HOW TO TEST YOUR RADAR DETECTOR FEBRUARY 1990 TECHNOLOGY - VIDEO - STEREO - COMPUTERS UILD THIS A REQUENCY PROBE ur 100-MHz frequency counter is he size of a logic probe! EST YOUR VIDEO HEADS his VCR service tool will save you time and money ISPLAY OF THE FUTURE! lew miniature display will evolutionize computers, /ideogames, and even TV CIRCUIT COOKBOOK lozens of pre-amps, playback imps, mixers, filters, and more IMYIS-th n your liyiBooi $2.50 U.S. FLU-KE AND PHILIPS - THE GLOBAL ALLIANCE IN TEST & MEASUREMENT FLUKI PHILIPS «- * •- • -QEIf Great Choice. More professionals in more industries make Fluke their first choice in multimeters. Fluke DMMs. Reliable. Accurate. Powerful. Tough. Versatile. Easy to use and simple to operate. Backed by the longest, most comprehensive warranty in the business. Made in the U.S.A. In short, Fluke makes meters you can bet your reputation on. More choice. No matter what the job, there's a Fluke to handle it. There's the new 80 Series— the most powerful, most complete test and measurement system available in a handheld package. The popular 70 Series-simply put, the most requested DMM in the world, with nearly 2 million units in service since 1984. And the Fluke 21 and 23-70 Series simplicity in high-visibility yellow. The Fluke 25 and 27— the most rugged meters ever built, totally sealed against water, dust and other contaminants. And the precise 8060 Series— with the versatility of a test lab, the accuracy oi a bench instrument, and the convenience of a handheld. Smart choice. Compare Fluke DMMs with any other handheld. No one else gives you as much meter for your money. And no other meter costs less to own. CIRCLE 121 ON FREE INFORMATION CARD Your choice. For the name of your nearest Fluke distributor, call toll-free 1-800-44-FLUKE, ext. 33. And make a great choice. John Fluke Wig. Co.. Inc. P.O Bo* C9C9C MIS 250C Everell, WA 9B206 J S.: (206) 356-54M. Canada: (316) B90 76Q0 Older Countries: (2061 155-5500. '• 1389 John RuM Mlg. Co . Inc Al! rights '(served Ad N0.043I-F70 FROM THE WORLD LEADER IN DIGITAL MULTIMETERS K / February 1990 Electronics Vol 61 No. 2 ComputerDicest 31 FREQUENCY PROBE A togic-probe-sized frequency counter. Michael A. Lashansky 37 RADAR DETECTOR TESTER Prove which radar detector is the most sensitive. John B. Ayer 39 ACOUSTIC FIELD GENERATOR Time to enjoy this project's multichannel sound. Tod T. Templirt 51 HEAD-AMP TESTER Stop replacing video heads that don't need replacing. Ed Bathgate BUILD THE PORTAMJmc EOTKHTS Work _ . Bench _=U PAGE 75 EEECEHM 43 THE PRIVATE EYE A new, revolutionary type of video display. Brian Fenton 54 CIRCUIT COOKBOOK Dual audio preamplifier IC's. Ray Marston El PAGE 43 75 BUILD THE PORT A MATIC Finish it up, and keep an eye on your expansion bus Robert Grossblatt EfflMms 6 VIDEO NEWS What's new in this fast- changing field. David Lachenbruch 17 EQUIPMENT REPORTS SonyCRF-V21 Visual World Band Receiver. 67 HARDWARE HACKER Cold-fusion kits. Don Lancaster 24 AUDIO UPDATE Hi-fi hearing aids. Larry Klein 72 DRAWING BOARD The video waveform. Robert Grossblatt 75 EDITOR'S WORKBENCH Modular IC programming system. Jeff Holtzman 96 Advertising and Sales Offices 96 Advertising Index 8 Ask RE 97 Free Information Card 14 Letters 83 Market Center 20 New Products 4 What's News m CD 33 C > CD CO O 07 y o I LLI _J LiJ 6 < (X HOW TO T(ST TDUB flADAJt DETECTOR BUILD THIS FREQUENCY PROBE *• mull MfK ■>***' If you do any kind of electronics troubleshooting on a regular basis, then a frequency counter is a must- have. The problem is that most fre- quency counters are too cumber- some to take along on a field job. However, our 100-MHz frequency probe will easily fit in your shirt pocket, and take accurate measure- ments. Turn to page 31 for details. T.T THE MARCH ISSUE GOES ON SALE FEBRUARY 1. BUILD A UNIVERSAL LABORATORY POWER SUPPLY Two fully floating supplies offer outputs of 0-50 volts DC at 5—5 amps, plus fixed + 5— volt logic supply adjustable from to 3 amps. THE ION METER Discover the concentration of negative and positive ions in your environment — it could be affecting the way you feel. BUILD AN AUDIO LIMITER Eliminates distortion due to overdriving an audio amplifier. ALL ABOUT BATTERIES Ni-Cd's, alkaline, carbon-zinc, lithium — which one is right for your application? AUDIO AMP COOKBOOK Dozens of practical IC audio power-amplifier circuits that are easy to build ComputerDigest A 68705-based, keyless entry system is programmed for top security! As a service to readers, RADIO-ELECTRONICS publishes available plana or information relating to newsworthy products, techniques and scientific and technological developments. Because ol possible variances in the quality and condition of materials and workmanship used by readers. RADIO.ELECTRONICS disclaims any responsibility for the sate and proper functioning of reader-built projects based upon or from plans or information published in this magazine. Since some of the equipment and circuitry described in RADIO-ELECTRONICS may relate to or be covered by U.S. patents, RADIO-ELECTRONICS disclaims any liability for the infringement of such patents by the making, using, or selling of any such equipment or circuitry, and suggests that anyone interested in such projects consult a patent attorney. RADIO-ELECTRONICS, (ISSN 0033.7362) February 1990. Published monthly by Gernsback Publications. Inc. 500-B Si-County Boulevard. Farmingdale. MY 1 1 735 Second-Class Postage paid at Farming dole, NY and additional mailing offices. Second -Class mail registration No. 9242 authorized at Toronto. Canada, One-year subscription rate U.S.A. and possessions St 7.97. Canada $23 97, all other countries $26.97. All subscription orders payable in U.S.A. funds only, via international postal money order or check drawn on a U.S.A. bank. Single copies S2. 50. C 1990 by Gernsback Publications. Inc. All rights reserved. Printed in U.S.A. POSTMASTER: Please sand address changes to RADIO-ELECTRONICS. Subscription Dept- Son 55115. Boulder, CO 80321-5115 A stamped self-addressed envelope must accompany all submitted manuscripts and/or artwork or photographs if their return is desired should they be rejected. We disclaim any responsibility for the loss or damage of manuscripts and/or artwork or photographs while in our possession or otherwise- Electronics Hugo Gernsback (1884*1967) Founder M. Harvey Gernsback editoMivchiet emeritus Larry Stockier, EKF, CET, editor-in-chief and publisher EDITORIAL DEPARTMENT Brian C. Fen ton* editor Marc Spivw — collabo- rating with scientists from the New Jersey Institute of Technology, the University of California at Davis, and Lawrence Liverrnore National Laboratory in California — -have created a silicon needle whose tip is 50,000 times smaller than the di- ameter of a human hair. Only the width of a few atoms at its tip, the needle could play a vital role in the resurgence of vacuum tubes, serv- ing as an electron emitter. The new vacuum tubes are quite different from their predecessors. Today's tubes are so small that they can only be seen through a micro- scope, and electrons are pro- duced in them by applying voltage to a very sharp tip, rather than using a hot filament. While the new vacuum-tube technology is still in its infancy, it could never- theless offer several advantages over transistors. Electrons can be made to travel much faster in a vacuum tube than in a solid-state transistor, permitting faster speeds for data transmission. Vac- uum tubes are also much less sus- ceptible to temperature changes and various types of radiation, so they might be more suitable for use in hostile environments such as those that are found in outer space and nuclear reactors. The problem facing researchers has been to create an emitter tip sharp enough to produce many electrons at low voltage. Until now, the sharpest tips were be- tween 20 to 40 nanometers wide. By applying an oxidation-treat- ment process to tiny silicon cones, the research team has developed tips that are less than 1-nanometer wide. (A human hair is 50,000-nm wide; the diameter of an atom is about three tenths of a nanometer.) The microscopic sil- icon tips can produce substantially more electrons while using less voltage. Besides vacuum-tube ap- plications, the needles could be used for examining atoms with scanning tunneling microscopes and as biological probes for medi- cal research. w u z o CE H O LU O Q < DC Diamond-film technology A new diamond-film-coating process created by Professor Roin- tan Bunshah, Dr. Chandra De- spandey, and colleagues at UCLA's School of Engineering and Applied Science offers key advantages over the deposition methods that are currently in use. The new technique removes obstacles that have limited the ap- plications of diamond-film tech- nology — particularly the inability to deposit high-quality, smooth, transparent, and no n -faceted dia- mond films. Called Plasma-As- sisted Physical Vapor Deposition {PAPVD), the process involves using an electron beam to evapo- rate graphite to form carbon va- pors. The vapors are introduced into a gas-plasma that contains hy- drogen. When the material to be coated is held in the gas plasma, the resulting reaction deposits a diamond film on the material's sur- face that has all of the required attributes. The process is also done at lower temperatures — 350°C, as compared to 85O-1G00 D C. The PAPVD process opens up a broad range of novel industrial ap- plications, including protection of high-cost infrared and UV optica! components, heat sinks for high- power and microwave devices, di- aphragms for high-fidelity loud- speakers, and very-high-speed microelectronic devices that can operate at temperatures much higher than current silicon and gallium-arsenide devices. R-E r Radio /haek Part/ Plaee 1 BIG SELECTION AND LOW PRICES— COME IN TODAY! join the Fun of Ham Radio Novice and General Class Study Packages Prepared by Gordon West, WB6NOA 19 95 Each Durable Storage Binder Included Novice. Two self-paced code cassettes, study guide with exam questions, answers and full explanations, FCC Form 610. #62-2402 General. 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Operates Viz to 3VDC About 1V2" long, •*s" dia. #273-223 99* Switch Bargains I 1 § I (.ii»w4 wH (1) SPST Momentary Button. #275-1556 1.99 (2) SPDT Toggle. 5A at 125 VAC. 7 /is" stem, #275-603 1.59 (3) SPST Push On/Push Off. 3 A at 250 VAC. #275-617 . . 1.39 (4) PC-Mountable Light-Duty SPST. #275-645 1.99 TNC Adapters in I •J (2) s (3) Here's just a sample of our selection of RF adapters. big F;:). ftcoBpta Plugs Into Cat. Md. Each *. 2 3 PL-259 TNC Male PL-259 Female TNC TNC Female Mini LI HF 278-116 278-143 ;?b 17.; 3.49 3.99 3.99 Soldering Accessories (1 ) Dual-Wattage Iron. Go from 15 10 30 watts wish Ihe Hick of a swilch. Has a replaceable tip and it's B'A" long. UL listed AC. S64-2055 8.9S Chisel Tip. #64-2056 1.19 Replacement Tip. #64-2065 99* (2) Vacuum Desoldering Tool. #64-2120 . . . 6.95 Battery Special-Order Service In addition to our large in-slore stock. Radio Shack can now supply almost any battery. Our expanding selection even includes special batteries for walkie-talkies and pagers. Batteries are sent from our warehouse to the Radio Shack near you. Never a postage charge! Super speaker Accessories (4) o- \ > HI (8 (s> (J (1) MEGACABLE". 12-ga. braided pure copper. #278-1268 Per Font 99* (2) Speaker Terminal Plate. For large speaker wires. Features special-design %" diameter knobs. Mounts in 3% x 2¥is" hole. #274-626 4.99 (3) One red, one black knob as above, less plate. #274-619 Set of 2/5.95 (4) Large Gold-Plated Terminals. 4 red, 4 black. #64-401 Set of 8/4.99 inductor values — if- (1) v (2) ' o) 91 m (1) 1:1 Audio Transformer, Z: 600-9000. #273-1374 3.59 (2) Audio Output Transformer. #273-1330 1.69 (3) Inductor Assortment, 30 pieces! #273-1601 . 1.98 Lighted Switches .* t |~ (2) (1} SPST. Rated 5A at 250VAC. In- cludes 12-volt lamp. UL listed. #275-678 6.99 (2) SPDT Push-On/Push-Off. Rated 3A at 125VAC. 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Major source countries were Thailand (mostly Emerson recorders produced there by Orion, a Japanese manufacturer), Malaysia (made by a JVC subsidiary there), and Singapore. How about the U.S.? A few VCR's are being assembled here from Japanese parts — by Matsushita (Panasonic) in Vancouver, WA; by Hitachi in California; and by Toshiba In Tennessee. In the same period, the major sources for imported color-TV sets were — in order of quantities — Mexico, Taiwan, Korea, Malaysia, Singapore, and mainland China. Japan came in seventh, followed by Hong Kong and Canada. Where did the U.S. rank as a source of color TV sets sold here? Despite what you might have read elsewhere, it was number one — ahead of all other countries. • New names in video. Two well-known audio names are entering the video field-— neither of them for the first time. Aiwa, which was a pioneer in Beta VCR's but has been out of the field for several years, is now moving back with VHS recorders. Aiwa, owned by Sony, will concentrate on high-end, four-head models. The company is also surveying the TV market, but has decided to stay out for the time being because of the tough price competition in that field. Sansui, however, plans to jump into the television-receiver as well as the VCR field with both feet. The venerable producer of high-end audio products had fallen on hard times, but recently received a fresh transfusion of capital from the British firm, Polly Peck International, which is acquiring 51% of Sansui stock in an extremely rare instance of a western firm acquiring control of a major Japanese company. Polly Peck, which produces consumer-electronics equipment in the Far East and Turkey, plans to DAVID LACHENERUCH, CONTRIBUTING EDITOR manufacture both TV sets and VCR's for sale under the Sansui label. Also in the works are Sansui-brand fax machines, Sansui once fielded VCR's without much success. • Movies on VHS-C? One of the top priorities of JVC, inventor of VHS recording, is lengthening the recording time of the miniature VHS-C (for "compact") cassette to two hours. To date, the recording time in the SLP mode on the longest playing VHS-C cassette is 90 minutes— not quite enough for today's long-winded movies. JVC obviously is concerned about the inroads of the 8mm Video Walkman, developed by Sony, which is extremely compact and can accommodate full- length movies with carry-along portability There are two Video Walkman models, both with LCD color screens. The VHS-C format is doing well in Japan and Europe, particularly for camcorders, but in the U.S. it Is lagging behind 8mm. In addition to a longer-playing cassette, another high priority for JVC is the development of a VCR tliat can play both VHS and VHS-C cassettes without an adaptor. Prototypes of those so-called "F/C" (Full-size/Compact) recorders have been shown and JVC hopes to have them on the market late this year or early in 1991. • SAP is rising. In 1984, when the FCC approved Multichannel TV Sound (MTS), the breakthrough involved more than stereophonic audio. In addition to stereo sound, each TV station was authorized to transmit a Secondary Audio Program (SAP). Although a few stations have transmitted bilingual sound, SAP has not been widely utilized. PBS's flagship station, WHET, New York, is aiming at virtually full-time SAP some time this year. Its first major use of SAP was for descriptive commentary for the blind accompanying the musical, "Show Boat." WNET also is planning to add a Spanish translation of the "MacHeil-Lehrer Hews Hour," and might even present the BBC World Service from shortwave transmissions — as well as music, book readings, and even countdowns for videotaping — all on its extra audio channel. Out of about 550 TV stations with MTS capability approximately 100 are equipped to transmit a SAP channel. R-E ONCE YOU'VE GOT IT DESIGNED, YOU'VE GOT IT MADE. Now you can take those hot, new logic or block design diagrams, and quickly, easily bring them up to reality... in minutes... without solder Build circuits as fast as you can think. Test. Modify. Expand. Without burned-out parts or burnt fingers. Save time, money... and prove that you know that you're talking about... before you use your CAD. Specify PROTO BOARD Brand, Today's rec- ognized Standard for Quality in breadboard- ing. Here are five expandable breadboards, offering countless arrays of solderless sock- ets and bus strips that emulate pc board lay- outs. Pop in components. Pop them out again. Microprocessors. Memory. Large DIPs. Tiny discretes. Makes no difference. The pat- ented aluminum backplane lets you work at Call toll-free for details 1-800-572-1028 frequencies from DC to half-a-GigaHertz or 500MHz. Need power? A powered PROTO BOARD Brand offers up to triple voltage power supplies. +5V, +12V, - 12V, with reg- ulated/current limited DC power. Over 2,250 tie points with 24 IC capacity and 14 pin DIPs. Super for TTL, CMOS, Op-Amps and microprocessor circuits. And lots more. Best of all, your hassle-free American-made PROTO BOARD Brand comes with an unlim- ited lifetime guarantee on all the breadboard sockets. Prices are so modest, you'll wonder why you waited this long to specify PROTO BOARD Brand- Order today. GLOBAL SPECIALTIES CIRCLE 184 ON FREE INFORMATION CARD mm-^mMf™ Global Specialties. An Interplex Electronics Company. 70 Fulton Terrace, New Haven, CT 06512. Telephone: (203) 624-3103. Vi Interplex Electronics 1989 All Global Specialties breadboarding products made in USA. MX) 10 Ask R'E WRITE TO: ASK R-E Radio-Electronics 500-B Bi-County Blvd. Farmingdale, NY 11735 to Q o DC H UJ Q < DC BINARY TO DIGITAL READOUT I'm looking for a circuit to con- vert 8-bit binary into a digital read- out. The solution is probably very simple and I'm just overlooking it. I'd be grateful if you could point me in the right direction. — H. Vaughn, Mt. Airy, NC. The easiest way is to use an EPROM to translate binary to decimal. Think of the address pins as inputs and use the data outputs to drive a 7-segment dis- play. Entering the binary number could be done via DIP switches, and the decimal equivalent would immediately appear on the display. Although that'd in- volve programming an EPROM, doing that is much easier now since most computer clubs, parts suppliers, and even some computer shops offer it as a ser- vice. The cost for such a service is minimal. The circuit you'd have to set up is something like that in Fig. 1. The parts count is minimal, and it could be built using any con- struction method. Since each EPROM output controls a display segment, the best way to create the EPROM code is to use a chart Hke that in Fig. 2. If you're usinga common-cathode display, as shown in Fig. 1, a high will light the segment, and a low will turn it off. Common-anode displays work just the opposite. That sub- ject was covered in considerable detail in recent issues of "Draw- ing Board," so you should look them up. DOS ON A MOTHERBOARD I have an XT clone with a spare FIG, 1 socket next to the one containing the BIOS EPROM. I've noticed that some manufacturers are building boards that have IBMIO.COM, IBMDOS.COM and COM- MAND.COM burnt into EPROM's on the motherboard. That lets the computer boot DOS immediately without loading from a disk. I'd like to do the same using the empty socket on my motherboard, but I haven't been able to get any infor- mation. Any ideas? — T. Dunn, No. Miami Beach, FL, Several, but first some obser- vations. I've never seen the ads you mentioned and, although I don't doubt you've seen them, I'd take them with a grain of salt. You're right in assuming that those three ROM files would give you a permanent DOS, but there are some things you're probably overlooking. IBM DOS (and IBMIO.COM and lBMDOS.COM which are part of PC-DOS) is owned ex- clusively by IBM. People sell it, but I've never heard of it being licensed for use in a PROM. IBM is very quick to jump on copyright infringement. MS- DOS is the version that's licensed to various manufacturers. The history of DOS and the reasons behind the two versions are in- teresting, but both are proprie- tary. Be careful that what you're buying is legal before you whip out your credit card. If it's legal, and you want to do the same thing yourself, you need some information on your motherboard's EPROM sockets. Although there's a wide variety of XT clone boards around (a gross Discover Your Career Potential In The Fast Growing Field Of High-Tech Electronics! CIE Gives You The Training You Need to Succeed... At Your Own Pace...& In Your Own Home! If you're anxious to get ahead ...and build a mi career... you owe it to yourself to find out about the Cleveland Institute of Electronics! CIE can help you discover your career potential in the fast growing field of high-tech electronics. A career that will challenge and excite you every day... reward you with a powerful feeling of personal accomplishment... and deliver a level of financial security you may have only dreamed of before! As the leading school in home-study electronics, CIE has helped over 150,000 students in the U.S.A. and over 70 foreign countries get started in this exciting field. To find out how CIE could be helping you,,. read on... then send for a CIE catalog TODAY! A Growing Need For Trained Professionals! 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Please send me your independent study catalog (For your convenience, CIE will have a representative contact you— (tee is no obligation.) Print Name . Address . Apt* City/ State/Tip Area Code/ Phone No. Check box for G.I. Bill bulletin on educational benefits: □ Veteran □ Active Duty Mail This Coupon Today! m CO c > 3 -< 10 (5 o 11 e/>xc/A4 TZt/r/j T/*Si-£. INPUTS O(STj0L/7-5 DATA DATA £>7 DP '0' 0S~ •P" D>3 "d' OX. £>/ Da DATA. /.££>' S L/T O 00 O O a / / / / / / JS^ OOO / / a O O O O / / O as / o 0/ ao// A, a / O / / / / s& -a •3 / O O / / / / 03 j FIG. 2 understatement), most have empty socket space to let them copy IBM's PC and XT mother- boards. The IBM boards had a strip- ped-down BASIC in ROM on the motherboard. When you bought DOS (you did buy it, I hope), you got a file called BASICA.EXE. That BASIC wasn't the complete lan- guage; it was an overlay that en- hanced the ROM version, that could only be run if you already had the more primitive half on the motherboard. Since clone makers want to produce clones, putting empty sockets on the motherboard was as close as they could legally get. Real IBM's have five64K ROM's on the motherboard, one for BIOS, and four for BASICO. Given that, you can assume that the empty socket on your moth- erboard is mapped to the same address range occupied by BASICO on the real IBM boards, or F6000h-FDFFFh. Since you only have one empty socket on you board, I'd guess that it was designed for a 27256 EPROM. That'd let one chip hold the same amount of code as the four 64K PROM's on the IBM board. That is just an educated guess, but a pretty good one. The BIOS, of course, is mapped from FEOOOh-FFFFFh. Unless your motherboard is radically different than those I've seen, its EPROM space is limited to 32K bytes (the addresses for BASICO), and the 8K bytes used by BIOS, or a total of 40K to play around with. Since DOS usually takes up at least 60K for DOS 2X, and 80K for DOS 3X, it'd take mir- rors and a lot of heavy equipment to squeeze both DOS and the BIOS into the available address space. But wait, there's more bad news. DOS was designed for a par- ticular place in memory, inside the 640K memory space. The EPROM space on your mother- board is way outside that, so you'd probably be faced with having to rewrite the DOS code (jumps, destinations, and any absolute address references). You could do that, but assuming you overcame those obstacles, you'd have a pretty strange ver- sion of DOS, and upgrading to a new version would be a Her- culean task. The basic con- clusion is, that you'll probably be better of if you boot DOS like the rest of us. R-E y z o s. F o LLI _J LLI o Q < 12 CIRCLE 191 ON FREE INFORMATION CARD HITACHI SCOPES AT DISCOUNT PRICES Digital Storage Scopes VC-6025 20MS/S 50MHz Bandwidth 2K Word Memory Capacity $2349.00 Advanced storage (unctions create new dimensions in scopes such as one shot observation, flicker free display. bright display for even high speed event, trace observation lor low speed event, hard copy by plotter and data output to computer VC-6045 100MHz 40MS.S 4K word Memory cap (call) Ail Hitachi scopes include probes, schematics, and Hitachi's 3 year worldwide warranty on parts and labor Many acces- sories available for all scopes- List|595 Save $160 DC to 20MHz Dual Channel V-1060 <1 ocq List $1595 * '' ja3 • DC to 100MHz • Dual Channel • Delayed Sweep • CRT Readout • Sweep Time • Autoranglng • Trigger Lock • 2mV Sensitivity 40 MHz 40 MHz 40MHI 60 MHz 1 COM Hi V-1100A 100MHz V-1150 150MHz LIST PRICE O.T.. 1 mV sens. DC Offset Ven Mode Trigger, Alt Mag *94u S740 D.T „ 1 mV sens, Delayed Sweep , DC Offset, All Mag $1 ,02S $825 D.T.. 1 mV sens. DC Offset, CRT Readout. Cursor Meas $1 .070 $849 D.T„2mV sens, Delayed Sweep. CRT Readout $1,295 $1,145 D .T, . 2m V sens, Delayed Sweep. CRT Readout, Cursor Meas $1,895 $1,670 Q.T., 1 mV sens. Delayed Sweep, CRT Readout, DVM, Counter $2,450 $2,095 O.T, , 1 mV sens. Delayed Sweep, Cu rso r Meas. DVM, Counla r $3.1 00 $2,675 SAVE $200 $200 $221 $150 $225 $355 $425 ELENCO PRODUCTS AT DISCOUNT PRICES 2QMHz Dual Trace Oscilloscope $375 MO-1251 > 6" CRT ■ Built In component tester 1 TV Sync FREE DMM with purchase of ANY SCOPE SCOPE PROBES 35MHz Dual Trace Oscilloscope $495 P-1 65MHz. U, 10x P-2 100MHz. 1x. 1 0n $13.95 $23.95 M0-1252 'CRT • High luminance 6 • 1mV Sensitivity • 6KV Acceleration Voltage • 10ns Rise Time • X-Y Operation * Z Axis • Delayed Triggering Sweep Top quality scopes at 3 very reasonable price. Contains all desired features. Two 1x, 10x probes, diagrams and manual. Two year guarantee. PRICE BREAKTHRU on Auto Ranging DMMs 3 to choose from: MDM-1180 $24.95 MDM-1181 $27.95 MDM-1182 $29.95 • 3 t/2 LCD Display ■ 27 Functions ■ Auto /Manual Ranges * Audible Continuity •Data Hold (MOM-11 82) ■ .1% Accuracy [MOM-1 181) True RMS A Vi Digit Multimeter M-7000 $135 ,05% DC Accuracy ,1% Resistance with Freq. Counter and deluxe case Bench DMMS M-3500 M-4500 3W digit $125 *V> digit 5175 .1% accy .05% accy Multimeter with Capacitance and Transistor Tester $55 CM-1500 Reads Volts, Ohms, Current, Capacitors, Transistors and Diodes with case AC Current Meter ST-1010 $69.95 1000 Amps Data&Peak Hold 8 Functions Deluxe Case Digital Capacitance Mater CM-155Q $58.95 9 Ranges ,1pf-20,000ufd ,5% basic accy Zero control with case Solderless Breadboards 9430 1,100 pins $15 9434 2,170 pins $25 9436 **c 2,560 pinsSaa Ail have color coded poets 9436 SHOWN Digital LCR Meter — LC-1801 $125 ^^JV Measures <^^' Coils 1UH.20OH siSXa Caps ■ 1 P , '2O0u' ! RBS.01-20M f AC Clamp-On Current Adapter ST-265 $25.00 0-10QOAAC Works with most DMM Wide Band Signal Generators SG-9DD0 $129 RF Freq 10OK-45QMHz AM Modulation of 1KHz Variable RF output SG-9500 with Digital Display and 150MHz built-in Freq Ctr 1249 TRIPLE POWEfl SUPPLY XP-620 I __ 4 Assembled $ 65 •« Contains all we desired features tor doing exparimsrils. Features short circuit protection all supplies 2 10 15V at 1A. -2 to -16V at 1A lor A to 30V at ia; and 6V at 3A Function Generator Blox moo $28.95 Provides sine.rn.squ wave Irom 1Hz to imhj AM or FM capability Decade Blox ■•■— ™- r #9610 or --! $18.95 #9610 Resistor Blox 47 ohm to 1M & 100K pot #9620 Capacitor Blox 47pt to 10MFD Digital Triple Power Supply XP-765 $249 0-20V at 1A 0-2QVat 1A 5V at 5A Fully Regulated. Short circuit protected with 2 Limit Cont.. 3 Separate supplies XP-660 with Analog Maters $175 Quad Power Supply XP-580 $59.95 Fully regulated and short circuit protected XP-575 without meters $39.95 2-20V at 2A 12V at 1A 5V at 3A -5V at.5A LEARN TO BUILD AND PROGRAM COMPUTERS WITH THIS KIT! INCLUDES: All Parts, Assembly and Lesson Manual MODEL MM-8000 Four-Function Frequency Counters F-100 120MH $179 F-1000 1.ZGH Frequency, Period, Totalize, JZaS Self Check with High Stabilized Crystal Oven Oscillator, 8 digit LED display GF-8016 Function Generator with Freq. Counter $249 $129.00 SiESM Sine, Square, Triangle Pulse. Ramp, .2 to 2MHz Freq Counter .1 ■ 10MHz GF-8015 without Freq. Meter $179 WE WILL NOT BE UNDERSOLD! fA C C AT F<% INC UPS 8hipplng:48St a iM5'i« czza _ - ^ 1245 Rosewoodi Deerfield, 1L 60015 (800) 292-7711 (708) 541-0710 [fiLtJSHOU! iPHlfilFil— " Starling from scratch you bus la a compete system. Our Micro-Master trains teaches you to write into RAMs, ROWS and run a 8085 microprocessor, whist uses similar mxhm? language as IBM PC You will write the initial Instructions to tall the A05& processor to get started and store Uiese instructions in perm anent memoiy i n a 261 6 E PROM . Teaches you all about input and outpu! ports, computer timers. Build your own keyboard: and learn now to scan keyboard and display- No previous computer luicwled-ge requied- Simple easy to understand in- struction teaches you to write in machine language. 15 Day Money Back Guarantee 2 Year Warranty ft** subi** ■<> o^s' WRITE FOR FREE CATALOG CD u c > DO -< 8 CIRCLE 109 ON FREE INFORMATION CARD 13 Put Professional Knowledge and a COLLEGE DEGREE in your Technical Career through HOME STUDY O z o a: F o in GRANTHAM College of Engineering 10570 Humbolt Street 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 computers. 