broken off later. Check your work carefully Ex- amine your soldering under an illuminated magnifier for solder bridges. Install the ICs in their sockets. You will need 8 256K x 4-bit dy- namic RAM's (no slower than 120 ns) for each megabyte of memory you wish to install, starting with the row nearest ICl. continuing toward the rear edge of the board. Table 2 indicates how to set Jl (the DIP switch or jumpers) for the amount of memory and type continued on page 94 MICRO TECH contin u ed fro m. page 74 a is the cathode radius in meters. Figure 8 shows a simultaneous plot of the Hull and Hartree crite- ria for a conventional magne- (ron, where the electric field E„ is a (unction of magnetic flux den- sity B„. The electric field between two conductive surfaces is always the operating potential divided by the distance between them. Since the geometry of the magne- tron is fixed, with the anode- cathode spacing a constant, then that proportionality is valid. The Hull curve is on top, the Hartree cui-ve below They intersect at two locations: at the origin, and when the Hull and Hartree poten- tials are equal, which really also means that E^,, equals E„|^. If V„ is greater than ¥„, and B„ is greater than B^,, anode current is cutoff and the magnetron os- cillates; otherwise, anode cur- rent flows and oscillation is cut- ofi". FIG. 9— THE VARIAN SFD-352 TUNABLE, conventional magnetron; the output waveguide llange appears on the top of the front. It has a tuning range of 8.5-9.6 GHz set by the vernier, a peak power of 220 kilowatts, a nominal anode potential of 22 kllovolts, and a peak anode current of 26 amps. Conclusion Figure 9 shows a typical exam- ple of a magnetron, the SFD-352 tunable, coaxial version from Varian Assocs, A coaxial version differs from a conventional ver- sion by a high-Q stabilizing cav- ity that surrounds the anode. The output waveguide fiange ap- pears on the top of the front, and it has a tuning range of 8.5— 9.6 GHz set by the vernier dial, r-e 76 !fn;^■^vn;^:«;rlH'■1:^; This month we look at various types of filters and a digital thermometer. DON LANCASTER Our no-charge Hardware Hacker helpline sure gets a lot of traffic on filters and filtering. So thiis month. I thougfit we might go over some filter fundamen- tals, especially in deciding just what kind of filter sfiould get used where. Passive filters An electronic filter is some fre- quency-selective network that favors certain frequencies at the expense of others. Filters are normally used to strengthen wanted signals while try- ing to reject unwanted ones. Traditionally, filters were built by using combinations of inductors and capacitors. These are called passive filters, and three examples appear in Fig. 1. In 1-a, we have an example of a low- pass filter. At very low frequencies the inductor appears as a piece of straight wire and the capacitor's reac- tance is extremely high. So DC and very low audio frequencies are readily passed. At very high frequencies, the inductor looks like a high blocking impedance and the capacitor looks like a very low shunting impedance, so all the high frequencies will get strongly attenuated. The one-two punch of this example makes it a second order filter. At low frequencies, the response is flat. At very high frequencies, the response will quarter with each doubling of fre- quency or fall off at a - 12-decibel- per octave rate. What will happen at the corner fre- quency with this circuit? Well, that depends on the ratio of the induc- tance to capacitance. Should you want the smoothest possible re- sponse, you can adjust the ratio of L to C so your response ends up pre- cisely 3 decibels down, or roughly 70 percent of the amplitude at the cor- ner frequency This -3-decibel point could also be called the cutoff fre- quency. Such a low-pass filter with the smoothest possible passband is usually called a Butterworth filter The L/C ratio of the circuit is also known as the damping. If you are critically damped, you will get the smoothest possible response. If you are underdamped, you get a rising or a peaked response at your corner frequency. If you are overdamped, you get a very droopy result. A simple treble control on a Hi-Fi is an example of a low-pass filter A 6and-pass filter appears in Fig. 1- 6, At rather low frequencies, the ca- pacitor provides a high reactance, and your response increases at a -1- 6-decibel per octave rate. At reso- nance, otherwise called the center frequency, the reactances cancel, giving you unity gain. At the higher frequencies, the inductor provides a com^ c^JlMiL-l % (A) LOW PASS (B) BAMD PASS (C) HIGH PASS FIG. 1— THREE EXAMPLES OF SECOND-ORDER passive LC filter sections. high series reactance, and the re- sponse decreases at a -6-decibel per-octave rate. The ratio of the inductance to the capacitance sets the damping, which in turn will set the sharpness of your resonant peak. Since very low damp- ing values are usually involved, a fac- tor called the "Q" is used instead. The Q, or "quality" factor is the in- verse of the damping. The Q is also the bandwidth of the center peak be- tween its -3 decibel points. Note that, no matter how high the 0. the slopes at very low and ver/ high frequencies will stay at -1-6 and - 6 decibels per octave, Your choice of determines only the narrowness and the peakedness of the response at or near resonance. The tuning dial on an AM radio is an example of a band-pass filter A second-order high-pass filter ap- pears in Fig. 1-c. Here, the high im- pedance of the series capacitor and the low impedance of that shunting inductor attenuates the very low fre- quencies, creating a double whammy attenuation rate of -i- 12 decibels per octave. At higher frequencies, the ca- pacitor's reactance is low and the in- ductor's is high, freely passing the highs without attenuation. Once again at the corner frequen- cy, you will get a peaked, smooth, or drooping response depending on your L/C ratio and its damping factor. The bass control on a Hi-Fi is one example of a high- pass filter Actually, there is no such thing as a true electronic high-pass filter, since one of these would also have to pass microwaves, heat, light, and X-rays. At very high frequencies, the circuit strays (such as a capacitor self-reso- nating on its own leads) can alter the response. High-pass filters also tend to be q "noisy," since they freely pass all the Ej harmonics of all supposedly rejected § waveforms. Compared to a low-pass 53 filter, which performs one or mor'e ^ integrations, a high-pass filter does o 77 one or more differentiations, or slope extractions. This also can add to the overall noise. Fancier filter responses are picked up by using additional inductors and extra capacitors to increase the order of your filter Unfortunately, you can not just "stack up" passive sections. Each in turn has to play a specific and non-obvious part in your overall desir- ed response. My favorite design book on pas- sive filters remains Louis Weinberg's ainnost ancient Network Analysis and Synthesis CMcGraw Hill. 19623. The Radio Amateur's Handbook also has lots of good passive filter design infor- mation in it. as do most college-level circuit or network texts. These days, you usually try to avoid passive filters like the plague, since they are bulky and expensive, and hard to redesign, calibrate, or adjust. They also lack gain and do need care- fully conttxDiled source and load im- pedances. So, you'll w^ant to avoid passive filters at all costs — unless you happen to be working with ex- o o DC LU o § DC NEW FROM DON LANCASTER HANDS-ON BOOKS Hardware Hacker Reprints II 24.50 Ask The Guru Reprints 1 or II 24.50 CMOS Cookbook 18.50 TTL Cookbook 16.50 Active Filter Cookbook 15.50 Micro Cookbook vol 1 or II ie.50 Lancaster Classics Library 39.50 Enhancing your Apple 1 or II 17.50 AppleWrlter Cookbook 19.50 Apple Assembly Cookbook 21.50 Incredible Secret Money Machine 10.50 LaserWriter Reference (Apple) 19.50 Post Scrip! Cookbook (Adobe) 1S,50 PostScript Ref. Man. (Adobe] 22.50 PostScript Prog, Design (Adobe) 22.50 Type 1 Font Format (Adobe) 15.50 Real World Postscript (Roth) 22.50 UNLOCKED SOFTWARE LaserWriter Secrets (iie/Mac/PC) 29.50 PostScript Show & Tell 39.50 Intro to PostScript VHS Video 39.50 PostScript Beginner Stuff 39.50 PostScript BBS Stuff 19.50 The Whole Works (ail PostScript) 249.50 Absolute Reset lie & lie 19.50 Enhance 1 or II Companion Disk 19.50 AppleWrlter CB or Assy CB Disk 24.50 ^FREE VOICE HELPLINE i/ISA/MC SYNERGETICS Box 80g-RE Thatcher, AZ 85552 (602) 428-4073 NEED HELP? Phone or write your Hardware Hacker questions directly to: Don Lancaster Synergetics Box 809 Thatcher, AZ 85552 (602) 428-4073 tremely low signals, at very high power levels, or at very high frequen- cies where nothing else will do the job. The usual way of filtering stuff today involves... Active filters With an active filter, you can use combinations of resistors, capaci- tors, and operational amplifiers to fake the response you would get from a passive LC filter The energy from the power supply is used to sub- stitute for the energy normally stored in an inductor's magnetic field. Important advantages of the active filters are that there are no inductors involved, they are easy to design, and they are easy to tune. Since active filters can also provide buffering and gain, they are far less sensitive to source or load imped- ances than passive filters. While there have been many dif- ferent active-filter design methods in the past, only two have really suivived and stay popular today. These are the everyday Sallen-Key single op-amp filters and higher performance State Variable filters that need three or four op-amps per second-order section. Figure 2-a shows to you a second- order Sallen-Key low-pass filter nor- malized to a 1 0K impedance level and a 1-kHz cutoff frequency. The original horse's mouth on this was R. Sallen and Key's A practical mett)od of designing RC active filters from the IRE Transactions on Circuit Theory, March 1955, pp 74—85. Their prototype Sallen-Key filters were intended for use with cathode followers, the vacuum-tube precursor to a transistor emitter-follower circuit. These were designed to work with a unity or slightly lower gain, which forced you to select weird ratios of capacitors and caused an interaction between the comer frequency and the desired damping. Many years ago, I played araund with the Sallen-Key math in detail and came up with a twist that made these filters far simpler to design and use. 1 39K 39K X (2-d) ,||— jyVA-^t WVV 10K 10K IN o- — WA — t — W/r-^ — 0.16 i " j^^ 0.16 -o OUT (A) SIMPLE SECOND ORDER SALLEN-KEY SECTION 39K 'li WW- 6.2K -^VIM- 33K 47K 10K 10K 0,16 ■ ^ 0.16 ,1} wA-^r — — "WAr 10K 10K J> 0.16 ^ Tf: o; -O OUT (B) FOURTH ORDER BUTTERWORTH LOW PASS AUDIO FILTER FIG, 2— TWO SALLEN-KEY LOW-PASS active fillers. Most any premium grade of op-amp can be used. Components stiould be 5% or better. 78 ^ J^ renamed it the Equal Component Val- ue Sallen-Key filter In the Fig. 2-a design, both capacitors are of identi- cal value and set only frequency. Both resistors are of identical value and also set only frequency The op-amp gain independently sets the damping. To scale your frequency you just increase either resistor pair or either capacitor pair to /ower frequency, and vice versa. To scale impedance, pro- portionately raise the resistors and lower the capacitors. Full details ap- pear in my Active Filter Cookbook. Normally, you combine, or cascade second order sections to build up a fancier filter of higher order. By very carefully selecting the damping value and that comer frequency of each second-order section, you can pro- duce an overall filter response of most any desired complexity Some of these fancier responses do have specific names. For instance, a Sesse/ filter vtfill give you the flattest possible time delay at the expense of the amplitude fall-off. As we've just seen, a Buttetworth filter can give you the smoothest possible ampli- tude response. If you are willing to allow some ripple in the passband, you end up with a Chebychev filter Popular Chebychev filters could be created with one, two, or even three decibels of passband ripple. Finally, the Cauer, or Elliptical type filter will NAMES AND NUMBERS Emulation Technology 2344 Walsh Avenue, Bidg. 