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 us 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 o < Los Alamitos, CA 90720 Letters DIGl-COMPASS PARTS I've heard from a number of "Digi-Compass" builders (Radio- Electronics, November 1989) that the TLC-548 ADC \C is impossible to find. It has been discontinued by Radio Shack, although it's pos- sible that some stores may have still have a few available (part #276-1796, $6.95). As a special service to Radio- Electronics readers, I will supply the part for $6.95. Those who don't want to download the software file can also purchase that from me, for $6.00. (That might be cheaper than downloading the 100K file at 1200 baud from the RE BBS.) It will be supplied on a 360K PC data flop- py diskette. To order, please send a check or money order only (California resi- dents add 6.5% sales tax) plus $1.75 shipping and handling to Digital Products Company, c/o Thomas E. Black, 134 Windstar Circle, Folsom, CA 95630. This offer is subject to change and is valid for a short time only. Thanks for publishing my arti- cle. I'm thrilled that it has stirred up some interest. THOMAS E. BLACK Folsom, CA PCjr PROBLEMS As a long-time reader of Radio- Electronics, I'd like to say thanks. Over the years I have literally taught myself how to design, build, program, and implement my own single-board computers from the articles and information you have presented. I have used what I learned to advance my ca- reer from a simple warehouseman to an operational research techni- cian — and I'll be going back to school shortly to obtain the piece of paper that says I know what I know I know. It was your magazine WWW flWJfT muf WM¥W tsrrsxs #AD/0-EL£CTX OAf/c s SQO-M 3f-COi/A/rr 40tH-£ VAKG fAAM/MGML£, NY f/735 and the interesting projects and theories that your staff brings to attention that stirred my interest and helped improve my life. I owe you a great deal. Now, after all this time, I need to ask for some personal assistance from your readers and staff: I recently fell into a tremendous piece of luck, and purchased an IBM PCjr (Peanut) for $30.00 at a garage sale, I've decided to use this machine for a dedicated pro- cess control in real time. Does any- one know where I can obtain any documentation for hardwiring my own interface boards for its very limited expansion slots, or where I can get a pin-out designation for same? I contacted IBM and, after finally finding someone who even remembered the IBM PCjr, was disappointed to find that IBM no longer has anything to do with any attachments or peripherals. Il seems that IBM has virtually dis- owned the product. Thanks again for all your help. SHAWN D. BOBBITT 403 Green Street, #1 Martinez, CA 94553 UP TO DATE 1 was amused with Michael Catudal's letter (Radio-Eelctronics, December 1989), chastising the magazine for not keeping up with "new technology." In late 1995, the Galileo Probe will start its descent to a moon of Neptune. What will control its last 45 seconds before it is crushed by atmospheric pressure? Why, the venerable RCA 1802 micro- processor, of course. Remember 14 the old "Cosmac Elf"? As 1 recall, Radio-Electronics had a construction project on that in the 1970's ! ! I wonder if the project manager thought the designer was nuts when he saw the 1802 in the design. I think not. Keep up the good work. JOHN CONNELLY Naperville, It BELATED THANKS I just want to show my apprecia- tion for the article and BASIC pro- gram, "Coping With Coils," that appeared in the November1988 is- sue of Radio-Electronics. When I first got that issue, I didn't really look at the story, since I wasn't in need of any coils. Recently, how- ever, I had to calculate coil sizes for several inductances, and I hap- pened to remember seeing the program. I used it on my PC, and it worked much better than I ex- pected — particularly in that it lets you select various wire and form sizes to determine the best ar- rangement. Another thing I discovered from using the program was that there is a mathematical correlation be- tween AWS wire gauges and equiv- alent inch diameter. I always thought that gauge sizes were just arbitrary. It's one of the most useful programs I've ever worked with. J.F. BURTON Downers Grove, !L PC BOARD RECIPE I would like to share the results of my experiments with re-flow solder plating of homemade printed-circuit boards with other Radio-Electronics readers. After the board is etched, but before drilling, the resist can be removed with a little paint stripper, and the copper can be cleaned with a mix- ture of vinegar and salt. Solder can be smeared onto the PC board with a hot iron with a wide tip. Use a minimum of solder. At this point, the board looks ugly; the solder now needs to be re- flowed to provide a uniform solder surface. A hot bath of peanut oil (avail- able at the supermarket) can facili- tate the reflow process. I have found that heating the peanut oil slowly with the PC board sup- ported above the surface of the pan with standoffs works well. If the board rests on the bottom sur- face of the pan it will de- laminate • the fiberglass. I placed a piece of solder into the oil to determine when the temperature is high enough to reflow the solder; using a thermometer should work even better. The board can then be re- moved with tongs and wiped with a rag to remove the excess solder. It can then be dipped again to pro- vide a shiny surface. It can be cleaned with some kind of grease- cutting cleaner (like Era, liquid Tide, or Freon TF) to remove the oily film. That method will surely benefit those experimenting with surface- mount technology, I've tried elec- troless tin plating, but after build- ing circuits on reflow-soldered boards I'll never go back to un- plated copper or tin-piated copper again. RON DOZIER Wilmington, DE OPTOELECTRONICS You Have Counted on Us for 75 Years You have counted on OPTOELECTRONICS Hand Held Frequency Counters lo be the best quality, to be affordable and reliable. We have been there for you with Frequency Counters that are compact and ultra sensitive. And more and more of you are counting on us, technicians, engineers, law enforcement officers, private investigators, two-way radio operators, scanner hobbyists, and amateur radio operators, just to name a few. Hand Held Series Frequency Counters and Instruments MODEL 2210 1300H/A 2400H CCA CCB RANGE: FROM 10 Hz 1 MHz 10 MHz 10 MHz 10 MHz TO 2,2 GHz 1.3 GHz 2.4 GHz 550 MHz 1.8 GHz APPLICATIONS General Purpose Audio-Microwave RF Microwave Security Security PRICE $219 $169 $189 $299 $99 SENSITIVITY 1 KHz < 5 mv NA NA NA NA 100 MHz < 3 mv < 1 mv < 3 mv < .5 mv < 5 mv 450 MHz < 3 mv < 5 mv < 3 mv < 1 mv < 5 mv 650 MHz < 3 mv < 20 mv < 5 mv NA < 5 mv 1.3 GHz < 7 mv < 100 mv < 7 mv NA < 10 mv 2.2 GHz < 30 mv NA < 30 mv NA < 30 mv ACCURACY ALL HAVE +/- 1 PPM TCXO TIME BASE. All counters have 8 drgil red 26" LED displays Aluminum cabinet is 3.9" H * 3.5" x I*, internal Ni-Cad batteries provsde 2-5 hour portab.Ee operation wilh continuous operation (rom AC line charger/power supply supplied. ModeS CCft uses a 9 volt alkaline battery. One year parts and labor guarantee. A lull line Ql probes, antennas, and accessories is available. Orders to US, and Canada add 5% lo total (S2 mm. 3iQ max). Florida residents, add §% sales tax. COD lee S3. Foreign orders add 15% MasterCard and VISA accepted. Orders to U,S, and Canada add 5*to lo lotal (S2 mm, S10 max). Florida residents, add 6% sales tax,. COD lee S3. Foreign orders add 15%. MasterCard and VISA accepted. OPTOELECTRONICS INC, 5821 N.E. 14th Avenue • Fart Lauderdale, Florida 33334 1-B00-327-5912 FL (305) 771-2050 FAX (305) 771-2052 CIRCLE 186 ON FREE INFORMATION CARD ■n m 00 13 c > 3J -< —« to to o 15 PACKARD BELL Amvms grew up thtening lo us* it stitt does- PACKMATE 286 COMPUTER WITH VGA COLOR MONITOR 3^ * mb -i S 3-1/2" J 2-7 Erriw ' \^ a '" i £0286 microprocessor (operates at 12 MHz). » One 3-1/2" 1-44 MB floppy drive. • One 5-1/4" 1 .22 MB floppy drive - 30 MB hard drive. ■ 1 MS RAM on mother- board: expandable to 3 MB. - includes VGA 14" color monitor & VGA card. * High res. monitor: 480 x 600. & 256 colors, * IBM compatible. * AT compatible. • 8 expansion slots. - Dual FDD/HDD controller. - 2 half height drive cavities exposed. • 1 half height drive cavity enclosed. ■ 2 serial ports. * 1 parallel port. * System configuration in CMOS with battery back-up. - Included software: MS DOS 33 & GW BASIC ■ 145W Universal power supply, ♦ Socket for 80287 co-processor on motherboard. * Zero wait sEate. « One Year Warranty! ^SHSyWfactoSy PERFECT! Due to a special ar- rangement, we wrr-n able to obtain a large inventory ot these computers with color monitors. As a result. we can now offer them to you at HUGE SAVINGS! Manufacturer's Suggested Retail $3,449.00 I— a 1499 Item No. B-1 729-1 321 42 Insured Ship/Hand.: $39.00 I S FOR FASTEST SERVICE CALL TOLL FREE 1-800-729-9000 □A MARK INTERNATIONAL, INC. S707 Slrirrgle Creek Parkway. Minneapolis. MM £5430 Customer SaiYscc ■ 6 1 2-566 4940 Please rush me: Packard Bell Computers) @ $1439 each, plus $39.00 s* each. Item No.B-1 729-1321 42. MN res. add 6% sales tan. Name. City.Slate.zip _ □ ChwkiMO □ VISA □ Master Card □ Discover Card Mo Exp. Date Signature .Ph. » ( |_ NO MORE FRIED BATTERIES For those of you who have nu- merous handheld transceivers — and, therefore, numerous bat- teries—here's an idea for a battery- charger shutoff that 1 have used for some time. Obtain the "garden- variety" light-timer from any drug- store, market, or junkbox. Re- move the cam that turns the timer on, leaving only the off cam in- tact. Plug the battery charger into the timer and set the timer to the appropriate time (8 hours or what- ever). Then plug the timer in an AC outlet, turn the timer on manually, and forget it. The timer will turn it off but not on — thus, you won't have to deal with those fried bat- teries anymore. DON R. SMITH, K6CHS Palm Springs, CA AMATEUR VIDEO CONTEST The Western Washington Amateur Television Society (WWATS) and Amateur Television Quarterly (ATVQ) are sponsoring a contest for licensed amateur-radio operators. To enter, you must sub- mit by March 1, 1990 a video tape about ham radio that you make on your home video equipment (VH5, Beta, or 8mm). It can be about any aspect of ham radio, and can be a documentary, educa- tional, technical, or entertainment film. It must be less than 15 min- utes in length and be made using only consumer-grade equipment. All licensed amateur-radio oper- ators (except members and fam- ilies of members of WWATS and ATVQ and publishers and staff of ham-radio magazines) are eligible to win some fantastic prizes in- cluding an I COM IC 1275 1.2-C Hz transceiver and an ABA FS430 ATV transceiver. Entry forms and complete rules and regulations for the contest can be obtained by writing to the ad- dress below. WWATS/ATVQ VIDEO CONTEST 353 South 116th Street Seattle, WA 98168 R-E 1 1; \i5\ vc it CLEANING/MAINTENANCE/REPAIR EARN UP TO $1000 A WEEK.WORKING PART TIME FROM YOUR OWN HOME! DELIVERY TO 48 U.S. STATES ONLY THE MONEY MAKING OPPORTUNITY OF THE 1990'S IF you are able tu work with common small hand tools, and are familiar with basic electronics (i.e. able to use voltmeter, understand DC electronics). . . . IF you possess average mechanical ability, and have a VCR on which to practice and learn. . . .then we can teach YOU VCR maintenance and repair! FACT; up to 90% of ALL VCR malfunctions are due to simple MECHANICAL or ELECTRO-MECHANICAL breakdowns! FACT: over 77 million VCRs in use today nationwide! Average VCR needs service or repair every 12 to 18 months! Vlejos400 PAGE TRAINING MANUAL (over 500 pho- tos and illustrations) and AWARD-WINNING VIDEO TRAINING TAPE revealsthe SECRETS of VCR mainte- nance and repair — "real world" information that is NOT available elsewhere! Also includes all the info you'll need regarding the BUSINESS-SIDE of running a successful service op- eration! pREE | HF0RMAT | ON CALL TOLL-FREE 1-800-537-0589 Ot wile to: Viejo Publications Inc. 3540 Wilshire BL. STE. 310 Los Angeles. CA 90010 Dept. RE CABLE TV DESCRAMBLERS! BARGAIN HEADQUARTERS! ■ JEHROLD • TOCOM • HAMLIN • SCIENTIFIC ATLANTA • ZENITH Ock H3SB ONLY $60 6 month wnrenty! We ehip C.O.O.I Loweet re tail/who leaele price* I FREE CATALOG: Global Cable Network 1032 Irving St. Suite 109 S.F., CA 94122 ORDER TODAY! 800-327-8544 REMOVE VOCALS FROM RECORDS AND CDs! **U Sing With The World's Best Bands* An Unlimited supply of Backgrounds from standard stereo records! Record with your voice or perform live with the backgrounds. Used in Professional Performance yel connects easily to a home component stereo. This unique product \s manufactured and sold Exclusively by LT Sound - Mot sold through dealers. Call or write for a Free Brochure and Demo Record, LT Sound, DepLRL-3J980LT Parkway Lithonia, GA 30058 (404)482-4724 Manufactured and Sold Exclusively bv LT finnnd »"'■''■• iiila ±!U ULL CIRCLE 180 ON FREE INFORMATION CARD Equipment Reports Sony CRF-V21 Visual World-Band Receiver The first of a new breed of communica tions receivers. IF WE ASKED THE READERS OF TH IS MAG- azine what features they would want in a communications re- ceiver, we'd probably get a long and greatiy varied list. At the top of the list would be frequency coverage from below the standard broadcast band up through 30 MHz, followed by the ability to re- ceive AM and SSB signals. Un- doubtedly, extensive memory and scanning features would be a pop- ular request as well. We doubt, however, if many people would request the ability to decode RTTY (Radio TeleTYpe) and radio facsimile. Although those features are desired, they're not expected on a communica- tions receiver. Well, Sony Corpo- ration (Sony Drive, Park Ridge, NJ 07656) apparently ignored stan- dard expectations when building their CRF-V21. They've packed so many features in the receiver that it's likely to become the new stan- dard against which all other com- munications receivers are judged. sous i!1T4II Fit* J CI IS ttlMD ice commons and eoiecast foi the kstew unit ISSUED AT ISM LTC MTl'JUttr 22 JCLV 1WI 11 ESVIKBilffift CAKAOA ICE COTRI OTTtfi ici eke EsmtuB man tkj; coast keai keismeli ism D TO HSOS USBOt TO H40« UiSil tC> 7010S UMOl 10 CAPt BATIKS T losnr OPES TO VHV OPEN DtlFT INSIDE TIE ICE EDGE SCOT! OF I 01. THE Smtm EKE OMUAU ICE LIES AMIIT 50 IILES OFF TCI PES INSULA AND SBOn SO MILES OFF THE ALASLA COAST AS FA It IEST AS BASTEB ISLAM: «(lkST90IHVl SEP INCREASES TO ABOLT 101 MP LES HOITH, OF BA1K05 FIG. 1 CIRCLE 25 ON FREE INFORMATION CARD Basic specifications The CRF-V21 receives long-, me- dium-, and shortwave broadcasts from 9 kHz through 30 MHz; FM broadcasts from 76 through 108 MHz; satellite frequencies of 137.62 and 141.12 MHz; and, as- suming an optional dish is used, decode fax and RTTY adds another dimension to monitoring and DX- ing. Figures 1-3 give a good feel for the types of activity that exists on the airwaves. Figure 1 is a partial printout of a broadcast from Environment Can- ada that lists ice conditions for the western Arctic. Figure 2 is a trans- mission from the Naval Eastern Oceanography Center in Norfolk, Virginia that shows wave heights in the Atlantic. Figure 3 is a satellite image from GOES, the Ceostation- ary Orbiting Fnvironmenlal Satellite. While that is the sort of image that the satellite capability makes possible, we received the image as it was rebroadcast from Norfolk. We did not have the op- portunity to give the satellite ca- JfcttiMK*-* -t"< < z^^C iff? .-"tew ?'■■ -~^. /■' s 1 \ S -.* v ■ FIG. 2 1.691 and 1.6945 GHz. Audio-de- tection modes include AM wide, AM narrow, wideband FM, narrow- band FM, USB, and LSB. The CRF- V21 can also decode and print RTTY, radio fax, and satellite fax broadcasts. While most people are familiar with what is available on the stan- dard broadcast and shortwave broadcast bands, RTTY and radio fax is a mystery to most — most of us know only the sounds that such transmissions make. The ability to pability a workout. All the images here were received using Sony's active telescopic antenna, which is supplied as standard equipment with the receiver. Satellite recep- tion requires the optional AN- P1200 satellite dish. Microprocessor power The CRF-V21 offers a host of fea- tures that its microprocessor control makes possible. For exam- ple, up to 50 "pages" of memory can be stored. Each page can hold ■n m 03 3D c > < o 17 NEXT MONTH IN o z o DC F o LU < Exciting Features, Projects, Reports, & Columns • EXPERIMENTS IN • MODEL TRAIN AND ELECTROPHOTOGRAPHY SLOT-CAR CONTROLLER Explore the world of Kirlian photography, Lichtenberg figures, and more • RECEIVER CIRCUITS YOU CAN BUILD Cook up a radio that meets your needs with these useful circuits Build a model controller that outperforms many more-expensive commercial units • A VISION SYSTEM FOR ROBOTIC TOYS Give your robotic creations the gift of sight And there is more! PRODUCT REPORTS— zenith VM7150 Camcorder, MicroTac Soft- ware French Assistant, and more DX LISTENING— What's new at the Voice of America COMPUTER BITS— The king of the Pascal programming hill PICK UP CIRCUIT CIRCUS— Shortwave converters, active antennas, and RF filters and more HAM RADIO — Awards for award- winning hams SCANNER SCENE— DX pos- sibilities for scanner enthusiasts AT YOUR FAVORITE NEWSSTAND, CONVENIENCE STORE, OR SUPERMARKET. FIG. 3 up to seven stations, for a total of 350 stations. An identification tag can also be stored along with each page. We found that feature es- pecially useful for finding the best frequency for a given time. For ex- ample, in one page, we pro- grammed seven different frequen- cies on which the BBC broadcast. By calling up our "BBC" page, we found that we were able to easily switch between the seven entries to find the best possible reception conditions. On another page, we stored some stations we happened across on the 25-meter band. Rather than listen and log the transmission times, we decided to let the re- ceiver do the work for us. Using simple menu-chosen commands, we instructed the receiver to monitor the frequencies on that memory page for a 12-hour period. A printout of the activity is shown in Fig. 4. It shows rather clearly that there is a five-hour period where little activity takes place. While any active shortwave lis- tener knows when the 25-meter band is active, that particular fea- ture is invaluable when you're try- ing to determine the broadcast times and signal strength of, for example, a news bureau's wire ser- vice transmissions. 18 Of course, most SWL's would never be content in letting the re- ceiver find stations to listen to. But even as you hunt around the bands finding new stations, the CRF-V21 has ways to make the task of logging easier. A single push of a button will feed all of the display information to the built-in high- resolution printer. A sample printout, which also serves to il- lustrate the amount of information that the receiver's huge LCD read- •- .FAX 8. 080 3mhz P •SCAU R8E: '/««; irDP iBI«.:!B!z ■;«EEB:l2B 'SEE :<1 _ ■Sffll :BSP •SinF1;«B ■I ill u : ;: -: »■■;- E . BWCI L 5H;F * 4 '-'~*:l ''**:'- ¥ :: /i T FIG. 4 out supplies, is shown in Fig. 5. The receiver offers three scan- ning modes. First, it's possible to scan through the entire frequency range of the receiver. The receiver has enough "smarts" to change FIG. 5 the scanning steps and reception mode based on the frequency. For example, in the range between 88 and 108 MHz, the receiver would automatically set the reception mode to wideband FM, and the step frequency to 50 kHz. (It is pos- sible to override any of the pre- sets.) The second scanning mode allows the user to select the upper and lower limits between which scanning will take place. The third scanning mode scans only those stations stored in memory. As if those scanning modes aren't adequate, Sony adds yet an- other way to search for broadcast- ing stations: a spectrum analyzer. Any part of the receiver's frequen- cy coverage can be examined in spans of 200 kHz, 1 MHz, or5 MHz. Fig. 6 shows a display of the activity of a 200-kHz segment in the 25- meter band. It is also possible to use a pointer to tune into only those stations that are strong enough to guarantee good recep- SPEANA 9- •SPAN FREQ:290kHz 8- 7- ■MARKER FREQ: 6- S +- 9- 8- 7- 6- 5- 4- 3- 2- 1- j j i 11.753 et-'HzRB --■ ■ " d- 2- 1- ■ L START: 1 ■ ■ .759 8MHz • ■ ■ SIOP:11.950 9MHz 3PAN uSEHHlARKER RECEIVE I P ™ I I FIG. 6 tion. To those of us who take noise, interference, and fading as a necessary consequence of short- wave listening, the ability to by- pass inter-station static and to stop at only clear, strong broadcasts is almost eerie. We had a lot of fun examining Sony's CRF-V21. This review only touched the surface of the re- ceiver's capabilities. For example, we've mentioned only a handful of the receiver's 7 knobs, 10 jacks, and 59 pushbuttons (many of which serve several different func- tions). If not for the $6000 price tag, we'd buy one tomorrow. Despite the price, we expect that there is a market for this inno- vative receiver. The most enthusi- astic shortwave enthusiasts will want one, as will, perhaps, gov- ernment and embassy personnel, and navigators. R-E MORE THAN LOGIC 286 SupersPort Laptop by Heathkit Your logical source for quality computer and elec- tronic product needs, the FREE Heathkit Catalog is your key to a fun and exciting hobby. The Heathkit Catalog contains powerful kit laptop and desktop computers, test instruments, weather equipment, and home theater components, plus self-study electronics courses. Order your FREE Heathkit Catalog today! It's the logical thing to do! n -800-44-HEATH (1-800-444-3284) Send to: Heath Company, Dept. 020-854 | Benton Harbor, Michigan 49022 Name Address L Cily Slate Zig | ^ A subsidiary of Zenith Electronics Corporation | to A subsidiary of Zenith Electronics Corporation CIRCLE SG ON FREE INFORMATION CARD 19 N ew Products VIDEO/ALL-CHANNEL GEN- ERATOR. Providing more than 80 test patterns, Leader Instruments' model 408 gen-lockable NTSC Video Test Signal Generator out- puts in composite, S-VHS, RGB, Y, R-Y, and B-Y formats with RF channel coverage of all broadcast and cable channels. A sampling of those test patterns includes multiburst, video sweep, 5MPTE color bars, modu- lated and unmodulated staircase, convergence, and Crosshatch. A menu-driven, multi- purpose data-control panel with LCD is used to set up channel frequencies and video signal-level specifica- mz^mz^^^^^mm^ CIRCLE 10 ON FREE INFORMATION CARD tions. On-screen program- ming makes the 408 easy to use. Control of key video- signal levels — -such as burst, sync, luminance, chromi- nance, and setup — is pro- vided, along with RF-fre- quency selection. As many as 100 sets of video-level specifications can be stored in memory, ready for instant recall. The model 408 multi-for- mat video/all-channel gen- erator costs $3,395.00. — Leader Instruments Corpora- tion, 380 Oser Avenue, Hauppauge, NY 11788; Tel. 1-800-645-5104 (in NY, 516-231-6900). DIGITAL PANEL METER. A battery-powered, 3K>-digit panel meter, the DP-176S from Ace u lex, offers true single-ended (built-in nega- tive rail generator) input and very wide primary- power operation — from + 3.5 to +7.5 volts DC at only 145 mA. That extremely low power drain allows up to 8000 hours — one year — of continuous operation from any battery source in that range. The meter can also be used for mobile, portable, and other applica- tions using a 12-volt DC au- tomotive-type battery with voltage divider. It is easy to mount, requiring only a small screwdriver; an op- tional bezel kit is available, co The DP-7765 uses a highly ^ accurate, dual-slope-inte- O grating ADC in conjunction fE with a single-ended input, ^ an integral DC-to-DC con- rj verter, and common-mode O rejection ratio of 85 dB. It g can be configured for ana- rr log inputs from ±200 mV 20 ffiHB CIRCLE 11 ON FREE INFORMATION CARD through ± 200 volts DC. The enhanced-contrast LCD has user-selectable deci- mal-point placement, exter- nal-reference capability for ratiometric measurements, and an all-digits test pin for checking full functionality. Other features include au- tomatic polarity change- over, over- and under-range indication, 100-megohms input impedance, and an in- put-offset adjustment. The DP-I76S digital panel meter costs $64.00; the op- tional bezel kit {B-1B) costs $3.00. — Acculex, A Metra- Byle Company, 440 Myles Standish Blvd., Taunton, MA 02780. RADIO VCO'S Z-Comnumi- cations' D-900 Series of 700- to 1000-MHz Voltage-Con- trolled Ocillators (VCO's), based upon coaxial reso- nator technology, are de- signed for use in cellular phones and for commercial and military radio applica- tions, where low noise and high stability are required. The series has exceptional phase-noise characteristics of -95dBc/Hz at 1 kHz, -105dBc/Hz at 5 kHz, and CIRCLE 12 ON FREE INFORMATION CARD -120dBc/Hzat25kHz. The VCO's tune ±20 MHz from the user-specified center frequency. A modulation port has sensitivity of 0.3 to 0.9 RMS ±10% flatness, and maximum modulation dis- tortion of 3%, for audio- modulation rates of 5jQ Hz to 5 kHz. The D-900 's have buffered outputs of +3 ±2 dBm and operate off 8- o re- volts DC at 25 and 40 mA, respectively. The com- pletely enclosed VCO's have a standard operating- temperature range of to 70° C. They are also available with an extended military temperature range of 55 to 105° C. Sample units of the D-900 each cost $85.00.— Z-Com- munications Inc., 5450 NW 33rd Avenue, Ft. Lauder- dale, FL 33309. AC CURRENT METER. De- signed for use by hobbyists as well as electricians, ser- vicemen, and technicians, csT J CIRCLE 13 ON FREE INFORMATION CARD Elenco's ST-10IQ AC current meter is reliable and com- pletely portable. It mea- sures AC current up to 1000 amperes, and has nine func- tions: AC and DC volts, re- sistance, AC current, diode test, data hold, peak hold, audible continuity, and in- sulation test (with an op- tional 500-volt insulation- tester unit. The hand-held instrument features a Vh- digil LCD readout, a wrist strap, and a tarrying case. It runs for 150-200 hours on a standard 9-volt battery. The ST-1010 AC current meter costs $99.00. — Elenco Electronics, Inc., 150 West Carpenter Avenue, Wheel- ing, I L 60090. DATA-ACQUISITION SYS- TEM. Hewlett-Packard's HP 75000 System 10 is a data-ac- quisition package that re- quires no programming to collect data and obtain re- suits. All the necessary mea- surement hardware and menu-driven software to at- tach to a personal computer are included in the system. For a total solution, a PC/ printer option is available that provides the user with an HP Vectra PC and an HP Quietjet printer. System Ws hardware in- cludes a 5^-digit multi- meter and a thermocouple- relay multiplexer for accu- rate temperature measure- ments on as many as 16 thermocouples. Two other multiplexers are also in- cluded, providing more than 100 channels of high- accuracy measurements. Two counters are available: a 4-channel counter mea- sures counts, frequency, period, pulse width, inter- val, and up/down counts on signals up to 4 MHz and a 3- channel counter measures those same functions (ex- cept up/down) to'IGHz.A4- channel digital/analog de- vice allows users to output either voltage or current on each channel, A built-in quad 8-bit digital I/O card allows the system to conlroi devices and sense whether they are on or off. An HP 75000 B-size cardcage con- tains five empty slots that can be used with a variety of other plug-in measurement cards. Additional cards can be factory installed if they are ordered at the same time as the system. LABTECH NOTEBOOK data-acquisition software is used. The flexible, menu- driven package allows users CIRCLE HON FKEE INFORMATION CARD to set up mmli pie-scan lists that can be scheduled to be- gin at user-determined times and executed at user- determined rates. The dis- play can be customized, and data can be stored in various formats. An on-line learning aid is included. Color graphics screens show the user how to attach transducers to the System 10 and how to create setups on LABTECH NOTEBOOK. The software contains both Fast Fourier Tr a n s f o r m a n d curve-fit analysis routines, and a seamless link to Lotus 1-2-3 is provided if you wish to do custom analysis and data sorting. The HP 75000 System 10 costs $5,750.00, and the PC/ printer option costs an addi- tional $4,650.00.— Hewlett- Packard Company, Inquir- ies, 19310 Prune ridge Ave- nue, Cupertino, CA 95014; Tel. 1-800-752-0900. COMPUTER/CONNECTOR HARDWARE. Collections of computer and connector hardware — consisting of turnable jack screws, "D" subminiature jack screws, and captive screws — are of- fered by Keystone Elec- tronics. The Turnable jack Screw selections, primarily used to secure computer connections, are available in a variety of configurations and are supplied with or without screwdriver slots. The turnable jack screws have knurled heads and are available in lengths from 1.75 to 4.5 inches with 4-40 threaded lengths, and in 0.125- to 0.250-inch diame- ters. They are made of steel with a choice of black zinc- plate, yellow chromate, or nickel-plate finishes. The "D" Subminiature jack Screws include 0.250- , 0.312-, and 0,625-inch lengths, and are made of CONNECTION PROTECTION QV/TC. & SOCKETS PLUGS PO^ ^ ^ ~tlN G CA' && CRAMOLIIU co^ eC * T£RM(N AL STRIPS G°LD PUTTED Even the finest equipment in the world cannot guarantee noise-free operation. One "flirty" connection anywhere in the electrical path can cause unwanted noise or signal loss. "MORE THAN A CONTACT CLEANER" CRAMOLIN ' is a fast-acting, ami-oxidizing lubricant that cleans and preserves all metal surfaces, including gold. 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CIRCLE 127 ON FREE INFORMATION CARD REMOVE IC'S FASTER with this simple in- vention than any other method, including $6,000,00 vacuum desoldering stations. Sal- vages hundreds of good IC's per hour from junk boards, and also speeds up repairs. Won't damage IC's or circuit board. Removes 6 thru 40 pin IC's. This is a money making labor saving tool. Order now. Complete set ot 8 desoldering bits $89.95. VRS ELEC- TRONICS, P.O. Box 813-R, Selmer, Tenn. 38375. (601) 287-1594. ORCLE 183 ON FREE INFORMATION CARD GET YOUR RECHARGE CATALOG FREE...EARN BIG $$ IN YOUR SPARE TIME— All supplies and Do-lt-Yourself kits with complete instructions available. Sup- plies cost from $9.95 in qty and you can sell recharged toner cartridges for $40.00 to $55.00 each. Printers include HP LaserJet and Series II, Apple LaserWriter, QMS, etc. Canon PC-25 Copier also. CHENESKO PRODUCTS, 62 N Coleman Rd., Cen- tereach, NY 11720, 516-736-7977, 800-221-3516, Fax: 516-732-4650 CIRCLE 190 ON FREE INFORMATION CARD ACTUAL SIZE The REGEN-I module maintains the volume level of amateur, business (Police, Fire, Power, Fleet, etc.), CB, marine radios and scanners. The REGEN-i will amplify signals and attenuate a strong audio signal keeping volume at a nearly constant level regardless of incoming signal strength and reduce un- squelched FM hiss. Simple installation. $49.95 phone orders OR $39.95 Pre-paid, mail orders only. EMULATION ASSOCI- ATES, 520 GLEN BROOK RD, STE 203-B, STAMFORD, CT 06906 SALES: 203- 356-1632 FAX: 203-323-9044 CIRCLE 192 ON FREE INFORMATION CARD AMAZING POCKET REFerence.: 480 pages of tables, formulas, constants, con- versions and maps and it fits in your shirt pocket! (3.2" x 5.4" x 0.6") Chapters include Electronics, Computers, Math, Tools, Glues & Solvents, Chemistry & Physics, Con- struction, Carpentry, Geology, Hardware, Au- tomotive, Air, Water, Welding, Plumbing, Pipe. 1 -800 Airlines, Area Codes, Money, and much, much more. $9.95 + $2.00 shipping (Colorado inc. 56c tax). Check/Visa/MC. Se- quoia Publishing, Inc., Dept. 951, P.O. Box 620820, Littleton, CO 80162. 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. CABLE TV CONVERTERS AND DE- SCRAMBLERS SB-3 $79.00 TRI-BI $95.00 MLD-$85.00 M35B $89.00 JRX-DIC $129.00 Special combos available. We ship COD. Quantity discounts. Call for pricing on other products. Dealers wanted. FREE CATALOG. We stand behind our products where others fail. One year warranty. ACE PRODUCTS, P.O. Box 582, Saco, ME 04072 (207) 967-0726. CIRCLE 75 ON FREE INFORMATION CARD 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 battery! Up to Vt mile range. Adjusta- ble from 70-130 MHZ. 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 IBllSfJIIIiBfflilHK TEST EQUIPMENT HAS SURK COME A long way since the days of the bulky analog meter. The newest generation of portable test gear boasts features that would make technicians of a decade ago green with envy. Single instruments can measure everything; voltage, re- sistance, capacitance, logic levels, and even frequency. In fact, an en- tire test bench of equipment can now be packed away in a shirt pocket, and carried easily to the source of the trouble. As good as those new meters are, they still have a few limita- tions that can be rather disconcert- ing at times. Frequency measure- ment is a good example: the highest range on most portable D MM -si zed instruments is usu- ally less than 1 MHz, and the 3-!/: -A-V2 digit LED displays on most meters don't offer much resolu- tion. It seems as if most manufac- turers add frequency measurement as an afterthought. As newer de- signs hit the market, those short- comings will improve. Bui why wait? You can build the frequency probe described here. It offers benchtop performance at a frac- tion of what you'd expect to pay. The frequency probe is a unique combination of a logic probe and an 8-digit, 100-MHz frequency counter. It uses only three IC's. 100 MHz PROS Our 100-MHz frequency counter offers benchtop performance in a pocket- sized logic-probe case. MICHAEL A. LASHANSKY w o z c DC 1- o LJ _i 111 o o < tr TABLE 1— FREQUENCY PROBE SPECIFICATIONS Parameter Measurement Range Input Sensitivity Maximum Period Logic High Logic Low Supply Voltage Maximum Current Input Impedance Waveform Type Any Sinusoid Square Any Any Any Any Any Any Condition Unmodified PC Board, XTAL1 is 1 MHz Modified PC Board (see text), XTAL1 is 1 MHz Unmodified PC Board, XTAL1 is MHz Modified PC Board {see text), XTAL1 is 10 MHz N/A N/A N/A N/A N/A N/A N/A n/A Performance {*) Frequency 00000.000— 99999,999 X 1 kHz, 10-s gate 000000.00— 099999.99 X 1 kHz, 1-s gate 00000.000— 0999.999 X 10 kHz, 1-s gate 000000.00— 009999.99 X 10 kHz, 0.1 -s gate Period 00000.500— 99999.999 X1 \iS, 1 0-s gate 000000.50— 099999.99 X 10 (jls, 1 -s gate 00000.500— 99999.999 X 10 jiS, 1 -s gate 000000.50— 099999.99 X 1|j.s, 0.1 -s gate 35 mV p-p 50 mV p-p — 2 MHz 3 VDC 1.8 VDC 4.5-15 VDC 190 mA DC 51 ohms (*) NOTE: Ail leading zeros are suppressed during normal operation of the frequency probe for both frequency and period measurement, and are re- produced here merely for illustration. and fits in a standard logic-probe case, modified for the purposes of the 8-digit LED display. Table I lists the probe's specifications. It features switchable AC/DC coupling and both frequency- and period- measurement capability. The builder of the probe can modify the useful frequency range by selecting a different crystal, and can also modify the gate time (or sampling time) by making a simple PC-board modification. The effects of the modifications are summarized in Table I, and we'll discuss how they're made shortly. The probe can be powered either by the circuit-undcr-test, or by con- necting its leads to +9-volts DC. Building the probe isn't difficult, but it requires care and patience, because the components are very tightly packed. Circuit operation Figure I shows the block diagram of the frequency probe. The input can be AC- or DC-coupled to the divide- by- 10 prescaler, whose output is fed to the main counter section and the LED display block. That counts the pre- scaler pulses, and includes the neces- sary logic for the 8-digit LED display. The logic block indicates with LED I and LED2 which coupling mode is in use, and indicates logic levels. The frequency-probe schematic is shown in Fig. 2. SI either DC -couples the input through Rl, or AC-couples it through CI. The center pole of SI goes to the clock-pulse input (cp) of ICl , a National Semiconductor 1 1C90 prescaler. The HC90 is an ECL di- vide-by-10 prescaler, uses +5 volts, has TTL-output, and operates over a DC-650 MHz bandwidth with only an RF-bypass capacitor on V cc , In- put sensitivity for AC -coupling is 350 mV p-p from DC- 1 00 MHz. and 250 mV p-p above 100 MHz. The frequen- cy response of the 1 IC90 is shown in Fig. 3, but that's the guaranteed mini- mum, and actual performance can ex- ceed it substantially. S2 is located between the frequency counter and the LED display, and selects between the frequency- and period-measure- ment modes. Triggering is simplified in ICl by connecting the reference terminal (pin 15) to clock pulse (pin 16). By doing so, the probe input is automatically centered about the input threshold. A 50% duty cycle gives the fastest oper- ation, and since the flip-flops are mas- ter-slaves with offset input thresholds, there are no minimum frequency re- strictions. That ensures that the cir- cuit will operate with inputs with very slow rise and fall times. The 11C90 can divide-by- 10 or -1 1 depending on the levels on pins I and 2 (mi and M2). A logic low on those pins places the divider into divide-by- 11 mode, while tying them high produces divide- by-10 mode, ICl is enabled by tying pin 1 (chip enable) and pin 14 (async MASTER SET) low. There are two V KK terminals (pins 12 and 13). The TTL output operates from the same V cc and V EE levels as the counter, but a separate pin is used for the TTL V Ht -. That minimizes noise coupling when the TTL-output switches, and reduces power con- sumption by leaving pin 12 open when the ECL outputs are used. Be- cause the IC operates linearly with the transistors always on, the current drawn can go up to 80 mA, with 35 mA typical. Thus, the IC's run pretty warm, but heat-sinking isn't needed. The TTL-output of ICl is pulled up to CMOS levels by R6 and connected to the clock input of IC2, an ICM72I6B frequency counter. The 721 6B has gating, timebase, latching, decoding, and 8-digit LED display- driver circuitry. In addition, the 72I6B measures period, frequency ratios (f A /f B ). time intervals, or total 32 AC SI -O^HjUPUNG 1C1 DIVIDE-BY- 10 PRESCALER IC2 FREQ COUNTER LATCH LED DRIVERS S2{ ®LED1 (GREEN1 OSPV FREQUENCY^ LED DISPLAY ) PERIOD OSP2 □ □ □ □ .u.u.u.u □ IZl □ o .U.U.U.U FIG. 1— FREQUENCY PROBE BLOCK DIAGRAM; the input is either AC- or DC-coupled to the divide-by-10 prescaler (IC1) then sent on to the counting (IC2) and LED display (DSP1 and DSP2) blocks. counts. Due to limited space, only the frequency and period functions were used. The 7216B has a 10-MHz crystal timebase, and accepts inputs up to 10- MHz, which are divided internally bv 10 5 . Inputs are gated with that clock for a period determined by the range input (pin 14) setting, and passed to the main counter. The range; input automatically adjusts the LED display decimal place, and allows longer gate periods for lower frequency inputs. When presealers like IC1 are used, XTAL1 should be scaled accordingly. Thus, the input was divided-by-10 using IC1 and a 1-MHz crystal. That multiplies the internal gate time by 10 (from the original range times), al- lowing 1 00- MHz measurements with 1-Hz resolution. Also, the 7216B has 10-ms, 100- 55°C 200 400 600 800 1000 INPUT FREQUENCY • MHi FIG. 3— SENSITIVITY OF IC1 AS A FUNC- TION of sinusoidal input amplitude in mV p-p vs. frequency, for -55°C, 25"C, 75°C, and 125°C. ms, 1-s, and 10-s gate times. Selec- tion of the gate time and decimal- point location is achieved by con- necting the range input (pin 14) through RIO to digit-driver terminals DI-D4 (pins 4-7). The digit-drivers are time-multiplexed with the range, con- trol, external decimal point, and func- 9 s a d b c f 0SP2 NSB3831 f C h d a e g LSD .u. .L) D4 02 D3 01 f c b d a e g dp iORIG PC B0AHD v FOIL N CONNECTION) (MODI- FIED A PC 80ARQ FOIL CONNECTION) 1!) * M 13 16 tS •>, II VI 12 2 a D4 D3 D2 Dl I c b 7(1 22 15 23 g dl IC2 ICM7216B osc GND HOLD 25 C4 \i 60pF R9 100K IF ■5V- FIG. 2— SCHEMATIC DIAGRAM FOR THE FREQUENCY PROBE. Note the dotted line connecting R10 with pins 5 or 6 of IC2; that variable connection controls the decimal point and total count appearing on DSP1 and DSP2. The relative intensities and durations of ON/OFF time for LED1 (green) and LED2 (red) give a rough indication of logic level and duty cycle. m 3 CO 33 CO o o cr H O LU g < en tion selects to save on pin count. The range was fixed at 1 s, or ! 00 counts of the 10-Hz reference counter (100 Hz/10). That gave a 10-s gate time, which is inconvenient at times, but necessary for I -Hz resolution from DC-100 MHz, without using space- grabbing range-select switches. To achieve a l-s gate, you can either modify the PC board by connecting the range input (pin 14) to D2 (pin 6). or you can use a 10- MHz crystal. If you modify the PC board, the decimal place shifts one digit right (XXXX- XX. XX instead of XXXXX.XXX). and the least-significant digit means 10 Hz, not 1 Hz. The interpretation of the display remains as multiples of 1 kHz, but the absolute range of the probe increases from 10 MHz to 100 MHz. To do that, cut the foil on the component side from pin 5 of 1C2. and solder a jumper from the foil side to pin 6. If you change the crystal frequency, the decimal place stays unchanged (XXXXX.XXX before and after); the LED display value reads in multiples of 10 kHz instead of 1 kHz. A 1-MHz crystal provides a 10-s gate, and a 10- MHz crystal provides a l-s gate. The longer the gate, the more accurate the measurement, but the measurement itself will take longer. If you use a 10- s gate, the probe might slip off a con- nector or IC pin before the 10 seconds are up. The best of both worlds would be to go with a 10-MHz crystal, because you'll save some money ($2.00 for 10-MHz vs. $12.00 for 1-MHz), and you'll also be able to take quicker, easier measurements. After all, a 10-s gate isn't that much more accurate than a l-s gate, as to warrant the addi- tional cost (see Table 1). The 7216B crystal goes between pins 25 (osc in) and 26 {osc out) in parallel with R8. Pin 26 goes to V cc through C3; use a nonpolarized (NPO) version to minimize frequency drift due to temperature. Trimmer C4 on pin 5 lets the user adjust the os- cillator output to 1 MHz for maximum accuracy. S2 selects the counter oper- ating mode ( frequency or period). The pole of S2 is connected through R7 to the function input (pin 3) of IC2. In the period position, S2 goes to D8 (pin 12), so 1C2 is in period count- ing mode. In frequency position, S2 is connected to di (pin 4). Also, R7 and R8 prevent false triggering due to AC-coupled signals from the multi- plexed digit drivers, which is a prob- lem at higher multiplex frequencies. Next, DSPI and DSP2 are each 4- digit, common-cathode, multiplexed LED displays with the segment anodes wired together to form a single LED display. Each digit has a separate cathode which is sourced by IC2. Current-limiting resistors aren't needed with NSB3881 LED displays, but if a high-efficiency LED display is substituted, use 40-ohm resistors on the segment drivers. The LED display multiplex rate is directly related to the crystal frequency. For a 10-MHz crys- tal, the multiplex rate of the LED dis- play is 500 Hz; the 1-MHz crystal yielded a 50-Hz rate. As was shown in Fig. 2, pin 28 (hold) is grounded through R9, which pulls pin 28 low, and allows the internal counter con- tents to be displayed after each mea- surement cycle. Power is supplied by IC3, a Nation- al Semiconductor 2940 low- voltage dropout +5-volt regulator. Ordinary voltage regulators need an input volt- age at least 2 volts above the desired output. The 2940, however, needs only an additional 500 mV, so if you put in 5 volts you're guaranteed 4.5 volts out. That's a must for the fre- quency probe, since it's supposed to operate from 4.5-15 volt supplies. ICI and IC2 need from 4.5—6 volts max- imum, so some voltage regulation is needed. That's not a problem if you attach the power leads to 12 volts, but the probe may be rendered useless when measuring 5-volt signals, be- cause the output of a +5-voit reg- ulator with a 5-volt input will be a maximum of 3 volts. The 2940 is, however, noisy, and needs a filter capacitor, sometimes on each side. The output capacitor (C3) takes up considerable PC-board space. The level-indicating circuit composed of Q I, Q2. R2-R5, LED1, and LED2, is a easy way to indicate logic levels and the position of SI. The probe tip goes to the base of Q I through R2, and when brought low or allowed to float, Ql is cutoff and Q2 conducts, since the base is positive with regard to the emitter. With Q2 conducting, LEDI should light. Touching the probe to a logic high makes Ql and Q2 complement states (Ql conducting and Q2 cutoff), and LED2 should light. That feature indicates the position of SI since, in DC-coupled mode, the reference voltage of ICI is coupled through Rl and R2 to the base of Ql. That's about 3 volts (a logic high), so LED2 should light. In AC-coupled mode, no DC voltage from ICI is passed to the base of Ql, and it's al- lowed to float (a logic low), so LEDI lights. That's a useful way of visually checking the coupling mode with no signal applied. When a low frequency is applied, LEDI and LED2 should light, and a rough idea of duty cycle, whether high or low, can be made by inspection. Construction "tou should use the PC board in the kit (see the parts list), because it's double-sided with plated-through holes. If you wish to etch your own, foil patterns are given in PC Service. Before soldering the PC board, use a metal file along the edges to get it to FIG. 4— THE FREQUENCY PROBE CASE. Cutout dimensions for DSPI, DSP2, and C4 are shown in (a). Cutout dimensions for SI and S2 are shown in (b). 34 PARTS LIST All resistors are Vs-watt, 5%, un- less otherwise indicated. R1— 470 ohms, 'A-watt R2, R3— 4700 ohms R4— 100 ohms, '/4-watt R5 — 150 ohms, Vi-watt R6— 3000 ohms R7, R10— 10,000 ohms R8— 10 Megohms, Vi-wati R9— 100 ,000 ohms R1 1—560 ohms, 'A- watt Capacitors C1 — 0.47 p.F, ceramic C2 — 0.1 )j.F, ceramic C3— 33 pF nonpolarized (NPO) ce- ramic C4— 15-60 pF trimmer (Active Com- ponents # 17016} C5— 22 n-F. tantulum Semiconductors IC1 — 11C90 National Semiconductor 650-MHz, divide-by-10 prescaler IC2— ICM7216B Intersil 8-digit, fre- quency counter/timer IC3— 2940 National Semiconductor + 5-volt regulator Q1, Q2— 2N2222 NPN transistor DSP1, DSP2— NSB3881 National Semiconductor 4-digit, 7-segment LED display LED1 — green light-emitting diode (miniature) LED2— red iight-emitting diode (min- iature) LED3 — yellow light-emitting diode (miniature) Other components XTAL1— 1- or 10-MHz crystal (case size HC49) S1, S2— SPDT switch (Active Com- ponents # 22196} Miscellaneous: Logic-probe case with probe tip and clip leads (Global industries # CPT-1), sol- der, wire, etc. NOTE; A complete kit of parts, log- ic-probe case, and carrying case is available for $139.95 U.S. or $159.95 Canadian from Tristat Electronics, 66A Brockington Crescent, Nepean, Ontario, Can- ada K2G 5L1, (613) 225-9883. The kit without the PC board is $117.95 U.S. or $137.95 Canadian (Visa orders welcome). The PC board alone is $22.00 U.S. or $25.00 Canadian. All orders re- quire $6.00 for shipping and handling. The sources for cer- tain components are Active Components, 1023 Merival Road, Ottawa, Ontario, Canada K12 6A6, (613) 728-7900, and Electrosonic, 1100 Gordon Baker Road, Willowdale, On- tario, Canada M2H 3B3, (416) 494-1555. LED3 \\ YELLOW o « PROBE ^SS ft , W~ 0.1 ^•lyiBOBaaBBBCflBiili Mitiag Baaoaci a DSP1 0SP2 D8 D7 D6 05 D4 03 02 Dl 1 16 1 16 FIG. 5— THE PARTS-PLACEMENT DIAGRAM for the frequency probe, showing the foil (a) and component (b) sides. In (a), both 1C3 and XTAL1 are bent flat. lit in the case. If you're using the case in the parts list, clip the four plastic standoffs extending from the top with a pair of wire cutters as close to the base as possible. Next, cut the open- ings for the LED display and switches in the case as shown in Figs. 4-« and b. The case is polyethylene, so it can be CLit initially with an X-acto knife, and finished with a jeweler's file or emery board. Solder SI andS2 first; clip the leads so their length is identical to that of the pads. Next, place each on top of its pads, and secure with solder, tweezers, or tape. Solder the three terminals to the pads, and repeat for the other switch. The bodies of SI and S2 should fit snugly into the recess in the PC board, and the fronts of both switches should line up with the edge of the PC board. Then, solder all parts except IC3 and LED1-LED3, which go on the foil side. When soldering a component on a two-sided PC board without plated-through holes, you must solder the leads on both sides of the board . You must also solder short pieces of wire through any holes that do not have component leads going through them. Mount C2 on the foil side, leaving a slight space. Solder the leads as they go through the com- ponent side, clip as close as possible. SOLDER LUG PROBE TIP SOLDER FLUSH WITH BOARD . BOARD s& FIG. 6— TO MOUNT THE LOGIC PROBE TIP onto the frequency probe PC board, file Ve-inch of the bottom of the hex-nut- shaped solder lug flat down to the cen- terline of the logic probe tip, Then, solder it flush to the correct pad on the compo- nent side of the PC board. and inspect for poor solder joints. Care here will go a long way to having the probe work on power-up. Next, install XTAL1; it lies flat along the PC board surface, so bend the leads at a 90° angle as close to the crystal housing as possible. Use heat- shrink tubing or electrical tape to in- sulate the housing against the foils. Next, solder R8, ICl, and 1C2, insert- ing from the component side, and sol- rr der all the pins on the foil side. Solder i the rest of the component-side com- > ponents , paying attention to the parts- -c placement diagram of Fig. 5-a and b. £ Also, R2-R7 and RIO are mounted c 3i w o z o IT F O LJJ o D < FIG. 7— YOU MUST CONNECT pins 2, 7, 8, 11, 12, 13, and 16 of DSP1 to the corresponding pins of DSP2 using wirewrap. FIG. 8— THE PROTOTYPE OF THE FREQUENCY PROBE; note the callouts. Views are shown from the component side (a), edge-on showing the header strip for DSP1 and DSP2 (b), from the foil side (c), and edge-on showing C4, 1C2, IC1.S1 andS2, from left to right (d). vertically, and Rl, R9. and Rll hori- zontally on the PC board. The foil layout forC4 should accept different size trimmers, but they shouldn't exceed 0.5-inch in height or diameter. Strip l inch of insulation from the leads of the alligator clips. Solder the white stripped lead to the positive pad on the foil side, and the black lead to the negative pad. The probe tip should be 0.125 inch down to its center line as shown in Fig. (j-a, and soldered flush to the component side as shown in Fig. 6-b. Once the probe is soldered, let it sit for awhile because it'll get pretty hot. The 8-digit LED display is com- posed of two National Semiconductor NSB388I 4-digit displays DSP1 and DSP2, and their segment anodes have to be wired together to form one com- plete display. Insert a 32-pin, single in-line male header through the un- derside of the LED display boards (LED side up), so that the LED dis- play sits on the header insulation strip. Solder the LED display to the header from the top; don't apply excessive heat, or the LED display pads may lift. Using wirewrap or fine insulated wire, connect the pins of DSPI indi- cated in Fig. 7 to the corresponding pins of DSP2. If you use wirewrap. use 4—5 turns because you'll need to leave about 14- inch of header pin bare to insert into the PC board. Wirewrap is recom- mended, and once the pin has been wrapped, a little solder will ensure that the connection is sound. Once DSPI and DSP2 are wired correctly, insert the header into the PC board until the back of the LED display board touches the top of 1CI and IC2. and solder the header in place. Fig. 8 shows the prototype from several perspectives, with component callouts. Fig. 8-« was taken from above and shows DSPI, DSP2, and the component side of the PC board . Fi nected to the emitter, and you must < determine which they are. Use an ^ ohmmeter if you are not sure. (The o 37 w G z O o < a: 38 FIG. 2— PARTS-PLACEMENT DIAGRAM. Resistor R1 must be in a different location, depending on whether you're building an X- or K-band unit. Also, when aligning the unit, the strip line must be cut in a different location depending on the type of unit. emitter leads are the only two that will exhibit a dead short from one to the other.) Cut off the left-hand emitter lead, as shown in Rg. 2. After removing the extra lead, place the transistor in the hole on the board so that the base lead is on the strip line and the collector lead is on the positive bus, and solder them in place (see Fig. 2). Place R2 on the board and, keeping both leads as short as possible, solder one of its leads to the remaining emitter lead of Ql. The other resistor lead should go through the hole in the PC board, and soldered on both sides (a through hole, if you will). A scrap piece of component lead must go through the other hole on the left side of the board, and also soldered on both sides (another through hole). Cut one lead of Rl so that it's Sc- inch long. Refer to Fig. 2 for proper placement of Rl for either the X or K band. Then solder the shortened lead of Rl to the strip line so that the re- sistor is standing on end. The longer lead of the resistor should then be soldered to the positive bus of the PC board (see Fig. 2). Using a silicone adhesive, glue the PC board into the enclosure that you have selected. DO NOT use a metal enclosure. The microwaves need to escape from the box, and you will PARTS LIST R1 — 10.000 ohms, '/4-watt resistor R2 — 470 ohms, fe-watt resistor Q1— MRF-901 Motorola transistor for X band, or NE68137 California Eastern Laboratories transistor for K band. B1— 9-volt battery S1 — push-button switch PC-board material — 6 x 6-inch piece of 0.0158-inch thick teflon-fi- berglass (Taconic Plastics, part number TLT-9-0150-C1/C1) Plastic project case Note: A complete parts kit is avail- able from MICROSERVE, 60 Thompson Street, Maynard, MA 01754. Besides the parts, the kit also includes a custom plastic enclosure with an integrated battery holder and decorative face plate. X-band kits are $55, and K-band kits are $65. Ship- ping and tax extra. Spare parts list available on request. Motorola Semiconductor Products 3102 N 56th St. Phoenix, A2 85018 602-952-3000 or 800-521-6274 California Eastern Laboratories 3260 Jay St. Santa Clara, CA 95054 408-988-3500 Taconic Plastics LTD. Petersburg, NY 12138 518-658-3202 defeat the entire project by using a metal box . Be sure to orient R I so that it's closest to the front of the hox, because most of the radiation is emit- ted from that point. Attatch the battery and switch as shown in Fig. 2, being careful not to reverse the polarity. Route wires away from the strip line and components, because stray wires can de-tune the oscillator. Construction is now com- plete and you are ready to tune the transmitter (see Fis. 3), FIG. 3— GLUE THE PC BOARD into the plastic enclosure using a silicone-type adhesive. Alignment To align the unit, you will need a radar detector and an X-acto knife with a fine blade. Turn on the radar detector and the tester. Now make an initial cut in the strip line starting at the point specified in Fig. 2 for either the X- or K-band unit. Be sure to cut all the way across and through the copper trace. If your detector does not sound an alarm, make another cut about Mi-1-inch closer to the transistor. At some point your detector will sound an alarm, and the tester will be properly tuned. Be careful not to cut too much at one time, because if you go too far you will have to carefully solder the line back together. However, if you go just a Utile too far, you can save some work by cut- ting nicks in the remaining strip line (cuts that go part way across the strip line). That has the effect of making the strip line electrically longer. If you find that your range is limited you may have tuned to the wrong har- monic resulting in low output. It will be necessary to experiment with dif- ferent line lengths to achieve max- imum range. %ur tester is now ready for use. Simply hold the unit near a detector and turn it on. The range of the X- band transmitter is about 12 feet, while the range for the K-band unit is about 5 to 10 feet. r-e D P^^OM ACOUSTIC FIELD GENERATOR Our AFG will turn any livingroom into a full-sized movie theater or concert hall. f -^ R LAST TIME WE DISCUSSED Till-. ARTS CIR- cuitry. So. by now. you must be anx- ious to experience its special sound e Heels. Without further ado, let's continue with complete construction details. Construction All of the electronic components are mounted on a single PC board as shown in Fig. 9. The board can be made using the foil pattern provided in PC Service or purchased from the source mentioned in the parts list. Only the power transformer, the input and output jacks, and the function switches are mounted off-board. The chassis shown is readily avail- able, but it makes for a rather light fit. If you plan to use a similar chassis, study the pictures of the prototype carefully before drilling. If you choose a different chassis, keep all the leads between jacks, switches, and the circuit board as short as possi- ble. Locate the power transformer as far away from the circuit board as pos- sible to avoid 60- Hz hum. If you must mount the transformer near the circuit board, wait until your unit is opera- tional before you choose a final posi- tion for the transformer. Then, while listening, you can try the transformer in different positions until you find a location where no hum is coupled into the circuit. Begin stuffing the board by mount- ing all of the fixed resistors and the small potentiometers. Note that R35 and R69 arc mounted upright. Next mount the 1C sockets. Position each socket's pin 1 identifier so that it matches the small dot indicating pin I on the circuit board (do not insert the IC's into their sockets at this time). Next mount ihe capacitors. Please note where polyester and metal-film capacitors are called for in the parts list. Do not substitute ceramic capaci- tors; they perform poorly in audio cir- cuits and their use will destroy the performance of the AFG. Also, don't substitute polarized electrolytic ca- pacitors where bi-polar units are spec- ified in the parts list. Using some of the excess leads clipped from the capacitors, install bare jumpers where indicated, except for the six long jumpers. The two long jumpers in ihc audio power amplifier should be made from insulated heavy- gauge wire, as they carry relatively high current — no. 18 will do. The other four long jumpers in the decoder section should be made from lighter gauge insulated hookup wire. Finish stuffing the circuit board by installing Dl. D2. IC7-IC10. and the three large potentiometers, R77, R78, and R79. You can plug in the IC's now, but you should take static- electricity precautions with them. Finish up the wiring between the PC-board pads and the switches, the input/ output jack panel, the speaker terminal jacks, the power transformer, and the pilot LED. Use shielded ca- bles for the leads to the input/ output jacks. Try to keep all wiring as short and direct as possible to avoid crosstalk and hum. Use no. 18 or heavier wire for the speaker connec- tions. To simplify construction, the prototype used inline fuse holders in the positive speaker leads and the power transformer primary circuit, as indicated in the schematics. The power-supply regulator IC's are being operated very con- servatively and thus do not require heat sinks. However, the LMS875T audio power amplifiers must always be operated w r ith a heat sink. Failure to use a proper heat sink will cause the IC's to quickiy overheat and possibly destroy themselves. Although they contain on-board circuitry to shut them down in case of overheating un- der normal operating conditions, it is best to leave fate untempted and re- frain from operating the AFG until after the heat sink has been installed. The heat sink used on the prototype was homemade from a 2- x 2- x Sc- inch thick piece of aluminum angle stock cut 5S4-mehes long and notched out in the front to fit over R77. If you use a commercially made heat sink, be sure that it provides about 8 to 10 square inches of surface area for each IC. Assuming that you are using a homemade heat sink like the one shown, temporarily position it so that the bottom edge is even with the bot- tom of the IC cases, or about 3/8" above the circuit board. Be sure that it does not touch Dl . Mark the heal sink where the holes in the IC tabs fall and drill mounting holes at those points. In order to provide additional sup- port, holes were also added at the top comers of the heat sink in line with the PC-board mounting holes. 3-inch screws with double sets of nuts were then used to mount the PC board as well as to hold the heat sink in place. Carefully examine the photographs that are shown in Fig. 10 to see how that was accomplished. Because the metal tab of the LM1875T is not at ground potential. CD 30 C > 33 < to o PARTS LIST w a z o cc H O W 6 Q < All resistors 1 /4-watt, 5%, except as noted. R1— 1500 ohms R2, R3, R54— 22,000 ohms R4, R5, R32, R33— 1000 ohms R6. R7, R61, R62, R74— 20,000 ohms R8, R9— 1 ohm, Vj-watt. 5% R10-R13, R19, R34, R35— 47,000 ohms R14-R17, R20-R25, R47-R49, R55, R56— 100,000 ohms R18, R57— 330,000 ohms R26-R31, R66. R70— 150 ohms R36-R43, R67— 8060 ohms, 1% R44~R4e— 16,000 ohms R50, R51— 5600 ohms R52— 2400 ohms R53— 8200 Ohms R58-R60, R63-R65, R71-R73— 10,000 ohms R68— 9530 ohms, %-watt, 1% R69— 102,000 ohms, '/.