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One thing that many beginning hackers miss; if your filter is made up of cascaded and isolated second- order sections, the only difference between ttiese filter types lies in how you select the damping and the cor- ner frequency of each section. That's all. Thus, once you have a filter built, all you need do is change the damp- ing and the corner frequency of each section to get any desired result from Bessel on through Chebychev. As with passive filters, you do not simply stack up identical second- order sections. Instead, you must carefully select your damping and corner frequency of each section to properly interact v^^ith the others to get the final desired response. Figure 2-6 shows a fourth-order Butterworth low- pass filter having a 1- kHz cutoff frequency and a - 24-deci- bel per octave rolloff. Note that the two sections are not identical. Also note that a DC return path to ground must be provided back through the input source resistance for a low- pass active filter to work properly. It has been pretty much proven to everyone's satisfaction that you can not build up a high-Q active band- pass filter using only a single op-amp. The impedance levels, interactions, and gain requirements all gang up on you as you raise the Q. Figure 3 shows you the best of a sorry lot of single op-amp second- order band-pass filters. This one is called a multiple feedback circuit. It is recommended only for Q values much less than 10. Thus, while that type of filter is useful for such things as an equalizer or a simple psyche- delic lighting filter, it is strictly limited ACTIVE FILTER RESOURCES Analog Devices Muts & Vofts One Technology Way Box 1111 Norwood, MA 02062 Placenlia, CA 92670 (617) 329-4700 (714) 632-7721 CIRCLE 230 ON FREE INFORMATION CARD CIRCLE 237 ON FREE INFORMATION CARD Burr-Brown Plessey Signal Technology 6730 South Tucson Blvd 9630 Ridgehaven Court Tucson, AZ 85706 San Diego, CA 92123 (602) 746-1111 (619) 571-7715 CIRCLE 231 ON FREE INFORMATION CARD CIRCLE 238 ON FREE INFORMATION CARD Exar PMI Box 49007 1500 Space Park Drive San Jose, CA 95161 Santa Clara, CA 95052 (408) 732-7970 (408) 727-9222 CIRCLE 232 ON FREE INFORMATION CARD CIRCLE 239 ON FREE INFORMATION CARD Synergetics Linear Technology Box 809 1630 McCarthy Blvd Thatcher, AZ 85552 Milpitas. CA 95035 (602) 428-4073 (408) 432-1900 CIRCLE 240 ON FREE INFORMATTON CARD CIRCLE 233 ON FREE INFORMATION CARD Teledyne Semiconductor Maxim 1300 Terra Bella Avenue 120 San Gabriel Drive Mountain View, CA 94043 Sunnyvale, CA 94086 (415) 968-9241 (408) 737-7600 CIRCLE 241 ON FREE INFORMATION CARD CIRCLE 234 ON FREE INFORMATION CARD Motorola Texas Instruments Box 20924 RO. Box 1443 Phoenix, AZ 85036 Houston. TX 77001 (800) 521-6274 (800) 232-3200 CIRCLE 235 ON FREE INFORMATION CARD CIRCLE 242 ON FREE INFORMATION CARD National TRW 2900 Semiconductor Drive Box 2472 Santa Clara, CA 95051 La Jolla, CA 92038 (408) 721-5000 (619) 475-1000 CIRCLE 23B ON FREE INFORMATION CARD CIRCLE 243 ON FREE INFORMATION CARD to lower Q applications. The higher performance work- horse second-order active fitter cir- cuit is called a state variable filter and is built using three or four op-amps per Fig. 4. This one has three sepa- rate low-pass, band-pass, and high- pass outputs, is very well behaved, and can work with very high Q or low damping values. A fourth op-amp can be added to the circuit shown to make the gain independent of the damping. Finally, Fig, 5 shows you a Sallen- Key single op-amp high-pass circuit. This one is simply the low-pass circuit of Fig. 2 "insided out" to get the complementary response. o OUT FIG. 3— THIS SINGLE-AMPLIFIER multi- ple-feedback band-pass active filter can be used only for Q values of 10 or less. Active filters are limited by the fre- quency response, the slew rate, dis- tortion, and noise floor of the op-amp used. They are best used at audio and low video frequencies having signals which are neither very small nor ex- cessively large. Quality op-amps for active filters are available from Linear Technology, Burr-Brown, Analog De- vices. Maxim, National, and PMI. By one of those utterly astounding coincidences that seem to infest this column, I've written an Active Filter Cookbook that somehow has gotten up to its fifteenth printing. It includes everything you need to build ail your own real-world active filters. Write or call for an autographed copy, OtKer filter types Besides passive and active filters, there are several other major new methods of filtering electronic signals that are of more than passing hacker interest. These now include switched capacitor filters, digital signal pro- cessing, and surface wave devices. A switched capacitor filter is just that — some integrated circuit which contains a bunch of small capacitors roK r — VAV- lOK IN c^^VWf 3,3K 3.3Kx(3Q-1) LP OUT O BP OUT FIG. 4— THIS STATE-VARIABLE ACTIVE FILTER gives low-pass, band-pass, and high- pass outputs and is best used for high-Q or lovv-damplng applications. 2 OK 0.16 IN o — ](- 1DK : 0.16 20K I t2-(Jl ^ 10K -o om FIG. 5— THE SALLEN-KEY HIGH-PASS second-order filter section is simply the lovK-pass circuit of Fig. 2-a inside out. Val- ues are for 1 kHz. that are switched on and off to sam- ple an input signal. If the switching is just right, the charge on the capacitor will follow and reinforce the input sig- nal. If it is wrong, the charge on the capacitor will average out to zero. By carefully arranging the network of properly switched capacitors, you can favor certain frequencies and re- ject other ones. The big advantages of switched ca- pacitor filters are electronic tunability and minimum cost. In the past. 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IFyou possess average mechanical ability, and havea VCR on which to practice and learn. . . .then we can teach YOU VCR maintenance and repair I FACT: up to 90% of ALL VCR mall unctions are due to simple MECHANICAL or ELECTRO-ltflECHANICAL breakdowns! FACT: over 77 million VCRs in use today nationwide! Averagp VCR needs service or repair every 12 to 18 months! ViejO'S 4D0 PAGE TRAINING MANUAL (over 500 pho- tos and lltuslralioiK) and AWAnO-WINNING VIDEO TRAINING TAPE reveals the SECRETS ol VCR mainte- nance and repair — "real world" information that is NDT available elsewhere! Also it^cjudes all the info you'll need regarding the BUSINESS-SIDE of running a successful service op- eration! ppjj INFORMATION CALL TOLL-FREE 1-SOQ -537- 0589 Or write to: Viejo Publications inc. 5329 Fountain Ave. Los Angeles, CA 90029 Dept. RE CIRCLE 190 ON FREE INFORMATION CARD The LOW COST, EASY Way To Learn AboLit Computers FRIENDLY VIDEOS presents COMPUTER HOW-TO VIDEOS VdsoTape Is A tot Teachef ■HOW TO BUILD YOUFI CWN IBM 266/388 CLONE- $39.65 + SHIPPING AND SALES TAX ■SHAKE HANDS WfTH YOUR IBM PC/XT/AT COMPUTER' sae.as + shipping and sales tax ■UPGRADE YOUR PC TO A 286- AT FOR UNDER $1 50" SS4.95 + SHIPPING AND sales TAX ■HOW LASER PRINTERS WORK" $39.95 -^ SHIPPING AND SALES TAX ORDER NOW! VISA Friendly Videos ^S PO Box 5684 '*■ Garden Grove, CA 92645 (714) 898-4055 switched capacitor filters were noisy and produced significant distortion. Today's circuits are far better, but they still don't handle extremely small input signals very well. Important uses for these switched capacitor filters are modems, touch- tone detection, disk drives, CD play- ers, industrial instrumentation, and data acquisition. Several large suppliers of switched capacitor filters now include Linear Technology, Maxim, and Exar. All three sources have detailed data sheets and ap notes available. A digital signal processor is just a specialized type of microcomputer To do filtering using digital signal pro- cessing, you first analog-to-digital (A/D) convert your input signal into strings of numbers in memory. Then you use digital techniques to modify these numbers in memoty. Finally, you digital-to-analog CD/A) convert your hitered results. While that may sound like a real runaround, these days you can digital signal process in one single and rea- sonably priced chip. There are many big advantages to DSP filtering. One major advantage is that you can easily create filters that can be extremely difficult or impossible to handle with passive or active analog techniques. Examples include "brickwall" filters with near-infinite response slopes, and filters with constant phase or controlled group delay. Another major advantage is full program mability. Nothing changes except some software words if you w/ant to completely change what your filter does or how it does it. Most of the DSP chips are really specialized microprocessors. Usu- ally they have powerful internal firm- ware commands which let you rapidly multiply, shift, and add. They also usu- ally provide specialized functions such as barrel shifting and zero time testing and branching. Both fixed point and floating point processors are available today DSP is obviously limited to lower frequencies unless you do not need real time results. You also have the usual aliasing problems and the A/D quantization noise limitations to cope with as well. Important use areas for DSP in- clude geophysics, for biological re- search, in speech synthesis and recognition, radar, and electronic mu- sic. Just about all of the latest per- sonal computers and synthesizers have gone the DSP route for most of their sound capabilities. The main manufacturers of DSP products in- clude Analog Devices. Texas Instru- ments, Motorola, and TRW. All of these folks have extensive data books and detailed application notes available. Surface acoustical wave, or SAW devices are a specialized type of low- cost filter which is quite popular in television and cable systems. They consist of a piezoelectric disk which has an acoustical transmitter and an acoustical receiver on it. Unlike your usual audio devices, these acoustical waves involve sound waves whose frequency typically lies in 40- to 400- MHz range. Special finger-like contacts are placed between the transmitter and receiver. These fingers cause con- structive and destructive interference patterns that give the SAW device a specified response. Typical uses are for TV vestigial sideband filtering, for various descrambling circuits, and to set the IF amplifier passband in TV receivers. The big advantages of SAW filters are that they're cheap, accurate, sta- ble, and need no tuning. Sadly the SAW filters don't really hack all that well, even though you can readily find them for a buck each surplus. A SAW filter handles one and only one specified job in a care- fully specified manner at one spec- ified frequency and into a specified load from a specific source. They are not in any way tunable or adjustable. What you got is what you get. And your own custom SAW filter involves a very steep setup charge, compara- ble to a full custom integrated circuit. One leading supplier of SAW filters is Plessey Signal Technologies, while bunches of surplus sources are avail- able. Let me know if you need any more details or use circuits forany of these alternate filter technologies. This month's resource sidebar is on active hlters and shows you many of the names and numbers you will need to get started. A digital tliermometer Radio Shack now has an amazingly sophisticated digital thermometer that sells for less than twenty bucks.. It is part number 277-123, This beauty runs off a single AA 82 R-E Engineering Admart STds are 2/4" x 2W. One insertion $950. Stx insertiorrs $925.eachlWfilve insertions SS95.each, Closing dale same as regular rate caret. Send order with I remittance to Engineering Admart, Radio Electronics Magazine, 500-B Bi-Coytity Blvd., Farrningdaie, NY 11735. Direct telephone inquiries to Arline Fishman, area I code-516-293-30(J0. Only 100% Engineering ads are accepted for litis Admart. ^ INCREASE YOJR EARNING POWER! LEARN TO DESIGN WITH SINGLE CHIP MICROCOMPUTERS! SINGLE CHtP MECROCOMPUTER PHIHEH FOR MOTOROLA eaus IncludBft - EfiMW ■ AM*7itiLef ' SJ00ef . . *MS UCPM-SPrognnirntr TDr Molwaljl MCUitC^DSCB, iQSC4 Parts kn w/dr^cr prny«m . , , . , . - - *1TE FulV aESBrriblBd w/dnvor pf^rjm (3E4 Fuiiy assemdled Wi/Einvor aSl;em&''*r.j-muljE3r,'cretVMer . . S*&5 TEC/I ETiullSOfS PrCigr.ir'ArAei't Aittmbltrt Slmurilofu'Dabugigicrt RL W3, BoxSC TELMB02) 525-J15« Barton. VT, USA 05SSS_ FA>i: (902} SBS-S'IBI FCC LICENSE PREPARATION The FCC has revised and updated the commercial license exam. The NEW EXAM covefs updated marine and aviation rules and regulations, transistor and digital circuitry. THE GENERAL RADIOTELEPHONE OPERATOR LICENSE - STUDY GUIDE contains vital information. VIDEO SEMINAR KITS ARE NOW AVAILABLE. WPT PUBLICATION 979 Young Street, Suite E Woodburn, Oregon 97071 Ptione (503) 981-5159 Dept. 50 Surface Mount Chip Component -^ „ Prototyping Kits- Only CC-1 CapoQior Kit cental ns 365 piece;;. Sea. of every lOMi value from tpf lo .33|if CR-1 ftesislor Kii eonlains 1340 pieces ; 10 ea of every 5^ vaJue frorr lOfl to 10 megn . Slies are 0805 and 1206 Each KH is ONLY S49,e5 and available (or Imimediate One Day Delivery! Ofdsr by to3l-free phorva, FAX, or mail. We accept ViSA, MC, AMEK.COD, or Pre-paid Orders. Company P-O.'s accepted with approved crediT- CalE (or free detailed brochure. ICOMMUNICATmS SP£CIAUSTS,IUC. 426 West Tatt AvB. ■ Orange, CA ga665-4?96 Local (714)998-3021 ■ FAX (714)974-3420 Entfre USA 1 -800-854-0547 CIRCLE 196 ON FREE INFORMATION CARD CIRCLE 191 ON FREE INFORMATION CARD CIRCLE 1&5 ON FREE INFORMATION CARD battery and has a four-digit LCD to display temperature in Fahrenheit or Centigrade over a -40- to 122-de- gree F range- Incredibly, there is both a recording max-min feature and a settable alarm and controller capability Both on-off levels and a 2-kHz piezo tone are pro- vided as outputs. You have a choice of a one-second or a fifteen- second update for your display. Total operating current is in the microamp range. The out-of-the-box accuracy is only a degree or so Fahrenheit, but the circuit seems stable enough that you might custom calibrate it for such things as a hot-tub controller or for cave-stream temperature logging. Unit-to-unit variations are also within a degree. The resolution is a tenth of a degree and seems real. Although not waterproof, that is easily fixed with a tube of silicon bathtub caulk. As received, the device displays Centigrade at fifteen seconds per up- date. To select Fahrenheit with a one- second update, just jumper pins 13, 14, and 16 on the edge connector. We'll probably look at this gem in more detail in a future column. For now, let's make a contest out of it. We'll have all the usual Incredible Se- cret Money Machine book prizes, along with an all-expense-paid (FOB Thatcher, AZ) tinaja quest for two go- ing to the very best of all. Either CA) show me a new and un- usual application for a miniature and micropowered max-min ther- mometer, or CB) show me some sim- ple and clean way to get the digital data out of the 277-123 thermometer into a remote computer. Send your written entries directly to me, and not to the Radio-Electronics editorial offices. New tech literature New data books this month include the Microcontroller Handbook from Siemens, a new Optoelectronics Data Book from Sharp, an Op-Amp Macromodel Data Manual and Disk from Texas Instruments, and that Semiconductor Data Book and Ap Notes from Unltrode. From International Rectifier, a Micnjelectronic Relay Design Man- ual, and an /GST prciduct catalog. There's a stupendously impressive Selection Guide to Integrated Cir- cuits from Telefunken that is chock full of unusual TV and auto chips. Inks which let you plot patterns di- rectly onto all your printed circuit boards are available through Loch Ness. They also have some low-end multilayer prototyping systems you may find of interest. Testing surface-mount devices and other weird or tiny packages can be a real hacker challenge. So. Emulation Technology has all sorts of adaptors and accessories that ease interfac- ing. Ask for their current catalog. An Overview of SCSI Concepts is a great new manual available free fnam Peer Pn)tocols. Three off-the- wall odd magazines are Extraordinary Science, Surplus News, and Science Frontiers. Free software demos this month Include the 48SX calculator disk from Hewlett-Packard, and the 945 heater controller demo from Watlow. A free mechanical sample of GUR is available from Hoechst^ This is a new plastic which is tough, cheap, self-healing and slippery. Turning to my own products, for the fundamentals of digital integrated cir- cuits, check into either my TTL Cook- book or CMOS Cookbook. And for those of you interested in the PostScript language or in Book-on- Demand publishing, our ongoing roundtable is doing fine on Genie. By the time you read this, over 1000 free downloads should be available. Finally. I do have a new and free mailer for you which includes dozens of insider hardware hacking secret sources. Write or call for info. Our usual reminder here that most of the items mentioned appear either in the Names and Numbers or in the Active Filter Resources sidebars. As always, this is your column and o you can get technical help and off- " the- wall networking per that Weed § Help? box. The best calling times are 3 weekdays 8-5, Mountain Standard 5 Time. Let's hear from you. r-e o 83 AUDIO UPDATE The Sound of Audio: An AES conference report, Part 2 ■wn rr '■ ^ ' LfcLoaij^i^ en O z o CE O LU _l o Q < Last month I started my report on a special Audio Engineering Society Conference held early last may in Washington, D.C. The four-day conference was a wide-rang- ing exploration of the latest findings on the perception, measurement, and reproduction of sound. I regret that because of space and time lim- itations, these two reports are at best a once-over-lightly review of an ex- tremely enlightening series of lec- tures and discussions. The audibility of distortion has been a controversial matter, probably from the moment the very first ampli- fier was designed. In the beginning, there was simple harmonic distortion (HD) that had an important virtue: It was easy to measure. However, the correlation between high HD and sonic unpleasantness was far from perfect — which lead researchers to discover/invent other types of distor- tions and new ways to measure them. During he 1950's, intermodulation distortion OM), which is the unwanted arithmetic sum and difference prod- ucts of two interacting frequencies, achieved instant fame as being more audibly obnoxious than HD. That was said to be true because, unlike HD, its spurious products are not harmon- ically related to the desired signals. In any case, as I've said in these pages and Richard Cabot stated in his conference paper, "Audible Effects vs. Electrical Measurements in the Electrical Signal Path," HD and IM are nof different kinds of distortion as much as they are different effects of the same nonlinearities in the equipment being tested. And be- cause with most amplifiers there is a predictable relationship between IM and HD levels, either measurement can be used to somewhat predict au- dible performance. Distortion data As I did for the authors in Part 1 , I'll extract and paraphrase (when neces- sary) some of Mr Cabot's more inter- esting points. In his bibliography, Cabot cites the previous relevant re- searches of more than 50C!) inves- 52.5dB FUNDAMENTAL eOdB FUNDAMENTAL rOdB FUNDAMENTAL 4 5 6 HARMONIC FIG. 1— THREE TEST-TONE LEVELS showing the amounts of jusl-audible dis- tortions up to the 8ttT harmonic. tigators. certainly a daunting task to evaluate and synopsizel • The audibility of distortion clearly does not depend on its relative per- centages alone. Other significant fac- tors are: CI) the characteristics of the equipment's nonlinearity; C2) the in- stantaneous level of the reproduced sound; (3) the type and complexity of the audio test signal; C4) the spatial qualities in the reproduced sound field; (5) the characteristics of the listening environment; C6) the distor- tion levels in the associated equip- ment and in the program material itself; and C7) the listener's ability to marshal his talents, if any, as a "gold- en ear." • Crossover distortion (CD), which became an important factor during the early days of transistor amplifiers, results from a push-pull amplifier's nonlinearity in the area where the sig- nal passes through zero on its way to the set of output deviceCs). A ' 'witch 's brew" of high-order HD and IM prod- ucts are produced whose relative am- plitudes increase as the signal level decreases. This means that, like noise, CD is mom audible at low sig- nal levels. • Different nonlinear conditions that measure the same with a given test setup may afflict the ear quite dif- ferently depending upon the levels and frequencies of the test program. • Although the distortion in today's best analog audio equipment is bare- ly measurable and Cto most listeners) completely inaudible, digital has intro- duced several potentially ear-disturb- ing phenomena. For example, the digital sampling process introduces a new and different type of distortion known as "aliasing." Spurious har- monics are produced in the audio band in the range above half the sam- pling-rate frequency. For example, with a 44-kHz sampling clock, the third-harmonic of a lO-kHz tone will appear at 14 kHz (44 kHz minus 30 kHz). Such problems can occur even in units with well-designed anti-alias filters, if nonlinearity is present after the filtering. Today, the problem seems well taken care of, but it illus- trates the fact that new circuitry can produce new distortions. Dynamic range results Dynamic range does not appear to be an important factor in distortion, other than in the obvious situation where the signal level exceeds the capabilities of a component. Clipping and other overload effects are the prices paid for pushing a component too hard. However, the other side of the dynamic-range coin — noise level — also has a great deal to do with the audibility of distortion effects. Here, we are looking at very low-level distortions and the masking effects on them of electronic and environ- mental noise. Specifically, if the noise is high enough in level and occurs in the same frequency areas as the dis- tortion, the distortion will be masked. Audibility of distortion As I noted earlier, the minimum level of distortion that can be de- tected by the human ear has been the subject of much ill-informed contro- versy over the years. The graph in Fig. 1 illustrates the results of a research project on the perception of HD using a 357-Hz test tone.At a listening level of 70 dB. fourth-harmonic distortion as low as 0.05 %C!) was audible. It was noted that the basic sensitivity of the human ear was the limiting factor in detecting distortion, That should come as no surprise, since distortion of pure tones or simple music such as 84 a solo flute is not heard as a wave- form aberration — wfiich is what it looks like on a scope — but rather as a distinct and separate tone or noise. That's why the addition of high- order harmonic distortion to single mid-range frequencies is so readily audible. But in real life, with complex classical or rock music, distortion has to reach 6% or so before even the most golden of ears become upset. There's no mystery to all this^it's our old friend masking at work. If there happen to be loud musical frequen- cies present in the same areas where the spurious harmonic and IM fre- quencies occur, the distortions sim- ply won't be heard. All this reaffirms the difficulty in generalizing about what we can and can't hear, and un- der what conditions. I can't resist adding a personal dis- tortion-oriented note to this report. More than 10 years ago, the Nakannichi Corporation held a press party to celebrate the opening of their East Coast offices. Part of the new facility was a small demonstration re- cording studio completely outfitted with Nakamichi tape decks, micro- phones, monitors, amplifiers, and so forth. As I came in through the con- trol-room door, Etsuro Nakamichi greeted me and pointed out that a live string quartet, specially hired for the The AES is an international organi- zation whose membership includes more than 10,000 persons involved on a professional, semi-professional and amateur level in all aspects of audio. For further information on The Sound of Audio Conference, on how to become a member of the AES, and/or a catalog of available publica- tions and technical papers, write to: Audio Engineering Society, 60 East 42nd Street, New York, NY 10165-0075. occasion, was about to perform in the small studio area. To my ears, the sound of the live musicians as reproduced in the con- trol room has a harsh, distorted quali- ty. I wondered what to say to Mr. Nakamichi, who was obviously proud of his new installation. I decided that honesty was the best policy, and opined that the sound we were hear- ing was "a little shrill." To my sur prise, Etsuro agreed with a grin, and ushered me through the sound-proof- ed door into the studio. I was shocked to discover that the live mu- sicians in the studio sounded exactly as distorted as their reproduction in the control room — which v^s a real tribute to thefidelity of the Nakamichi equipment. Etsuro explained that the acoustic design of the studio still needed some work — increased damping mostly — to control an over- emphasis of the highs, but they hadn't had time to complete the work before the scheduled opening. Two distortion-related morals can be drawn from that story: A boost in the upper half of the audio spectrum (due to room reflectivity or other causes) where the higher musical harmonics can easily be misin- terpreted by the ear as gross HID or IM, And even unamplified live music can sound distorted under Cim)proper conditions. R-E ISCET VCR .Cross Reference^ , VCR Model Number Cross Reference and VCR Parts Cross Reference UPDATED - Feb. 1990. 272- page reference guide. $35 plus $3 shipping. DISC - IBM-compatible disc with expandable data base. $99 plus $1 shipping. COHBO OFFER: Book and disc for only $125 plus $3 ship- ping. MORE INFO? Contact ISCET, 2708 West Berry St. Fort Worth TX 76109 (817) 921-9101 Allaw 4^ weaKs tinuvtr^ wnen usmg person iTclhecks or VISA and MasterCard- Money iprdcrs and cashiers checks processAd i.mm»dlalely. VJSA r. MastHCird c- Exc^ C*ia Ho. . Nuns City. jn« MHmter " JSCET, 7. NE.SDA Texas residenls mijltiply do))ar value k 7',k% lor isxCi- Fo^eiSn shipm.ent& please a■■ 2W. One insertion $950. Six insertions $925. each. Twelve insertions S895. each. Closing date same as regular rate card. Send older with remittance to Computer Admart, Radio Electronics Magazine, 500-B Bi-County Blvd., Farmingdale, NY 11735. Direct telephone inquiries to Arline Fishman, area code-51i6-293-3DD0. Only 100% Compuler ads are accepted for this Admart. ' PT68K4 68000-16MHZ upgraded version of PT68K2 featured in OCT 87 RE. • 4 MB of onboard DRAM • 4 RS232 + 2 Parallel Ports • Floppy Disk Controller • 7 XT Expansion Slots 12 MHZ Kits from $220 Assembled Boards from $599 Professional OS9/68000 $299 Peripheral Technology 1480 Terrell Mill Rd. Suite 870 Marietta, GA 30067 404/984-0742 1 PROMPT DELIVERY!!! -C SAME DAY SHIPPING {ySUALLV) '» 0.it-'t^rY'>lt I'Hir.FkSHO^^-Ji,,^ JULY «. 14M OU rStDE OKLAHORM NO SALES TAX 2MB UparaSc U IIP i III SI 83.001 DYNAMIC RAM 1 1MB COMP DcskPro 3S6S S225.00 | SIMM AST Preri3B6 33Mhz 160.00 SIMM 1M)r9 BO ns 72.00 SIMM ?56K!t9 100 ns 23.00 1Mbit IMkI 80 ns 7.15 41256 256Kil 60 ns 4.10 41256 256Kx1 80 ns 3.10 41256 J^Kil 100 ns 2.15 41256 J56KK1 120 ns 1.95 44G4 BAKkA 100 ns 2.45 41264" MKiJ 1 00 ns 5. 95 EPROM 27C1000 iseK!(8 200 ns S17.S0 27512 MKxB 200 ns 7. SO 27256 3?Kxe 200 ns 5.75 271 2B ISKxS 250 ns 3.75 STATIC RAM 52256P -10 3?Ki3 100 ns S7.50 62e4P- 3 SKjB 120 ns 4.50 OPEN E DAYS. Taj.itlO™ SHIP VIA FEO-EX ON SAT. EAT DEUVERV tHClUDEDOH fED-EX OflDERl RECEIVED BV- MiCHOPflOCESSOHSUNLJMITED. IMC rE^sVK-7.Jr (918)267-4961 No minlinum srdcf. " CIRCLE 180 ON FREE INFORMATION CARD CIRCLE 61 ON FREE INFORMATION CARD Sound editor The other main software compo- nent of Audio F/X is the sound editor. It, too, runs in a graphical mode, as shown in Fig. 2, but all commands must be executed from the keyboard, which is less convenient than the GEM environment of Sonata. Basic functions allow you to record and edit sound. To record, you press Alt-F3, and, specify the number of samples to record; the range is 1—65,000. Sampling rate is specified elsewhere, before you enter the rec- ord function. Naturally, the more often you sample, the higher the fidelity of the sound that is recorded, but the more disk space is used. A demo file containing a fairly hi-fi rendi- tion of a popular song requires almost one megabyte of space for about 50 seconds of music. An 8-bit A/D con- verter is used, so each sample com- prises of one byte with a decimal value of 0-255. After you specify the sample rate, the program displays a simulated VU meter that allows you to set the level of your source, after which you press any key to begin. The prcigram then digitizes sound at the specified sam- ple rate. After all samples have been collected (or you press the space bar to halt prematurely), the waveform is displayed, and you can piay it back CShift-F3). edit it, and save it to disk. The program supplies two cursors. Land R, that generally define an edit- ing area. Separate pairs of function keys move the two cursors; another key allows you to zoom the area be- tween them; yet others allow you to mark that area (for subsequent copy- ing), or to delete, reverse, amplify, or attenuate it. You can split the screen, and copy a marked block from one window to another. The split-screen mode is useful for creating special effects, particularly reverb and echo. It's also useful for assembling a waveform from bits and pieces of other wave- forms. To create a reverb effect, you mark a block, move the left cursor slightly to the right of its initial posi- tion, and then execute the mix com- FIG. 2— THE SOUND EDITOR runs in a graphical mode, but all commands must be executed from the keyboard, Basic functions allows you to record and edit sound. O O CD O 87 control we What Is the A-Bus? ABus is a system for connecting devices to your computer. Whatever your computer. use ABus for; Sensing. Detecting or reading a switch closure or voHage presence. Measuring. Determining a force, frequency. temperature, weight, or any other quantity. Control. Open or ciose a circuit. Switch any type of eiectrical device. Adjust ievei or position. Why should you choose A-Bus? It's aflordable. From a $65 Digital Input Card tc a $299 Motor Controller, you get much more than your money's worth. It's simple. Easy to connect to your computer and to your application. Designed to adapt to your software easily. It's versatile. You mix and match low cost boards to fit your project. It's proven. Thousands of applications installed around the worfd. Call for a Catalog (800) 221-0916 A Sampling of our Products Relay Card: 8 individually controlled relays. 