-watt, 1% R75, R80— 100,000 ohms, potentiometer R76— 10,000 ohms, potentiometer R77 — 50.000 ohms, PC-mount potentiometer R78, R79— 1000 ohms, PC-mount potentiometer Capacitors C1-C4— 2200 nR 25 volts, electrolytic C5, C6— 10 |j.R 35 volts, radial electrolytic C7-C12, C19-C22, C27, C28, C30, C31, C45, C49, C58— 0.1 jjlF, 50 volts, metal film C13, C14, C23, C24, C43— 2.2 |jlR 50 volts, bi-poiar radial electrolytic C15, CI 6— 22 jaR 16 volts, bi-polar radial electrolytic C17, C18— 0.22 u.R metal film C25, C26— 0.047 p.R metal film C32-C34— 3300 pF, polyester C36, C37— 2700 pR polyester C38-C41— 270 pR 5% ceramic disc C42, C47— 0.47 \xF, metal film C44 — 120 pF, 5% ceramic disc C46 — 0.56 (J.R metal film mica insulators and piastic shoulder washers must be used between the cases of the IC's and the heat sink. Use a small amount of silicone grease between the IC's and the heat sink to increase thermal conductivity. Make sure that the tabs of the IC's are actu- ally insulated from the heat sink be- fore operating the unit. Although adequate, the heat sink becomes moderately warm during operation, so be sure to provide good ventilation in your chassis. C48— 0.039 ixR metal film C50— 0.012 rxF, metal film C51, C56—0.01 nR metal film C52— 1000 pR 5% polyester C53-C55--0.027 p.F, metal film C57 — 5600 pR 5% polyester C58— 4700 pR 5% polyester C59— 470 pR 5% ceramic disc Semiconductors D1 , D2— 1 N5400 50 PIV 3-amp diode IC1-IC4— LF347 quad JFET IC5— MN3008 2048-stage bucket brigade device IC6— MN3101 2-phase clock IC7— 7812T +12-volt regulator IC8— 7912T - 12-volt regulator 1C9, IC10— LM1875T audio amp LED1— light emitting diode pilot lamp Other components T1 — Power Transformer 25.2 Volt Center Tapped 2 Amp. F1-F3 — 1-amp fuse J1^J8 — 8-pin RCA-style jack panel J9-J12 — 4-position pushbutton speaker-terminal panel S1, S2, S5— SPDT switch S3. S4— DPDT switch Miscellaneous: speakers of your choice, 5 14-pin IC sockets, 1 8-pin IC socket, 1 heat sink (2x2x5'A- inch aluminum angle stock), 2 T0-220 mica insulators with mount- ing hardware, silicone grease, 3 in- line fuse holders, 3 knobs, chassis, linecord, solder, etc. Note: The following items are available from T3 Research, Inc., 5329 N. Navajo Ave,, Glendale, Wisconsin 53217-5036: An etched, drilled, and piated PC board, $15.00; a basic parts kit consisting of all semiconduc- tors, resistors, and capacitors, $55.00; a piece of aluminum stock for the heat sink, $3,00. Please include 52.50 for postage and handling with your order. Wisconsin residents please in- clude appropriate sales tax. Setup and operation Figure 1 1 shows one method of inte- grating the AFG into a home audio- video system. As mentioned earlier, a separate power amplifier is required fur the subwoofer channel, in addition to the subwoofer speaker itself. In the setup in Fig. 1 1, the center channel is connected to the audio inputs of a monitor-style television receiver which has provisions for amplifying external line-level audio signals. If your TV set doesn't have audio in- puts, or if you use the AFG in a mu- sic-only system, you'll have to provide a separate amplifier and speaker for the center channel as well. Please note that although the sub- woofer-channel and center-channel speakers are a desirable part of any audio system, they are not absolutely necessary. The AFG may still be used as an excellent surround-channel de- coder simply by adding a pair of small speakers for the surround channels. The best place to patch the AFG into your system is between the pre- amplifier outputs and the power-am- plifier inputs of your receiver or am- plifier. Most component receiver/am- plifiers allow for that connection by providing removable jumpers be- tween the appropriate phono jacks on their rear panels. By placing the AFG in that loop, all the audio signals se- lected by the amplifier will also pass through the AFG. Furthermore, the volume and tone controls of the main amplifier will have control overall the levels in the system simultaneously; i.e. the subwoofer, sunnund speak- ers, and the center channel, as well as the regular left and right speakers. If your amplifier doesn't provide pre- amp out/main input jacks, you may still use the AFG by connecting it into a tape-monitor loop, or even more simply, to the audio output of a stereo VCR: but then you will have to adjust the levels of the subwoofer and sur- round channels independently of the main amplifier via the level controls on the AFG. Calibration of the AFG is easy. Be- gin by setting, R75, R76, and R3U to their center positions. Now feed a mono signal into the AFG from some source in your system {an FM tuner switched to mono operation is a good choice). Set the balance control on your amplifier to its exact center mark. With the AFG switched to the matrix position (L-R), adjust R80 for the minimum output from the sur- round speakers. Now switch the re- ceiver back to stereo and the AFG to concert (L + R). Adjust R76 for mini- mum distortion. R75 provides a means for matching the drive level of the AFG delay section to your sys- tem's normal audio levels. The BBD delay line has a maximum recom- mended input-signal level of 1 .5 volts. To maximize the signal-to-noise ratio of the delay amplifier, the signal go- ing into the delay line should be as high as possible without driving it 40 i\*.E%2 9— ALLOFTHECOMPONENTSmountonasinglePCboardasshown. FIG. 10— THE HEAT SINK AND PC BOARD are installed as shown. Two 3-inch screws with double sets of nuts are used to mount the PC board on one side and hold the top of the heat sink in place (a). Two shorter screws hold down the other side of the board (b). Be sure to use spacers to prevent the board from touching the metal cabinet. into distortion. While using the high- est normal level you are likely to feed the AFG, adjust R75 to obtain the maximum level that does not cause distortion. The speakers you choose for the surround channels don't have to match your front-channel speakers in sonic characteristics. The frequency response of the surround channe! is limited at the time of encoding to a bandwidth from approximately 1 00 Hz to 7 kHz by the Dolby process. Small bookshelf-style speakers mounted toward the rear of the room at ear level or slightly above are ade- quate. Although it is customary to use two speakers for the surround chan- nel, one placed to the right rear and one to the left rear of the listening position, the surround channel signal that feeds those speakers is really monaural. The internal power ampli- fiers in the AFG drive the signal to the two rear speakers 180 degrees out of phase. That tends to spread apart the sound field created between the rear speakers. However, that may or may m on ID C > CO CO o 41 Experimental Science Incredible two volume set from 1906. Build cameras, phonograph, hydraulic ram, Geissler tube, mi- 1 croscope, batteries, lenses, much, much more. Classic how-to refer- ence. Over 1000 pages. Two volume set only $34.95! OFFICIAL 1934 Shortwave Manual Build simple but powerful short- wave radios from plans in ihis 1934 handbook. Includes new chapter showing how to use transistors to replace tubes! Heavily it lustrated paperback! Excellent! Only $14.95 MANY OTHERS: Static Electricity $5.95, Electrical Designs $11.50, Experimental Physics $23.95, Storage Batteries $8.95, Power inverter Technology $4.00, Arma- ture Winding & Motor Repair $16.95, 50 Perpetual Motion Mechanisms $3.75, more! See Catalog! ORDER FROM THIS AD TODAY! Check, MO, Visa, MC. Handling: 75« first book, 25 1 each additional- Money- back guarantee. OR WRITE FOR A CATALOG! Write for your copy of Lindsay's unusual Electrical Books catalog and see for yourself what you've been missing! Send $1.00 (US & Canada) or $3,00 foreign air- mail. We'll send your catalog immediately! Write today! IM — r a£CiracAL SBS- BOOKS o z o or o L.I < rr 42 ! Lindsay's Electrical Books , PO Box 12-WA7, Bradley II 60915 I II Send the books marked and a free catalog! ~\ Send just a catalog! $1 .00 enclosed... I Name I I Address I | City St Zip J FIG. 11— HERE'S ONE METHOD OF INTEGRATING THE AFG into a home audio-video system. A separate power amplifier is required tor the subwoofer channel, in addition to the subwoofer speaker itself. not sound well in your listening en- vironment, depending on such things as speaker placement and actual lis- tening position, "ion may restore the speakers to in-phase operation by simply reversing the leads connected to one of the speakers. Try setting up both ways to find which sounds better to you. Note that phase integrity is maintained through the AFG for the left, right, center, and subwoofer channels. Actual level adjustment of the sur- round channels, center channel, and subwoofer is a subjective process. The source material itself, the listen- ing area, and personal preferences for tonal balance must be taken into ac- count. Use the AFG in the matrix and wide modes for surround-encoded movies. Use the concert mode to add ambience and depth to musical per- formances. Generally speaking, don't set the level of the surround channel so high as to make it over- whelming. The surround signal is in- tended to supplement the main channel, not to be a separate channel that is always equal in level to the front channel. That is particularly true for surround-encoded movies. The delay of the surround signal can be adjusted via R77 from about 5 to 35 milliseconds. In matrix opera- tion, delaying the surround signal tends to acoustically mask any leak- age of front-channel information into the surround channel. Setting R77 to the center of its range provides a delay of approximately 20 milliseconds, which is about right if your listening position is between 10 and 20 feet from your television screen and your surround speakers are located just to the left and right of that position. However, if your surround speakers are located any farther than that, sub- tract I millisecond for each added foot. Likewise, add I millisecond for each foot less. For concert operation, adjust the delay for a pleasing am- bience effect. R-E ILM^MM^L 7 Despite its size, you'll be seeing a lot of a new display called the Private Eye. It promises to change the way we look at portable computers, TV's, video games, and more. [F SOMEONE WERE TO SUGGEST REPLACING your computer monitor with a 1-inch display, you'd probably consider that person crazy. But that's exactly what Reflection Technology, a Waltham, Massachusetts-based company would like to do. Actually, no one — including Re- flection Technology — thinks that computer monitors will be replaced by their display called the Private Eye. But just as Sony's Walkman cre- ated an entire new category of stereo equipment, this "Walkman for the eye" promises to do the same for many other products. Pocket-sized computers arc only the first to hit the market. But just imagine the advan- tages of an oscilloscope display that is worn in front of your eye. Or imagine what the next generation of portable video games — with a true three-di- mensional image — will be like. Although the Private Eye is inno- vative, the technology it uses is nei- ther new nor dramatic. Instead, the display is a new combination of exist- ing technologies. At its heart is a hybrid circuit consisting of a column of red LED's and driver circuitry, along with a magnifying lens and a mirror. While those components are certainly not exotic, the way they're used, and the results, are impressive nonetheless. The entire display mea- sures slightly more than 1 X I X 3Vi inches and weighs 2 1 /: ounces. It can display text and graphics at a resolu- tion of 720 x 280 pixels, which is slightly better than a Hercules com- puter monitor. Total power consump- tion is just Vi watt. The idea of peering at a l-inch dis- play might not seem too comfortable. However, the Private Eye is a virtual screen display that creates an image larger than the screen itself — in this case 50 times larger. The user sees a completely readable, full-size, 12- inch screen by looking into a l-inch window. The image appears to be floating in the air a few feet in front of the user. The result isn't as strange as the description sounds. The user isn't aware that the screen's plane of focus is a distance in front of him. Rather, he simply sees a perfectly readable screen that he doesn't have to strain to look at, despite the fact that it is only a couple of inches away from his eye. It's all done with mirrors As shown in fig. I, the main com- ponents of the display are a column of LED's, driver circuitry, a magnifying lens, a mirror, a counter weight, and a case. At first glance, a column of LED's might not seem to be a logical way to create a display. The common ques- tion is, "Why not just use a matrix of LED's?" Unfortunately, while LED's are bright, efficient, fast, inexpen- sive, and easy to manufacture, current manufacturing technology is not ad- m CD 33 c > CO •■£ a 43 Take any BOOKS only values to s 168,40 when you join the ELECTRONICS ENGINEERS & DESIGNERS BOOK CLUB® o z o -C to to o 47 w o z I O LU _J LJ 6 Q < COUNTERWEiGHT/MAGNET SPRINGS(2I FIG. 1— A HIGH-RESOLUTION DISPLAY is packaged in a housing that measures about 3.5 x 1.2 x 1.2 inches (a). The heart of the display consists of an LED column, a magnifying lens, and a mirror (b). vanced enough to produce a matrix that is dense enough. An elegant solution was devised using a column of LED's, which can be manufactured reliably in long, dense arrays. Of course, a single col- umn of LED's is not very useful as a computer display. But instead of try- ing to add dots (pixels) by brute force to make a matrix, the developers of the display combined the single LED column with a scanning mirror and magnified the result. One column of dots is shown at a time, and the mirror is moved to spread the single column across the full screen as the pattern on the column changes. As shown in Fig. 2, that makes it possible to create the perception of a full-screen display. To improve the picture's resolution, two columns are used instead of one. They are laid out as a staggered, or zig-zag, array. The individual LED's (pixels) alternate between the col- umns. To create a single image, each LED column is illuminated at a slightly different time to allow the mirror's movement to combine the columns, making the pixels appear to touch each other, top-to-bottom. The image that results from this "hard- ware interlacing" is a solid field with- out any of the blank interrupt lines that are normally seen tin a CRT. Apparent brightness is achieved not by overpowering ambient light, as in most other displays, but by putting the display in a light-tight enclosure. The image appears as vibrant, high- contrast red characters on a deep black background. While the LED column is impor- tant to the success of the display, the scanning mirror completes the pic- ture. The mirror is hinged and sup- ported by springs at one end. As shown in Fig. 3, a small voice coil, similar to that of a speaker, is attached to the back of the mirror and pushes against a magnetic counterweight. The magnetic counterweight is also spring -mounted. The resonant fre- quency of the counterweight system is designed to be the same as the mir- ror's, so essentially the entire mirror/ counterweight/coil mechanism acts like a tuning fork. Not only does it consume very little power — only '/ion watt is needed to keep it going — but most of the vibration that would be created by the oscillation of the mirror alone is canceled out. The resonant system is also relatively immune to external shocks and vibration. Synchronizing the movement of the minor is achieved by using a pho- todctector sensor. As shown in Fig. 4, a tab mounted to the back of the mir- ror interrupts the photosensor light beam circuit as the mirror crosses maximum deflection. At that time, power is applied to maintain reso- nance. The advantage of this system is that the exact frequency of the vibration is not important. The photosensor signal also pro- vides the information to determine the right time to start turning on the LED's for each screen. Due to the sinusoidally varying speed of the mir- ror throughout its cycle ( it slows down to a stop at each end), a timing correc- tion must be applied to make the col- umns appear in the right locations. The spring mounts for the resonant system act as friction less pivots for TIME MIRROR MOVES THROUGH 15° ARC PERCEIVED FULL SCREEN IMAGE FIG. 2— THE MOVEMENT OF THE MIRROR forms a horizontal "raster" as the pattern on the LED column changes. In the actual display, the LED column is made up of two offset bars, which are blended together by the mirror's movement. 48 BACK OF MIRROR VOICE COIL -COUNTERWEIGHT WITH MAGNET m* u FIG. 3— THE SCANNING MOTOR. The mir- ror is set into motion by a small voice coil that is mounted on back of the mirror; the voice coil pushes against a magnetic counterweight. TO POWER , t TO SERVO CIRCUIT BACK OF MIRROR FIG.4— ACCURATE TIMING is essential to keeping the pattern of the LED column in sync with the movement of the mirror. A photosensor assembly makes the job easy. When the mirror reaches the end of its travel, the photodetector sends a sig- nal to the servo circuit, which gives the mirror a "kick" back. the mechanism and create minimal power loss. And, because the motions required are small (the mirror travels only 15 degrees), the springs are stressed to a small traction of their fatigue life. In addition, because of a resonant system's tendency to resist any disturbance to the system (such as rapid movement or outside vibration), the image is not only extremely stable and clear, but remains so under a broad range of conditions. The magnifying lens that sits be- tween the mirror and the LED array allows the user to adjust the optics so that the displayed image appears to be at a point in space anywhere between 9 inches and infinity. An image can therefore be located on the same plane as other objects in the user's field of view. Because the optics are adjusta- ble, users do not suffer from eye strain and do not need to re focus their eyes when shifting their gaze from the dis- play to other objects surrounding them. Other features If a portable display is to be suc- cessful, its power consumption must be kept to a minimum. We've already seen how the LED's and resonant vibrating mirror are very efficient. Additional power reduction is achieved by being able to use a low refresh rate of 50 Hz, Other displays that refresh at that rate, such as TV's in Europe, suffer from very notice- able flickering, particularly when viewed with peripheral vision. The Private Eye is flicker- free because it has high contrast and is seen through the central portion of the eye, which is relatively insensitive to flicker. The Private Eye runs asynchronously from the host device. The display has an internal control chip and screen buffer memory. The control chip takes bit-map data trans- mitted as serial data up the cable to the internal memory. It then takes the bit map and places it into shift registers. The display is automatically and con- tinuously refreshed with the current image until new data is sent by the host device. Future developments The technology we've described is still only in its infancy. In fact, the development kit that we examined when preparing this article used tech- nology that is already outdated. For example, the development kit, which is used with a PC, requires two plug- in cards. One card contains logic cir- cuitry, while the other contains the servo circuitry to control the mirror's motion. Most of that circuitry has been incorporated inside the display package for future versions. At the same time, the display has been made lighter and easier to manufacture, and the slight vibration of the develop- ment unit has been reduced to be even less noticeable. Wc wouldn't be at all surprised if future displays use a wire- less radio-data link to receive their images. Other improvements have been successfully demonstrated in the lab- oratory, but will have to wait for re- finements in LED manufacturing be- fore they become a commercial reality. Reflection Technology's five- year target is to produce a megapixel (1000- X 1000-pixel) full-color dis- play in an even smaller, but substan- tial package. Before thai goal — essentially HDTV in a matchbox — is reached, a number of smaller ad- vances are planned. First will be the addition of gray scale or, in the case of the Pn'vater Eye. "red scale." Showing brightness levels merely requires redesigning the electronics to vary the light cycles of the LED's according to the desired brightness. Resolution will increase continu- ously from model to model. Moderate increases within the existing packag- ing technology (perhaps to 640 x 480) will occur, and then larger in- creases as denser packaging becomes available. Only current wire-bonding manufacturing practices limit the de- velopment of higher-density displays. Integrating the components onto a single substrate and using conductive paths between them will certainly provide the leap that is needed for megapixel resolution. Color can be attained when green and blue LED's become available in arrays similar to those used for red LED's today. The scanning mirror will combine the red, green, and blue pixels from individual LED arrays to visually superimpose the pixels and produce colors (in much the same way that it now combines the staggered red LED columns). Blue and green LED arrays are still a few years from com- mercial availability. The price for the display can also be expected to drop. The only costly component is the LED hybrid, which, like other semiconductor compo- nents, will lower in price as produc- tion volume increases and new manufacturing techniques are used. Potential applications If you've ever used a laptop com- puter with an LCD screen, you're well aware of the need for improvements. Even the highest-resolution and easily read laptop screen has the disadvan- tage of having to be large enough to see. The Private Eye will dramatically shrink the minimum size of laptops. In fact, by the time you read this arti- cle, at least one company (Cyberspace of Norcross, Georgia) will have introduced a pocket PC about the size of a video cassette. 4! Electronics reprint bookstore C I 126 Radio-Eleclromcs Annual 1986 S6.00 ["! 12S Radio-Electronics Annual 1985 $6.00 [~l 109 Radio-Electronics (.1989 back issues) . . S3. 50 Write in issues desired □ 108 Radio-Electronics (1988 back issues . . S3. 75 Write in issues desired □ 107 Radio-Electronics (1987 back issues) . S4.0Q Write in issues desired □ 106 Radio-Electronics (1986 back issues) . 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We charge 50(. per page. Indicate the issue (month & year), pages and article desired. Include payment in full, plus shipping and handling charge. Make checks payable to Gernsback Publications, Inc. ARTICLE PAGES MONTH YEAR TOTAL PAGES (fi50<; each TOTAL PRICE MAIL TO; Radio-Electronics Reprint Bookstore. PO. Box 4079. Farmingdale NY 11735 SHIPPING CHARGES IN USA & CANADA $0.01 toSS.OO $1.25 $30.01 to 40.00 . . $5.01 to $1 0.00, $2.00 S40.01 to 50.00 , . S1O.01 to 20.00 $3.00 $50.01 and above. $20.01 to 30.00 S4.00 Total price of merchandise All payments must be in U.S. funds .55,00 $6.00 . S7.50 SORRY Canada We only ship to USA & Sales Tax (New York State Residents only) $ . Shipping Charge (see chart) $ . Name Address . Cily Total Enclosed $ . .State . -Zip - Ft-290 Another real product that uses the Private Eye is a pocket video fax (from Medbar of Queens, New York). Built-in memory allows the fax to store incoming pages for review. We expect that it's only a matter of time before that sort of feature becomes standard equipment on portable cel- lular phones. There are also a number of products that, while not on the market as far as we know, are sure to be in the works. The Private Eye could easily be used to develop visual assembly and main- tenance manuals. For example, some- one testing an electronic product at the end of an assembly line could see a picture that would show where to place a probe. Because the technician would not have to look away from the task at hand, he could presumably work more efficiently and accurately. Can you imagine being able to use an oscilloscope or meter without ever looking away from where you're plac- ing the probe? The same technique could be used by automotive techni- cians, who could read an engine ana- lyzer at the same time they're under the hood adjusting a carburetor. Sur- geons performing microsurgery — who now must look away from their work to see a magnified image on a video display — would find a head- worn display to be an immensely val- uable tool. A miniature display could also be incorporated into radio pagers or other mobile data displays. Potential users might include field engineers needing technical documentation, salespeople wanting access to product documentation during a sales call, drivers needing maps to their destina- tion, or subscribers to public service such as news, sports, or stock-market information. Another application that you can bet on is videogames. We can imag- ine goggle-like headsets with one dis- play mounted in front of each eye. That would allow for completely por- table, very exciting, true three-di- mensional games. In short, the Private Eye will be used wherever the information con- tent and clarity of desktop screens can be used — from pocket PC's, to elec- tronic instrumentation, from pocket fax receivers to ISDN telephone dis- plays, from educational devices to toys and games. Even more exciting are the applications that haven't yet been thought of. R-E 10 m Ul D ED BATHGATE ■nil- MAJORITY Of" I'KOBl.HMS THAT OCCUR in a VCR are mechanical in nature. Problems caused by dirty heads, worn idlers, stretched belts, and jammed gears are perhaps most common, but VCR's also have their share of elec- trical problems. Such problems may be bad end sensors, burned out motors, power-supply problems, etc. A good oscilloscope and a digital voltmeter can gel you through the ma- jority of VCR problems quickly and easily. However, problems involving the video heads, rotary transformer, head pre-amps, and head-switching circuits can be tough to troubleshoot. There are low-cost ($60) video-head testers, but they won't indicate if a head is contaminated or if the gap is clogged; in either case the output will seriously be degraded. You could replace the video head in question, but that requires that you have a spare head for every make and model of VCR you service. Changing heads is time consuming, and keep- ing lots of heads in stock is expensive. What's really needed is an instrument that can generate a known -to -be-good video-head playback signal, and one inexpensive source for such a signal is another VCR. A VCR creates that signal whenever it plays a tape, so a working VCR can be used to trouble- shoot a broken VCR (see Fig. I). [f you are repairing VCR's as part of a service business, you probably have more than one working VCR in the shop at any given time. What's needed is a video jumper cable to lake the signal from the source VCR and inject it into the VCR being repaired. This project makes it possible to do just that, with no modifications to ei- ther VCR. VCR operation There are several signals that a vid- eo head generates during playback. The luminance and sync is a signal from 3.4 to 4.4 MHz, frequency- modulated by video luminance and sync information. The chroma, or color information, is a 629.37 1-kHz signal recorded by amplitude modu- lating the 3.4 MHz FM carrier. The VCR HEAD AMP TESTER This inexpensive piece of equipment can turn a second VCR into a valuable troubleshooting tool. combined signals arc usually referred to as video-head RF or RF envelope. Two video heads are needed to "read" the information from a stan- dard VHS videocassette (see Fig. 2). The two heads are mounted 180 de- grees apart on a polished aluminum cylinder that spins counter-clockwise at 30 rpm. When one head completes a scan of the tape, the other head is ready to start its scan. In one scan, one video head generates a "field," a full top-to-bottom picture on the TV screen. The second video head also generates a field, but it is interlaced with the field from the first head. The two interlaced fields make one frame. A standard four-head VCR uses only two heads at a time, one pair for "SP" (two-hour standard play), and one pair for "EP" (six-hour extended play). If one of the video heads is bad, the VCR will send a full-size picture to the TV, but with only half the pic- ture information, with every other field composed of "snow." Each head has its own pre-amp, and the output of each one goes to an SOURCE VCR INPUT OUTPUT HEAD AMP TESTER FIG. 1— THE VIDEO HEAD-AMP TESTER enables you to use a good signal from a working VCR to lest a VCR with possible head problems. CO s 51 CO o Z o tr h- o LU o Q < FIG. 2— VHS BASIC MECHANISM. Two video heads are needed to generate the standard VHS format. The two heads are mounted 180 degrees apart on a polished aluminum cylinder that spins counter-clockwise at 30 rpm. electronic head switch (see Fig. 3). The head-switching circuit combines the outputs from each head pre-amp. by switching to the head which is in contact with the tape at that time. The head-switching control pulse is a 30- Hz square wave derived from the rota- tion of the head-cylinder motor. The output envelope (waveform d) is the PARTS LIST All resistors are '/i-watt, 5%, un- less otherwise indicated. R1, R4— 100,000 ohms R2— 220,000 Ohms R3 — 10,000 ohms, audio-taper potentiometer R5— 150,000 ohms R6— 2200 ohms - R7— 1000 ohms Capacitors Cl, C3, C4— 0.001 u,F, ceramic disc C2 — 39 pF, ceramic disc Semiconductors LED1 — red light-emitting diode Q1. Q2— 2N2222 NPN transistor Other components J1 , J2— RCA-type jack S1— SPST on/off switch Miscellaneous: Coaxial cable, PC board, metal case, solder, etc. sum of the two individual head prc- amp envelopes (waveforms a and b). If the head-switching pulse is not present, or if it's distorted or inverted in phase, the symptoms will be sim- ilar to bad heads or a bad pre-amp. Some examples of bad waveforms are shown in Fig. 4. Waveforms a to d are caused by mechanical misalignment of the tape guides, and the waveforms in e and /indicate proper alignment, but show a problem with the video heads, pre-amps, or head switcher. Head-amp tester circuitry The schematic for the tester is shown in Fig. 5. The input is an RF envelope from a working VCR, ap- plied to Ql through coupling-capaci- tor Cl. Ql is connected as an emitter follower, with a high-impedance in- put and a low-impedance output, and a voltage gain of I . Potentiometer R3 is used as the emitter load for Ql and level control for the signal applied to Q2. Capaci- tor C2 is Tor improving the frequency response of R3. Transistor Q2 is also a 2N2222, wired in the same config- uration as Qi, but with a lower output impedance in order to drive circuits in the VCR under test. The circuit draws only 12 niA, so a 9- volt battery