3A at 1 EOVAC. SPST. RE-1 40: $1 42 High-Spe«d 12-bit A/D converter: 8 10^s analog inputs. 0-5V. amp. FA-154: $179 8 Bit A/D: 8 inputs. 0-5.1 V in 20mV steps. 7500 convers ions/second. AD-I42:tl42 12 Bit A/D: ±4V. On-board amp. 7 read- ings/sec. 1 input, expandable AN-1 46: $153 Temperature Sensor: 0-200° TS-111 : $12 Digital Input: 8 opto-isolated. Read voltage presence or switch closures. IN- 141: $65 Latched Input: Each of 8 inputs is latched to catch switch closures LI-157: $85 Digital Output Driver: 8 outputs: 250mA at 12V. For relays, solenoids... ST-143: $78 Smart Quad Stepfwr Controller: On board processor controls 4 motors simultaneously. Simple English commands to set position, speed, units, read limits, etc. SC-149: $299 D/A: 4 Channel. 8 BH Output DA-147: $149 24 line TTL I/O: Connect TTL 0/5V levels or switches. (8255A) OG-148: $72 32 Channel Multiplexer; Switches up to 32 channels to a single common. MX-155: $83 Touch Tone Decoder: PH-145: $87 Counter Timer: 3 16-bit counters. Count pulses, measure frequency CT-150: $132 A-Bus Prototyping card: PR-152: $16 Odin Software: For PC's Control relays from inputs or time schedulesOS-189: $129 Motherboard: For 5 cards. MB-1 20: $1 08 ABus Adapters: IBM XT/ AT & compatibles. AR-133: $69 MicroChannel Adapter; AB-170:$93 Parallel Adapters also available for Apple II. Commodore 64.128. TflS-80 Serial Adapter: RS-232 SA-129: $149 y. Serial Processor: Built in BASIC for off- 9 line monitoring, logging. SP-127: $189 z tx. New! C'Net: Connect thousands of RS-232 ^ serial devices to one computer port. Prirtt- Lu ers. modems, data acquisrtton devices, etc. 6 .M^ ALPHA mm^kfsQs g 242- RE West Avenue. Darien, CT 06820 S Call (203) 656-1 806 or Fax 203 656 0756 88 CIRCLE 198 ON FREE INFORMATION CARD mand. Creating an echo is similar; you just move the cursor a little fur- ther to the right before mixing. Some experimentation is necessary to de- termine the amount of cursor motion required to achieve a particular effect. Each sound file normally consists of a maximum of 65,500 bytes. How- ever, the program supplies a direct- to-diskmode, in which larger files can be created and played back. When editing a large file, you can scroll through it in 32K chunks. A set of filters Clowpass, bandpass, htghpass) is available for the sound editor. In addition, drivers for Show Partner and GRASP are included; those programs allow you to create interactive, animated computer- based tutorials and training. The Au- dio F/X drivers allow you to syn- chronize sound with the on-screen presentation. Other companies have written drivers for other "multimedia" programs, including Autodesk's won- derful Animator; contact Forte for more information. Options and upgrades A programmer's kit is available; it allows you to get directly at the hard- ware. In addition, the company sells an amplifier/filter box that allows you to dnve the Audio F/X board with an inexpensive microphone. Impressions The first time I installed the board and played a demo Sonata piece. I was entranced. Sure, other comput- ers (Macs, Ataris) have sound ca- pabilities — but I'm mostly a PC chauvinist. So hearing full-bodied sound emanate from a board con- trolled by my PC was thrilling. In short. I haven't had as much fun play- ing with a PC product in a long time. UltraVision 2.0 Most VGA cards (and EGA cards as well) provide numerous hardware- enhanced modes, but DOS supports only the least-common denominator. As a consequence, that extra ca- pability often goes unused. A pro- gram called UltraVision provides a way of tapping those capabilities. In particular, it gives you full control over screen colors, the ability to change the display font, and the ability to use text-mode programs with more rows and columns than usual. The program also provides its own enhanced video BIOS, which speeds up video output two to five times. UltraVision's enhancements de- pend on the specific capabilities of your video adapter; 1 tested the pro- gram with a Video 7 VRAfvl board. With UltraVision installed, I could run text modes with just about any com- bination of 80, 94. 108, 120, or 132 columns, and 25, 36, 50. or 63 rows, (A maximum of 60 rows are available at 132 columns.) ITEMS DISCUSSED • Audio F.'X ($350). Forte, 72 Ka- renlee Drive, Rochester, NY 14618. (716) 427-8595. CIRCLE 10 ON FREE INFORMATION CARD • UltraVision 2,0 ($119.95), Person- ics, 63 Great Road, Maynard, MA 01754. (508) 897-1575. CIRCLE 11 ON FREE INFORMATION CARD DOS itself won't recognize the en- hanced modes, but many applica- tions will. Qedit. for example, picks up screen dimensions automatically. WordStar can be patched easily. The company also provides drivers and usage hints for many other programs, including 1-2-3, AutoCAD. Crosstalk, dBASE, Magellan, Word, WordPer- fect, and many others. I found that a 36 X 80 mode in Word running on a 19-inch NEC MultiSync XL was quite legible. A standard VGA system can run with a maximum of 94 x 63. The software driver occupies about 20K of memory, and in addition to the functional enhancements it provides, it also operates faster than the built-in BIOS, because it runs from RAM, rather than relatively slow ROM. In addition, the driver runs just fine from "high" memory on either a 386 or EMS 4.0 system (both of which I tested). UltraVision provides similar enhan- cements for EGA systems, including a hardware accelerator that provides VGA resolution for some EGA boards with multi-synchronous monitors. A separate program allows you to change screen colors; laptop and monochrome VGA users could use that capability to remap illegible screen-color combinations. Several other utilities are provided, including an enhanced version of ANSLSYS. If you're tired of the feeling that there is capability in your video sys- tem that is being wasted, UltraVision 2.0 can help. R-E MARKET CENTER FOR SALE GREAT buys! Surplus prices, ICs, linears, transfor- mers. PS. stepping motors, vacuum pump, phototransistor. meters. LSASE, FERUK'S, S400 Elta, Phiia.. PA 19120. DE5CRAMBLERS. All brands. Special: Combo Jerrold 400 and SB3 SI 65.00. Complete cable de- scrambter kit S39.00. Complete satellite de- scrambler kit $45.00. Free catalog. MJM INDUSTRY, Box 531, Bronx, NY 10461-0208. TUBES: "oldest," 'latest." Paris, schematics. SASE for list. STEINMET2, 7519 Maplewood Ave.. RE, Hammond, IN 46324. ENGINEERING software, PC/MSDOS. Hob- byists — students — engineers. Circuit de- sign $49.00, PCB layout S99.00, Logic simulation $29.00, FFT analysis $69.00, Mathematics $39.00, Circuit analysis $29,00. Call or write for free catalog, (614) 491-0832, BSOFT SOFTWARE, 444 Colton Rd., Columbus, OH 43207. RESTRICTED technical information: Electronic sur- veillance, schematics, locksmitfiing, covert sci- ences, fiacking, etc. Huge selection. Free brochures. MENTOR-Z, Drawer 1549, Asbury Park, NJ 07712. RENTAL movie Stabilizer. Conned between VCRs or to monitor. Satisfaction guaranteed. S69.95, $4.00 handling. 1 (800) 367-7909, CB RADIO OWNERS! We specialize in a wide variety of technical information, parts and sen/ices for CB radios. 10-Meter and FM conversion kits, repair books, plans, high-perfonrance accessories. Thousands of satisfied customers since 1976! Cataiog $2. CBC INTERNATIOHAL P.O. BOX 31500RE, PHOENIX, AZ 85046 CABLE TV converters: Jerrold, Oak, Scientific At- lantic, Zenith & many others. "New MTS" stereo add-on: mute & volume. Ideal for 400 and 450 ownersi 1 (800) 826-7623, Amex, Visa, M/C accept- ed. B & B lt VlH * COD'S * QuintllY Pricing LASERS. 1mw to 2kw, worlds largest selection o( new & used surplus. Free catalog. MWK INDUS- TRIES, 1269 Pomona Road, Corona, CA 91720. (714) 278-0563. TEST equipment pre-owned now at affordable prices. Signal generators from $50.00. Os- cilloscopes from $50,00. Other equipment, includ- ing manuals aivailable. Send $1.00 for catalog, refund on 1st order. J,B. ELECTRONICS, 3446 De- mpster, Skokie. IL 60076. (708) 982-1973. CABLE boxes, Zenith $225.00, Tocom $125,00, Hamlin S125 00 combo, Jerrold combo $125,00, Oak RTC-56 combo $150.00, M-35-B $45.00, S.A.C, orders 1 (SOO) 622-3799, Info (702) 647-3799. LOTTERY - IBM computer disk for all lotteries S10.00, ROBERTS, Box 63/6025, Margate, FL 33063. OAK Sigma descrambler, ctiannel 3 output, rare hard-to-find factory equipment, with free documen- tation, $150.00. Oal< Sigma modification documen- tation $20.00 postpaid. Oak VN12-4 (or Hamlin) descramblers with tree remote control converter, $85.00. Eagle remote control converter de- scrambler combos, $100.00, Send moneyorder, ship postpaid within 3 days. SURPLUS ELEC- TRONICS, POB 10009, (Colorado Springs, CO 80932. FREE CATALOG FAMOUS "FIRESTIK" BRAND CB ANTENNAS AND ACCESSORIES. QUALITY PRODUCTS FOR THE SERIOUS CB'er. SINCE 19BZ FIRESTIK ANTENNA COMPANY 2614 EAST ADAMS PHOENIX, ARIZONA 85034 MINIATURE electronics like James Bond. Catalog $4.00, refundable. F & P ENTERPRISES, Box 5t272, Palo Alto, CA 94303-L. CABLE-TV Scientific Atlanta 8580 Oty/price each 1/289, 5/249, 10/239, 6PM to 10PM EDT weekdays, (301) 791-5019. No Maryland orders accepted. SURPLUS electronics, motors, speakers, power supplies, adapters, etc... send for free catalog, WINDSOR DISTRIBUTORS, 19 Freeman Street, Newark, NJ 07105. DESCRAt^BLERS, alt tirands Eti stock, need tielp seEei:ting the right unit? COD orders ok. S.A.C, (702) 647-3799. PHOTOQUICK Z8, single board computer with pro- totype area, $69,00. SOFTWARE SCIENCE, 3750 Round bottom Road, Cincinnati, OH 45244. (513) 561-2060. TOCOM VIP converters w/remote from $199,00 Tocom super chips turn on everything, $69.00 each. Phone (219) 935-4128. TUBES Sylvania 6LQ6, 6LSGC, 20LF6 etc. Huge discounts. ARLEN SUPPLY 7409 West Chester Pike, Upper Darby, PA 19082. 1 (800) 458-1301. PHOTOFACT folders under #1400 $4.00, Others $6.00. Postpaid. LOEB, 414 Chestnut Lane, East Meadow, NY 11554. COMMUNICATIGNS/ElectronIc equipment sales, service, FCC licensed. Catalog 31,00, RAYS,POBox14862,FQrtWorth,TX761t7-0a6g. CONVERTERS all major brands. Info & orders 1 (800) 782-0552. FREWAY INC., SMP P0# 5036, Burnsville, }m 55337. No MN sales. FREE catalogue. Computers. Electronic parts and kits. Filters, arriplifiers, power supplies. Radio Shack dealer. MCDOWELL ELECTRONICS, Box 1206, Brewton, AL 36427. (205) 867-8805. INCREASE your radar detector's range up to 50%. Lens and instructions SI 5.00. Send moneyorder to GREG MEADE, 11169 Riverview, Grand Blanc, Ml 48439. CABLE-TV Scientific Atlanta 8580. Save $200,00 add-on descrambler for receiving Pay Per View for subscribers without telephone or unlisted number. Authorization from your catjie company is required to use tliis device, Qty/price each i.'SIOO. 5.'$85, 10/$75. 6pm to 10pm weekdays (301) 791-5019. No Maryland orders accepted. CABLE TV DESCRAMBLERS' BARGAIN HEADQUARTERS! •JEHROLD'" •TOCOM 'HAMLtN •OAK •ZENITH •SCIENTIFIC ATLANTA 6 month v/arranty! We ship C.O.D. 1 Lowest retail/wholesale prices! FREE CATALOG: Global Cable Network 1032 Irving St, Suite 109 S.F., CA 94122 NO CALIFORNIA SALES!!! ORDER TODAY! 800-327-8544 TV troubleshooting solutions 450 solutions by area and component. Symptom remedy make model Sams ref. Save time, you1l love it. Send $24.50 to BOX 222, Chanhassen, MN 55317. S-A test chips. Enables full tiering. 8550: $22.00 each/10 $180.00. 8500: $20.00 each/10 $160.00. tuloney order or COD. R.V., Box 771, Ridgefleld, CT 06877. BOOKS! Catalog of most exciting electronic and science books, free!. Box 596-1, Logan, Utah 84321 . 1 (800) 359-0466. TOUCH Tone Decoder displays dialed numbers from telephones, scanners, tapes. Connects easily to phone line, radio, recorder. Information tor SASE, W,E.B., PO Box 2771-R. Spring Valley, CA 92077. BELOW wholesale: Capacitors, ICs, transistors. Special: new 27128A $3.00. flyer SASE SANTECH ELECTRONICS, 11 Revere Place, Tappan, NY 10983.(914)359-1130. PRINTED circuit boards made to order - layout engineering, assembly available, high quality fully fabricated boards -short or long run. Call or write for products and pricing. SHORE PROTO CIRCUIT, 36 Fairview Avenue, Little Silver, NJ 07739. 