is well suited for the project . Construction The circuit should be built on a PC board, because RF as high as 4.5 MHz will be present. A single-sided board was used in the author's pro- totype with no problems. The board layout is very simple and can be drawn by hand directly on the copper with an etch-resist pen. See Fig. 6 for a parts-placement diagram; a foil pat- tern is provided in PC Service. The assembled circuit should be mounted in a shielded box and coaxial leads should be used for input and output. Keep the lead length as short as possible (2-foot leads were used on the prototype with no problems). Checkout After assembly, check the voltages on Ql and Q2, and the current draw, to verify proper circuit operation. Con- nect the VCR to be used as the sisinal TO VIDEO DEMODULATOR o- WAVEFGRM c O WAVEFORM a o- HEAD 8 HFAD A CHjfC T ROTARY RANSF0RMER CEite: ^"L^h PRE AMP A HEAD SWITCHING CIRCUIT WAVEFORM 6 0- PRE AMP B HEAD SWITCHING PULSE O— WAVEFORM d i B III b 1 FIG. 3— EACH HEAD HAS ITS OWN PRE- amp, and the output of each one goes to an electronic switch that combines the outputs from each head pre-amp. 52 MECHANICAL f ALIGNMENT PROBLEMS WORN OR BAD HEADS, ROTARY TRANSFORMER OPEN.SHQHT PROBLEMS IN PREAMPS OR HEAD SWITCHER FIG. 4— IMPROPER WAVEFORMS. Waveforms a-d are caused by mechanical misalign- ment of the tape guides. The waveiorms in e and Vindicate proper alignment, but show that there's a problem with either the video heads, pre-amps, or head switcher. FIG. 5— THE SCHEMATIC for the head-amp tester. *-| FIG. 6— PARTS-PLACEMENT DIAGRAM. Use the foil pattern provided in PC Service to make your own board. source VCR for proper flatness. The RF envelope should be between 100- and 500-mV p-p in most VCRV Now turn on and connect the head- amp tester to the source VCR at the same point in the circuit that you mea- sured the RF envelope (Fig. 3-r) with the oscilloscope. There may be a slight amount of signal degradation but if the entire picture disappears, it is loading down the source and the output signal will be unusable. Check the output signal of the head-amp tester with the oscillo- scope; it should be the same ampli- tude as the input signal with the level control at maximum. The output should be 0-V with the level control at minimum. source to a TV or monitor, and play a tape to use as the test signal ; i t can be a test pattern, or a home-made record- ing of the news or some other show. Use an oscilloscope to cheek out the head RFenvelope (Fig. 3-<), from the Using the tester To substitute a signal in place of bad or questionable video heads, first put the source VCR into play, connect the head-amp tester, and adjust the output for5-10-mV p-p. Put the VCR to be tested into play with a blank tape, and connect the output of the tester to the input of one of the head amps. That may be done at the con- nector end of the cable between the rotary transformer and the head amps. You can also capacitively inject the signal by clipping the output lead over the insulation of a non-shielded wire (no electrical connection), and in- creasing the output level to about x h to % of maximum. Signals can also be injected into the input and output of" the head switcher. The output level should be high and direct electrical connections should be made. The rotary transformer (one that can couple a signal from a rotating drum to the rest of the circuitry) can be tested with the VCR under test in "stop" mode, but the source VCR must be in "play" to supply a signal. Connect the output lead directly across one head at a time, and mea- sure the output at the pre-amp input connector, "rou should disconnect the pre-amp connector from the pre-amps if possible. The signal from the rotary transformer should be equal or greater in voltage than the applied signal volt- age. Test each head and the corre- sponding transformer winding. The head-amp tester is not going to replace any major test equipment, but it does help you to troublcshoot some problems. And, after all. why wouldn't you want all the help you can get? r-e 52 D L' a AUDIO PRE AMP IC'S An in-depth look at National Semiconductor's LM38X series of audio preamp IC's. RAY M. MARSTON ONE OF THE MOST VERSATILE SERIES OF linear preamp IC's is the LM38X ver- sions from National Semiconductor. They're extremely useful for audio and tone-control applications, and have excellent ripple rejection, low signal distortion, wide bandwidth, and low noise. You'll find them in virtually any modern piece of audio gear. This discussion will investigate how they work, and look at several useful applications. The LM38X IC's Figure 1 shows a representative block diagram of a conventional ster- eo system channel with both volume and tone control. National Semicon- ductor produces five !ow-noise dual preamps in the LM38X series, the LM381, LM381A, LM382, LM3S7, and LM387A: the "A" denotes ver- sions with superior noise figure per- formance. Figures 2-4 show the con- figurations of the three different ver- sions for one of the two amplifiers in TAPE IN TONE- CONTROL SYSTEM ■tfmiOVZ m ^Xv- R1 VOLUME POWER AMPLIFIER ■SW-iWisSS.il SPKK , FIG. 1— BLOCK DIAGRAM OF ONE CHANNEL of a stereo system. each DuaF/nline Package (DIP), while Table I gives a performance sum maty. Tone control may involve refine- ments like "scratch" and "rumble" filters. AH five IC's in the LM38X family use single-ended power sup- plies, and have the same basic ampli- fier circuitry, but differ in internal de- tails and pinouts. Also, all five have internal compensation, power-supply decoupling and regulation, large ca- pacity for output-voltage swing, and wide power bandwidth. They'd be used for both the preamp and tone- control blocks in Fig. I, since both functions occur prior to power ampli- fication. The differences are: • The LM38I and LM381A, shown in Fig. 2, allow external noise figure optimization and compensation (nar- rc>w-band or low-gain use). They're normally used differentially, but can be used single-ended for ultra-low- noise purposes. • The LM382, shown in Fig. 3, doesn't provide for external compen- sation or single-ended operation, but has a built-in resistor matrix to let the user select from among several closed-loop gain and frequency-re- sponse options. • The LM387 and LM387A. shown in Fig. 4, are utility versions of the LM381/1A, with only the input and output terminals accessible, and no provision for external compensation or single-ended operation. LM381 1A basics All the IC's in the LM38X family can be understood by examining the r > f \ * \ ' » ' * Hi H4l l3i-l!WS|- Y ■£' Y Y Y FIG. 2— THE LM381/1A DUAL LOW-NOISE PREAMP. 54 FIG. 3— THE LM382 DUAL LOW-NOISE PREAMP. +T ' it M 200K 250K -VA- w-1 IDK I 1 | 1 3 t- FIG. 4— THE LM387/7A DUAL LOW-NOISE PREAMP. LM381/IA shown in Fig. 2. It has a first stage (Ql and Q2), second stage (Q3-Q6). output stage (Q7-Q10), and bias network (Q11-Q15); Fig. 5 shows a simplified equivalent. The first stage is biased at 1 . 2 volts via R 1 , and can be operated either differen- tially or single-ended, although dif- ferential operation generates 41% more noise. In differential use, the first stage has to be balanced by externally bias- ing the base of Q2 at 1.2 volts. In single-ended mode, Q2 has to be turned off by grounding its base, and Ql has to be balanced by externally biasing the emitter of Q2 at 600 milli- volts. The first stage has a differential voltage gain of 80, or 160 when used single-ended. The second stage uses common- emitter Q5 and constant-current load Q6, and is driven by Ql via Darlington emitter follower Q3-Q4. Its voltage gain is 2000, and it's inter- nally compensated via CI for unity gain at 15 MHz, giving stability at closed-loop gains of 10 or more. At lower gains, an external capacitor can go in parallel with CI for compensa- tion purposes. The output stage uses Darlington emitter follower Q8-Q9, with active current sink Q7. Then, Q10 provides 3 LM387 7A -IN 1 (iND 0UT1 -t-lN 2 -IN 2 OUT 2 6 short-circuit protection by limiting output current to 12 mA. The bias network gives 120 dB of supply-signal rejection, and includes the high- im- pedance constant-current generator Q11-Q12-Q13, which generates rip- ple-free reference voltage across D3. That reference voltage operates the first two stages via Q14 and Q15, and biases the base of Ql internally. Differential operation In differential mode, the 1C output is given a positive quiescent value in- dependent of supply- voltage varia- tions, by connecting divider R1-R2 as a DC negative-feedback loop, as ■n m CD C > 33 < (£> <-D O 55 CO o z o DC 1- o UJ o < DC shown in Fig. 6. The inverting input is biased internally at 1.2 volts. When Rl and R2 are used as in Fig. 6, DC negative feedback makes the non- in- verting input go to 1.2 volts, and the amplifier output to 1.2 voltsX[l + (Rl/R2)]. In practice: R2<250K. Figure 7 shows a non-inverting AC amplifier with an input impedance of 250K; input signals must be limited to 300 mV RMS to avoid distortion. The DC voltage gain is determined by Rl and R2, while the desired AC gain is set by AC shunting one of the bias resistors. Here, the DC gain is fixed by Rl and R2 at less than 10, but the AC gain is fixed by Rl and R3 at 100. That shunting technique can be ex- panded for frequency-dependent AC gain in various filter applications. Fig- TABLE 1— PERFORMANCE OF THE LM 381/1 A/2/7/7 A LINEAR IC'S Characteristic LM381 LM381A LM382 LM387 LM387A Supply Voltage (VDC) 9-40 9-40 9-40 9-30 9-40 Quiescent Current (mA) 10 10 10 10 10 Power Bandwidth (kHz)* 75 75 75 75 75 Supply Rejection Ratio (dB at 1 kHz) 120 120 120 110 110 Equiv. Noise Input Typ. 0.5 0.5 0,8 0.8 0.65 Figure (|xv RMS) Max. 1.0 0.7 1.2 1.2 0.9 * NOTE: Power bandwidth is the audio frequency range over which an amplifier can produce half of its rated power, without exceeding its rated distortion. It indicates how much power is available at the critical high and low frequencies, and the wider the power bandwidth, the better the amplifier. BIAS NETWORK I QI1 hi Di !"02 03 3" , ..... 1ST- STAGE AMPUHEfl R2 < 2MK^ 4 Rl >250K -^€0^ R3 10K mSTAGE AMPLIFIER !..'i:;f,.',| .;'• COMPARATOR ( FIG. 5— EQUIVALENT CIRCUIT OF THE LM381/1A amplifier. inverting terminal is grounded, and the input signal is fed to the inverting terminal via Rl. The AC gain is R3/ R2= 10, the quiescent output is + 12 volts, and the input impedance is about Rl. Figure ll shows a unity- gain, 4- input audio mixer. FIG. 6— DIFFERENTIAL BIASING OF THE LM381/1A. ure 8 shows the same amplifier con- figuration used as a low-noise phono preamp with Recording /ndustries As- sociation of America (RIAA) equal- ization, while Fig. 9 shows a similar tape-playback amplifier with National Association of Broadcasters (NAB) equalization. Figure 10 shows an in- verting AC amplifier; here, the non- Single-ended operation The differential first stage of an LM381 composed of QI-Q2 is powered via the internal 5.6-volt reg- ulator, and the collector of Ql is fed to FIG. 8— AN LM381/1A USED AS A low- noise phono preamp with RIAA equaliza- tion. FIG. 7— A LOW-NOISE LM381/1A non-in- verting amplifier, with a gain of 100. FIG. 9— AN LM381/1A used as a tape play- back amplifier with NAB equalization. the output via a DC amplifier. The IC can be operated in single-ended mode by grounding the base of (and disab- ling) Q2, but it needs to be biased 56 -o our SIGNAL INPUT FIG. 1 0— TH IS LM381 A low-distortion (less than 0.05%) inverting amplifier has 3 gain of 10. GAIN REQUIRED CAPACITOR ■■OtlB 55dB 80dB Ct ONLY C2 0NIY CI AND C2 INI , t IN 1 SIGNAL , OUT LM381 1A >-*— < IN 3 FIG. 11— THELM381/1Aisusedhereasa4- input unity-gain audio mixer. FIG. 12— THIS LM381A ultra-low-noise preamp has a gain of 1000. _ = METAL FILM, 1% TOLERANCE . 33V •« - » C3 R 2 £ R1 300pF t50K ^S1K E C2 INPUT jftf ^r4( R5 4J.SK FIG. 13— LM381A ULTRA-LOW-NOISE magnetic phono preamp that includes RIAA equalization. using emitter feedback. Suitable DC biasing is obtained by connecting a voltage divider that ap- FIG. 15— THE LM382 is used here to make a 40-dB inverting amplifier. FIG. 1-4 — AN LM382 FIXED-GAIN non-inverting amplifier with a 12-volt power supply. for non- in verting use only, with a typ- ical input impedance of I0K. ideally, input signals should have source im- pedances below 2K, and all resistors should be of the low-noise, metal-film variety. Figure 12 is an ultra-low-noise version with a gain of 1000, where C3 limits the upper 3-dB frequency re- sponse to 10 kHz, and R5 adjusts the DC output voltage to half-supply val- ue. Figure 13 is a magnetic phono preamp circuit that uses RIAA equal- ization, with the DC output voltage set by R7. LM382 circuits The internal circuitry of each half of a LM382 is identical to a LM381, except for a 5-resistor matrix ant! elimination of certain terminal con- nections. Eliminating those terminals means that an LM382 can't be used single-ended or externally compen- sated. The resistor matrix greatly sim- plifies bias- and filter-network design. The matrix is specifically intended for applications where the IC is powered from a + 12-volt supply. Figures 14-17 show various ways to use the LM382 with a + 12-volt supply. Fig- ure 14 shows a non- inverting ampli- fier with 40, 55 or 80 dB of AC gain. Figure 15 shows an inverting amplifier with 40 dB gain, Fig. 16 shows a unity-gain inverting amplifier, and Fig. 17 shows a phono preamp with RIAA equalization. LM387 circuits The internal circuitry of each half of a LM387/7A is identical to an LM381, except for eliminating cer- tain terminal connections, letting the IC be used differentially without ex- ternal compensation. The IC is never- theless quite versatile, and Figs. 18-24 show some practical applica- rn tions. Figure 18 shows how to connect § an LM387 as a non-inverting ampli- > fier with an AC gain of 52 dB . The DC 5 gain and quiescent output voltage of ^ the amplifier circuit are determined o FIG. 16— SHOWN HERE IS AN LM382 uni- ty-gain inverter. FIG. 17— LM382 phono preamp with RIAA equalization. plies 600 millivolts to pin 3 when the IC output is at the desired DC level. If a quiescent + I2-volt output is needed, the divider needs a DC volt- age gain of 20. In practice, the noise from the input transistor varies with collector cur- rent, and is minimized at 170 pA. A sinide-ended LM38I is intended 57 FIG. 18— LM387 NON-INVERTING AC am- plifier with a gain of 52 dB. FIG. 21— THE LM387 CAN BE USED TO MAKE an active tone-control circuit. O z o tr o m _i LU 6 o < rx FIG. 19— LM387 PHONO PREAMP with RIAA equalization. PICKUP -VA — f 240K 20fiF 2.2MEG rWr 1801! 62K 5K.00S5 FIG. 20— AN LM387 USED AS a tape play- back amplifier (NAB). by Rl and R2. and the AC gain by Rl and R3. Figure 19 shows an LM387 used as a phono prcamp with RIAA equalization, while Fig. 20 shows how it can be used as a NAB tape playback amplifier for use in all kinds of devices ranging from cassette play- ers to telephone-answering machines. Figure 21 shows an active tone con- trol giving unity gain with its controls in the "flat" position, or 20 dB of boost or rejection with the controls fully rotated. The "rumble" filter of Fig. 22 is a 2nd-order high-pass active filter that rejects signals below 50 Hz at 12 dB/octave. Figures 23 and 24 show various ways of using an LM3H7 in inverting mode in active filters. The K3 470K FIG. 22— AN LM387 USED AS A "rumble" filter. FIG. 23— AN LM387 USED AS A "scratch- filter. FIG. 25— THE CIRCUIT SHOWN HERE can be used to eliminate RF pickup. Usage hints This article has examined various circuits using the LM38X linear IC's. These are high-gain, wide-band de- vices, and some care must be taken if they're to work. The two most fre- quent problems are RF instability and RF pickup. The former. RF instability, is usually caused by inadequate high- frequency power supply decoupling. In all preamps, the 1C power supply has to be RF-decoupled by wiring a ■■■■^la ?"S60pF <:2.2MEG ^J4V IN U 560j)F 430K \ -< SOLDER SIDE OF THE PORT-A-MATIC'S bus- interface board. 61 Take any one of these HANDBOOKS ELECTRONICS and CONTROL • your one source for engineering books from over 100 different publishers • the latest and best information in your field • discounts of up to 40% off publishers' list prices w o z o c h- o w _l w Q Q < 62 322/910 Publisher's Price $114.50 ANTENNA ENGINEERING HANDBOOK, Second Edition Edited by R. C. Johnson and H. 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Books are selected from a wide range of publishers by expert editors and consultants to give you continuing access to the best and latest books in your field. 2. Big savings! Build your library and save money, too! Savings range up lo 40% off pub- lishers* list prices. 3. Bonus books! You will automatically be eligi- ble to participate in our Bonus Book Plan that allows you savings up lo 70% off the publishers' prices of many professional and general interest books! 4. Convenience! 14-16 times a year (about once every 3-4 weeks) you receive the Club Bulletin FREE. It fully describes the Main Selection and alternate selections. A dated Reply Card is in- cluded, if you want the Main Selection, you simply do nothing- it will be shipped automatically. If you want an alternate selection - or no book at all - you simply indicate it on the Reply Card and return it by the date specified. You will have at least 10 days to decide, if, because of late delivery of the Bulletin you receive a Main Selection you do not want, you may return it for credit at the Club's expense. As a Club member you agree only to the purchase of two additional books during your first year of membership. Membership may be discontinued by either you or die Club at any time after you have purchased the two additional books. FOR FASTER SERVICE IN ENROLLING CUL TOLL FREE 1-800-2-MCGRAW McGraw-Hill Book Clubs Electronics and Control Engineers' Book Club : P.a Box 582 Hightstown, HJ 08520-9959 Please enroll me as a member of the Electronics and Control Engineers' Book Club® and send me the book 1 have chosen for only $14.95 plus local tax, postage and handling 1 agree to purchase a minimum of two addi- tional books during my first year as outlined under the Club plan described in this ad. Membership in the club is cancellable by me or McGraw-Hill any time after the two book purchase requirement has been fulfilled. A shipping and handling charge is added to all shipments. 1 wish to order the following book D ANTENNA ENGINEERING HANDBOOK (322/910) D MODERN ELECTRONIC CtRCLTTS REFERENCE MANUAL (404/461) □ STANDARD HANDBOOK FOR ELECTRICAL ENGLNEERS. 12/e (209/758) □ TELEVISION ENGINEERING HANDBOOK (047/790) O STANDARD HANDBOOK OF ENGINEERING CALCULATIONS (287 /35X) Signalu re \ame_ Addrcss'Apt, #. . City/Staie/Zip this order subject eg acce planee by Mc i inf. I hi. Offer eoodonty lo ne*c members. Foreign member acceptance subject lo special conditions. ECGA-02S c > n -< CO CO O 65 LU 6 D < 66 RADAR-DETECTOR TESTER foil pattern. Hardware Hacker Dew sensor circuits Direct toner pc update Hacker cold fusion kits Midnight Engineering mag Alarm & security resources Cold-fusion papers and kits DON LANCASTER THERE S LOTS OF EXCITING NEWS THIS month, including cold-fusion kits, an update on the direct-toner printed-circuit process, a major new hacker magazine, and some details on unusual dew-sensor components. So, let's just jump right on in... Cold fusion kits There seems to be lots of good news on the cold-fusion front these days. At a recent con- ference, several more indepen- dent researchers confirmed those excess heat production effects, verified expected nuclear by- products, and made lots of similar supporting observations. See the October 27th, 1989 Science on page 449 for a good summary. The key sentence: "The experimental evidence for cold fu- sion, or at least some unknown nuclear phenomenon, is too great to ignore." At the same time, many of those earlier measurements and experi- ments have been made far more precise, and many possible error sources seem to have been elimi- nated. In particular, tighter control experiments involving non-deu- terium and non-reacting cells have been carried out to the satisfaction of several prominent skeptics. The general feeling seems to be that something really is happening here. And the most reasonable ex- planation for that something is that cold fusion is actually taking place, or else some previously un- known nuclear reaction seems to be occurring. On the other hand, the exces- sive energy production is still very erratic, rather low, and highly un- predictable. Tremendous quan- tities of time and effort are usually required under extremely careful conditions to get any observable results at all. There's been two major cold-fu- sion developments this month that should be of major hardware hacking interest. The first is that all of the key fusion papers are now readily available, and the second is that you can now get your own low-cost ($27) experimental cold- fusion kit. By the time you read this, over a hundred key cold-fusion papers should be available by way of that Dialog Information Service that you will find through your local library. Figure 1 should get you started. I've listed two dozen ear- lier papers, gotten through the IN SPEC service within Dialog. The costs of generating your own complete and up-to-date cold-fusion abstract listing should be around $35, and should take twenty minutes. As a reminder, the best sources for current info on cold fusion are in the News and Comments sec- tion found in Science magazine, and the Technology section that is NEED HELP? Phone or write your Hardware Hacker questions to: Don Lancaster Synergetics Box 809- RE Thatcher, AZ 85552 (602) 428-4073 usually found on page B-4 of your Wall Street Journal. On to those kits: Guy Wicker is a name-brand hardware hacker and a well-known energy re- searcher. By a special arrange- ment, Guy has offered to put together several cold-fusion mini- kits for all you Radio-Electronics hackers. The kits cost only $25, plus $2 shipping and handling. As Fig. 2 shows us, the kit con- sists of a small test tube full of a 0.1- molar deuterium and lithium hy- droxide solution, a short piece of 50-mil palladium rod, and a small loop of nickel wire. Nickel is used instead of platinum for the anode. A classic cold-fusion cell is built up something like what you see in Fig. 3. Use a coiled nickel-wire anode, and a nickel suspended palladium-rod cathode. You apply a DCcurrentin the4to20 milliam- pere range, with positive to the nickel anode and negative to your palladium cathode. Be sure to carefully monitor your temperatures at several loca- tions. If possible, also monitor for radiation. A "charging" time of several hours or a few days seems normal for that size palladium rod. Look for both a very low level and a separate "burst mode" excessive heat production effects. Some sort of a continuous tem- perature recorder, possibly based on a personal computer, is proba- bly a very good idea. You'll want to rr work inside of a styrofoam block i which itself sits inside a picnic > cooler or other well-insulated box. * Guy reports that very small cells « like that one are far more likely to = 61 m o z D X 2 5 < f produce a low-level tritium radia- tion than excess heat production. Getting both to happen at once when someone is watching is usu- ally frustratingly difficult. It is also the Holy Grail of cold-fusion re- search. Some warnings here. Your cell is extremely small and the excess heat production, if any, is likely to be correspondingly tiny. Oppor- tunities of cell contamination are very great. Yourodds of yourcold- fusion cell working at all are only something like one in ten, and the odds of your being able to observe that operation when and as it oc- curs is also estimated as around one in ten or so. Thus, your esti- mated odds are only one in one hundred that you will be able to prove your cell actually works. So, what we have here appears to be a crap shoot. On the other hand, here you have a sure fire winner for a sci- ence fair entry, show-and-tell, or school report. And the "touchy- fee ly" and "See what I've got!" as- NEW FROM DON LANCASTER HANDS-ON BOOKS Hardware Hacker Reprints II 24.50 Ask The Guru Reprints I or II 24.50 CMOS Cookbook 18.50 TTL Cookbook 16.50 Active Filter Cookbook 15.50 Micro Cookbook vol I or II 16.50 Enhancing your Apple I or II 17.50 AppleWrlter Cookbook 19.50 Apple Assembly Cookbook 21.50 Incredible Secret Money Machine 10.50 LaserWriter Reference (Apple) 19.50 PostScript Cookbook (Adobe) 16.50 PostScript Ret. Man. (Adobe) 22.50 PostScript Prog. Design (Adobe) 22.50 Real World Postscript (Roth) 22.50 UNLOCKED SOFTWARE Lase rW rite r Co rn er (I le/M ac/PC } 29.50 PostScript Show & Tell 39.50 Intro to PostScript VHS Video 39.50 PostScript Beginner Stuff 39.50 PostScript Perspective Draw 39.50 PostScript Technical Illustrations 39.50 PostScript Work in Progress 39.50 PostScript BBS stuff 19.50 Absolute Reset Me & lie 19.50 AppleWrlter/Laserwrfter Utilities 49.50 Enhance I or II Companion Disk 19.50 AppleWrlter CB or Assy CB Disk 24.50 FREE VOICE HELPLINE VISA.MC SYNERGETICS Box 809-RE Thatcher, AZ 85552 (602) 428-4073 CIRCLE 83 ON FREE INFORMATION CARD Triple collision reaction of deutrons as a possible explanation of cold fusion E, Becker, Naturwissenschaften (W. Germany), May 1989, Vol 76 #5, pp 214. Cold fusion in metals J. Kondo, Journal of the Physical Society of Japan, June 89. Vol 58 #56, pp 1869-1670. Deuterium nuclear fusion in metals at room temperature P. Tomas, Fizika (Yugoslavia), vol 21 #2, 1989, pp 209-214. Exact upper bound on barrier penetration probabilities for cold fusion A Lettitt. Physics Review Letters, (USA), Vol 63 #2. 10 July 69, pp 191-194. Cold fusion; how close can deuterium atoms come Inside palladium? Z. Sun. Physics Review Letters {USA), Vol 63 #1, 3 July 89, pp 59-61 Search for fusion reactions between deuterium atoms inplanted into titanium Ft. Behrisch. Nuclear Fusion (Australia). Vol 29 #7, July 89, pp 1187-1190. Can solid-state effects enhance the cold-fusion rate? A. Leggett. Nature, (UK). Vol 340 #6228, 6 July 89, pp 45-46 Upper limits on neutron and gamma ray emission from cold fusion M Gai, Nature (UK). Vol 340 #6228 6 July 89, pp 29-34. Calculated fusion rates in isotopic hydrogen molecules S. Koonin, Nature (UK), Vol 339 #6227. 29 June 89, pp 690-691. Search for neutrons during heavy water electrolysis on palladium electrodes S. Blagus. Physics of the atomic necutl (Germany), Vol 333 #3, 1989, pp 321-32 Search for neutrons from cold nuclear fusion D. Alber, Physics of the atomic necuii (Germany), Vol 333 #3, 1969. pp 319-320. Screening corrections in cold deuterium fusion rates K. Langanke, Physics of the atomic necuii (Germany), Vol 333 #3, 1989. pp 31 7-31 S Cold fusion in the solid state? J. Goedkoop. Eneergie spectrum (Netherlands), Vol 13 #6, June 89. pp 156-162. Nuclear fusion ^____ P. Bulk), Bettrificazione (Italy), #5, May 89, pp 57-61. Neutron emission under particular nonequilibrium conditions P. Perfetti. Nuovo Cimento D (Italy), Vol 11D ser. 1 #6, June 89, pp 921-926, Theoretical considerations on the cold nuclear fusion in condensed matter F. Parmigiani, Nuovo Cimento D (Italy). Vol 11D ser. 1 #6. June 89, pp 913-919, Chemical forces associated with deuterium confinement in palladium J. Mintmire, Physics Letters A (Netherlands), Vol 138 #1-2, 12 June 89. pp 51-54. Cold fusion in condensed matter: is a theoretical description possible? W, Schommers, Modern Physics Letters 8 (Singapore), Vol 3 #8, 20 May B9, pp 597-60 Doubts grow as many attempts at cold fusion fail B. Levi. Physics Today (USA). Vol 42 #6, June 89, pp 17-19 Muon catalyzed fusion C. Petitiean, Fusion Engineering Design (Netherlands). Vol 11 #1-2, June 89. pp 255-264. Opening possibility of deuteron-catalyzed cascade fusion channel A Takahashf, J, Nuclear Science Technology (Japan), Vol 26 #5, May 89, pp 558-560 Computation of the cold fusion rate P. Dong, New Physics [South Korea), Vol 29 #2, April 89, pp 233-234 The observation of 2.2 Mev gamma-ray in electrochemical cell Y. Park, New Physics (South Korea), Vol 29 #2, April 89, pp 231-232. First steps toward an understanding of "cold" nuclear fusion T. Bressanl, Nuovo Cimento A (Italy). Vol 101 A ser. 2 #5, May 89, pp 845-849. Emission of neutrons as a consequence of titanium-deuterium interaction A. De Ninno. Nuovo Cimento A (Italy). Vol 101 A ser. 2 #5, May 89, pp 841-844 Fermi gas like hypothesis for Fleischmann-Pons experiment 0. Flossier, Z War. Phys. Chetn. Kosmophys (W Germany), Vol 44 A #4, April 89, pp 329. Observation of cold nuclear fusion in condensed matter S. Jones, Nature (UK), Vol 338 #6218, 27 April 89, pp 737-740. 