1 (800) 752-1574. QUALITY electronic parts at bargain prices. Free catalog with SASE, EAGLE TRADING, Box 341, Bigfotk, MT 59911. Phone (406) 837-5409. O O d CD m 33 CO 5) -k PratJjcs SoLTfl and BitgJi Red LEO Culpul * OpaiK Div 9V BallEii' (nol IncJ.) ■k Coma win PC Bean Pais and lAslruclioru C6441 $6,95 INFRARED MODULE Srall Irrirsred >'KEiw ncCjic is JEi^iiiv; lo airnosL ai irfrsftf fifrrts ffifitfoitfs ^ Isslirts Wgti gin. Has cfliy 3 NukLfi pirs. 0(X[2Es frgm 3VDC Jiti '-s my senMj^ (d wLl liC^I aniESor dcaabw^isgt rt^dylmm L« lo ^[»<^). Modiie jnj rccfcifj c^an opy-iiftj jifoviflfl oupui Uf^ioi G514 S1.2& cf LED & rtUy. 5ijE D^ PC Boar]: .r a T a .4". ^ INFHAn£0 LEO Jbmix di^ as. IWUmH THANSFOFIH£R SmiS 4 iHd bntoiMf la bi ustd. ifiti ^ tCdn^ticefflHllZVDC bSATAC FACH IdaSlTUlU (,1irjH.1UM ORDER: SIOOO tUS t31» SluppirlJ IK) hji v;t .Tuiep) WC, Vtsa and Mcnay Ordeis SEND ORDEHS TO: Tlw EteOlOni GOUlWiE PO Bm 54M Soooatlle. AZ 8S2ei PHONE OnOEBS: 1602] 451-74H CIRCLE 1S6 ON FREE INFORMATION CARD WtRELESS CABLE RECEIVERS 1.3 TO Z.7 GHz 3D CH PARABOLIC DISH SYSTEM St73 90 30 CM ROD ANICNN* SVSTEM S193 90 30 CM enVSIAL CONIROLLtD SfSTEM SJ94.3S tun HICaiWItW IHTT. inc. PO. SM »SJSH PKDEHIX.U.SSUT lUZI ZIU'Klll DUANTITV DISCmjNIS iUPsi.Doron MTM.OG ON THESE MIO OTHER FINE VIOEO FFlllOlIi:!; UFETIME WAnnudT MfWra Of TJIf JfTTFS JKSWf IS loflau TOCOM VIP test chip with Torx #7 wrench $45.00. R&S, (817) 293-4113. No Texas sales. TEST equipment bargains. Includes Tektronix, H-P, 6R, etc. Sold as is. Technician's and hobbyist's dream. Some units require minor repair or calibra- tion. Some useful for replacement parts. Prices start at $25.00. Nothing above $250.00. Catalog $5.00 (refundable with purchase). EDI, 180 Rodeo Drive, Brentwood, NY 11717. (516) 242-6400. TRANSISTORS, diodes, resistors, capacitors, MOVs, new, up to 60% off. Catalog:. MINUTEHAN SYSTEMS, Box 1427, Concord. MA 01742. HELP!! If you buy cable TV units, Interference filters any channel. Computer equipment and software. All types of electronic components, integrated circuits, capacitors, resistors, power supplies and lots more. StopI! whatever you're doing and call our toll-free number 9ann to 6pm EST Monday thru Friday 1 (BOO) 762-9730 we guarantee you won't be sorry. Piclt-up your phone now!! (Recorded message after daytime hours.) $1.99 software for IBM Compatibles. Quality at af- fordable prices! Huge selection: business, games, graphics, utilities, database, spreadsheets. Send SI .00 for catalog. AULT, 1556 Halford Avenue, #342, Santa Clara. CA 95051. WANTED INVENTORS! Confused? Need help? Call IMPAC for free rnformation pacitage. In US and Canada: 1 (800) 225-5300, CABLE TV TB-3 (Tri-Bi) or SA-3 Quantity Prices 10 20 $48. $43 Each 50 Each 100 $39a $35a Each Each Hours open 10:00 am to 4:00 ptn Eastern time Minimum order 5 units 55.00 ea. Dealers wanted. We stiip COD. King Wholesale 1-800-729-0036 Fax number 6173400053 "No one beats I he King's prices.'" DESCRAMBLERS Try the Electronics bulletin board system (RE-BBS) 516-293-2283 The mure you use it the more useful 11 becomes. We support 3DD and 12110 baud operation. Parameters: SN1 {8 data bits, no parity, 1 stop bit) or 7E1 {7 data bits, even parity, 1 stop bit). Add yourself to otir user Dies to Increase your access. Communicate with ather H-E readers. Leave your comments on R-E wilh the SYSOP. RE-BBS 516-293-2283 PLArfS AND KITS BUILD this five-digit panel meter and square-wave generator including an ohms, capacitance and fre- quency meter. Detailed instructions $2.50. BAG- NALL ELECTRONICS, 179 tHay, Fairfield, CT 06430. MINIATURE FU transmitters! Tracking transmillers! Voice disguisers! Bug detectors! Phone Devices! More! Available in l(its or assembled! Catalog S2.0O: XANDI ELECTRONICS, Box 25647, Dept. 60J, Tempe, AZ 85285-5647. CATALOG: hObby.'broadcasling.'HAM/CB: Cable TV, transmitters, ampliliers. surveillance devices, computers, morel PANAXIS, Box 130-F10, Para- dise, C A 95967. SURVEILLANCE transmitter kits! Four models of each; telephone, room, combination telephone/ room transmitters tune from 65 to 305 MHz. Catalog with Popular Communications and Popular Electronics booit reviews of "Electronic Eaves- dropping Equipment Design," $1.00. SHEFFIELD ELECTRONICS, 7223 Stony Island Ave., Chicago, 1160649-2806. REMOTE CONTROL KEYCHAIN Complete w/mini-transmitter and +5 vdc RF receiver Fuliy assembled Including plans to build your own auto alarm Quantity discounts available <^0^ nc Check, visa or M/C $C^.BO Add S 3 shipping VISITECT INC. /Dept. R (415) 872-0128 PO BOX S442.SO.SAN FRAN.,GA 94080 INVESTIGATORS, experimenters — Quality plans. Micro and restricted devices. Free catalog. Self ad- dressed stamped envelope required KELLEY SE- CURITY INC., Suite 90, 2531 Sawtelte Blvd.. Los Angeles, CA 90064. CB Tricks II book. Power amplifier design and theo- ry, UHF CB tune UPS. Send $19.95 MEDICINE MAN CB, PO Box 37, Clarksville, AR 72830. STRANGE stuff. Get the advantage! Laser listener, surveillance, descrambling, underground informa- tion. Plans, kits, complete Items. Informational package $3.00 refundable. DIRIJO/BOND, Box 212, Lowell, H.C. 28093. TRANSFORMERS. Learn to build your own. Easy, Smart Send $1.00 (refundable). W. CHARLES TECHNOLOGIES, 2S740 S.W. Parkway #A1, Wilsonville, OR 97070. COtVIPUTER KITS CcBCDd Tnh'lti C-^fDitt K , rfvik 1 ™me>rte tM ilfc Wd J» mufclj- 'Fhw nc d««jn(a id offrr TV/it KhfrfiVct^U^ad, iikKitkViaL iullr JJOt Mn- paiAk. ^ty n^ffii t *nJ q W 4Uinfa1f tnunuil. Kifiwicf, {itu ftir «irruiry i3d our 14 luKir suppcz^'DciltT ' l^ne liu. Atumblj' It a'iiilibL< ask for your frte catalog General Technics ptm Oftrn Dan nre Ll«» Bor^onfcontf , HY 1 17Tt {516) BSI .M73 BUILD this 400W stereo amplifier designed for mobile systems. Super nice. Plans $8.00. MD ELECTRONICS, Box 2208, Zephyrhills, FL 33539. KITS — alarms, games, and test equipment. Send $1.00 for catalog. RAKJAB, PO Box 1875, Apopka, FL 32704. DEVICES unavailable in USA. Kits, parts, plans. Catalog S2.00, WORDWAND, 612 Orange Street, Palm Harbor. FL 34683. PC/TV Interface — RGB to TV,'video/VGR. Switch- able between PC and composite video inputs. Channels 3 or 4, RF output. Complete PC card kits $59.95. PC board only $19.95 Mass. residents add 5% sales tax. I NO VON I CS CORP. 9 Bartlett St., Dept. 36, Andover, MA 01810. FREE laser catalog lightshows, pointers, hologra- phy, etc. lowest prices! Write to: MIDWEST Laser products, po box 2ie7, Bridgeview, il 50455 or call (708) 403-6984. SURVEILLANCE — audio/video equipment — de- bugging. Industrial or private. 500 item catalog S7.00. SECURITY SYSTEMS, 3017G Hudson, New Orleans, LA 70131. 90 NEWHENE ^;:^ LASER TUBES $35 ^^ Dealer Inquiries Invited. Free Catalog! MEREDITH INSTRUMENTS: 5403 N, 59lh Aw. Glcndalc. AZ 85301 • (602) 934-9387 ^'The Sourer for Ijisir Surptui ^ ' LASERS Build gunsights, pointers, liteshow, nitelite. lab. Blueprints and instnjctions $9.00 each. 3fDrS20.00. Free fist NIGHTWRITER, POB441B8, Phoenix, AZ 85064. ^_ POWERFUL single-chip FM room transmitter, size of a postage stamp, transmits to any FM radio up to one mile away. Complete kit S19,95 postpaid. HERTZ MICRODEVICES, Box 41771, LA, CA 90041-41771. DESCRAMBLING, new secret manuai. Build your own descrambiers tor cable and subscription TV. Instructions, schematics for SSAVI. Gated Sync, Sinewave, {HBO, Cinemax, Showtime. UHF adult} $8.95, $2.00 postage. CABLETRONICS, Box 30502R, Bethesda, MP 20824. VCR amplifier. Transmits to any TV In ttie house. Complete unit only $49.95. Mitsiature FM transmit- ter-stie of postage stamo, up to 1 mile range, $29.95. Free info. CAS ELECTRONICS, 1 526 Avia- tion Blvd., Suite 136. Ftedondo Beach, CA 90278, RADIO jammer plans. Blocks out any FM radio station reception for 1,'4 mile. Send $4.00 to P. KA- TCH UK, Suite #102. 5 Vanderbuilt Parkway, Com- mack, NY 11725. RECEIVE ali cordless telephones on your scanner Send $2.00 for frequencies to: ADLER ELEC- TROf^lCS, Box 41771, LA. CA 90041. LASER bug - theory, schematics 20 pg. S9-95. DATATEK, PO Box 801866, Santa Clarita, CA 91380-1866. Kii:M=4:^iH f REMOVE VOCALS FROim RECORDS AND CDs! ^ k ^ X ,<* JA1 ii.llhl^'.M}IJ.Wt.HL>IJfl!.mhl^B^ll:lM PLANS! Remote controi tester $9.95. Zone r diode tester (plug into DMM) S9,95. Eiectronics' stethoscope $9.95. D.E. STENGER, Box 1136. Brooks. Alberta TOJ OJO. ETCH your own printed circuit boards using the photographic method. The oniy inexpensive step- By-Step process that guarantees professional re- sults. A book that every serious electronics hobbyist should have. Send $12.95 to ETCHING INFO, PO Box 8064, Westfieid. MA 01086-8064. PROJECTION TV. Convert your TV to project 7 foot picture... Easy... Results comparable to $2.5000 projectors... Plarjs and 8" lens S27.95... Profes- sional systems available... Illustrated catalog tree... MACROCOMA, 15GB Main Street. Washington Crossing. PA 18977, Creditcard orders 24Hrs. (215) 736-3979. CABLE-TV BONANZA! ITEM 1 UNIT 10 OR MORE HAMLIN MCC rjOOO 36COHOEO HEMOTJ CONVERIEH rCli l.iiilv 39 00 IB 00 PANASONIC winELeSSCOr^VERTEH lOur MSI Diiyl 9SO0 79 00 STAB SATE 2000 88 00 69 00 ■JERHOLD JOO COMBO 169 CO 119 00 J6RR0LD -too HAND HEWOTE CONTROL 29 00 IS 00 ■JEHHOLD 450 COMBO 199 00 139 00 ■J£HHOLD 4^0 HANO REMOTE CONTROL 25 00 1800 JERROLOSB.ADO.ON 99 00 53 00 "JERROLD SB-ADC3-ON WITH TRIMODE 109 00 75 00 ■M-?.S 8 COMaO UNIT iCn iOLirpLiI oofy, 99 00 ?0 0tl ■M-35B COMBO UNIT WITH VAHISYNC 109 00 75 00 'MINICOUE i,N-J?. 99 00 63 00 ■UINICODE (N.I21 WITH VAniSVNC 109 00 65 00 'MINICOOE VARI5YNC WITH ALITO ON-OFf 145 00 105 0O ECONOCODE immrcodu iunilituEi.'i 69 00 42 00 ECONOCOOE WrTH VARISYNC ■9 00 46 00 ■ MLO- 1200-3 (C^ 3u.jrpuli 99 OC 62 00 "MLD-S3O0'?ilK«lf or vmt pruniunn obit cturitttlj viihoul pr«Hr Mlh«i£itian irDnv Itiin ■cut ah OMnpMy ind httil^ dK^r* iiikdir Hnjlhf or iWnKv 1Mi> -^ prodvCEL ItiUU'H fEdiripljrdvjrKiiTi.EtJtiuin Ifir umuihgriKil UH. 520 GLENBROOK ROAD. SUITE NO 202 STAMFORD, CT 06906 o.d«5 0niy 1-800-622-9022 Calalog & imo; (203) 975-7543 CIRCLE 64 ON FREE INFORMATION CARD CABLE DESCRAMBLERS OAK IVI35B COMBO S39.B5 Jerrold, Zenith. Hamlin, Sci. Atlanta, Pioneer & MORE! OUR PRICES ARE BELOW WHOLESALE! CABLB+PLUS 14417 Chase Si. #4B1-A Panorama City, CA 91402 1-80O-822-9955 • Other Info. 1-S18-785-4500 NO MLIF. MIES - DEALERS WAHTEO SATELLITE TV VIDEOCIPHER II manuals. Volume 1 - Hardware, Volume 2 - Software - either $34.95. Volume 3 - Projects/Softwara, Volume S - Documentation or Volume 6 - Experimentation S44.95 each. Volume 4- Repair S99. 95. Cable Hacker's Bible -534.95. Clorie Hacker's Bible - J34.95. Catalog - S3. 00. COD'S (602) 782-2316. TELECODE, PC Box 6426- PE, Yuma, AZ 65366-6426. FREE catalog — Lowest prices worldwide, save 40 — 60%. Systems, upgrades, parts, ail major brands factory fresh and warranted SKYVIStON, 2009 Collegeway, Fergus Falls, MN 56537. 1 (800) 334-6455. SCHANIBLE NEWS FflONTHLY sllil tlie liest original Infoimalian focus ini J month iiswiielKscatileJKijiving enuipntwni and flescramMino hanlwjrfc^oBti«are and lurn-<«(. SutucripHwi SI 3.95^r. Sampii! 53-- Tt« ^ TV anfl ^jellE I (basics Of aH s^sEsmsj 514.951 quuij Satrilile Sysiems UfldefSSOO SI 2.95 Wire|HS Cable Wjnual S9.95. AJi-y 3^29 or b!Si2 - H«vi 1all catalog Si or cjlE COD'S are OK. 7 1 £■ 974 -2085. ScramUlinj News. 1552 HertBl Ave, «iza, Butlalo. NY. 14216. 1716) S742038 CABLE TV secrets — the outlaw publication the cab iecompaniestried to ban. HBO, Movie Channel, Showtime, descramblers, converters, etc. Sup- pliers list included $9.95. CABLE FACTS, Box 711- R, Pataskala, OH 43062. CABLE TV EQUIPMENT Converters, Remote Cotiliols, Descramblers, CD Players. JERROLD-OAK-SCIENTIFIC ATL ANTA-H AMLIN ZENITH MANY MORE CALL TODAY! ">/ Only quality produas sold V Easy to use vSaiisfactiofi guaianteed ^ Knowledgeable sales staff V Most orders shipped within 24 hours CALL FOR YOUR FREE CATALOG 1-800-228-7404 MAKE THE CONNECTION WITH NU-TEK ELECTRONICS 5114 Balcones Wood Dr.#307 D^l298 Austin. TX. 7S759 VIDEOC^PHER II descrambling manual. Sche- matics, video and audio. Explains DES. EPROf*/), CloneMaster, 3Musketeer, Pay-per-view (HBO. Cin- emax. Showtime, adult, etc.) $13.95, $2.00 postage. Collection of software to copy and alter EPROM codes, $25.00, CABLETRONICS, Box 30502R, Bethesda, MD 20824. BUSINESS OPPORTUNITIES EASY work! Excellent payl Assemble products at home. Call for information (504) 641-8003 Ext. 5192. CO O 2 o CE I- O o a < 92 COLLIMATOR PEN (tNFRA-HED) LASER DIODE (INFRA-RED) LASER DIODE (VISIBLE-RED) LASER DIODE (V(StBLE-RED) UHICORH - YOm I.C SOUIKE! • Output: 2.5 mW (max.) •Current: 90-150 mA • Operating Voltage: 2,2-2.5V • Wavelength: e20nm ■ Collinnation: .ISmrad (typ.) ■ Size; 1 1 mm diameter STOCK* SB1052 PRICE $39.99 • Output; 10 mW (max.) •Current: 90-1 50 mA • Operating Voltage: 2.2-2.5V • Wavelength: 820nm STOCK# SB1053 PRICE $9.99 • Output: 5 mW (max.) •Curent: 65-1 00 mA • Operating Voltage: 1.75-2.2V • Vvavelengtti: 780nm STOCK* LS022 PRICE SI 9.99 • Output: 4 mW (max.) • Current: 20 mA • Operating Voltage: 2.2-3.0V • Vvave length; 665nm STOCK* PRICE LS3200 $129.S EPROMS 1 STDCK» PINS DESCPIPTIOrJ 1.2J jS9a 100. 170; 24 J55 J 4 i.js 3.95 3 79 3,41 2708 24 1021x8 450ns 6,49 6.17 5,55 2758 24 1024x8 450na 3.99 3.79 341 271S 24 2043x8 450ns (25v) 3.29 3.13 2,82 2716-1 24 2048x8 350nE(2Sv) 3.79 3.60 3.24 TMSi716 24 2048 X 8 450ns 6.29 5.98 5.38 27C16 24 2048x8 450ns {2SV-CM0S) 3.99 3.79 341 2732 24 4096x8 4S0ls(2Sv| 3.79 3.60 3.24 i732A-Z 24 4096x3 200ns (21vl 3,79 3 60 3,24 IJilk 24 4096 X a 250ns (21v| 3.69 3.51 3,16 2T32A-4 24 4096113 450ns (21v) 3.19 3.03 2.73 TMS25a2 24 4096x6 450ns (25v) 5.79 560 4.95 TMS2532P 24 4096 K a 450ns {SSv.Qne Time Programmable) 1.99 1,89 1.70 27C32 24 4096x8 450n5 {25V.CMOS) 4,19 3,98 3 59 2T64-20 28 8192x8 20Dns(21w) 3.99 3.79 3.41 2764 28 8192x8 250ns (21 ») 3,79 3,60 3.24 27S4A-2CI 28 8192x8 20Qrs (12.6V) 3.99 3.79 3.41 27e4A 28 8192x8 250ns (12.5V) 3.29 3.13 2.82 TMS2664 28 8192x8 850ns (25v) 6.79 6.46 5.81 27Ce4 23 8192 X 8 250ns (Jtv-CMOS) 419 3.98 3.58 27120-20 28 16,384 X 8 200ns (21v) 5,79 5.60 4,95 27128 26 16.384 X 8 25Qns (21y) 5.09 4.84 435 271 ISA 29 16.384x8 250ns (21v) 5,79 5.50 4 95 Z7C1ZS 28 16.384 X 8 25ans (21v) 5.79 550 495 2T2S6-20 23 32,726x8 200ns (12.5V) 5.29 5,03 4,53 27256 26 32.763 X 8 250ni [12.5V) 4.79 4.55 4.09 27C2SG 28 32,768 X 8 2S0n5 (12.5v.CMOS) 5.29 503 4 53 27512-20 28 65,536 X 8 200ns (1 2, 5v) 7,49 712 6.41 2TS12 28 65,536 X B 250ns (12.5V) 6.99 6.64 5.98 27CS12 23 65,536 X 8 250ns (12,5v.CMOS) 6.99 6.64 5.98 27C1II24 32 1 31 ,072 X 8 2O0ns ( t2.5».CM0S| 17.99 17.09 15.38 Se7S4 24 8192x8 450ns 13.99 13.29 11,% 68766 24 9192x8 450n5 14S9 14.24 1282 tt^ E I E C T R N K S 10010 Canoga Ave., Unit B-S • Chalsworth, CA 9131 1 OUTSIDE CALIFORNIA: (800) 824-3432 (Orders Only) IN CALIFORNIA: (818 341-8833 OR DER BY FAX: (81 Bj 998-7975 Minimum Order: $15.00 CIRCLE 192 ON FREE INFORMATION CARD ANTIQUE RADIO CLASSIFIED Free Sample! Antique Radio's — r --.. largest Circulation Monthly. [K^J Articles, Ads & Classifieds. 6-Month Trial: $13. 1-Yr; $24 ($36-1st Class). A.R.C., P.O. Box B02-LE, Carlisle, MA 01741 MAKE $50/iir working evenings or weekends in your own electronics business. Send for free facts. INDUSTRY, Box 531. Bronx. NY 10461-020S. YOUR own radio station! AM, FM, TV, cable. Li- censed/unlicensed, BROADCASTING, Box 130- F10, Paradise, CA 95967. INVENTORSr We submit ideas to industry. Find out what we can do for you Call 1 (BOO) 288- 1 PEA. LET the government finance your small business. Grants/loans lo $500,000. Free recorded message: (707) 449-^600. (KS1j. EASY! Moneymaking one man CRT rebuilding machinery. $6,500.00 — $11,900.00. CRT, 1909 Louise, Cryslaiake. IL 60014. (815) 459-0666. MAKE $75,000 to $250,000 yearly or more fixing IBM color monitors (and most brands). No invest- ment. Start doing it from your home. (A telephone required.) Information, USA, Canada SI .00 cash. US funds, other countries S8.00 RANDALL DIS- PLAY, Box 2168-R, Van Nuys. CA 91404 USA. PROJECTION TV,,. Make $SS's assembling proj- ectors. Easy!,,. Results comparable to $2,500 proj- ectors... Plans, 8" lens & dealers information $25.50... Professional systems available... Illus- trated catalog free. MACROCOMA, 1SGBX Main Street, Washington Crossing, PA 18977... Credit- card orders 24HfS. (215) 736-2880. LEARN to clean/repair fax machines. Huge new marketl Earn S35/hour No experience necessary. Free details call 1 (800) 537-0589 or write to: VIEJO PUBLICATIONS, 5329 Fountain Ave.. Dept. FX200. Los Angeles, CA 90029. FREE CATALOG! 1-800-648-7938 For all information 1-702-362-9026 JERROLD HAMLIN OAK ETC. CABLE TV DESCRAMBLERS • Compare our low Low Retail Prices! • Guaranteed Prices & Warranties! • Orders Stripped Immediately! REPUBLIC CABLE PRODUCTS INC. 4Q80 Paradise Rd. #15 Dept. RE-SD Las Vegas, NV sgi09 WHY rent? Homes for SI .00, repos. Gov't give away programs! For intorrtiation (504) 649-0670 Ext. R-5192. NEW electronics products are waiting to be pro- duced. TED, (416) 747-5793. INVENTORS INVENTORS! Can you patent and profit from your idea? Call AMERICAN INVENTORS CORPORA- TION for free information. Over a decade of service 1 (800) 338-5656. In liflaSEachusetts or Canada call (413) 568-3753. SERVICES ENTHUSfASTSWfiynotusePALslnyourdeslgns? We program from your logic equations or MS-DOS media. Call or write about our "Janey's Ranch" spe- cial. fJEVADA COMPUTER ASSOC, Box 978, Bat- tle Mtn., NV 89820 (213) 666-2152. COMPUTERS FOR tE$$ JCI 10 MHz 8068 Syslem $ 399.00 • 10 MUl Motherboard w/MOKB RAM • Mali Co-Pro«aior Socket • Otk S.2S- im KB noppv * Con [rol ler • 101-Key Enhanced Keyboard • 150 Wau Power Supp^ & Ciac • MonoGraphics Card -wf Parallel Pott • 12* Amber Monochrome Monitor JCI Standard Configuration; 1 MB HAM on hoard Wait Stale Built-in Real Time Qoct A Calendar Math Co- Processor Soclcet One 1.2 MB or \M MB Floppy Drive 1:1 Hsid; Roppy Diik Controller 2 Serial, 1 Parallel, and 1 Game Port 101-Ko,ard DcluM Caie w/ 200 Watt Pmier Supply MonoGiaphlcs Card w; Parallel Port IT Amber Monochrome Monitor JC1 12 MHz S0286 System $ 649.00 JC1 16 fVIHz 386SX Systenn $ 669.00 JCI 20 MHz 80386 System $ 1 149.00 JCI 25 MHz 336 32K Cache $ 1495.00 JCI 33 MHz 386 32K Cache $ 1850,00 Pj«a5« Cad For Custom Configurations One Yoar Parts & Labor Wan-anty 30 Day SatisfactEon GuaranlAfi Shipping & Handling Extra VISA & M/C add 3% Amax add 4% JINGO COMPUTERS INC. 5122 Walnut Grove Avenue San Gabriel, CA 91776 Tel: (318) 309-11 08 - Fax: (818) 309-1107 CIRCLE 187 ON FREE INFORMATION CARD 15" SUBWOOFER 10" POLY WOOFER Paper cone with gold toa© dusi [^p- B 02. magnet. 8 ohm. 1/2" letro Huid voice coil. Power handling: BOW RMS. 70W max. Froquerrey re- sponse: 3K-20KH2. #RM-271-020 $1"$1"95c II -9? |10'^Q,> (&0 LP] SUPER HORN TWEETER Original piezo tweeter made by Motorola. SPU94dBa.83V/lM. Response: 4KHi- 27KH2. Handles ap- proximately 50 wans. #RM-27(M)10 $5=° $4» $3« 2" DOME MIDRANGE Textile dome mittrange made by Philips. 8 ohm. SPugodB 1W/1M. sow RMS. 40W max, Respon.se: 550-5 KHz. Medium duty. 60 W RMS, BOW max. 14 oz. magnet. Response: £5-2. S KHz. (s=2aH2. #flM-290-096 Dtjal voice coil. 40 oz. magrtet. € ohm Imp. 100W RMS, MOW max. Response: 20-1. 2KHi. Resonant tteqtjency: 21 Hz. SPL.93CIB1W/IM #RM-290-190 $54=° $49" (B-3J [4-upl SUBWOOFER XOVER #RM-280-210 200W RMS crossover designed specifically tor use with tiua& votce coil sub MToofers. 12 dB per octave rQll.otf at 150Hz #RM-2eCI-220 $28*° $24* $18«> $16*= TITANIUM COMPOSITE TWEETER Ttie advantages of both hard and soft dome technologies- 8 ohm. Ferro fluid cooled voice coil. SPL=90dB1W/1M 50W RMS, 70 W max. 4" round. Polydax #DTW100T125. #RM-270-047 12" CAST FRAME WOOFER iW. ■ \T woofer made in the USA by Eminence. Paper cone and dust cap with treated dolh surround. 80oz. magnet. 2-1/2" vented voice coll. 8 ohm. 170W RMS, 235W max, 40-4.5KHZ response. #RM-290-147 SPEAKER BUILDING BOOK i,;;;.,-... Revised edition >■■- »■_; of David We«ms' thQst selling book. Learn to build low cost sp&akers that rival the high priced models, #RM-50(M)21 $16»* 340 E. Fir^tSt., Dd^lon, Ohio 4$402 LMal: 1-513 2&2-0173 FA>!: 513-222 *64* - 15 day moneif back guarantM' * $15.00 minimum order - We accept Mastorcord, Visa, DiEcover. and CO-O. flfde;s ■ ?■! hour shipping ■ Shipping charQfl = UPS chart rale t 51 .00(S3.[» mtntmurn charge) * hhjiurs S:30 am- 7:00 prp EST. Monday - Friday ■ Wail ordor cusiom- efs, please ca:il Tar shipping usiimate on orders exceedirig & lbs. Foreigra cuslomers please send $9.00 U.S. Funds \or ^^:ais.\qq posEaj^. CALL TOLL FREE 1-800-338-0531 CIRCLE S6 ON FREE INFORMATION CARD CO o z o CE f- u m O a < CONSOLIDATED s^^ss^^^ Umoi • THE ULTIMATE ELECTRONICS CATALOG Order your 260 page catalog and price Hit with over 14,000 mon&f laving cilectronic parta and equipment] Sfind $3.00 in a check or money order^ or call 1 '<600-S43-356S iod Eiy and use your Mai tercard or Viia. Conioli dated Electnnici, Incorporated 706 Watervliet Ave., Dayton, Ohio 4B420.2699 Name City -Zip_ CIRCLE 70 ON FREE INFORMATION CARD CABLE T.V. CONVERTERS WHY PAY A HIGH MONTHLY FEE? All Jerrold, Oak, Hamlin, Zenith, Scientific Atlanta, Magnavox and all specialized cable equipment available tor shipment within 24 hours. For fast service MC / VISA or COD, telephone orders accepted (800) 648-3030 60 Day Guarantee (Quantity Discounts) 8 A.M, to 5 P.M. CS.T. CLOSED WEEK- ENDS. Send self-addressed Stamped enve- lope (60c postage) for Catalog. P.O. Box 5O0D Suite }11(R) ' CarpentersvMIe, IL BDtIO lmiOU]»T EDUCATION & INSTRUCTION MAGIC! Four illustrated lessons plus inside infor- mation shows you how. We provide almost 50 tricks including equipment for four professional effects. You get a binder to keep the materials in, and a one- year membership in the International Performing Magicians with a plastic membership card that has your name goid-emtiossed. You get a one-year sub- scription to our quarterly newsletter "IT's MAGIC!" Order now! $29.95 tor each course ^ $3.50 postage and handling. (fJew York residents add applicable state and local sales tax). THE MAGIC COURSE, 500-B BiCounty Boulevard, Farminqdale, NY 1173S. ' CABLETV ^ DESCRAMBLERS ***** STARRIfitG ***** JKRROIO, HAMUN, CMK AND OTHER FAMOUS MANUFACTUREFR 4 FINf Sr WAAAAM1T PfiOGRAM A\AiUEJUIL£ • LOU^rn ITETAJL/^HiStiSAU PWCES IN U S, • Chtders sjHipno from sitdck vi/nxiN » hour;, Fo« f«f« CATAioo o«Lv l-^SOChS 45-092 7 V rem ALL iNFCWMATTOH 1-Af 0-7O9»9917> PACIFIC CABLE CO., INC. Reseda, CA 91335 F.C.C. Commercial General Radiotelephone license. Electronics home study. Fast, inexpensivel "Free" details. COMMAND, D-t76, Box 2924, San Francisco, CA 94126. VIDEO tape VHS basic cleaning and maintenance. TV one and a half hours, VCR one hour $38 00 each, JAMES BRADFORD, TO Box 38359, Detroit, Ml 48238. LEARN IBM PC assembly language. 60 pro- grams. Disk $5,00, Book $18.00. ZIPFAST, Box 12236, Lexington, KY 40581-2238. TURN your love into a living I The professional video industry needs qualified technicians, institute of Au- dio Research, the world leader in audio education, announces the Video Techrtology Program for people like you. In under a year turn your flair for electronics into highly marketable skills. Grads work in broadcast television, production companies, manufacturers, corporate communications, etc. Fi- nancial aid available if qualified, HS diploma or GEO required. INSTITUTE OF AUDIO RESEARCH, 64 University Place, New York. NY 10003 1 800 544-2501 . NY, NJ, CT j212) 777-6550, LOW power radio broadcasting - Your own sta- tion! License unnecessary! Reach entire commu- nities! Comprehensive hook! $29,95 money order or certified check - SOUTHEASTERN TECH- NICAL SERVICES, Box 8, Stonewall. OK 7487 1, Cable TV Descramblers If you find a better deal, ,^p, we'llbetterourdeal. ^A. 'Jorrold 'Tocom 'Hamlin 'Oak 'Sclonflfic Atlanta 'Zenltti Ask about our extended warranty program. COO, Visa, M/C welcome. Free Col! - Free Catalog, Video Tech 800-562-6884 2702 S. Virginia St., Ste. 160-304 Reno, NV 89502, CABLETV "BOXES" Converters— Descramblers Remote Controls— Accessories * Guaranteed Best Prices t * 1 Year Wairanty — C.O D s * * Immediate Shipping * * FREE CATALOG < Call or Write TRANS-WORLD CABLE CO. 1 Z062 Southwest 1 1 7th Court. Suite 126 Miami, Florida 3 3tes I 1-800.442-9333 LASER JET MEMORY continued from page 76 of printer. An "X" indicates a closed switch or that a jumper is installed. An "O" indicates the opposite. Jl is viewed with pin 1 to the left. Installation and checkout Plug the 48-conductor cable onto J2 so that the cable runs out and over the front edge of the board. After turning the power off and removing the power cord, remove the memory expansion panels of your printer (see the manual supplied with the printer). Slip the memory board into the card guides inside the printer and plug the free end of the cable into the 48-pin con- nector. Power up the printer and run a memory test as described in the printer's manual. Check to see that the amount of memory re- ported is correct. If problems oc- cur refer to the guide in that manual, and check your work, r-e BEST BY MAIL R»l««: Writa National, Bibc 5, Saraaota. FL 34230 BOO KS;C ATA LDGSJMAGAZINES FflEE CATALOG . DESIGNER Clolhing. OMEGA, 101(RE> Clemalis, Pensacola, FL 32503- 2634, »],000 + CATALOG LISTING! $5.95: Catalogs, Box 924S2GT, Atlanta, GA 30311. MONEYMAKING OPPORTUNITIES $50,000 IN 3 Months: Onl/ 3 piscas of paper, no membership or company start up fees. Our wtiole program cosl you iust S3.0O, send to: TSCOA, POB 670(BE), Lewiston, NY 14092, CLOSEOUTS EXTREMELY PROFITABLE Postcard Pro- gram. S5,0OO.OO weekly possible! 1-800.264.2625. CABLE TV DESCRAMBLER LIQUIDATION! • Major Makes & Models! • W\\\ match or beat anyone's prices! • Dealer discounts at 5 units! • Examples: HAMLIN COMBOS , $44 ea, (Min, 5) OAK ADD/ON $40 ea, {Min, 5) OAK M35B $60 ea, (Min. 5) WEST COAST ELECTRONICS For Information: 818-709-1758 Catalogs & Orders: 800-628-9656 mUTS& VOLTS (M A Gl A Z I N E, PlncvtintlB, CA SeG70 DIVE VnUflSELf A flflEAX - A PRICE BREAK I NUTS E VOLTB UUIU ^d^ VOU MONET QH ELECTflONIC PARTS £ EQUIPMENT Pllll ^HDW TDU WHEHE TO FIND UNIQUE. UNUSUAL AFVD HARO-TO-FIND ITEMS. WSMmmmmmim li^ClHiMkthLttA am 11 bA St2«i k. iM '< I«IH m Ci^ Mwc iln\ Tin USA }2a» C.bip. UF>ira tIJM Air Mail ro-i Ls ■ '. JESM ^ A f/tfiamlPiihlfatim hf Jh Bo^k)^ AndStfikif OfBtcimk Efui^tut 94 QUALITY PARTS • DISCOUNT PRICES • FAST SHIPPING im^mmm^ mmmmmmmmmmmimmmiimHmmiimm 12VDCGEARHEAD MOTOR Pt^O 6\)Z2m staff HMB-06 Opoiates from 4-e Vll«- 25' high X 115' wWa Prograrnmlngaryj hooK-ipinsinxitrons mdudsd CAT* LCD-1 iS SO aadl :=-Cl|^ Soho» GBL 35-DH-210eo-10Y Powerfui little gaarhaad motor. 40 RPIi/( (B> t2 Vdo. 0.5 amps (no ioad), 32 HPM with ioad. Op«rat«s ai lowar voitagee wHh reduce ^wed and lorque. G. 3 pound Indi^ I0fqu». aali: 27 pound ln(*iet. 3.1" iong X 1 .075' d|. amBtar. Shaft: 0.1 ar dla. X 0.7S' long. CAT« MOTG-14 $1 i 50 each lOfor $100.00 12VDC2.1 AlUIP POWER SUPPLY Lambda* LUS-9A-12 Fuiiy endrjsod s^lchlng powor supply with $cf9W tormina! connodlons. Input: 120 Vac 60 H7. Oupul:1ZVdc±5%@ 2.1A wdrvoltageand overctirrsnt proieciron. Compact ventiialsd cate measuree 5.24- X 3.81" X 1.38" owrall. Includes instructjon sheet. CAT«PS-122 $23 50 each SWITCHES ^ ITT PUSH BUTTON ITT MDPL Hn« 3"' X ^fSr gray rftcungi^r k«y tajj. S.P.S.T. NO. Pujh laclDH. RATED: 0.1 amp vtvitchlng. O.SS Amp cany currant. P.C mount. CATaPB.s escHch • iot«$e.oa lOOtorSSl.DO SPOT PUSHBUTTON Min^uindt* 1M3 Ratwj e impi $ 125^50 Vac. 6lpd^ plastic pLi«hbunort. S*i(ch body: .02" X .84- X .SS" CAT«PB-ie ti.ESia -lotorSis.Co PUSHBUTTON SWITCH c~, GC/Thornuna ^5-420 ^^ S.P.S.T. mrmill^ op«n rnoirwntBry ^^ pustibtrQoo switch. Rad plastic rj actuator 0.&7'dianistar. CI«roms bajai O.&fi- ctiamatar. Thraadad buihin^ mounis in .SO" diamatar hota. Ratad 3 amp ^ 250Vac. Sokiar k^op larmina^ CATN PB-20 (1.00 each THUMBWHEEL SWITCH 1 pola 10 position [^ j^ dacimal ancodad i,^'>. Ij'' ' ■ ■wilchaa wliich I f^ ll•l■^^\ intarkMHt lo rruka upd4Sir«dnunib«r or cigita. Tarminf t#» to 1 1 pc pns (1 com- mon ancl 10 polae). Each sac^on iriaasuras .31- wida X .20" hah X .73- d«p End platas can ba addad lo tomi a .04" high bazaL CAT«SWTH-« $1 2Saach 10 (or 31 00 aEN0PLAT13-CAT«SW-«EC SI 0CATtI>CTX-13S S4.Sa 9 VdC l9 1 arp CATt DCTX-«S1 $5 00 24 Vk 9 e2S ma CAT4 ACTX-i4E2 33.00 TELEPHONE COUPLING TRANSFORMER MuN Products tnlamationatf A1fiN-W>-1l^1 Prtmayy: 6O0 ohm Sacondary : SOOreOO ohm 77- X 61- X 63" high S p.c pins on 0.187- canlara. Pnmsry induclanca: 300 mH rrin., at lltHt. 