04. >64. Electrochemically induced nuclear fusion of deuterium M. Fleischmann, Jour. Electroan. Chem. (Switzerland). Vol 261 #2A, 10 April 89, pp 301. Cold nuclear fusion A. Rusu. Energetics (Romania). Vol 3 #6. June 88. pp 258-261, On the practical use of the cold fusion (problems and prospects) Y. Peirov, Muon Catalyzed Fusion (Switzerland), Vol 3 #1-4, 1988, pp 525-535. Observation of enhanced low-energy charged-particles in cold fusion U, Gollerthan, Physics Letters B (Netherlands), Vol 201 #2, 4 Feb 88, pp 206-210. FIG. 1— SOME KEY COLO-FUSION PAPERS. For a complete and up-to-date list, use the Dialog Information Service at your local library. Start with their INSPEC resource data base. Fleischmann's paper started it all. pects of all those kits are com- pletely off scale. Colly gee, Mr. Science. Guy also offers fancier cold fu- sion kits and other products for serious researchers. Contact him 68 FIG. 2— LOW-COST HACKER FUSION KITS consist of a small test tube filled with heavy water, a short palladium-rod anode, and a nickel-wire cathode. While the odds of positive results are rather low, this is a great show-and-tell item. directly for more information on those kits. Needless to say, be sure to let us know the outcomes of all your test experiments. That is a wide open field with mind-boggling hacker potential. Midnight engineering There's a brand new magazine out called Midnight Engineering, It is specifically aimed at you hard- ware hackers and software de- velopers who are trying to market their high-tech products on a small-scale or startup basis. Its shoot-from-the-hip style is very much cast in the same mold as my Incredible Secret Money Ma- chine. Emphasis is on real-world solutions and new hacker oppor- tunities. Free sample copies are available to you. It really is a "must have." ALARM & SECURITY SYSTEMS RESOURCES ADEMCO 165 Eileen Way Syosset, NY 11791 (800) 645-7492 CIRCLE 200 ON FREE INFORMATION CARD King Alarm 145 English Street Hackensack, NJ 07601 (800) 526-0162 CIRCLE 205 ON FREE INFORMATION CARD Alarm installer & Dealer 2512 Artesia Boulevard Redondo Beach, CA 90278 (213) 376-8788 CIRCLE 201 ON FREE INFORMATION CARD Security Dealer 210 Crossways Park Drive Woodbury, NY 11797 (516) 496-8000 CIRCLE 206 ON FREE INFORMATION CARD ARIUS 959 Concord Street Framingham, MA 01701 (800) 241-3278 CIRCLE 202 ON FREE INFORMATION CARD Security Distributing 1350 E Touhy Avenue Des Plaines, IL 60017 (312) 390-2117 CIRCLE 207 ON FREE INFORMATION CARD Cain Security Systems 2593 Wexford Bayne Rd, S301 Sewickley, PA 15143 (412) 934-1000 CIRCLE 203 ON FREE INFORMATION CARD TechniTool 5 Apollo Road Plymouth Meeting, PA 19462 (215) 825-4990 CIRCLE 208 ON FREE INFORMATION CARD Jensen Tools 7815 South 46th Street Phoenix, AZ 85044 (602) 968-6231 CIRCLE 204 ON FREE INFORMATION CARD Valley Security PO Drawer J Thatcher, AZ 85552 (602) 428-2142 CIRCLE 209 ON FREE INFORMATION CARD Printed-circuit update There sure were a lot of helpline calls and letters over our PostScript direct toner prototype printed-circuit breakthrough in the December issue. I thought I would summarize some of your hacker suggestions to date. They appear in Fig. 4. FIG. 3— A TYPICAL COLD-FUSION test setup. Apply a DC current around 10 mA. The anode and cathode should not con- tact. You measure for excess temperature, neutrons, and tritium. Many of you totally and com- pletely underestimated just how crucially important the PostScript language is to that breakthrough process. Among its many other ad- vantages, PostScript lets you exact- ly trim your final image size to pre- cisely 1:1; it is totally output- independent, meaning that you can use either a desktop laser printer or a more precise pho- totypesetter; it easily lets you work1X,2X,4X, frontward or back- ward, normal or reversed, to as many as eight layers at once; it has no upper size or any complexity limit; it is totally host-indepen- dent, which allows you to use any old-world processor on any old personal computer; it simply lets m you pass layouts over any BBS sys- § tern in the world as a plain old > textfile; and is compatible with vir- 5 tually all of the existing CAD/CAM £ programs, either through a direct o tn o z. O cr LU 6 Q < PostScript driver or by a PostScript HPGL emulator. Similarly, using the heated- roller method works far better than an iron. The obvious reasons for that are the far more uniform pressure and temperature. You also gain bunches in dimensional stability, since the Mylar transfer sheet does not get any chance to distort all at once. As we've seen, I recommend a fake Kroy Kolor ma- chine to do the transfer. We'll look at some cheaper alternatives for that in a future issue. Several readers have now sug- gested substituting Kapton film in- stead of the polyester overhead sheets since it has better high- temp stability. Two of the sources of Kapton include DuPont and Rogers Corp. It also seems a very good idea to do your final cleaningwash of your bare copper board with distilled water. A brief pre-etch before transferring your toner image does appear to be quite important as well. The etch will both guaran- tee an extra-clean board and gives you just the right "tooth" for the toner to grab onto. Some other suggestions: Pre- heat the copper board as much as you dare before doing the transfer. The idea is to keep the copper from acting as a giant heat sink. Something around 150 degrees Fahrenheit should work. Note that gloves are an absolute must at that temperature. And run an ice cube on the back of the transfer sheet before sepa- rating it from the PC board. That seems to improve the transfer pro- cess bunches. Be sure to send in your own tips and techniques for getting perfect 1:1 toner transfers. When all of the dust settles, we'll try to separate the black magic from the reality and standardize on a useful direct- toner process. Alarm and security resources To continue our ongoing series of resource sidebars, this month we'll look at what you need to know to pick up insider informa- tion on burglar alarms and security systems. Those magic names and numbers appear in that Alarm and Security Resources sidebar. As with any field at all, your best NAMES AND NUMBERS Analog Devices One Technology Way Norwood. MA 02062 (617) 329-4700 CIRCLE 210 ON FREE INFORMATION CARD Dialog Information Services 3460 Hillview Avenue Pato Alto. CA 94304 (415) 858-2700 CIRCLE 211 ON FREE INFORMATION CARD DuPont 1007 Market Street Wilmington, DE 19898 (302) 774-1000 CIRCLE 212 ON FREE INFORMATION CARD IGLIDE/IGUS Bearings PO Box 4349 Rumford, Rl 02914 (800) 521-2747 CIRCLE 213 ON FREE INFORMATION CARD Kroy Kolor 14555 North Hayden Road Scottsdaie, AZ 85260 (800) 521-4997 CIRCLE 214 ON FREE INFORMATION CARD Lehman Scientific RD1 Box 580 Wrightsville, PA 17368 CIRCLE 215 ON FREE INFORMATION CARD Midnight Engineering PO Box 7041 Fort Collins, CO 80525 (303) 491-9092 CIRCLE 216 ON FREE INFORMATION CARD Ming Engineering 977 S. Meridian Avenue Alhambra. CA 91803 (818) 570-0058 CIRCLE 217 ON FREE INFORMATION CARD muRata Erie 2200 Lake Park Drive Smyrna, GA 30080 (404) 436-1300 CIRCLE 218 ON FREE INFORMATION CARD Panasonic 50 Meadow I and Pkwy, Secaucus, NJ 07094 (201 ) 348-7000 CIRCLE 219 ON FREE INFORMATION CARD bet is to start with the trade jour- nals. A complete list of all trade R&D Electronics 1224 Prospect Street Cleveland, OH 44115 (216) 621-1052 CIRCLE 220 ON FREE INFORMATION CARD Rogers Corp 100 S. Roosevelt Avenue Chandler, AZ 85226 (602) 961-1382 CIRCLE 221 ON FREE INFORMATION CARD Samsung 3725 N 1st Street San Jose, CA 95134 (408) 434-5400 CIRCLE 222 ON FREE INFORMATION CARD Science/AAAS 1333 H Street NW Washington, DC 20005 (202) 326-6400 CIRCLE 223 ON FREE INFORMATION CARD Synergetics Box 809 Thatcher, AZ 85552 (602) 428-4073 CIRCLE 224 ON FREE INFORMATION CARD Taiyo Yuden 714 W Algonquin Road Arlington Heights, IL 60005 (312) 364-6104 CIRCLE 22S ON FREE INFORMATION CARD Thompson Nyliner Shore Road & Channel Drive Port Washington, NY 11050 (516) 883-8000 CIRCLE 226 ON FREE INFORMATION CARD Toshiba 1220 Midas Way Sunnyvale, CA 94086 (408) 739-0560 CIRCLE 227 ON FREE INFORMATION CARD Wall Street Journal 420 Lexington Avenue, 14th Ft. New York City, NY 10170 (212) 808-6960 CIRCLE 228 ON FREE INFORMATION CARD Guy Wicker 30437 Fairfax Southfield, Ml 48076 (313) 647-1820 CIRCLE 229 ON FREE INFORMATION CARD journals is available as Uhlrichts Periodicals Dictionary on the ref- 70 [ The PostScript language is essential to the direct toner process. Its totally overwhelming advantages include precise scaling to 1:1, total format flexibility, host and printer independence, easy BBS downloads, and the ability to use nothing but a word processor. 8. Heated roller transfer methods work much better than an iron. Use a fake Kroy Kolor machine or its equivalent. The reasons include better stability and tighter temperature control. Use a "dry" (silicon oil free) fuser wiper pad for several copies before your transfer sheet is run. ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ For extreme dimensional stability, try using a Kapton film, rather than polyester or mylar. ^^^^^^^^^^^^^^^^^^^^^^^^^^^ Do your final washing of your cleaned copper board with distilled water. A brief etch before your final washing step is essential to give the proper "tooth" for toner transfer. ^ ^^^^^ Preheat the copper to 150 degrees or so before the transfer to minimize any heat sinking effects. . Rub an ice cube over the back of the transfer sheet before seperating it from the pc board. FIG. 4— HERE'S AN UPDATE on the direct-toner printed-circuit prototypes we first looked at in the December 89 issue. 1 +5vdc 750K PANASONIC EYH-SQ210 DEW SENSOR 100K 1K 74HC14 i^T^^ ® MPS6521 ® GREEN = LOW HUMIDITY RED = DEW OR MOISTURE FIG. 5— A DEW-SENSOR TEST CIRCUIT The red LED lights when the humidity exceeds 100 percent; the green one turns on in the absence of dew. erence shelf at your neigh- borhood library. A second source that is almost as good is the Interna tio nal Stan da rd Pe rio dica Is Dictionary on the same shelf. Typical trade journals for the field include Security Dealer, the Security Distributing and Market- ing, and the Alarm Installer and Dealer. Trade shows play an important part of the alarm industry. A pair of the largest are the International Security Conference and Exposi- tion, and The Security Show. They do move around from town to town. Check any of the trade jour- nals for the show dates. There are a number of specialty wholesale distributors that cater to the alarm trade. You'll find lots of ads for them in all the trade jour- nals and their directories. Three larger examples are King Alarm, Arius, and Ademco. Two sources of general installa- tion tools and test instruments in- clude Jensen Tools and TechniTool. Sadly, both of those yuppieized outfits are rather pricey. But all of their products happen to be both first-rate and top-quality. There are now hundreds of se- curity consultants that will be glad to help you for a sane and reason- able fee. Two examples here are Wyatt Palmer (no relation) of Valley Security, and Jeff Lancaster (my widdle brudder) of his Cain Security Systems. Please let me know if you know of any other similar kinds of re- sources that you think should be added to the list. continued on page 74 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 now to take advan- tage of the growing demand for people able to work at the engin- eering 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. (\rJ\y V Banner Technical Books, Inc. 1203 Grant Ave. Rockford, IL 61103 CIRCLE 67 ON FREE INFORMATION CARD 33 Ways to Help You Qualify for the Job You Want Free Fads about Career Diplomas and Degrees Now at home in your spare time, without any previous experience, you can train for a money-making career ...even get a Specialized Associate Degree. Call or send for free information on the career field that interes ts you most and how to train for il. 1-800-228-5300^ CALL ANY Tl ME— 2* hours a day. 7 days a. week. £ No cost Kg oh: gaiion No salesman wil visit * OR MAIL COUPON TODAY * International Correspondence Schools Oepl. D E51 0,925 Oak Street. Scranion. PA 18515 Send free facte on now I can study at home for the career I have chosen. No obligation Uo salesman will visit CHECK ONE BOX ONLY. ASSOCIATE IN SPECIALIZED ASSOCIATE IN SPECIALIZED BUSINESS DEGREE PROGRAMS TECHNOLOGY DEGREE PROGRAMS newness Managemeni DMEhancal EngmeeriAQ □ Accounting THftnology G Business Managemen I Qfiiri EngirwenngTetihnaiogy with aptnn in Marketing □ Electrical Engineering □ Business Management ! e: ^ nolagy with npi. nn In Finance Q Electronics Technology CAREER DIPLOMA PROGRAMS □Computer Programming 1-1 Personal Computer Specialist H.gh School Caienng.^o^r,Tie^ Cooking ! Microcomputer Repair iAgto Mechancs _ MotefReslauram Ma na gement □ Drafting □ Air Gorcbtjorung £ ReHngeralion Q Electronics UPohcs Sciences Name Ad dress □Art □ Small Busthss Management □ Wildiire/Torestry Conservation □ Diesel Mechancs □ Gun Repair □Motorcycle Repair QSBTWM04 Mapping □TWCR Repair □ VeterrnaryAssjstar.t □ Travel Agent □ Photography □ JcwrrHlismShort Story 'Wining _Ap1#_ Clty/Slate ■ Phnnet )_ -ZIP- iy A Subsidiary of Nattonas Education Corporation CIRCLE 185 ON FREE INFORMATION CARD ■n m c > < — i (D O 71 Drawing Board A crystal-controlled video timing generator. ROBERT CROSSBLATT, CIRCUITS EDITOR 05 o o EC < □c 72 WHEN YOU START FOOLING AROUND with video circuitry, there are three things you always have to keep in mind: timing, timing, and, above all else, timing. The key to designing video circuits is making sure that the right voltages show up at the right time. The values can be slightly off, but if they don't show up exactly when they're sup- posed to, they might just as well not show up at all. Since video is fairly complex, ev- eryone has his or her own ideas about the best way to get into it. Theory is important; after all, the video waveform is an agreed-upon standard, and you have to under- stand its component parts before you can design hardware to pro- duce it. But the best way lo learn is to do, and the easiest way to pick up theory is by having it demon- strated; so let's see what's involved in designing basic hardware. Hardware basics Thewaveform in Fig. 1 is one line of National Television Standards Committee (NTSC) standard hori- zontal color video. We've already discussed its component parts, but this time I've included all the liming. There are several basic fre- quencies to be generated, and the pulse width is strictly defined. Na- tional Semiconductor, and other manufacturers, make IC's that can take a basic clock frequency in at one end, and put out all needed video frequencies at the other end. They are good chips for de- signing real-world circuitry, and we'll look at some later; but first let's re-invent the wheel so we know how it works. - 0/V£. i-W£. oF/rrsC -JK4MC>A£0 COCP.*? V/0-EO COL.OS. a«?s? (3.57 f 5*5 MHz) ff.ii^i- ■*- •t.SSfti-r- //. / At/cfosscoms S2,-r M/CX03£ corns FIG.1 C^ock GJ5N£.#J72P#. FIG. 2 Designing a video sync gener- ator is an exercise In pure logic and arithmetic. We need clock gener- ators to control production of the needed frequencies, and one- shots to produce pulses of the right width. Since the most basic signal needed is horizontal sync, that's the place to start. The block diagram in Fig. 2 gives a good overview of the circuit to be designed. There's a master clock generator, whose frequency is divided down to produce hori- zontal and vertical sync clocks. They will trigger pulse generators to output the actual sync pulses. By deriving everything from a mas- ter clock, the generated sync sig- nals maintain constant timing with regard to one another, an absolute must for video. The sync-gener- ator accuracy will depend com- pletely on that of the master clock, so we have to use a crystal-based circuit. That creates certain prob- lems, but it's the best way to go. The master clock Crystal oscillators used to be ex- otic and expensive, but are now cheap and easy to build. The issue now is what frequency to use, and what chip will produce it. Every- one has his or her own prefer- ences, but one that's often overlooked is the 8284 shown in Fig. 3, in an appropriate oscillator circuit. It was originally designed by Intei as the basic clock for the 808X microprocessors, and any 8(J8X~based computer will have one on the motherboard. Its fre- quencies and duty cycles are really geared to Intel's microprocessors, but it's a handy general-purpose clock generator, also. M ost of the 8 284 control pins like AENi (pin 3), aenz (pin 7), rdyi (pin 4), rdy2 (pin 6), reaoy (pin 5), and csync (pin 1) are used only when you're using the chip in a computer; we won't use them here. They have to be tied either high or low to make the chip work for our purposes. All we want the 8284 to do is to act as a stable oscillator. That's easy to set up, and the 8284 has several free extras. The pins used here are crystal inputs xi (pin 17) and X2 (pin 16), and clock outputs use (pin 12), ci.k (pin 8), and pclk (pin 2). In Fig. 3, the 8284 takes the crys- tal and provides three different output clocks. The osc output (pin 12) is a buffered version of the crys- tal frequency, the ctKoutput (pin 8) is Vi the crystal frequency at a 33% duty cycle, and pclk (pin 2) is half the clk frequency with a 50% duty cycle. The clk output has an un- usual duty cycle for use with an Intel microprocessor. Also, note the f/c (Frequency or Crystal) input on pin 13. Since the chip is a collection of flip-flops and buffers, it needs an input frequen- cy divided down internally to pro- vide the output clocks. The state of f/c determines the origin of the in- put clock. If h/c is tied low, the 8284 will look at its internal oscillator, the frequency of which depends on the crystal hanging off inputs xi and X2. If f/c is high, the 8284 will look at the clock being fed to efi (External Frequency In) input at pin 14, That means that you can change theoutputclocks simply by chang- ing the logic level on f/c (pin 13). Most two-speed IBM-XT clones use that feature to switch from "normal" to "turbo" speed. By trapping a scan code from the key- board and using it to toggle a flip- flop, they change the level of f/c, and switch the master clock speed of the microprocessor, giving a two-speed computer. Now that we have a circuit to FIG. 3 produce our clock, we have to de- cide on what clock to produce. It would be really nice if all the fre- quencies needed were derivable from one easily available crystal frequency, but they're not. There's just no easy number to provide ev- erything we need. For reasons that'll become apparent when we are farther along in our design, 14.318 MHz is a good choice. One obvious reason is that division-by- four will give 3.579545 MHz, the colorburst frequency. Getting a horizontal frequency of 15734 kHz, however, will take a little more work than that. The 12-pF capacitor in series with the crystal helps start the 8284 's internal oscillator. Since it's similar to an amplifier, the resis- tance of the crystal network has to be kept as low as possible. If it's too high, the gain drops; and if it's too low, it won't oscillate. The two resistors reduce the effects of stray board capacitance and voltage fluctuations on the frequency. A breadboard is a good choice for construction, but there's consid- erable capacitance between rows. Since the crystal frequency is pret- ty high, that stray capacitance can wreak havoc, so the two resistors will keep the oscillator frequency fairly stable. If your oscillator frequency is outside the 14. i I4.4 MHz range, there's a problem on the bread- board. The easiest way to fix it is to accept the breadboard-induced error as unavoidable, and correct the frequency by varying the ca- pacitor value over 4.7-47 pF. If you're really ambitious, replace it with a small trimmer capacitor. R-E Be an FCC LICENSED ELECTRONIC TECHNICIAN! No costly School. No commuting to class. The Original Home-Study course pre- pares you For the "FCC Commercial Radio- telephone License". This valuable license is your "ticket" to thousands of exciting jobs in Communications. Radio-TV, Micro- wave. Computers, Radar. Avionics and more! 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Six insertions $925. each Twelve insertions S895.each. Closing date same as regular rate card Send order with remittance to Engineering Admart, Radio Electronics Magazine, 500-B Bt-County Blvd., Farmingdale, NY 11735. Direct telephone inquiries to Arline Fishman. area code-516-293-3000. Only 100% Engineering ads are accepted for this Admart. 6805 MICROCOMPUTER DEVELOPMENT SYSTEM The MCPM-t system allows the IBM PC and compatibles lo be used as a complete development system for the Molorola MC687Q5P3. P5. 113, US. R3 and R5 single chip microcomputers. The system includes 3 cross assembler program, a simulator/debugger program and a programming hoard that connects to a serial port Price— $449,00 VISA and MASTERCARD accepted THE [KCWCCItS CSUIBBIUTIVf. i»t RR#3. BOX 8C Barton. Vermont 05822 Phone C802) 525-3458 FAX (802) 525-3451 Surface Mount Chip Component — Prototyping Kits- \ Only , CC i Capacitor Kit contains 365 pieces, 5 ea" ol Bvery 10% value from tpf to 33>f. CR-1 Resistor Kit contains 1 540 pieces, to ea . of every S°,*> value tram ion to 1 rnegn . Sizes are OS05 and 1206 Each kit is ONLY $J9 95 and available for Immediate One Day Delivery! Order by toll-free phone, PAX, or mail. We accept VISA, MC, AMEX, COD, or Pre-paid orders Company P.O.'s accepted with approved credit. Call for free detailed brochure. 'COMMUNICATIONS SPECIALISTS, INC. 426 Wesl Tafi Ave. • Orange. CA 92665-4296 Local (714) 996-3021 ■ FAX (714) 974-3420 Entire USA 1-800-854-0547 CIRCLE 181 ON FREE INFORMATION CARD CIRCLE 193 ON FREE INFORMATION CARD CIRCLE 182 ON FREE INFORM ATiON CARD HARDWARE HACKER continued from page 71 to o o BE LU g 5 < re- Dew sensors We've looked at humidity sen- sors in several earlier columns. One unique and low-cost humidi- ty detector is called a dew sensor. They cost oniy a dollar each and are intended to protect moisture- sensitive VCR drums. Three typical part numbers would be the Murata HOS 101-100, the Taiyo Yuden TD-P-100, or that Panasonic EYH-S0210. At a 100 percent humidity, the air retains all of the moisture it possi- bly can. Beyond that, the moisture in the air will condense out, form- ing a rain or a dew coating. Aspecial moisture-sensingpaint dramatically raises its resistance well beyond 1 Megohm whenever it gets wet. Thus, your sensor is typically al 10K when dry and 1 Megohm when wet. A good deci- sion point is to split up the dif- ference on a log basis, and do your tripping at a 100K level. Figure 5 shows you one possible sensing circuit. Because you have to keep the total system power un- der two milliwatts, the maximum DC voltage that you are allowed to apply is only 0.8 volts. The sensor acts as a current-robber. At low hu- midities, the sensor's resistance is around 10K and steals so much cur- rent, that the NPN transistor re- mains off. When wet, the sensor impedance goes above 1 megohm, and conventional current flows into the base of the NPN transistor, turning it on. That inverting CMOS Schmitt trigger gives you an on-off snap action. Your red light-emitting di- ode lights when wet and the green when dry. Tellyawhat. For this month 'scon- test, just tell me about a new or unique use for dew sensors. There will be all of those usual Incredible Secret Money Machine book prizes going to the best dozen or so entries, with an all expense paid (FOB Thatcher, AZ) tinaja quest tor two for the best of all. As usual, all entries must be written and should be sent directly to me here at Synergetics, rather than to the editor of Radio-Elec- tronics. Show me what you can come up with. New tech literature Data books this month include the Da fa Conversion Products Databook from Analog Devices, and an absolutely astounding new Semiconductor Product Guide from Samsung. That latter gem is chock full of new hacker inte- grated circuits for use as scientific calculators, speech synthesis, melody chips, cassette recorders, watches, for alarm clocks, and bunches more. Two surplus catalogs are avail- able from R&D Electronics, and Lehman has weather radiosonde transducers that include humidity, pressure, and temperature sens- ing for only $3.50. Stock number is MC-1019-MOD. Some surprisingly cheap and high-quality digital voice record- ing and playback modules are available from Ming Engineering. The singfe-quantity prices start at $49. They are all fully EPROM-pro- grammable. They apparently use that new Toshiba TC8830F speech synthesis chip. Turning to mechanical stuff, low-cost nylon bearings and a free calt li I a lor arc available from Thompson Nyliner, while the ICUS folks offer all sorts of the self-lubricating plastic bearings. Prices for them start at fifteen cents in quantity. A reminder here that I am book- on-demand publishingacomplete set of the edited, indexed, and up- dated reprints of everything you've seen here in these columns since day one. Ask for my Hardware Hacker, volume II, now available through Synergetics. For those of you who are not yet into PostScript, I also stock an Intro to PostScript VHS video that shows you what you need in order continued on page 88 74 ComputerDigesj BUILD THE PORT-A-MATIC Building the Port-A-Matic ROBERT GROSSBLATT The Port-A-Matic is a fairly complex circuit that depends on tight signal timing. Although you could wirewrap it on perf board, you're better off using a PC board: patterns are shown in PC Service and a supplier is listed in the "ordering information" box. The Port-A-Matic was designed to be built on two PC boards; an internal bus interface (that in- stalls in any 8- or 16-bit PC-com- patible expansion slot) and an external display board. The two boards are connected by ribbon cable, and the pins are arranged in the same order on both boards so you can use a straight- through ribbon-cable connec- tion. Sixteen conductors are re- quired, but you'll probably want to use 20-conductor cables, be- cause they're easy to obtain (and inexpensive) because they're used as data cables connecting controller cards and hard-disk drives in PC compatibles. To install the components, use the diagrams shown in Fig. 1 and Fig. 2. Of course, be sure to ob- serve the polarity or diodes, tran- sistors, electrolytic capacitors, and IC's. None of the IC's on the board are rare or expensive, but you should still be careful when you're handling them since blown IC's look an awful lot like good ones. Since you'll probably make oc- casional changes to the look-up table in the EPROM, you'll want to install it in an IC socket. In fact, all IC's should be socketed because there is no absolutely safe way to desolder a suspect IC. If you suspect that an IC is fried, desoldering it to check it may make your suspicion a reality if you don't know what you're doing! Although you can put parts on the board in any order you want, assembly is easier if you start with the IC sockets, then go through the passive components (resistors and capacitors), and fi- nally the active components (di- odes and transistors). That's a good order to follow because continued on page 78 EDITOR'S Work- bench Announcement Mario Maniscalco's $ 100 chal- lenge to Computer Digest readers to crack the secret mes- sage published in the April 1988 issue has gone unanswered, so he will now send the key to any- one who sends an SASE to P.O. Box 110082, Cleveland. OH 44111. (The address published in the October 1989 issue is incor- rect.) Mario also plans a newslet- ter on the encryption program; write to him at that address for more information. Modular IC programming system It wasn't so long ago when EPROM's were novelties, and 2716's (2Kbytes) were considered high density. Now 64K EPROM's are common, 128K EPROM's are becoming economical, and there are several other types of pro- grammable devices, including PAL's, EEPROM's, standard bi- polar PROM's, and more. You can spend thousands of dollars for a universal programmer for dif- ferent types of devices. Or you can latch onto JDR's modular S system, let your PC provide the § intelligence, and buy only the > modules you need when you need < them. 5 Several modules are available. 1 75 CO o z c — o LL -I 6 5 < -•= MODIM CIRCUET TEGHH010GY M I DDEL : NCT-HEP (0 SEP 1988 ly Hodular Circuit Technology PIG. I * TYP. I 27C254 ttUpp.: 12.SU LME M j XPROG. : intelligent sUCC: i.W 1, DIR 2, LOAD OBJ FILE TO I1EI10RY BUFFER 3, SflUE MEMORY BUFFER TO DISK I DEBUG MEMORY BUFFER 5, BANG SIZE I PROGRAKNING ALGORITHM 7, SET tlEMORY BUFFER SIZE H. MANUFACTUREK T. TYPE 8, BLANK CHECK P, PROGRAM A. AUTO R, READ y. VERIFY C, COMPARE D. DISPLAY 8 EDIT (I. QUIT ELECT UHICH NUMBER ? FIG. 2 tested the EPROM/EEPROM module (shown in Fig. 1), which lists for about $120: 4-, 8-, and I6-socket versions are available for volume production. Other programmers include one for PAL's ($250), one for micro- processors ($180), and one for bi- polar PROM's ($260). An 1C tester20is also available for $130, and PAL development software for $ 100. Each module includes a ZIF (Zero insertion Force) socket (or several, for the multi-gang models). If you're planning to buy two or more modules, you'd probably be better off going with the Univer- sal Module, which lists for about $500. and can perform all func- tions of the individual modules. Whichever module(s) you choose, you'll need a $30 host adapter/cable. The adapter is a short card that fits in any 8- or 16-bit expansion slot. The cable is a quality molded 25-conductor job with 25-pin D connectors on both ends. Unfortunately, the connector on the card is identical to a standard PC printer con- nector; make sure you don't con- nect a printer cable to that port— a high -voltage pulse could have the misfortune of frying your printer instantly! Installing the card requires set- ting a couple of jumpers that de- termine the card's I/O address. Installing the software consists or copying the contents of a 360K disk to a subdirectory on your hard disk, and then running a setup program in which you specify your computer type and speed. Neither my computer type nor its speed were listed, but I picked the closest match and had no trouble. The module can program all common and several uncommon EPROM's that you might want to use ranging from the 2716 to the 27010. CMOS versions thereof, and 2816. 2817. and 2864 EE PROM's. However, it can't pro- gram paged EPROM's. such as the 27011. The software is menu-driven, as shown in Fig. 2. You can list a directory and load a file into a memory buffer. You can then modify the contents of that buffer using either the software's built- in editor or DEBUG.COM, which ITEMS DISCUSSED 75C188N driver. 75C189N re- ceiver ($0.75/M). Texas Instru- ments, Literature Center, P.O. Box 809066, Dallas, TX 75380-9066. CIRCLE 48 ON FREE INFORMATION CARD • The XT-AT Handbook ($9.95), John Choisser and John Foster, Annabooks, 12145 Alta Carmel Court, Suite 250-262, San Diego, CA 92128. (619) 271-9526. CIRCLE 47 ON FREE INFORMATION CARD • (E)EPROM Programmer (MOD-MEP $119.95) and host adapter (MOD-MAC, $29.95). JDR Microdevices. 2233 Branham Lane, San Jose, CA 95124. CIRCLE 46 ON FREE INFORMATION CARD 76 R-E Computer Admart GETTING THE MOST FROM YOUR PRINTER Getting The Most From Your Printer BP181— It is probable that 80% of dot-ma- trix, printer users only ever use 20% of the features offered by their printers. This book will help you uniock the special features and capabilities that you probably don't even know exist. To order your copy send $6.95 plus $1.50 for shipping in the U.S. to Elec- tronic Technology Today Inc., P.O. Box 240, Massapequa Park, NY 11762-0240. Rates: Ads are 2-A" x 2W. One insertion $950. Six insertions $925.each. Twelve insertions $895. each. Closing date same as regular rate card. Send order with remittance to Computer Admart, Radio Electronics Magazine, 500-B Bi-County Blvd., Farmingdale, NY 11735. Direct telephone inquiries to Ariine Fishman, area code-516-293-3000. Only WQ% Computer ads are accepted for this Admart. ' SECRETS OF THE COMMODORE 64 COMMODORE 64 BP135— A beginners guide to the Commodore 64 pre- sents masses of useful data and programming tips, as well as describing how to get the best from the powerful sound and graph- ics facilities We look at how the memory is organized, random numbers and ways of generating them, graphics-color-and sim- ple animation, and even a chapter on ma- chine code. Get your copy today. Send $5.00 plus SI. 25 for shipping in the U.S. to Electronic Techology Today Inc., P.O. Box 240, Massapequa Park, NY 11762-0240. PROMPT DELIVERY!!! SAME DAY SHIPPING (USUALLY) QUAMT IfYQHE P RK.; ■. -"'..'.'■ 'w OCT ILJW* emtaaasaEffiSiMiBEaHaaj DYNAMIC RAM SIMM AST Ptemrjee jSMta S3GQ.QQ 1 SIMM '1 256Ki36 80 ns 300.00 1 80 ns 100 ns 100 ns 60 ns 80 ns 100 ns 120 ns 120 ns 100 ns 1MX9 256Kx9 1MX1 256Kx1 256Kx1 256Kx1 64KX4 EPROM 128KxS 200 ns 64KX8 200 ns 32KX8 150 ns I6K18 250 ns STATIC RAM IB2256P10 32Kj8 100 ns 6264P-12 skxb 120 ns I6116AP-I2 2Kx8 120 ns INCLUDED "'J. FED-EX OflDEflS RECEIVED n.' Ik i! HJI4h Fr *-■ till! , h MWfclill-fliHaJ.BI MislurCird VtSA jy UPS CASH COD MrC HO PROCESSORS UNLIMITED. INC. 24 COD 5 PftON* Ave " BEGG5. OK 7**2t Ns mlrnmurn order. "t*n m (918) 267-4961 CIRCLE 61 ON FREE INFORMATION CARD the software will load for you when you choose item 4 from the menu. The built-in editor is rather weak, but by using DE- BUG you can search the memory buffer, fill it with a constant, as- semble code into it, etc. You can also save all of the contents of the memory buffer to disk if you like. Other functions allow you to set up the programming param- eters, including (E)EPROM man- ufacturer, type, and program- ming algorithm. Not all manufac- turers are represented, however, so you may have to do some re- search (or experimentation) to determine the proper program- ming voltage and algorithm for some types of EPROM s. I had no trouble burning Intel EPROM's, but I burned up several junk-box varieties of EPROM'S that the programmer didn't support. Also, the software doesn't allow you to set the programming volt- age independently of the pro- gramming algorithm. Other functions allow you to verify that an (E)EPROM is eras- ed, to read the contents of an (E)EPROM into the memory buff- er, to program an (E)EPROM, and to verify programming by com- paring buffer contents to (E)EPROM contents. You can specify starting and stopping ad- dresses for all activities. A sepa- rate utility is provided with the package that converts hex format files output by some assemblers and compilers to binary image format. A short user's guide explains how to use the programmer, and outlines several programming al- gorithms, but it sorely lacks tech- nical information on (E)EPROM pinouts, programming al- gorithms, and programming voltages. My only other complaint is that it is possible to crash out of the program by pressing Ctrl-C at the wrong time. If you did so while the programming pulse was being applied, you could fry a chip. So the software should Lake control of the DOS interrupt lBh handler. Otherwise, the product per- formed flawlessly. At $150, it's an excellent buy for anyone who needs that kind of equipment, ♦CD* TI's new RS-232 interfaces er and a line receiver, both of which are pin-compatible with the 1488 and 1489 standards. Overall power consumption of the new devices is reduced by a factor of about 2000, compared with standard IC's, In addition, the new drivers contain on-chip slew-rate limiters that eliminate the need for external capacitors. The 75C188N and the 75C189N are priced at $0.75 in quantities of 1000. *CD4 The XT-AT Handbook lexas Instruments recently in- troduced an RS-232 line driv- This 70-page booklet fits in 3 your shirt pocket and ™ modestly proclaims that it con- > sists of "a collection of hardware 5 and software facts and data on £ continued on page 82 o 77 PORT-A-MATIC continued from page 75 there are lots of holes on the board and mounting the IC sock- ets Tirst gives you reference points for locating the other com- ponents. Also, several compo- nents are mounted on pads by feedthroughs, so be sure not to install a component in the wrong pad! Speaking of feedthroughs, both Port-A-Matic boards are double-sided, and several con- nections "jump" from one side of the board to the other by means of feedthroughs. The pattern was designed to make most of those jumps at component mounting holes, but there were several places where that wasn't possi- ble. In each of those places you'll have to solder a piece of hookup wire to both the foil and the com- ponent sides of the board. (Of course, that applies only if you make your own boards. If you use plated-through boards, the con- nections will be made automat- ically by soldering one side.) Several of the jumps are done on the legs of the IC's, and that can be a problem is you use stan- dard low-profile IC sockets. You can get around the problem by using machined-pin sockets with long legs. Mount the socket slightly above the board so that you can solder the legs to both sides of it. A better solution is to use socket strips, which are sin- gle strips of machined socket pins. They're similar to Molex pins, but they have the advan- tage of being mounted in pieces of plastic. Wirewrap sockets are not recommended because their legs are too fat. The three FND-500 digits on the display board have rows of pins that are spaced 0. 6-inch es apart. You can make a socket for them by doing a bit of surgery on a 40-pin socket. There's a space of 0.2 inches between each digit, so you really need a 38-pin sock- et. Make one by removing the un- wanted pins from a 40-pin socket: you'll find that there's more than enough room at the sides of the digits to fit a 40-pin socket on the board. Lookup tables The Port-A-Matic needs two programmed EPROMs to work. Listing 1 shows the binary file for the character generator; Fig. 3 shows how the characters look. You can change them any way you want; just beware that it's difficult to distinguish between 6 and b. In our design, the 6 has a "tail" on the top segment, but it's still easy to mistake one for the other. The Port-A-Matic won't work without a port-select EPROM in- , ° o I a 3 DC Fig. 1 BUS INTERFACE BOARD PARTS PLACEMENT DIAGRAM. 78 Fig. 2 DISPLAY BQUiD PARTS PLACEMENT DIAGRAM. stalled, and a blank EPROM pro- duces the same effect as no EPROM. Listing 2 shows one pos- sible port-decoding table. When your Port-A-Matic is up and working, you can alter the table to decode any addresses you want, but for the purposes of testing, go with the default. That table decodes the five most com- monly used port addresses: COM1. COM2, LPT1, floppy disk, and joystick 1. Oh no — it doesn't work! If you build the Port-A-Matic on PC boards, you shouldn't have much trouble getting it to work. If you do have trouble, most likely you've made some sort of assem- bly error. Before you start any heavy-duty troubleshooting, check for solder bridges and cold solder joints. Before we discuss trou- bleshooting, remember that the Port-A-Matic is sitting in an ex- LISTING 1— ( )ON 5B TENTS OF CHARACTER-GENERATOR EPROM IC1C 000 - 3F 06 4F 66 6D 7D 07 7F 6F 77 7C 39 5E 79 71 010 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 020 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 030 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 040 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 050 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 060 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF The rest Of the EPROM is not used 770 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 780 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 790 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 7A0 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 7B0 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 7C0 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 7D0 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 7E0 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 7F0 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF pansion slot, and even the best designed motherboards are noisy places, electronically speaking. Putting a scope probe on an ex- pansion-slot pin is a real eye- opener; you'll find so much ring- ing, noise, and hash that you'll be amazed the computer can work at all. Realize that the Port-A-Matic processes high-frequency sig- nals, and there's no way you're going to be able to troubleshoot complex problems without an os- cilloscope. Too much is happen- ing too fast to be able to use logic probes and multimeters. How- ever, as we go through the trou- bleshooting procedure, we'll try to provide alternatives for signal monitoring. If the computer hangs up with the Port-A-Matic in a slot, but it works fine when the board is re- moved, you've probably got a short between two of the lines on the board that are connected di- rectly to the bus. The cure for that is a strong light, a magnifier, and careful inspection. Assuming that your computer works with the Port-A-Matic in- stalled in a slot and that you have installed a suitably programmed port-selector EPROM in the Port- rr- - C > EC to a 79 LISTING 2- LISTING FOR BASIC PORT SELECTOR EPROM 1C11 Port No LED Comment 220 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 230 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 3F8h First serial p 240 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 2FSh 1 Second Se rial Fort I COM2 ) 250 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 3BCh 2 First Parallel Port (LPT1) 260 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 3F5h 3 Floppy Dl 3k Data Fort 270 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 201h 4 First Joystick Data Fort 2B0 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 290 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 000 - FF 04 FF FF FF FF FF FF FF FF FF FF FF FF FF FF 2A0 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 010 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 2B0 - FF FF FF FF FF FF FF FF FF FF FF FF 02 FF FF FF 020 - FF FF ,; FF FF FI FF FF FF FF FF FF FF FF FF FF 2C0 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 030 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 2D0 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 040 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 2E0 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 050 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 2F0 - FF FF FF FF FF 03 FF FF 01 FF FF FF FF FF FF FF 060 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 300 - FF 04 FF FF FF FF FF FF FF FF FF FF FF FF FF FF 070 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 310 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 080 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 320 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 090 - FF FF FF FF FF F W FF FF FF FF FF FF FF FF FF FF 330 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF OAO - FF FF 1 F FF FF FF FF FF FF FF FF FF FF FF FF FF 340 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF OBO - FF FF FF FF FF FF FF FF FF FF FF FF 02 FF FF FF 350 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF OCO - FF FF FF FF FF FI FF FF FF FF FF FF FT FF FF FF 360 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF ODO - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 370 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF OEO - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 3S0 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF OFQ - FF FF FF FF FF 03 FF FF 00 FF FF FF FF FF FF FF 390 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 100 - FF 04 FF FF FF FF FF FF FF FF FF FF FF FF FF FF 3A0 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 110 - 1 20 — FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF XV FF FF FF FF FF FF FF FF FF FF FF FF ~F FF FF FF FF FF "F FF FF 3B0 - SCO - 3D0 - Ff FF FF FF FF FI FF FF FF FF FF FF FF FF 02 FF FF FF : . . - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FI FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF Fr FF 140 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 3E0 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 150 - FF FF FI FF FF FF FF FF FF FF FF FF FF FF FF FF 3F0 - FF FF FF FF FF 03 FF FF 00 FF FF FF FF FF FF FF 160 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF I | | 170 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF The rest of the EPROM is not used 180 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 1 i 190 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 770 - FF FF FF FF FF FF FF FF FF FF FF FF FF ff'ff FF 1A0 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 780 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 1B0 - FF FF FF FF FF FF FF FF FF FF FF FF 02 FF FF FF 790 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF ICO - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 7A0 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 1D0 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 7B0 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 1E0 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 7C0 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 1F0 - FF FF FF FF FF 03 FF FF CO FF FF FF FF FF FF FF 7D0 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 200 - FF 04 FF FF FF I F FF FF FF FF FF FF FF FF FF FF 7E0 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 210 - FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 7F0 - FF FF FF FF FF FF FF FF FF FF FI FF FF FF FF FF (0 g z o IE F b -i LU 6 < Fig. 3 THE PORTAMATICS CHARACTER SET. You can modi/y any or all by program- ming the characler-genemlor EPROM (IC101. A-Matic, here's a step- by-step pro- cedure you can follow to trou- bles hoot the circuit. Load BASIC and type in the simple program shown in Listing 3. That may not be the worlds most elegant program, but it will repeatedly access a port that the Port-A-Matic is set to decode. The alternating reads and writes to the port will test both halves of IC9 (shown in Fig. 3 of the Janu- ary 1990 installment) and the de- lay loop will cause a visible change on the activity LED's on the display board. You'll have to adjust the length of the delay loop to match the speed of your com- puter, but the number in the list- ing is a good starting point The key to the operation of the circuit is pin 6 of IC2-b. which is where the master- enable signal is generated. If you have a scope you should see a series of negative- going pulses there. The frequen- cy of the pulses will depend on the speed of your computer, but a 12-MHz AT will access the port at a rate of about 1 kHz, so set the scope's sweep speed accordingly. If the signal is there, you'll see a trace similar to the one in Fig. 4-a. You may have a hard time locking the scope to that signal because the time between pulses isn't constant. However, reg- ularity isn't important, since all you want to do is make sure it's there. If you don't have a scope, you can use a logic probe, but it will be hard to tell whether the signal is actually present or you're just detecting noise. The presence or absence of the master enable signal determines what troubleshooting route to follow next. With the master enable If the signal is present, you've got a problem farther down the line. The most logical places to check are the outputs of the time- rs, since those are the signals that enable the displays. You should see something similar to the trace shown in Fig. 4-b at the output of IC8-a. The reason that signal doesn't swing closer to the 80 supply rails is that the timer Is retriggered so often that the out- put is driven high before it has a chance to go low. The test program causes the outputs of IC9 to swing alter- nately high and low. The frequen- cy will depend on the number in the delay loop and on the speed of your computer, but you should be able to see that activity with just about any test equipment there is; a scope, logic probe, even a multimeter. If you're getting activity at the timer outputs, your problem is probably on the display board. Check the cable and make sure that you have the correct orienta- tion on the connectors. If that's correct and the board is generat- ing the master enable signal, you've narrowed the problem to the timer circuits, which are so simple that the problem should now be easy to find. Chances are you've got one of the assembly er- rors discussed earlier, such as poor soldering. The presence of the master en- able signal means that the major- ity of the Port-A-Matic is happy. Aside from the timers, there are several other places on the board that can help you locate the prob- lem. Some of these points can be tested with logic probes and mul- timeters, but once again you should look at them with a scope. As with the other test points, the frequency will depend on your computer, but the exact number isn't important. 1. The Q2 output of IC7, the data multiplexer, should look like the trace in Fig. 4-c. If there's nothing there, check IC8-b. IC13. and the reset logic made up of THE MASTER ENABLE SI6MAL 1 1 IT 1 | V T I s OUTPUT PULSES AT IC7 PIN 12 ^ _ .__ ' OUTPUT PULSES AT ICU PINS 7 & 9 f-^ r^. r~- ' '^^ r**, .^ , l __ , B OUTPUT PULSE AT ICtl PIN 211 ! IC2-d and ICl-b. 2. You should see square waves similar to Fig. 4-d at the otitputs of IC12. the digit multiplexer. Look at IC8-a and IC13, as well as Q4— Q6 on the display board. If the waveform appears when you disconnect the ribbon cable, you've got a short somewhere on the display board. 3. The two least-significant outputs of IC13, QO and Ql {pins 7 and 9). should have square LISTING 3— TEST PROGRAM 4 REM ****************************** 5 6 8 7 8 REM * Exercise the Port-A-Matic * REM * by reading and writing * REM * to Port 3F5h * REM * * REM ****************************** 9 REM 10 X=INP( 1013): FOR N = I TO 500:NEXT 20 OUT 1013, X: FOR N = 1 TO 500: NEXT 30 GOTO 10 40 END 1C8-8 OUTPUT PULSES — — IE 1 1 b IC12 OUTPUT PULSES PINS 15 & 14 *■ 1 1 OUTPUT PULSES IC11 PINS 22 & 23 r 1 1 1 c 1 I Fig. 4 THE MASTER ENABLE SIGNAL (a) appears at pin 6 of !C2-b. The out- put oflCS^a pin 5 tb) drives decoder IC12. The Q2 output oftCT pin 12 tcl drives ICIQ. The digit-enable pulses /mm IC1 2. should look Uke id), the QO and Ql outputs oflClS le) drive IC12. the A8 and A9 outputs of IC I I if) drive IC10. and 1C11 pin 20 looks like (g). waves like the ones in Fig. 4-e. A problem here can be caused by a constant high on the reset line (pin 11), or by the absence of in- put clock pulses on pin 10. Check IC2-b. ICl-b. and IC8-b. 4. The waveform in Fig, 4-J should be present on IC11, which is the port-select EPROM, at pins 22 and 23. Also make sure that you check ICl-c, diodes Dl and D2. IC5 pins 11 and 13, and the outputs of IC3. ORDERING INFORMATION A set of two double-sided printed circuit boards is avail- able for $38.95 from Systems 80 Instruments Ltd., c/o CF Liebert, Inc., P.O. Box L, Blaine, WA 98230. The two programmed EPROMs (2716-1, 350 ns) as described in the article are also avail- able from Systems 80 for $19.95. All prices include shipping and handling. m 03 33 C > o 81 Without the master enable No master enable signal means either an error in the IC3 latch, the control circuitry, or the input buffers. The first place to look is the control circuitry, since the rest of the circuit won't work at all unless the control circuitry is operating properly. The output enable line (pin 20) oflCll, the port selector, is a good place to start, A signal here, as shown in Fig. 4-g, means that IC2-a and ICl-d are properly de- coding the I/O pulses from the computer bus. That can be checked with a logic probe since the frequency isn't very high. If you've got a constant high at that pin and you're sure there axe no shorts or opens on the board, look at the output of IC2-a. That is only one step away from the computer bus and the absence of a signal there is an indication that either the 74LS00 is bad (unlikely), or that it isn't seeing the I/O lines from the bus. The next place to check is the output of ICl-a (pin 1), since the signal here has a direct effect on the generation of the master en- able signal. The pulses there should resemble Fig. 4-g, but de- layed by the access time of IC11. You can catch them with any good logic probe but a scope is better. The general appearance of all the control-circuit signals will be the same; very narrow, irreg- ularly spaced, positive- or nega- tive-going spikes. The input buffers (IC4 and IC5), are more difficult to check since nothing will happen there unless the master enable signal is being produced by the control cir- cuitry. There is one trick you can use, but it's probably going to cost you an IC. Remove IC2 from the PC board (you do have them in sockets, don't you?), bend pin 6 out straight and put the IC back in the socket. Run a piece of hook-up wire from pin 13 of IC1 to the opening of pin 6 in the socket of IC1. What we're doing is triggering the Port-A-Matic directly from the computer's I/O pulses. Check the outputs of IC4 and IC5 for data pulses. Since we're accessing the same port over and over, you may only see unchanging highs and lows on the various pins. That's fine. If you write down the state of the pins in binary order you'll find that they're carrying 11 1111 0101 or 3F5h. the port address in the test program. If you're still not getting any- thing, there are a few things left you can check to help locate the source(s) of your problem(s). 1. Make sure the port-selector EPROM is properly programmed since any sort of error here may keep the Port-A-Matic from work- ing completely. 2. Lift pin 6 of IC2-b from its socket and then check it for the presence of the master enable signal. If you see it when you do that, you've got a board problem further down the line (most likely a solder short). 3. Check the values of Rl and R12. 4. Check the value of C3. The Port-A-Matic will work with a val- ue less than 0,001 p,F (although operation may be flaky), but a larger value will stop the Port-A- Matic completely. If you sub- stitute a 0.01 |jlF capacitor for C3, it wili completely swallow the nar- row master enable pulses, so the circuit won't work. There are sev- eral systems used to mark capac- itor values, so lets just state for the record that a marking of 104 is 0.1 n.F, 103 is 0.01 \lF, and 102 is 0,001 |xF. Putting the Port-A-Matic to work Although the Port-A-Matic was originally intended to be a diag- nostic tool for hardware, it's also a terrific aid in debugging soft- ware. A standard troubleshoot- ing technique in program de- velopment is to use a PRINT statement in BASIC (or the equiv- alent in whatever language you use) to track program flow. The Port-A-Matic can decode sixteen different port addresses (or thirty two if you distinguish 1/ O reads and writes), so you could program some unused port ad- dresses into IC11 and replace PRINT statements with ENP and OUT arguments. The operation of the Port-A- Matic is totally transparent to the computer and that makes it es- pecially valuable for those times when you're doing graphics pro- gramming and PRINT state- ments can't easily be seen on the screen. There's no reason why you can't use the Port-A-Matic to con- trol a variety of external devices. Remember that accessing a valid port will result in a unique half- second pulse. Although they're being used to light LED's, there's no reason why they can't turn ex- ternal hardware on or off, as well. The Port-A-Matic is a valuable addition to any PC and the number of uses it has is limited only by your imagination. Even if all you need is something that tells you if that new I/O card is properly set up or not. the amount of time it will save you may very well be worth having one in your computer. |CD| WORKBENCH continued from page 77 ? the PC-compatible family and its £ operating system." That's the 5 truth, but it's not the whole 3 truth. K The XT/AT Handbook contains 5 in summary form darned near ev- c erything a systems integrator. technician, or designer needs to know about the PC family, in- cluding bus pin-outs, memory maps, cable connections, card dimensions, programmable regi- sters in the DMA20 and other system controllers, interrupts, BIOS entry points, switch set- tings, keyboard scan codes, the hard-to-locate diagnostic error codes, DOS commands, and more. I'd like to see a complete listing of the DOS interrupt (21h) services, and printer codes for the IBM/Epson and HAP LaserJet families. But, as it is, the book can replace a foot of fancy (and expensive) documentation. 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FREE CATALOG FAMOUS "FIRESTIir BRAND CB , AND ACCESSORIES. QUALITY PRODUCTS FOR THE SERIOUS CB'er. SINCE 1962 FIRESTIK ANTENNA COMPANY 2614 EAST ADAMS PHOENIX, ARIZONA 85034 LASER Listener II, other projects. Surveillance, descrambling, false identification, information. Plans, kits, other strange stuff. Informational pack- age $3.00 refundable. DIRIJO BOND ELEC- TRONICS, Box 212, Lowell, NC 2809a. ENGINEERING software, PC/MSDOS. Hob- byists — students — engineers. Circuit de- sign $59.00, FFT analysis $69.00, Mathe- matics $49.00, Logic Simulation $49.00, Circuit Analysis $29.00. Free catalog. (614) 491-0832, BS0FT SOFTWARE, 444 Colton Rd., Columbus, OH 43207. RESTRICTED technical Information: Electronic surveillance, schematics, locksmithing, covert sci- ences, hacking, etc. Huge selection. Free bro- chures. MENTOR-Z, Drawer 1549, Asbury Park, NJ 07712. CB RADIO OWNERS! We specialize irtawidevanetyof technical information, pais aro services for CB radios. 10-Meter and FM converaon kits, repair books, plans, high-performance accessories. Thousands of satisfied customer since 1976! Catalog 52. CBC INTERNATIONAL P.O. BOX 31500RE. PHOENIX. AZ B5046 TEST equipment pre-owned now at affordable prices. Signal generators from $50.00. Os- cilloscopes from $50.00. Other equipment, includ- ing manuals available. Send for Catalog. J.B. ELECTRONICS, 3446 Dempster, Skokie, IL 60076. (312) 982-1973. COMMUNICATIONS. Electronic equipment, sales, service, FCC licensed, free catalog. RAYS, PO Box 14862, Fort Wo rth.TX 76117-0861. CABLE TV converters: Jerrold, Oak, Scientific At- lantic, Zenith & many others. "New MTS" stereo add-on: mute & volume. Ideal for 4O0 and 450 owners! 1 (806) 826-7623, Amex. Visa, M/C accept- ed. B & B INC., 4030 Beau-D-Hue Drive, Eagan, MN 55122. DESCRAMBLERS. Lowest prices on top name brands. Tocom, Zenith, Oak, Jerrold, SA, Pioneer, Hamlin. Examples: RTC 56 $150,00 — tO @ 130 each. Tri-Bi <£' $79.00 in lots of 10. COD ok same day shipping. MOUNT HOOD ELECTRONICS, (206) 896-6837. ELECTRONIC test equipment, laboratory equip- ment, — surplus and priced to go! Catalog $1.00. LEHMAN, R.D. 1 Box 580, Wrightsville. PA 17368. MICROWAVE TV RECEIVERS 1.9 to 2.7 GHz 2 CH Compact Dish System -S77.95 5 CH Dish System - 593.95 12 CH Yagi (Rod) System - S123.95 30 CH Dish System -ST63.90 Yagi -S 183.90 SUN MICROWAVE INTL. INC. Send $1" tor P. a BOX 34522 catalog en Man PHOENIX. Kl 85067 ind other line |60Z] 230-0 WD video products. VISA/MC/CDO QUANTITY MSCCUHTS LIFETIME wAHRAHTY SURPLUS CATV converters and descrambfers at wholesale prices. Unmodified units only. Oak M35B $30. Jerrold 400 D1C wftemole $60. (41S> 566-9815. STEPPER motor drive & control with Commodore 64. Affordable hardware, interface, & software. Send for detailed literature & prices to: MASE, R.D. #2 Box 166. Mohrsville, PA 19541. FEB 87 Triparfs $59.00. Feb 84 SB parts $49,00, $3.50 shipping. OCTE, Box 276, Alburg, VT 05440. (514) 739-9328. RENTAL movie stabilizer. Connect between VCRs or to monitor. Satisfaction guaranteed. $69.95, $4.00 handling. 1 (800) 367-7909. PARABOLIC reflectors. 18" spun metal dish focuses RF, light, sound, $25.00; PJC, 2981 Tess Ave.. Granger. Utah 84119, MINIATURE electronics like James Bond. Catalog $3.00, refundable F & P ENTERPRISES, Box 51272, Palo Alto, CA 94303-L. CABLE boxes, all types in stock, lowest prices, guaranteed, COD ok, same day shipment, Tocoms, Tocoms, Tocoms. G.D. ELECTRONICS, (602) 829-9441. TUBES, new, up to 90% off, SASE, KIRBY, 298 West Carmel Drive, Carmel, IN 46032. BOARDS for Radio- Electronics and Popular Elec- tronics projects. Inexpensive! Free sample! IN- DUSTRIAL MICRO Box 596, Logan, Utah 84321. 1 (800) 359-0466. TOCOM 5503 V.I, P. descrambler "Turnon." All channels; formats. New easy hookup; parts in- cluded! Manual and remote tuning. Free "detailed" schematic. $39.00. MIKE, Box 743, Oldsmar, FL 34677. ANTIQUE RADIO CLASSIFIED Free Sample! Antique Radio's — r Largest Circulation Monthly. (Pjfij j Articles, Ads & Classifieds. 6-Month Trfal: $11. t-Yr: $20 ($30-1 st Class). A.R.C., P.O. Box 8Q2-L4, Carlisle, MA 01741 LASERS from $35, for free catalog write MWK IN- DUSTRIES, 1440 South State College Building 3EJ- R, Anaheim, CA 92806 or call (714) 956-8497. ENGINEERING development tools, IBM PC ex- tender boards, timing software. DETROIT DATACOMM, 1409 W. 14 Mile. Mod Hgts, Ml 48071. CABLE converters and descramblers, wholesale prices, full warrantys, RTC-S6 w/r $150.00, MLD-1200 $45.00, Pioneer 125, Jerrold-400 w/r 5125.00. These are just examples, all makes in stock, new this month only, Tocom w/r $199.00. S.A.C., Orders 1 (800) 622-3799. Information (702) 647-3799. CABLE TV converters and descramblers. We sell only the best. Low prices. SB-3 $79.00. We ship C.0,0. Free catalog. ACE PRODUCTS, P0 Box 582, Dept. E, Saco, ME 04072, (207) 967-0726. TEST equipment reconditioned (guaranteed). Ter- rific prices, NBS calibration available. Visa, M/C, Amex, COD. ELECTRONIC SURPLUS, INC., 4350 Town Plaza, Suite 203, Houston, TX 77045. (713) 723-9718. SAMS closeout sale. #2 to #2600 $6.00 each postpaid. MC/Visa Call 1 (800) 688-1328. 9-5 CST. MEMORY chips, Simms and Sipps: 4164-100 $2.50, 41256-100 $3.50, 41464-100 $4.60. Call ED/ DATAFIX, (201) 322-7666. COMPUTERIZED linecard system for IBM compati- bles. Fast. Easy. Just $24.95. NORTHSTAR, 2924 Stark, Eugene. OR 97404. CABLE TV converters/descramblers. All major brands. Are you tired of ordering cable TV equip- ment and receiving inferior merchandise, not at K.D. Video. We are a well established company that will offer you the best quality, service and prices. Our units have worked where others have failed. Call Toll free 1 (800) 327-3407. K.D. VIDEO INC., PO Box 29538, MLPS., MN 65429. JOB? Top electronic firms addresses and PH#s. $2.00. ENGINEERING, 6611 Edgemont. Hunt- ington Beach, CA 92647. TUBES Sylvania 6LQ6 6L6GC 20LF6 etc. Huge discounts. ARLEN SUPPLY, 7409 West Chester Pike, Upper Darby. PA 19082 1 (800) 458-1301. SCIENTIFIC & ELECTRONIC PRODUCTS GRA1- ANTI GRAVITY GENERATOR sic co ^ LC7- 40 WATT BURNING CUTTING LASER $20,00 ggltWM- HI POWER PULSED DRILLING LASER .$2000 M a BTC5 - ERMCP1- 1 MILLION VOLT TESLA COIL .S2O00 HI VELOCITY COIL GUN .S15J00 S5LLS1- LASEH LIGHT SHOW 3 METHODS .