1 voK. CATsTCTX-l 31.23aach -lOTofSltOO NICKEL-CAD BATTERIES (RECHARGEABLE) AAA SIZE 31,50 each 1 2 volts ISO mAh CATi KCe-AAA AA SIZE 32 OC each 1.25 voNs 500 m«i CAT#MCB-AA AASIZE 32 20aach VtfiTH SOLDER TABS CAT#NCB-aAA CSIZE M 25 each 1.2 vela 1200 mAJi CAT«NC»C DSIZE 34,50 each 1.2 volts 1200 tnAh CAT(NCB-I> sixENONiTuee- r tor^ Itaihtuba wiUl 3 1/2" rad ■rwj tiadt taadi, idaai for tl^c^ ^onic fl«h or strobe pfDjacb. CATsn.T-3 2IMJ1M RELAYS ^ G VOLT D.C - S.P.D.T. Aromst • RSO-eV Super sinl II relay, Retad: 1 arnp ® 30Vdc TTLdiractdrivapossi- bls, Operates on 4,3 to 14 Vdo, Coil: 220 ohms. 1 aiie" X 13/32" X7/1S-. C*T*HSO-«V St SO each ■ IOIorS13Sa 12 VOLT D.a O.P.DJ. DIP RELAY rAnieiu/e relay tits slendard 1$pin (dp) sockets or will diradiy mouritop.c. beards G I Clara* LM44D00 • 260 ohm ' 30 va suHtching. CAT>CHLY-12 S2 50 each 24 VOLT D.C. COIL KUP style 11 pin base can pa sodialad, direct eokjefed or quick connect terminBlscBn beusad, 1 Si's- 1 1 1/2-1 2- 3PDT,- 3 amp contacts ' 470 ohm CATi RLY-3S24 32 26 each 0*6 HOUR AUTO SHUT-OFF TIMEft M H Rhodes I no Mark-Time* 90007 Timer Fits starrdard 3" Peep walbox. Rated 20 amps @ 125 Vac. Turn knob to desire cj lime. Includes han^ara. beige waHptate, and knob. UL and CSA listed CAT«TiMC-« 15,75 each ■ 10forS50,00 I SPECIAL PURCHASE 210 MFD 330 V PHOTOFLftSH CAPACITOR Rubicon CE phOEofkisSi capaciior 0.7r dia.X i.r hiflh. Th*s*are rww capacitors thai havs bvvn propped wifih l.^"" blach and r4d wir» l&ads ukd«red u> iha tAitTHnab. CATiPPC'2lO £2 50MCh 10forS£2 50 ■ 100 for S2O0.Q0 Largo quanlilios avaikib]» Call for pficing. STEPPER WOTOR AlrpaxP/N 08^711 -Ml 17 VdcduaJcoil. pormananl magnet islepper. 33.25 ohm cotl. 7.5 dogroes per stop. CAT# SMT^ %6.00 ea<^ ' 10 lor S50.00 JNSTRUMENTENCLOStlRES: Hi gh quality mokJod ABS instnimfinl anclosuE'Aa. ints^fatfld PC board sTandoHs and two »ts of vQilcal mounting slots lor front and rur aub panels. All Anctoutvs ar» S'wJdaX 6l/4*or1«4i «nd hardwaJ't: Availabla in twigfr, hfory. biKk. ind blu», Ptn&i hL CATi 2 1/r CATtHB-A (75aHCh tOtff tSS M> 2&a- CATrH»-B VTSmmch T0hT(e7 5O 3- CAT«MB-C taOOvicfi 1 fcr (70 00 Pi*aM spKffy color tlG->1^ 7S OHM VIDEO CABIE 100 It or 200 ft roll* of RQ 1 1/U tAiminatKl to httiTf liuif F oonn^ctoft. Include 75 ohm t^rrnnftlor ^ and F-61 ifaicw on oo* and. N*w CAblas manufAdurftd for IBM PC n«l- wo&i IBM P/NI 501*08 CO^t^COPE CATiRO'11'1 100 ri I^IF^ISOO CATi Fta-1 1-2 £00 tL roll £27.50 t6D"S STANDARD JUMBO DIFFUSED T t 3/4 tat ^^^«ED CAT»LEB-1 10 lor $1 50 -I PS IH 313.00 CRECM CATt LEI>-2 10fcrS2,00-IOOIsrt1700 rEUOW CAT* LEO-] 10lorI200 'ton lor $17.00 FLASHING LED wilhburltinnsshinfi drcuil l cperateton Svolia,,, ^J ftfO $1.00 each CAT*LED-4 1D fa 39 50 GHEEN t1 ,00 eeih CATtLED-aO lOtorStSO LEO HOLDER . TwA} ptaca hoidir. I CAT*HL£P 10tor»« RECTANGULAR L.E.D- SPECIAL «HLIt1P0301 ^^^ Rsd dif^l»«l ^^"^ ft =a (KSangle. 0.2r X 1" X 29" N^h. ideal for bargiaphs, chas- ers, etc. CAT* RLE 0-4 IOIorSI.50 -100lorS12 00 IWJOIOfSIOOOO LED GRAB BAG LE D.'» Many dlbranl ■hapat, txAoTh, hzbk. Rounds rtct«rgul«r, cuirv»d, ale CAT* GRLED M.OC F>«'' attortnant lb bA^ OPTO SENSOR U ahapad packa^ with mouiiting aars 1/8" opaning 3/4- rrounlinoaars. CATiOSli-e 50Caach 10 lor ^.50 - 100 lor ^0 00 REFLECTIVE OPTOSE^OR Opt*l K-e7l 1 w*do# shaped davioa with IR llaf and r*c«ivarpc4rtting ih* lama diraction. Ughi rays Irofn amittaf bounct off rtaarby cbjaci and rt{}J3taron racaivar. EfTacbva rangaapprox. 0.15". CATiOSR-1 75taach t.Ea FLASHEt^ KIT TwoLED sILashtn uncBonwhan a flvoH :^«^ -^Iv^^t^-^ baltory b attachad. jT^^^ J, The Nil irBtudas a rt^lS?" — '^ p.C- board, all Iha pans ^^"'^ and pnslructiorH to Rnaha a smipla tlashar circurt A quick and aasy pfojacl (or any- one wiih basic soWoring skills. CAT* LEDK3T SI 75 por kri LEDCHASeRKiT BlhIo this varublfl \ ~^ 5peod Jod chaMf. \ „ % o o ju J! -B-ll saQuentiaNy at whatO'Var £pe«^ you s*( tham for. E3S)f to buird kil jrchJdM pc board, pa ill ar»d JnstructiorA. Idaal lor special ligNIng alfocts. oostumas. otc. Operat«s or\ 3 to 9 voRi PC board ii 5" X 2 25" A graai orw hour projact. CATi AEC S€.50 eacH STEPPING MOTOR CONTROLLER KIT. Learn about steppjngi molon while building ths simple circuit. Indulges circuft boajd and alE parts except 12 Vdc power supply. CAT#SHKIT Sl&.OOeacfl ELECTROLUMINESCENT STRIP(GLOW$TRIP) ANDtNVEfiTER [^ U**d for bacfcSghiing controt p«ntla or H dacoraliva of amargancy pnma Ighling ■Durca. Thin, lough and flanbia,. Ihay opar- ata on low currani AC vollag*. Tti* pra- farrvd powar »cvr<« w a minia^r* DC to AG irtvartar. Thaa* hava ■ bit ol an odd ng X 1 .72^ wda and hai ona cwnar cul ofTi laavjng auivhilaraa of liirly good pro(>Oi1k&4ia Wt mm aatkng Th« tdripi f nd iiv vartart a» a padiag* invanor oparataaon 6 Vdc.Gkm ilnp, invarlai and hook-up diagram CATi OS-SOO $5.00 par aal EXTRA INVERTERS I i^xit: 6 Vdc OuTput : 225 Vac CATi \H^'\ %2 00 aach ORDER TOLL FREE 1-800-826-5432 FAX (818) 781-2653 • INFORMATION (818) 904-0524 Call Or Write For Our Free 60 Page Catalog Outside the U.S.A. send $2.00 postage for a catalog. Minimum Order $10.00 'Alt Orders Can Be Charged To Visa, Mastercard Or Discovercard • California, Add Sales Tax • Shipping And Handling $3.50 For the 48 Continental United States - All Others Including Alaska, Hawaii, P. R. And Canada Must Pay Full Shipping • Quantities Limited • No CO. D. • Prices Subject to change without notice. MAIL ORDERS TO: ALL ELECTRONICS CORP - P.O. BOX 567 - VAN NUYS, CA 91408 o o w m o CIRCLE 107 ON FREE INFORMATION CARD 95 in- Mail Order Eleclfonics -Worldwide I® ameco ELECTRONICS 24 Hour Order Hotline (415) 592-8097 QUALITY PRODUCTS • COMPETITIVE PRICING • PROMPT DEUVERY Intel Math Coprocessors 808S or 8086 Systems 8087 5MHz $89.95 B087-2 BMHi $129.95 8087-1 lOMH^ $169.95 80286 Systems 80287 6MHz $139.95 80287-8 8MHz S209.9S 80287-10 10MHz $239.95 80386 Systems 803B7-16 16MHz $349.95 BO367-20 20MHz $399.95 80387-25 25MHz $499.95 80387-33 33MHz $649.95 Memory Modules SIPPs 41256A9A-80 BDns. 2MK)i3 S32.95 41256A9A-10 t DOns. 256Ki9 $23.95 4210(10A9A-70 70iis.iMe9x9 $104.95 421[K]0A9A-S0 SOns. 1 Megx9 $99.95 421tJ0OA9A-10 iOOns, 1 Meji9 S89.9S 94[KIOL-eO eOn$.4Megi9 $449.95 SIMMs 41256A9B-S0 aOns. !56K)i3 $32.95 4125fiA9B-10 lffl)ns.266Ki9 $29.95 «10O0AeB-10 IMfis. IMegiB $79.95 421090A9B-7() 7O11S. 1 Mi^cS $109.35 421ODCIA9B-S0 30ns. 1 UegtS $99.95 42100OA9B-1O lOOfls. 1 MegiS $89.95 940003.80 sons, 4 WegiO $449.95 NEC V20 & V30 Chips UPD701(1B.5 SMHi.VfflCllip S5.25 UPD7010B-3 8MHj,V20Ctiip $6,95 UP D701 08-10 lOMHi.VMChip $10.95 UPD701 1 6-a fiMHi. V30 Chip $7.95 UPD701ie-10 1OMH1. V30 Chit $12,95 Dynamic RAMs THS4416-12 ISOns, I6K34 S2.49 TMS4416-15 150ns, 16Ks4 $2.25 4116-12 120ns, 16ltel $1.49 4116-15 iSOrvs, 16K1I $1.19 4116-20 200rvs. ISKll $.99 4164-100 100ns. 64Kll $2.25 4164-120 120ns. 64K1I1 $2j09 4164-150 150ns. S4K)i1 $1J5 4164-200 200ns. S4K)I1 S175 41256-60 60ns, 256Ki1 $4.95 41256-80 sons, 255Kil $375 41256-100 100(15. 256KX1 $3.15 41266-120 120ns, 256K«1 $2.95 41256-150 ISDns. 256XJ11 $2.53 41464-80 Mns.&4Kx4 $3.95 41464-10 lOOns. 64Kl(4 $3.25 41454-12 120n5.$4KK4 S2.35 41464-15 150ns, 54KX4 $249 S1100OP-70 70ns, 1 MegKl SI 049 51100OP-80 BOns. t Mejii $9.96 5110O0P-10 lOOns. 1 Megxl $3.95 514256P-30 80ns.266K)i4 $10.49 514256P-10 100ns. 25et;i4 $10.25 to o z o cc h- o m _i LU Q < . CC 6116P-3 62641.P-10 6254LP-15 43256-1 OL 43256-1 5L 52256LP-15 Static RAMs t50iis,16KICMOS) iOOns,64K(CMOS) t50ns.64K(CMOS) 100ns. 256K 150ns. a66K 150n5.256KlCMOS) S2.59 $5.49 $4.95 $8.95 $8.49 $9.49 PROTOTYPING PRODUCTS Jameco Solder less Breadboards Part nm. ConlacI Binding No I'xW Poinls Pasts Pilo JE21 JE23 JE24 JE25 JE26 JE27 3.26 1! 2.125 6.5 X 2.126 6.S X 3.126 5.5x4.26 6.876x5.76 7.2517.6 400 830 1,360 1.660 2,390 3.220 $4.95 $6.95 2 $12.95 3 $17.95 4 $22.95 4 $32.95 Oscilloscope Probes • Atlenuation: Xl /KlO ■ Capacitar>ce: 100pF/22pF ' Bandwidth: 3MHz«0MHz ■ Length: SO" LFieO 40MHz Oscilloscope Proba $19.95 GoldStar 2DMH2 Oscilloscope and 1GHz Frequency Counter * \sfg& 6" rectangular display - Higii sensitivity: 1 mVydiv GS7020 Os diiosaipe $399.95 ■ Wide measuring range * Measure value hold lunction FC71 02 FfcqiiefKy Countec. ...... $299.95 Metex Digital Multimeters General Specs: '. l-lendneid. high accuracy ■ AC^DC voltaae. AC'DC current, resistance, diodes, continuity. IransisEOr hFE - h^nual ranging vtl overiaad proledion M365a, 3650e i M4e60 cnly: > Aisc measure frequency and capacitance M4650Dniy: ■ Data hold switch '4.5 digit M3610 3 S D^il Uuilimeler $49.95 M3650 3.5 Digil M'jtiiinetet w.'FrequerKy 5 Capacitance $69.95 M3650S Same as M3S60 w,'3argrapli $74.95 M465G 4.S Digii wfFr«iuericy, Capacitance and DataHoWSwilcti S99.9S Multimeter Specials MSO: - AC^DC vcliage, AC/DC curreni, rflsislance, diodes, continuity & Irequenoy * Full auu>- ranging on DC voltage * High/low semt. auloranging for AC'DC curreni and ohms * Data lioid switcii » Exira-iarge display MEIO 3.75 Dign Miiilimeler $S9.9S M3900: ' AC/DC voltage. AC'DC current, resistance, diodes, coniinuily. dwell angle and engine RPM » High surge voilage prelection M3900 3 e Digit MuitnsBief $59.95 Prototype Design Stations WM2 WM1 St W^2 Features: ■ Removable sdderiess breadt}ciard • Vafieljle and (lied DC power supply • Multi-frequency sig- nal generator • Analog rrultimeler ■ B bicolor LEDs [red a green) * 8 logic sviritches * Logic probe * Lighted power switch ■ Fuse overload protected • Sturdy ruggedtzed case WM1 special Features: ' 4 potentiometers - Built-in speaker WM2 Special Features: - Pulse Generator - Binary coded decimal (BCD) to 7-segment decoderMriver • DB25 oonneclor * Frequency counter (1 Hz to 1 MHz) WM1 Analog Prototype Station $199.95 WM2 Digital Prototype Station ,. $249.95 A.R.T. EPROM Programmer UVP EPROM Eraser • Programs all current EPROMs in the 2716 to • Erases all EPROM's • Erases 1 chip in 15 27512 range plus the X2864 EEPROM Min. and 8 chips in 21 min. - UV Intensity: - nS232 port - Software included 6800 UW/CM^ EPP ,.$1 79.95 DE4 $69.95 Soldering and Desoldering Stations BO Wall Analog Display Soldering Station * Electronic Ismperature control Irom 200° to B78°F - Cartridge healing element for a longer life of tha soldering lip XY1683 $59.95 50 Wan Analog Display Soldering Slalion • Eieclronic temperawre controi from 200^ to S78^F * Ceramic heating eiemeni lor a steady temperature and long life XY_2660 $89.95 60 Watt Digital Display Soldering Station • Electronic temperature control from £00^= lo S7S°F - Temperalure displayed on easy lo read .560"H 3-dig3t LED readout » Nichrome heating elernent XY960 ■ $99.95 30 Watt Electronic Temperature Controlled Desoldering Station * Electronic lemperalure conlroi Irom 212^ lo S42^F ■ Self-conlained higti rotary vacuum pump XY999 ....$279.95 51-Piece Electronic Tool Kit The MS305 provides the tools needed tor building, repairing and genera] maintenance ot most eieclronic equipment. A convenient and durable carry-along combination loch case safely protects and secures this 51-p]ece tool kit. From ttie digital multimeter to the desoldering pump this kit Is the perfect Item for technicians and electronic enthusiasts. • 10' measuring tape ■ Electric tape • 6" long tweezers ■ 7" brush and scraper • 7" fine point probe ■ 7" slotted probe • Rosin core solder • 30 Viiatt soldering iron • Desoldering pump • Soldering stand Tools Included In Kit ■ stainless steel scissors ■ Utility components box • B pes. hex key wrench • Digital Multimeter • Round needle file ■ Flat needle file • 6" adjustable wrench • Utility knife with extra blade • Bent needle nose pliers ■ Diagonal cutting pliers • 5.25" needle nose pliers • 6 piece precision screwdriver set • Brush • 10 piece screwdriver set: 5 Slotted a 5 Phillips ■ Flat nose pliers ■ Carrying case: 17.63"Wx12.5"Dx3.5"H MS305 ...$119.95 96 Partial Listing • Over 4000 Components and Accessories in Stocl(! • Call for Quantity Discounts CIRCLE 114 ON FREE INFORMATION CARD J Mail Order Eleclronics ■ WoddwicJe ameco ELECTRONICS Request Jameco's 1990 Catalog for a Complete Listing of Components, Test/Measurement Equipment and Computer Products Jameco 20MHz 80386 Desktop Computer Kit Fully IBM Compalible Free! Concurrert 3S6 (Disk OpBrating System) Soltware Included 4MB RAM Included, Expandable to 8MB on board, 16MB wrlh optional eifpansJon board 8/20MHZ Keyboard Swilchable Operation Am BIOS ROMs Included Fliptop Case w/200 Watt Power Supply Conner High-Performance IDE 3.5" 40IVIB Hard Disk Drive Teac 1 .2MB Floppy DSHD Disk Drive Multl I/O Card with Urilversal Floppy Controller Fujitsu lot -Key (Entranced) Keyboard Shown wttti VGA Option (not inctgded) JE20S9 Multiscan Monitor and VGA Caid....$eS9.3D (See Below) JE3551 20MHz 80386 Compatible Kit $1949.95 Jameco IBM PC/XT/AT Compatible Cards JE1077 JE1043 36OKBfrz0KB/1.2MB/1.44MBFIOppyDiskConlrollerCard( PC/XT/AT) .. $49.95 JE1050 Monochfome Graphics Card w/Parattel Printer Port ( PC/XT/AT) $49.95 JE1052 Color Graphics Card wl Parallel Printer Port (PC/XT/AT) $49.95 JE1055 EGA Card wl 256KB Video RAM [PC/XT/AT) $139.95 J E1 060 I/O Card w/ Serial, Game, Printer Port S Real Time Cloclt (PC/XT) ,...$59.95 JE1062 RS232 Serial Hall Card (PC/XT/AT) $29.95 JE1065 I/O Card w/ Serial, Game ar^d Parallel Printer Port (AT) $59.95 J El 077 Multl I/O Card w/ 360KB/720KB/1.2MB/1.44MB Floppy C^ontroller (AT). ..$99.95 EGA, VGA & Multiscan Monitor Packages Relisys 14" EGA monitor and EGA card package (640 X 350 max. resolution) JE1 059 EGA Monilor S EGA Card $509.90 Relisys 14" Multiscan monitor and 16-bit VGA card package (64(3 x 480 max. resolution) JE2059 MultlscanMoniioraVGACard ....$669.90 Relisys 1 4" VGA monitor and 1 6-bit VGA card package (640 X 480 max. resolution) JE2061 VGA Monitor & VGA Card... $629.90 JE20E1 IBM PC/XT/AT Compatible Keyboards ■ircnn MEI 100-Key Mi c retype Keyboard ' Normal si3e ol I 101 key enhanced Vheyboa^d FKB470a JE201 5 34-Key standard AT Style Layout $59.95 FKS4700 101-KeyEnriancedLayout with 12 Function Keys $69.95 ■ IBM PC/XT/AT/386 Compatible ' Saves an amazing 60% ol the desk spatiie used by equivalent standard keyboards MIRU $129.95 Jameco Digitizer Tablet \ • AutoCAD 10 template and four- button puck • Resolution: up to 1016 lines per inch ■ Accuracy: ±025" ■ Emulates three ol the worlds most popular tormals: SummagrapfiFCS MM, Summa- graphics Bit Pad One, Caiconip 2000 • EEPROM allows custom CO nligu ration JCAD Digitizer Tablet $199.95 Stylus Two Bijiun Stylus .... $39.95 DPI Handy Scanner • IBM PC/XT/AT Compalible • 4" Scanning Window ■ 4tK) dpi HS3000 ZZ.....$^ 29.95 Limiied Quantity in Slockl Logitech Mice MSER Soria] Mouse S MouseWare Software $89.95 MBUS Mouse w,BusB4ar(]&Mouse- ware Scjrtware ..... $99-95 PS^ Motjse & Mous^Ware SotWa.e $79.95 Modems MPS2 Externa) Modems t200C OautmnicslStnBiiH S89.95 2400C Sjtabgnes 2400 Baud $149.95 9600 E I>rii!n«l>:us96l»Bauo $699,95 Internal Modems 1200B j9i»»i2«iBsuii $49.95 240aB Jxi>Ko»[»Biiud $99.95 Modems listed abcwe Include PrcCoftirti SottMa^e IBM Compatible Cases and Power . Supply M , yiill'ltWIi JElOtl! JE1010 FifhropstiniartPDxrcaie....... $39.95 JElOtt SKStSunaMFCXTCsH $33.95 JE1It32 w^mBibiAJPtmiSui^ $69.95 DFTC VEmai Ca» *^sm ?tr. Sifti, $259.95 Floppy Disk Drives Sony MPF11 3,6'7!(Hr MPF11 ..$14.95 Mitsubishi MF353B 3 S- 720Ke tnternat Pnve $99.95 MF355B 3.5' 1 .'t4MB Intamal Dave.. $1 1 9.95 DD1 MF355S Soltware for systems witltMjt 1-44MB disk drive BFOS capat^ility ... $14.95 Teac FD55B 5-25" 3S0kB internal Ome ... $89.95 FD55G 5-25- 1 2MBInteiiialDnve.... $99.95 Hard Drives & Tape Back-Up XT Hard EJrives also available Conner (16-bit IDE} CP3Q44 40WB (25ms) 3.5-Low Profile, $429.95 CP3ie4 eOMB i25ms|3.6'HH .....$649.95 CP3104lOOM8(26ms)3.6'HH $699.9S Above Drives Incfude Hard Disk Drive. Cantrallar £ Cables Micropolis (ESDI) 16B4-7 150MB (16ms| S-JS'HH.... S1 199.95 1558-15 3130MB(18ms) 5.25"f=H $1699.95 Colorado Memory Systems ■ IBM PCWT/AT/SBS Compatible • Back-up 40MB in 40 minutes ■ Back-up 60 to 120tv1B with extended tapes artd data compression sottware ■ Includes 40MB tape canridge DJ1 4m8 Tape BadtUp $329.95 KE10 Exlemal Enclosure Kit St 49.95 TB4t) iOMB Tape Oartridje -.., $24.95 TBEO 60MB Tapa Cartiidgt S32.95 Mvll Order Electronics -WofidwJdF ameco ELECTRONICS 1355 ShoreW9v Road, Belmont, CA 94002 24 Hour Order Hotline (415)592-8097 SSO.OO Minfmuni Order FAX'S (415} 592-2503 or (415) 595-2664 Telex 176043 - Ans. Back: Jameco BImt Data She&ts - 50c each For a FREE 4e-Page Filer send $2,D0 to cover First Class Postage and HandUnig £■1990 Jameco Eiectronets 1I3.'9Q CA Residents Add 6.25%. 6.75% or 7.25% Sales Tax ShippirtQ • Add 5% pfus $1-50 Insurance (May vary according tc wei^Tii ar^j sliipping method) T&rms: Prices Subject to change withcul noiioe. items subject to availabiiily and prior sale. Coinpisle tist dF IP ms^'w^rfinties is avaiiabl* upon ffque^t IBM ■( fl Te^tsred Imdomirk t^t IntennitKiful Bus^iflu MiKMr>Mi VISA' ! MMC Please rafar to Mail Key 2 w^len ordering ■1 rSSfftb^'i;.^- ^^^^^9 ^^ o o m to o 97 Customer Service •Technical Assistance • Credit Department 'All Other Inquiries ■(415)592-8097 • 7AM -4PM P.S.J. CIRCLE 114 ON FREE INFORMATION CARD GW» - ANTI GRAVITV KNERATOR uj LC?- 40 WAn BURNING CUTTING LASER . .. = ^HUB4- HI POWER PUISED DRILLING LASER ... egmS- 1 MIL LION VOLT TESLACOtL BMCP1 - HI VELDCITV COIL GUN 25ULS1- LASER LIGHT SHOW 3 METHODS eO EH1- ELECTRONiCHVPNOTISMTeCHNIQUES . Z EML1 - mwER PCWERED COIL GUN LAUNCHER 3JL3- JACOB LADDER 3 MODELS SOS- SEEINTHEDAflK Q. LEVI- LEVITATIONOEVCE .J10.00 KOOD $200D $2aoo SISiOO sjimo .ssoo .S£00 SIOOC siooo US. f2 FHV1K - 3 MILE FM VOICE TRANSMITTER SM.50 PFS1K- HAND CONTROLLED PLASMA EIRE SABER USSD Nt67K-HIFUJXNEGAT1VEI0N GENERATOR . . . S34.50 P6SK - PLASMA LIGHTNING GLOBE S4950 LHCJK-VISIBLESIMULATEDSCDLOR LASER S4450 H0D1K - HOMING/TRACKING BEEF^fl TRANSMITTER . $44.50 LGU6K - 2SMW HAND-HELD VISIBLE LASER GUN S24950 BTi; 3K - 260flOO VDLTTABLETDPTESLACOIL ....Sa4950 I0G2K — ION RAY GUN. [iraject energ/wiirrout wifBS . S12M5 TKEIK-TELEKINETICENHANCER'ELECrfllCMAN . . S950 VWPM7K - 3 MILE AUTD TELEPHONE TRANSMITTER . W950 Q ASSEMilED IN DUfI UBS HuSTIO-INFINITVXMTRListenmvlaphMielmBS . .$19950 ^IPG7D- INVISIBLE PAIN FIElDBLASrWWEGENEflATDRiT). 50 CD nM10 - 100.000 VOLT INTIMIDATOP UP TO 20' $9950 SIAT30-ADTDMATICTELEPH0NEREC0RDtNGDEVICE.S245O S PSP4D - PHASOR SWJIC BLAST WAVE PISIDL S8950 eODNE10-ALLNEW26-VIVI0C0L0REDN£0NSTICK. IH.50 COl-GU?0-5TQ1MWVI3IBLEfiEDHcNeLASERGDN St99.50 "*8L$10- KW.OOWAnBLASIfR DEFENSE WAND SS9iO EdSV ORDERING PROCEGUHE ■ TOLL FREE 1-8I)0.221-17D5 or 24 HRS ON 1.6O3-S73-4730 or FAX FT TO 1-6fl3-67?-5406 VIS*. MG. CHECK. MO IN OS FUNDS. INCLUDE lOf* SHIPPING. ORDERS (lOO.mS.UPONLYADOSlO.OO.CMALOGSLOOOflFREEWIIHORDER. INFORMATION UNLIMITED P.O. BOX 716, DEFT. RZ, AMHERST. NH 03031 CABLE TV DESCRAMBLERS 10 Lot ,„ Mj n;RROLD™Tri-Bi Mode. $105,00 135.00 OT Vi JbRROLD™ SB-3 OR 2 $89.00 $65.00 O ^ ii LU llimlfflMlX)-lMO SW.95 J61C0 ^ Z ? — OalcN-UW/V.S S99.95 JfilOO O < "^ 0«k-M-3S-B W/V.S $99.00 $78.00 CC X "-^ S OAKE-13 $99.95 $58.00 >" O t^ 3< ZaiithSSAVl $185.00 $145.00 O |— ^ ^ (;a^cPD-3 $120.00 $85,00 ^ < t^; ^ ScieMifitAlitnU- $129.95 $105.00 [jj S f|- ^ SA-Combo'i CALL $Cjill . —I tr X Tocom. $35000 $395.00 D ^ g H OilcN-12W/Auto $140.00 $105.00 2" 5 < ^ fcrrnld Swinm CSV..,, $139.95 Call *NEW STARGATE 2000 CABLE CONVERTER g z o •cc & LU _J LU O Q < CC 98 1 -$89.00 10-$69.00 100-Call Last channel recall- Favof its channel select- 75 channel-Channel scan- Manual fine tune- One year warranty-surge protection- HRC & Stand - ard swilehable- and much more. Cnll Todnv! INFORMATiON(402)554-041 7 Orders Call Toll Free 1-800-624-1150 M.D. ELECTRONICS 115 NEW YORK MALL SUTTE 133E OMAHA, NE. 68114 M.C. VISA ADVERTISING INDEX RADIO- ELECTRONICS does not assume any responsibility for errors that may appear in the index beiow. Free Information Number Page CIRCLE 53 ON FREE INFORMATION CARD 108 AMC Sales 19 75 Ace Products. 46 107 All Electronics 95 198 Alpha Products 88 — Amazing Concepts 98 197 Avex Probes 85 77 B&K Precision 27 67 Banner Ttehnical Books 19 181,182 Beckman Industrial 13,15 183,184 Beckman Industrial !7.19 98 Beckman Industrial 79 109 C&SSales 11 70 CEI 94 — CIE 25.31 — Command Productions 15 185 Communications Specialists S3 58 Cook's Institute 17 201 D&D Electronics 13 — Damark International 81 127 DecD Industries 46 186 Electronic Goldmine 90 — Electronics Book Club 32 121 Fluke Manufacturing CV2 — Friendly Videos .82 — Global Engineering 16 193 Global Specialties 3 — Grantham College 18 86 Heathkit 14 — ISCET 85 114 Jameco 96, 97 104 Jan Crystals 15 1 15 Jensen Tools 46 187 Jinco Computers 93 — King Wholesale 90 200 Klockit 18 53 MD Electronics 98 93 Mark V, Electronics 30 61 Microprocessors Unltd 87 117 Mouser 17 — NRl Schools 7 194,195 Optoelectronics 22, 29 — Pacific Cable 91, 94 56 Parts Express 93 188 People's College of Indep. Study . 26 180 Peripheral Technolt^ .87 179 Photronics, Inc. 46 101 Pomona Electronics 21 199 Print Products International 28 — R.E. Video CV3 78 Radio Shack 9 176 Sencore 70 — Star Circuits 28 196 TECl 83 92 Tektronix CV4 123, 189Test Probes 36 225-228 Test Probes 36 192 Unicorn 92 64 Universal View 92 190 Viejo Publications 82 191 WPT Publications 83 ADVERTISING SALES OFFICE Gems back Publications, Inc. 500-B Bi -County Blvd. Farmingdale, NY 11735 1-t516) 293-3000 President: Larry Steckler Vice President: Catby Steckler For Advertising ONLY 516-293-3000 Fax 1-516-293-3115 Larry Steckler publisher Arline Rshman advertising director Denise Haven adverttstng assistant Christina Estrada advertising associate Kelly McQuade credit manager Subscriber Customer Service 1-800- 2 B8- 0652 Order Entry for New Subscribers 1-800-999-7139 7:00 AM - 6:00 PM M-F MST SALES OFFICES EAST/SOUTHEAST Stanley Levitan, Eastern Sales Manager Radio- Electronics 259-23 5 7th Avenue Little Neck. NY 11352 1 -718-428-6037, 1-516-293-3000 Fax 1-718-225-8594 MID WEST/Texas/ Arkansa s/O kla. Ralph Bergen, Midwest Sales Manager Radio- Electronics 540 Frontage Road — Suite 339 Northfield. IL 60093 1.708-446-1444 Fax 1.708.446.8451 PACIFIC COAST/ Mountain State* Marvin Green, Pacific Sales Manager Radio-Electronics 5430 Van Nuys Blvd. Suite 316 Van Nuys, CA 91401 1-818-986.2001 Fax 1-818-986-2009 Ceuntersurveillance known. The building had co be torn down in order to remove all the bugs. Never before has so much professional infor- mation on the art of detecting and eliminat- ing electronic snooping devices— and how to defend against experienced informa- tion thieves— been placed in one VHS video. If you are a Fortune 500 CEO, an executive in any hi-tech industry, or a novice seeking entry into an honor- able, rewarding field of work in countersurveillance, you must view this video presentation again and again. ORDER LINE— 1-800-522-6260 Wake lip.' You may be the victim of stolen words — precious ideas that would have made you very wealthy! Yes, profes- sionals, even rank amateurs, may be lis- tening to your most private con- versarions. V^ake up! If you arc not the victim, then you are surrounded by countless vic- tims who need yout help if you know how to discover telephone taps, locate bugs, or "sweep" a room clean. There is a thriving professional service Steeped in high-tech techniques that you can become a part of! But first, you must know and understand Countersurveilance Technology- Your very first insight into this highly rewarding field is made possi- ble by a video VHS presentation that you cannot view on broadcast television, sat- ellite, or cable. It presents an informative program prepared by professionals in the field who know their industry, its tech- niques, kinks and loopholes. Men who can tell you more in 45 minutes in a straightforward, exclusive talk than was ever attempted before. Foiling Information Thieves Discover the targets professional snoopers seek out! The prey are stock brokers, arbitrage firms, manufacturers, high-tech companies, any competitive industry, or even small businnesses in the same community. The valuable infotma- tion they filch may be marketing strat- egies, customer lists, product formulas, manufacturing techniques, even adver- tising plans. Information thieves eaves- drop on courr decisions, bidding information, financial data. The list is unlimited in the mind of man — es- pecially if he is a thief! You know that the Russians secretly installed countless microphones in the concrete work of the American Embassy building in Moscow. They converted what was to be an embassy and private residence into the most sophisticated re- cording studio the world had ever Stolen Information The open taps from where the informa- tion pours out may be from FAX'S, com- puter communications, telephone calls, and everyday business meetings and lunch time encounters. Businessmen need counselling on how to eliminate this in- fotmation drain. Basic telephone use cou- pled with the user's understanding that someone may be listening or recording vital data and information greatly reduces the opportunity for others to purloin meaningful information. The professional discussions seen on the TV screen in your home reveals how to detect and disable wiretaps, midget radio- frequency ttansmitters, and other bugs, plus when to use disinformation to confuse the unwanted listener, and the technique of voice scrambling telephone communications. In fact, do you know how to look for a bug, where to look for a bug, and what to do when you find it? Bugs of a vety small si^e are easy to build and they can be placed quickly in a matter of seconds, in any object or room. Today you may have used a telephone handset that was bugged. It probably contained three bugs. One was a phony bug to fool you into believing you found a bug and secured the telephone. The sec- ond bug placates the investigator when he finds the real thing! And the third bug is found only by the professional, who continued to search just in case there were more bugs. The professional is not without his tools. Special equipment has been de- signed so that the professional can sweep a room so that he can detect voice-acti- vated (VOX) and remote-activated bugs. Some of this equipment can be operated by novices, others requite a trained coun- tersurveillance professional. The professionals viewed on your tele- vision screen reveal information on the latest technological advances like laser- beam snoopers that are installed hun- dreds of feet away from the mom they snoop on. The professionals disclose that computers yield informarion too easily. This advertisement was not written by a countersurveillance professional, but by a beginner whose only experience came from viewing the video tape in the pri- vacy of his home. After you review the video carefully and understand its con- tents, you have taken the first important Step in either acquiring professional help with your surveillance problems, or you may very well consider a career as a coun- tersurveillance professional. The Dollars You Save To obtain the information contained in the video VHS cassette, you would attend a professional seminar costing $350-750. and possibly pay hundreds of dollars more if you had to travel to a distant city to attend. Now, for only $49.95 (plus S4.00 P&H) you can view Countersur- veillance Techniques at home and take refresher views often. To obtain your copy, complete the coupon below. RADIO-ELECTRON iCS VIDEO OFFER RE ^(KJ-iJ Bi-Couflty Blvd. Fjrinmgdak', NY U715 Please rush my fopy wf the Counro-surveillanct' Tcchniqut-s Vidcn VHSCjsstttf for S4y.y5 plus S--l.(H) for pos[aj;t and hjndlin^. No. orCassctrcs (jrdtn.-d .^^. Amnunr of pay men c S Bdl my n VISA n MasitrCard Card N per VHScaSicric. No foreij