$2000 eoEw- ELECTRONIC HYPNOTISM TECHNIQUES , .58.00 Z EML1 - LOWER POWERED COIL GUN LAUNCHER . s&oo _JSD5- JACOB LADDER 3 MODELS ..now SEEINTHEDARK .. .. .S1000 ftlKI- LEVITAT10N DEVICE .S10O0 SJFMV1K- - 3 MILE FM VOICE TRANSMITTER $3*50 gpFsiK- - HAND CONTROLLED PLASMA FIRE SABER .S4950 5 NIG7S - HI FLUX NEGATIVE ION GENERATOR $3450 gSPGBK- PLASMA LIGHTNING GLOBE .. $4950 z|LHC2X- gSHODtt- - VISIBLE SIMULATED 3 COLOR LASER . . . $4450 - HOMING/TRACKING BEEPER TRANSMITTER $4450 ^glGUSK- - 25 MW HAND-HELD VISIBLE UlSER GUN . . $24950 SS£BTC3K- - 250.000 VOLT TABLE TOP TESLA COIL S24950 t/i I0G2K- ^TK£1K- K)N RAY GUN. pro ject energy without wires . . $12935 - TELEKINET1C ENHANCER/ELECTRIC MAN ..$7950 2 VWPM7K - 3 MILE AUTD TELEPHONE TRANSMITTER $4950 q ASSEMBLED IN OUR UBS Ijj UST10 - INF IN1TY KMTR Lislen in via phone Ins . $19950 _l IPQ70— !NVISIBLEPAINFIEL0BLASTWAVEGENERATOR$7450 AQITM10- 10C.OCOVOLTINTIMIDATORUPT020' $9950 STAT30- AUT0MATICTELEPHONEREC0RDINGDEVKE.S2450 LU PS P40 - PHAS0R SONIC BLAST WAVE PISTOL SB950 CQ DNE10 - ALL NEW 26 ' WW COLORED NEON STICK . S7450 CO LGUJ0- 5 TO 1MW VISIBLE RED HeNe LASER GUN . S199S0 < BLS10- 100.00 WATT BLASTER DEFENSE WAND . SB4S0 EASY ORDERING PROCEDURE - TOLL FREE 1-800-221-1705 or 24 HRS ON 1-603-673-4730 or FAX IT T0 1-603-672-5406 VISA , MC. CHECK. M0 IN US FUNDS. INC UJDE 1 Cflt SHI PPING . ORDE RS SI MOOS UP ONLY ADD $10.00. CATALOG $1 .00 OR FREE WITH ORDER. INFORMATION UNLIMITED P0. BOX 716, DEPT. FtZ, AMHERST. NH 03031 m □0 30 c > D -< to to o 1 CABLE TV CONVERTERS & EQUIPMENT S UNIT UNITS PANASONIC WIRELESS CONVERTER 85.00. . . 69.00 JERROLD 400 COMBO VWREMOTE (DRX3DIC) 134.00. . . 95.00 JERROLD 400 OR 450 REMOTE HAND UNIT 24.00. . . 15.00 JERROLD J RX 3DIC 84.00... 65.00 JERROLD SB ADD ON 74.00... 55-00 JERROLD SB ADD ON WITH TRI-BI 95 00... 70.00 OAK M-35 COMBO 79.00. . . 50.00 OAKMINICODE (N-12) 84.00 59.00 HAMLIN MLD 1200 64.00. . . 45.00 SCIENTIFIC ATLANTA SA-3 ADD ON .-, . . . 109.00. . . 75,00 INTERFERENCE FILTER (CHANNEL 3 OR 6) 24.00. . . 14.00 NEW SCIENTIFIC ATLANTA COMBO • 275.00. . 215.00 PIONEER DESCR AMBLER 250,00 200.00 TOCOM VIP 200.00. . 175,00 ZENITH FLASHING 175,00.. 150.00 ZENITH SSAVI 125.00... 90.00 EAGLE PD-3 95.00. . . 75.00 VIDEO-LINK Enterprises, Inc. 520 GLENBROOK RD.. SUITE 202 STA MFORD, CT 06906 ORDERS: 1-800-622-9022 CATALOG & INFO: 203-975-7543 MONDAY - FRIDAY 10 AM — 5:30 PM, E.S.T. IMPORTANT: Have make and model # of the equipment used in your area. QTV ITEM OUTPUT CHANNEL PRICE EACH TOTAL PRICE NO CONNECTICUT SALES. K SUBTOT. is nol the inlant ot VIDEO-LINK to defraud any pay television operator and we will not assist any company or individual in doing so. PLEASE PRINT: Shipping S3 /Unit COD: Add 5% TOTAL □ CASHIER'S CHECK NAME ADDRESS CiTYSTATE/ZJP PHONE SIGNATURE □ M.O. D C.O.D. WAIVER. Since I. the undersigned, (ully understand that Iho ownership of a cable decoder does not give Itie owner ol ihe decoder the righl lo decode or view premium cable channels wilhoul proper authorization from their local cable company, hereby declare under penalty of perjury I hat afl products purchased, at any lime, will only be used on cable TV sysiems wilh proper authorization Irom local officials or cable company officers in accordance with alt applicable federal and state laws. Federal and various stale taws provide tor substantial criminal and civil penalties for unauthorized use. Dated Signed: AUTO alarm. Deter ever increasing crime from striking you. Modern features and loud! Install your- self and save. Includes two RF keychain Irans mil- ters, $99. Feature-packed, $114. Money order or cashier's check only. Add $5.00 S&H. SASE for details. SURVIVAL SYSTEMS, PO Box 2627, Des Plaines. IL 60017, Be a TV/VCR Repair Specialist Now you can train at home in spare time for a money-making career as a TV VCR Repair Specialist. No previous experi- ence necessary. No need to quit your job or school. Everything is explained in easy-to-undersiand language wilh plenty ol draw- ings, diagrams and photos We show you how to troubleshoot and repair video -cassette recorders and TV sets, how to handle house calls and shop repairs lor almost any make ol television or VCR Tools are included wilh your course so you can gel "hands-on" practice as you tallow your lessons step by step Send lor free lads about Ihe exciting opportunities in TV VCR Repair and find out how you can start making money in this s ^auaie er_ MAIL_COUPqN TQDAY_ _ _*wc '[feCSl SCHOOL OF TV/VCR REPAIR, Depl. DEMO t«""""l 925 Oak Street, Scranton, PA 18515 Please send me full information and color brochure on how I can learn TV-'VCR Repair at home in my spare time. I understand there is no obligation and no salesman will visit me Name Age Address. CityfSl3le_ _ApL#_ -Zip PLANS 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 May, Fairfield, CT 0t3430. STEREO FM transmitter! Transmit your VC Ft/CD/ Walkman to any FM stereo radio. One chip does it all! Free schematic and info. Send a self addressed,' stamped envelope to: DJ INC., 847A Second Ave.. Suite 113, New York, NY 10017. ____ FM transmitter 88 to 108 MHz kit $12.95; power supply to 20 V 1 AMP kit $79.99; Flyback tester assembled $95.99; shipping and handling 4% unit, SASE for information. SIERRA ELECTRONICS, PO Box 709, Elfers, FL 34680-0709. ELECTRONIC kits! Tracking transmitters! Voice dtsguisers! Bug detectors! Surveillance items! More! Catalog S1.00: XANDI ELECTRONICS, Box 25647. 60A, Tempe, AZ 85285-5647. TtEMOTE CONTROL; KEYCHAIN Complete w/mini-transmitter and +5 vdc RF receiver Fully assembled Including plans to build your own auto alarm Quantify discounts available $1 9r\r- Check, Visa or M/C ' ,»0 Add $ 3 shipping VtSITECT iNCVDepL R (415) 872-0128 PO BOX 5442, SO, SAN FRAN, ( CA: S4OS0 SURVEILLANCE transmitter kits are available to professional City, State and Government taw en- forcement agencies that operate on frequencies they prefer. Our transmitters have proven generally to outperform theirs. Four models of each; tele- phone, room, combination telephone/room trans- mitters tune from 65 to 305 MHz. Send $1.00 (overseas airmail $2.00) for catalog. Included is Popular Communications book review of "Now Hear This! Electronics Eavesdropping Equip- ment Design" by Winston Arrington. Book contains 58 transmitter schematics, SHEFFIELD ELEC- TRONICS, 7223 Stony Island Ave., Chicago, IL 60649-2806. INVESTIGATORS, experimenters — Quality new plans. Hard to find micro and restricted devices. Free catalog. Self addressed stamped envelope to KELLEY SECURITY INC., Suite 90, 2531 Sawtelle Blvd., Los Angeles, CA 90064. RADIO Astronomy! Monthly magazine, books, components. $3.00 brings sample package BOB'S ELECTRONIC SERVICE, 7605 Deland, Ft. Pierce, FL 34951. CATALOG; hobby/broadcasting/HAM/CB: Cable TV, transmitters, amplifiers, surveillance devices, computers, more! PAN AXIS, Box 130-F2, Para- dise, CA 95967. Unlock the Mystery of the Automobile Computer! Buifd Your Own Diagnostic Scon Tooif The Key To Understanding Ihe Modern Electronically Controlled Automobile Engine Access- Stored ECM Data, Fteatf-Oul FauHI Cods*. / Challenging HEW Elecironie Assembly KIT— C PUuNS- PARTS— ASSEMBLEIXrESTED UNITS Call 1-SD0-53S-3M1 or write for eamptele Informa lion S & M Electro-Tech P.O. Box 34334 Blaine, MN 5S434 * CB Tricks II book. Power amplifier design and Iheo- ry. UHF CB tune upS. Send $19.95 MEDICINE MAN CB, PO Box 37, Clarksville. AR 72830. DETECTION — Surveillance, debugging, plans, kits, assembled devices. Latest high-tech catalog $5. DETECTION SYSTEMS, 2515 E. Thomas, #16-864F. Phoenix, AZ 85016. ELECTROLOCK prog ram able keypad door release system, complete kit including electric strike: $129.95. Assembled and tested: $149.95. Free bro- chure and orders: SYSTEMS ASSOCIATES INC., 1320 Cranston Street, Cranston, Rl 02920. (401) 943-2986. DESCRAMBLING, new secret manual. Build your own de scram biers for 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 20814. ALARM kit for home, 12vDC,. delay and in- stantaneous loop. Includes board and components. $47.50 + $3.50 S&H. For purchase or free info: K.E.P., PO Box 830123, Stone Mountain, GA 30083. NEWHENE LASER TUBES $35 Dealer Inquiries Invited. Free Catalog! MEREDITH INSTRUMENTS: 6403 N. 59th Ave. Giendalc, AZ 85301 • (602) 934-9387 " The Source for Laser Surplus ' ' V BUILD the "Invader," common construction mate- rials, electronic kits available, complete robot plans $11.95, details free, ROBOT WORKS, Box 1979, Colorado Springs. CO 80901 . SINGERS. At last, build your own vocal filter. Re- move lead vocals from standard stereo records, CDs, tapes, FM broadcasts, so you can be the lead singer of your favorite band. Theory, manual, sche- matics 56.95, WEEDER TECHNOLOGIES, 14773 Lindsey, Ml. Orab, OH 45154. MICROPROCESSOR alarm kit. For home, auto, RV. 8 zones. Delay, valet, continuous modes. $31.95 plus $2.00 S/H, Just add power supply, case, sen- sors. PRECISION ELECTRONICS, 4N306 Norris Ave , West Chicago, IL 60185. CLOSEOUT "TV Frequency Standard" April 1988 R-E, kit/antenna coil $55.00. finished units $200.00, PERSHING TECHNICAL, Box 1951, Fort Worth. TX 76101. DAZER protector kit $44.95! Exciting electronic kits! Catalog $1.00. QUANTUM RESEARCH, 17919-77 Avenue, Edmonton, Alberta T5T 2S1. LEARN electronics the practical way. Build your own kit or do tens of experiments with your own self trainer. For free catalog: ARLI ELECTRONICS, 2155 Verdugo Blvd. #22, Montrose, CA 91020. BUILD remote control car starter. Without keys from home turns on/off engine, heater/air condition, lights etc Locates car in crowded parking lot. Built-in anlttheft sensors, reliability. Detailed instruc- tions, send $5. SASE to N.Y. ENGINEERING CEN- TER, PO Box 0831, Syosset, NY 11791-0831 84 CIRCLE 64 ON FREE INFORMATION CARD STRESSED out? Relaxtion technique easily learned with the aid of a simple electronic device. Not hypnosis! Plans $9.95. BLUE CHIP ENGI- NEERING, Dept. 33, PO Box 1100, Walnut, CA 91789. 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 Shipped Immediately! REPUBLIC CABLE PRODUCTS INC. 40BD Paradise Rd. #15 Dept. RE-90 Las Vegas, NU 89109 SATELLITE TV CABLE TV secrets — the outlaw publication the cable companies tried to ban. HBO, Movie Channel, Showtime, descramblers, conveners, etc. Sup- plier's list included $8.95. CABLE FACTS, Box 711- R. Pataskaia, OH 43062. FREE catalog - Do-it-yourself save 40-60%. Lowest prices worldwide, systems, upgrades, parts, all ma- jor brands factory fresh and warrantied. SKYVI- SION, 2009 Collegeway, Fergus Falls, MN 56537. 1 (800)334-6455. DESCRAMBLER: Build our low cost video only, satellite TV descrambler tor most satellite channels. Uses easy to get, everyday parts. Board & plans $35.00 US funds. Board, plans & parts $99.00 US funds. Wired & tested unit $189.00 US tunds. Send check, money order or Visa to: VALLEY MICRO- WAVE ELECTRONICS, Bear River, Nova Scotia, Canada BOS 1B0 or phone (902) 467-3577. Sam to 4pm eastern time. Note: educational project only. Not to be used illegally. VIDEOCIPHER II manuals. Volume 1 — hardware. Volume 2 — software. Either $32.45, Volume 3 — projects/software — $42.45. Volume 4 — repair — $97.45. Volumes documentation — $42,45. Cable Hackerls Bible— $32.45. Clone Hacker's Bible— $34.95 CODs: (602) 782-2316. 220+ Megabytes IBM-PC/XT software — catalog -$3.00. TELE- CODE, Box 6426-RE, Yuma, AZ 85366-6426. VIDEOCYPHER II descrambling manual. Sche- matics, video and audio. Explains DES, EPROM, CloneMaster, SMusketeet, pay-per-view (HBO, Cin- emax, Showtime, adult, etc.) $13.95, $2,00 postage. CABLETRONICS, Box 30502R, Bethesda, MD 20814. CABLE TV :!•>:< =H Converters — Descramblers Remote Controls — Accessories * Guaranteed Best Prices * * l Year Warranty - CO □ s * * Immediate Shipping * • FREE CATALOG . Caller Write TRANS-WORLD CABLE CO, 1 2062 Southwest 1 1 7th Court. Suile 1 26 Miami. Florida 331 86 1 .800-442-9333 DESCRAMBLERS tor movies, networks, $175, vid- eo only, $450 complete. Visa, MC accepted. Cata- log $4. SKYWATCH, 238 Davenport Road, Toronto, Canada, M5R 1J6. CABLE-TV BONANZA! ITEM HAMLIN MCC .MXX> :S6 CCJflOtO HEMLHE CUNVER1EH iCM If, PANASONIC WIRELESS CONVERTER [QUI Scst buy) STAR GATE 2000 JERROLD 400 COMBO JERROLD JO0 HAND REMOTE CONIFtOL JERROLD 450 HAND REMOTE CONTROL JERROLD 450 COMBO JERROLD SB-ADD. ON JERROLD SB-ADD-ON WITH TRIMODE M-35 B COMBO UNIT iCh 3c.ilp..l only. M-3SB COMBO UNIT WITH VARISVNC MINICODE IN-12I MINI CODE IN- 12 1 WITH VARISYWC MINICODE VARI5YNC WITH AUTO ON OFF ECONOCOOE imioicoai" SLitisMLjU'i ECONOCODE WITH VARISVNC •MLO-1200-3 iCN limnpiin - MLD-'?O0-2 lCH 2fjiitfHih "ZENITH SSAVI CABLE READY INTERFERENCE FILTERS iCh 3onlyi EAGLE PD-3 DESCRAMBLER iCn Jiml|ml rjruy i 'SCIENTIFIC ATLANTA ADD-ON REPLACEMENT DF.SCRAMHL L H tOOR MORE ■CALL FOR AVAILABILITY Name Address . State _City_ □ Cashier's Check Acct # Signature . Zip D Money Order . Phone Number ( ) D COD D Visa Exp. Date Quantity Item Output Channel Price Each TOTAL PRICE SUBTOTAL from shipping any cable descrambling unit to anyone residing In the state ot California. Prices subject to change without notice. Shipping Add $3.00 per unit COD & Credit Cards — Add 5% PLEASE PRINT TOTAL D Mastercard FOR OUR RECORDS: DECLARATION OF AUTHORIZED USE — I, the undersigned, do hereby declare under penalty of perjury (hat all products purchased, now and in the future, will only be used on cable TV systems with proper authorization from local officials or cable company officials in accordance with all applicable federal and state laws FEDERAL AMD VARIOUS STATE LAWS PROVIDE FOR SUBSTANTIAL CRIMINAL AND CIVIL PENALTIES FOR UN AUTHORIZED USE. Pacific Cable Company, Inc. 7325V* RESEDA BLVD., DEPT. R-2 • RESEDA, CA 91335 (818)716-5914 • No Collect Calls • (818)716-5140 IMPORTANT: WHEN CALLING FOR INFORMATION Please have the make and model # of the equipment used in your area. Thank You m DO c > < (D WEST COAST ELECTRONICS For Information: 818-709-1758 Catalogs & Orders: 800-628-9656 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-S6S6. In Massachusetts or Canada call (413) 568-3753. COMPUTER BOOKS DISCOUNT computer books. All titles available, including recent releases. Please call or write for our latest catalog. BOOKWARE, 147 Campville Road, Northfield, CT 06778. 1 (800) 288-5662. SOFTWARE FREE software for IBM and compatible computers! Info $1.00. BLUE CHIP ENGINEERING, Dept. 33, PO Box 1100, Walnut, CA 91789. CABLE TV DESCRAMBLERS 10 Lol ._ mj JERROLD" rfZ JerroldSlJucomCSV.... $139.95 OH *NEW STARGATE 2000 CABLE CONVERTER 1 -$89.00 10-$69.00 100-Call Last channel recall- Favorite channel select- 75 channel-Channel scan- Manual fine tune- One year warranty-surge protection-HRC & Stand- ard swilchable- and much more. Call Todavl IN FORMATION (402)554-041 7 Orders Call Toll Free 1-800-624-1150 M.D. ELECTRONICS 1 15 NEW YORK MALL SUITE 133E OMAHA, NE. 68114 ML VISA CIRCLE 53 ON FREE INFORMATION CARD MARK V NEW FREE CATALOG iS NOW AVAILABLE! CALL (21 3) 888-8988 ORDER TOLL FREE 800-423-3483 IN CALIFORNIA 800-521-MARK FAX (213) 888-6868 A indicates the level of difficulty in the assembling of our Products. A Beginner A A Intermediate A A A Advanced * Fully Assembleo ,k TA-820A - ; *' m ^ T1 T2 TA-3600 TA-120MK2 TY-23B SM-333 SM-666 -|new^^-.^4 MISCELLANEOUS TA-28MKI V.Ml'i.lf-'IKHS MOO EL Td-OOl TA-006 TA-0O7 TA-10 TA-28MK2 TA-SOA/B TA-50C TA-1 20MK2 TA-300 TA-302 TA-322 1 TA-323A TA-377A TA-400 TA-477 TA-80Q TA-802 TA-820A TA 10O0A TA-1500 TA-220O TA 24O0A TA-25O0 TA-2BOO TA-30OO TA-3600 DESCRIPTION KIT 1 W Mini-AmplifierA S 5.07 6W Mini-AmplifierA 8.90 12W Mini-Amplifier A 1.1.20 Stereo Pre-Amp. w/magneiic mic. -irtipA 8.20 Digital Voice Recorder AA 30.00 Multl- Purpose Melody Generator A 1 1 .84 Multipurpose Melody Generator A — 1 2. 85 Class "A k Main Powei Mono Amp A A 27.16 30W Multi-Purpose Single Channel Amp A 20.00 60W Stereo Power Booster A A * 50.00 SOW +50W IC Stereo Amp. w/led leuel displayA 35.50 HQ 30W+- 30W Stereo Amp A 29,50 FET Stereo Pre-Amp. A A A... 59.95 40W Solid State Mono Amp A 2.8.00 120W Mostet Power Mono Amp A A 68 00 SO W-r 00 WDC Pre- Mam A Power Am p. A A 60.92 SOW+SOWDCStereoMainPowerAmp.AA. 45,94 SOW-y 60W OCL DC Pre-Main Stereo Amp A A . 40.39 100WCtaas ,L A" Main Power Mono Amp A A 59.69 1 OOW 1 2 Class A ' DC Stereo Pre-Main AmpA A A73.70 DC FET Super Class "A" Pre- Am p. 47.70 Electronic Echo& Revelation Amp A A A * 83.30 HQ Pre-Amp, w/10 band graphic equalizer* ... Hi-Fi Bi- Fat Pre- Am p. w.,'3 way tone control A A. 48,90 Stereo Simulator A A.-...,. - 30,20 3DOW HQ Hi-Fi Power Mono Amp. AAA 79.00 ASSEMBLEO 40.00 16,58 17.71 38.81 70.00 49.37 SO 58 95.81 SB. 24 116.80 90,80 MODEL TY-23B TY-2S TY-35 TY-36 TY-38 TY-41MK1 11 TY-41 MKV TY 42 TY-43 TY-45 TY-47 SM-32B SM-333 SM-666 T-1 T-2 DESCRIPTION 3 Channel Color Light Controler A A A* $ Stereo Loudspeaker ProtectorA FM Wireless MicrophoneA ..--. AC/ DC Quartz Digital Clock A- , ..---.., Sound/Touch Control SwitchA... .... Infrared Remote Control Uml AAA Inlrared Remote Conirol Unit AAA- - Bar/Dot Level Meter A A 3'.t Digital Panel Meter A... 20 Steps Bar/Dot Audio Level Display AA. Superior Electronic Roulette AA — 4 Channel Profe as ional Color Light Controller ..,, Audio/ Videos u rrou nd S o u n d Processo r A A A # Dynamic Noise Reduction A , LCD Thermometer Clock w/in-outdoor sensor* LCD Thermometer Clock w/ F A C measurement *>. KIT ASSEMBLED 56.04 *74.50 12.85 9.22 1B.0O 12.00 15.00 20.00 24.15 33.00 30.45 19.46 25.00 3500 62.00 26.00 150 1X1 83.00 34.00 15.40 14.40 POWER SUPPLIES MODEL TR-1O0A TR-35SA TR-355B TR-503 DESCRIPTION 0-1 5 V 2 A Regulated OC Power Supply - 0-15V5A Regulated DC Power Supply... O-30V 3A Regulated DC Power Supply . 0-501/ 3A Regulated DC Power Supply -- KIT 59.50 14.55 14.55 15.75 ASSEMBLED 69.50 20.76 20.76 22.65 INSTRUMENTS MODEL SM-43 SM4B SM-49 SM-48A SM-100 FC1O0OA DESCRIPTION 3V. Multi-Functinal Led O.P.M 4Va Hi-Preciiion D.P.M , 3J ' : ' .-.il i- USA AOI) 20^tilMIN SSOOl TRANSIT INSURANCE ADD S'ieOF TOTAL (OUTSIDE USAONLY) CARESIDENTSADDSALESTAJl' ALL MERCHANDISE SUBJECT TOPRlORSALE PRICESAflE SUBJECT TO CHANGE WITHOUT NOTICE ' WE ARE NOT RESPONSIBLE FOB TYPOGRAPHICAL ERRORS MARK V ELECTRONICS, INC. — 8019 E. Slauson Ave.. Moiucbcllo. CA 90640 CIRCLE 93 ON FREE INFORMATION CARD C3 33 C > 5 8 87 THE ELECTRONIC GOLDMINE INHtAREIJ DETECTOR KIT L'lt* Knuclyf KnHH I" I tlcVTJTPnil . ir EuiEiy in ittptiwid in ill typn of innrufJ TV r VCR. imill tU«, : J' x I.*". **ptritEi on VV b Decry (m( iiklu lr.l| kit lutnrii villi ill fVTl iTiiI rClMMnl C6441 SS.'t;. MINE CEIGER COUNTER KIT lm'M tit kti you drirci itw nuiinuM ilitr ire iir inp **-nni*d re' U^ ii in Jr| c (1 r>4> Jill* an " x 3 '. llperir.fi Imri on* W L*i iflor ■ririu Jftl). WhJl »ll r>4»tt Mul MI rrnri. t/MQUKKITS in .1 Ul f4IB - ^ Oil BTOtUt n : mw. -:. ;:J i | !-.,..., PARTIAL. USTLNC; OK OVfcR 130 AH oF our km cotii -nh in curtcd inJ dnlkJ frt Loud ItW Ijiiury *Jvi UM < it J-rrifrdl Kit! itUI chpn by ht«irird|triUr hmdukn viljr dvr 16 ACnlrtf U(hlnifl£Bd1 5lr<*e KJH12QYM") tfrOI S34.9S J Ch tnnd Color Qrjari Kil ( 1 20V AC) C4S30 S 1 2.M 1 Oi W nd LiKhl Sc| i» rccr fc \i { 1 10 V Af i C472S S28.91 Oil ten- Opmled E JkM ijhl Kil <6VDC) C6J56 5 ] ).«! Wheel of FoHurJM kil I'iVLK'l CiS06 SH.*S Lope Probe Kil (5VDC) C6 J 84 S 1 2.00 UltEUHiLc Ft it RcpcILrr Kit |yV|)Cl C6350 1 9.00 Hur^ir ibnn Kil ffrVDC) C«2<0 S S 74 J u ii cl f El i t J Ki [ <9V DC ] C£3?4 S 6,15 ElKiJonk Intercom Kit (9VDC) C4743 £12.49 Mkto Xenon Tul*Haih« kiril (^ I C«2«8 JH.« Stmulifed Likf KM (9VDC) CiJW & B.00 Bitltry Tcitcf Kit (Tnli ill Tvpci^VDC) C&4 14 £ t.^S uitntiniiuiit ikw SUPER BRIGHT LED jumira fix red Mil. f - fhiipuE JOflMflS. ■ \ -_■ gfn A 1012 J,'!1D0 OH I suRna mount chip tomtohfxis rone m iji in is in is tH IS jurrwmtEfr I'KIEIU uriaT«is W51.»»IM/M(1 !H)«.r.Kil INVERTER TRANSFORMER Bi i M ■)■» h o rit sss K » m IMC ii ™ ism h »4*t HHH hpt *. Skid lAntt I CIRCLE 176 ON FREE INFORMATION CARD HARDWARE HACKER continued from page 74 to get started with that outstand- ing graphics language, I also have a new and free mailer for you that includes dozens of in- sider and top secret sources for all hardware hacking. As always, this is your column and you can get technical help and off-the-wall networking per that Need Help? box. The best calling times are weekdays 8-5 in Mountain Standard Time. R-E 7 * -K -It ■* -it PRESENTING ■**** * CABLE TV T ***** STARRING ***** JERROLD, HAMLIN, OAK AND OTHER FAMOUS MANUFACTURERS • PNES1 -^/ARftANTY PftQC,R*M AVAJlAHIT • LOWEST RTrAJiyWrrOLElALf PUCES IN U t • OftMIBSH*^tOJTW«STt>^WTT>IWMHOUfft FOR FREE CATALOG ONVf T'JOO~345-t?27 FORAiLrNFOffMATJON I -816-7? 6-59 1 4 PACIFIC CABLE CO. INC. CABLE T.V. CONVERTERS WHY PAY A HIGH MONTHLY FEE? All Jerrold, Oak. Hamlin, Zenith, Scientific Atlanta, Magnawox and all specialized cable equipment available for shipment within 24 hou rs. For fast service MC / VISA or C.O.D. telephone orders accepted (800) 648-3030 60 Day Guarantee (Quantity Discounts) 8 A.M. to S P.M. C.S.T. CLOSED WEEK- ENDS. Send self-addressed Stamped enve- lope (60e postage) for Catalog ^ ■ ,.,,, 'L P.O. Box 5000 L€LeaRoni«inc : ^ e e ^!„, IL6irno TELEPHONE CALL SCREENING REAL telephone call screening! Protect tele- phones. Fax, computer, hearing Impaired, day sleepers. Eliminate wrong numbers, prank and sales calls. PlugSn unit provides variable ring cadence signaling. True unlisted number on any iouchtone private line. Automatic cali routing. Send $13.95 for complete theory and con- struction manual. ELECTRONIC CONTROL SYSTEMS, R.D. 2 Box 3308, Wemersvtlie. PA 19565. W O ~Z o rx H O ill o o < d: 38 But What Do All These Good Ideas Mean? Lower Prices! For the past few months we have been telling you, among other things, that because we ask for a S35 a year Membership Fee we do not force our customers to subsidize the cost of sending hundreds of thousands of Catalogs every few months to everyone on our Mailing List, and because our Catalog Is actually a 2-!nch three ring binder we don not waste money in sending the same old stuff to our customers over and over again. So what do all these cost saving ideas mean? Much lower prices than anywhere else on more than 10,000 items of electronic components. The following is a sample listing of some of these low prices: * 1/4 Watt, 5%, Carbon Film Resistors: $0.77/100, $4.76/1000 * 1/4 Watt, \%, Metal Film Resistors: $0^2/10, $1.16/100, $8.25/1000 74HC00, 74HCT00, 74LS00 Integrated Circuits: $0.18/1, $144.00/ 1000 * LM741 Operational Amplifiers: $2.00/10, $165.24/ 1000 78xx Positive Voltage Regulators (TO-220): $0.38/1, $30.80/100 * 79xx Negalive Voltage Regulators (TO-220): $0.48/1, $39.60/100 Cambion Low Profile 14-Pin Solder-Tab Sockets: $0.10/1, $73.92/1000 * Panasonic 15-Tum Rectangular Trim Pots: $1 10/1, $632.00/1000 Panasonic ECQ-V O.luF, 50V Bypass Capacitors: $0.93/10, $64.53/1000 * Panasonic Dipped Tantalum lOuF, 25V Capacitors: $5,1 1/10, $354.67/1000 Package of 50, 3.0" Overall Length Wire-Wrap Wire: $0.60/1 * AP Products (Associated Electronics/3M): 20% Off List 1N4001 Rectifier Diodes: $0.42/10, $2852/1000 * 1N4148 Switching Diodes: $0,28/10, $19.44/1000 2N2222A Transistors: $032/1, $2Z20/ 100, $185/1000 * 2N3906 Transistors: $7.20/100, $60.00/1000 Howard W. Sams and Hayden Books: 34% Off Cover Price -k Hammond Manufacturing Cases: 20% to 30% Off List These are not Just a select number of Items that we have chosen as 'Loss Leaders'. In fact we have been selling these Items for the same Cor lower) prices for the past 4 years! There are no grouping or volume purchase requirements to obtain these prices either! Become a Member today so you can start saving on all of the more than 10,000 items that we stock, 12 Months Saving Guarantee We will refund the first year Membership Fee of any member who has purchased $300 or more worth of products from Electronic Buyers Club and has not saved an amount greater than the first year Membership Fee, if buying the same items elsewhere. 30 Days Money Back Guarantee We will refund the full Membership Fee of any new member of Electronic Buyers Club who within 30 Days after receiving the Membership Binder, returns the Binder to EBC and asks for the cancellation of Membership. lectronic buyers (£lub A Division of Intecruiionil Canpooenu Corporation 1803 N.W. Lincoln Way ♦ Toledo, OR 97391 PHONE (All 50 States & Canada): 1 -800-325-0101 FAX: (503) 336-4400 • Hours: 6:00 AM - 6:00 PM PST MasleiCcrd CIRCLE 177 ON FREE INFORMATION CARD High Performance ii i Counter Timer Module/Panel Meter INTRODUCTORY PRICING Quantity Price 140 189.00 11-99 159.00 100+ 129.00 ENGINEERING EVALUATION KIT $250.00 ;. .... r-4t3B 'ffi$gffi^$@@ffii$l 1 FREQUENCY PERIOD RATIO INTERVAL AVERAGE PHESCALE OVERANGE A B 2 R R R R R R R R R R I 0.1)1 0.1 10 10 100 KM LOW BAIT Hlllllli jllllll Hi 1 MHi s 1 ttS ] fc-jr ... . . c? X c 8E CIRCLE 70 ON FREE INFORMATION CARD I a me co ELECTRONICS Mai I -Order Hour Order Hotline SIP & SIMM MODULES Pari Hp. Fpncllgn fl\a S&OT I8MPS2 iD0ns256Ki9SlW4[3l3CI . ! E9 95 2ME2><>r IBM PS2 1 00ns I MEG r 9 SIMM (2 nth) . 4 59 35 II256*3*..10 262 144*9 1Mns2MKi9SlPiH«L««ls) 1595 11 356*98 60 262.144*9 BOrfi 2S6K a 9 SIMM .64 95 <2 1000458 10 1, 041576ll IKns iMEGiISIMM 16495 42!000*9A-» I,041.57fa9 60ns 1MEG 1 9 SIP IHJ5 LeKKI 16995 (21000*96 BO l.046,S76i9 BDns 1MEG 1 9 SIMM I69S5 ■un'ti' fa mkms a. to; irf 60 7400 pan Nil 1-0 >6> 7400. . . .29 19 7402-. - 29 19 74(M .... .— .29 -19 7405 .... 35 .25 7406 - .39 --■; 7407 ._ .39 29 7408. .- . AS ffi 7410..... 29 ■•t 7411 J5 75 7414 49 39 7416 — - ... 35 .25 7417..._ — as -5 7420 29 .19 7427 ... 29 .in 7430 29 ■'i 7432. — 39 n 7*38 39 29 7442- ... 49 m 7445 75 .» 7446 89 .79 7447_ 89 79 7473 39 29 i-9 in- 7474. 7475.. 7476 7483... 7485 7486 7489 .. 7490 7493 7495 74107 74121 74123 741 25— 74147 74150- 74151 74154^-. 74161 — 74174..... 74175 74193 . .39 29 . .49 39 . .45 35 , .59 .49 . .55 55 . .45 35 . 225 2.15 39 35 .-15 .IS 29 J 3 39 .99 1.69 135 125 39 29 135 1 .25 69 59 59 49 59 49 79 .69 74LS 74LS00- 741S02. . 74LS03 .. 74LS04- 74LS0S . 74LS06- . 74LS07 74LS08. 74LS09 74'_S'0 74LS11 74LS14 74LS20 74LS21 74LS27 74LS30 74LS3J 741 S38 741S42. . 74LS47 74LS73 . . 74LS74 741S75 . .. 74LS76 74LS83. . 74LS6* 74LS90 74LS93 74LS123. 74LS12S. 74LS132 74LS13B 7b 28 26 -2B .59 ;j ;s te 26 29 49 28 29 35 28 26 35 49 65 39 35 39 35 55 .55 29 .49 •19 49 49 49 74S/PROMS 74LSI39... 74LS151... 74LS153. . 74LS154. 74LS157... 74LS161- 74LS163... 74LS164- 74U5165 . 74LS166... 7418173-. 74LS174-. 74LS175- 74LS191... 74LS1S2 - 74L5193. 74LS194... 7J,S^fl 74LS240. 74LS241, 74LS24J, 74LS245- 74L5257 ... 74LS2B9,. 74LS273... 74LS279-. 74LS367 74LS373... 74LS374.. 74LS393. . 74LS541 - 74LS590, . 74LS6BB- .49 39 49 39 49 39 1 2'3 1 19 .45 35 .49 39 .49 39 .59 .49 .75 .65 .89 .79 .45 35 39 29 39 .29 59 ,49 .69 .59 .69 .59 .69 .59 .69 .59 .59 .49 .59 .49 .59 .49 79 69 .49 ,39 .99 89 89 79 .49 39 .49 39 .79 £9 .79 .69 89 .79 129 1.19 5,95 5 65 3 33223 74500 74304 74S32 74S74 74511!..., 7451 24.., 745138,, 745153.,, 745163 745174.., 745175,, 25 ,.___-. 25 25 25 .._-_ 25 1.25 49 ™ 29 .78 29 745188' 745189 74S240. 74S244 74S287' 74S2B8' 748373. 74E374 745357' . 74S47T 745571 • 1.49 1.49 139 .99 1.49 149 .99 39 1 29 2 95 249 CD-CMOS CD4001 „ 19 CD4002 , ,19 CD4007 19 CD4Q11 19 OD4012 25 CD4013 29 CD401S 29 C04Q16 -29 CD4017 _ 49 CD4018 49 004020 - _ .59 CO4021 49 C04024 .45 CD4027 35 CD4028 -49 CCK029 £9 CL34030 35 CD4040 £5 CD4042 49 CD4043 59 CD4046- .65 C04047 .65 CD4049 29 CD4050 - -29 CD4051 . CD4052 CD4053 . CD4060. . CD 4066 C04069 CD4070 CD4071 CD4072. CD4073 C04081 ... CD4093 C04094 CD4503 CD4511 CD4518 CD4520 CD4522, CD4526 CD4536 CD4543 C 04584 C04585 .59 .53 .59 .65 .79 25 .25 .15 15 15 .19 35 .89 39 59 75 69 .75 .69 .79 .79 49 59 NECV20& V30 CHIPS Replace me 8D86 or tOtt in Your IBM PC and P t |j inr-reaio ll» Spocd by up lo L1D14 Prtc* UPD7Q 1 0B-3 (5MHz) V20 Chip 5.25 UPD701 OS-8 (8HH1J V20 Chip „ - ,.6.95 UPD70103-10 (IOMH2) V20 Chip 10,95 UPDT01T6-8 (8MH1) V30 Chip .795 UPD701 16-10 (ICMHl) V3Q Chip 13,49 MICROPROCESSOR COMPONENTS 180. Pin Ha, 780 280* I80A-CTC Z80AMHT ZaOA-PIO Z80A-510O.. Z80B 2B0BCTC Z80BPIO ZS400HB1 CPU4HHI 80OT SERIES 9031 80C31 , 8035 - 8039 6052AHBASIC 8080A 8085A , 80B5A2 8086.. 80H7[5MH2) 8067-1 (IOMHj) 8M7-2 I8MH1) . 808S15MHI) 6088-Z j BWHt) . 8155 1 25 1 29 1 65 49S 1 89 395 275 395 3.95 395 3 95 .995 ,.125 , 1.59 24 95 ... 1.9S ,1.95 3 59 , 3.95 . 89 95 16955 129 95 ,4.95 .,6.95 -249 SOW) SERIES Conlinu»d Pin No PfIm 8155-2 8ICS5- - ,375 425 82C11 8Z12. - 8216 8224 8228 8237-5 ,695 1.99 .,1.39 ,1.49 ...1.49 -4.25 8243 82S0A .1.95 495 B25O0 iFc *Mi 8251* 8253 595 -.1.95 1.69 82535 . 1 95 8254 ...4 95 .2 95 82C55A5 8256 . 4.49 ,11 95 225 8272 8274 8279-5 _ .3 49 .4 75 ,295 6282 6284* ,.295 ....1.95 STATIC RAMS Pin X a. 2016-12 2102 211! 211 IN !1UN2L 21C14 5101 61 If PI 6H6P-3 611 (LP. 1 SH6LP3 E264P 10 6K4P-15 6764L.P1Q 6264LP12 6264LP 15 6514 ij2B ■:. 43256 151 67256LP.10 62256LP-12 B8MI.P-1S Fmicl'p" 2046it 1024.1 25S>4 1024E4 ■.;:4i4 102414 250i4 20481! 2W!i! 2M818 204619 919219 9'92i9 619219 919219 919211 1D2414 32.76),! 32.76)i» 32.76916 32.76141 32,761il 120ns 350rs... 200ns UwPowtr. 200ns (CWSI 450rs (CMS: 100ns (16«] CMOS , 150ns (16K) CMOS 1 00ns (16K) IP CMOS, , 150nS (16K) LP CMOS 100ns (S4X) CMOS 150ns (64K] CMOS 100nj(64«ILPCMOS 1 20ns (64KJ LP CMOS 150nS 164K1 LP CMOS SSOmCMOS 100nsl256KJLo«P(wtt-. 150ns|256K)LwPl»«._ !00rB|!56K|LPCMOS. 120ns 12S6KJ LP CMOS 150ns |256K] LP CMOS. , . Prtet — 295 89 —.2,49 149 1> —.1,95 -....3.19 -..2 79 3.59 .335 -9,75 -629 S3', — 6.75 — (.49 325 -1095 — m 11 35 -1125 .1095 DYNAMIC RAMS TMS4416-12 TMS4415-15 411015 4121-15 4164100 4164120 4164150 41256 60 41256 90 41250-100 41256-120 41256150 41264-12 41464*80 4146412 41464-15 51255-10 5MOO0P-90 511000P-10 5I4256P 10 514251-10 16.31414 16.3B4i4 16364,1 120ns- 150ns... 150ns (MM5290N-2) , 13l.072it 150ns pqybact).. . 120ns. 65.536,1 05.536,1 05.53611 262.144x1 60W _ - 362. 141* I 90ns !62.144il 1001B 262.144,1 120ns.- — — 262.14411 150ns. B4Ki4 1 20ns Video 9AM- BOns 120ns — 150nS., -.5.95 513 ,1,09 ...4.49 _275 ,2.39 -2-15 . 6.95 6559614 6553614 65-53614 262.1 44i 1 1 oons Stale Cohjmn ., 1,04157611 00ns(1 M»JI...„ 1,0*1.57611 10flnsl1 M45) 262.14414 lOOnsn Mkj] 262.t44ri tOOnsSutcCoimm - ..5.75 -39S .,..3.69 ...3.25 ,10.96 ...5.95 ,,449 _42S S35 ,1395 ■2 35 ,14.49 -26J5 EPROMS TV525-E 7MS253J TMS2S32* ™S25H TMS2716 1701* 2701 2716 2716-1 27C1S 2732 2732A-20 27C32 2764 25 2764A20 2764*25 27C64 15 27126-20- 27126-25 27129* 15 27129*20 27C126 25 27256-15 27356 20 27256 35 27C256-15 27C256-25 27512 25 270512 15 27C5 12-25 27C0I01S (9764 6176S35 2049,1 4096,6 4096il 1192,1 20U>! 25>il 1024,5 2041<9 2041i6 204115 409619 4091i9 4096i5 119219 919319 519211 119219 1639411 1530411 16314,1 ll.314«l 16.314,6 32,76fal 32.765,1 32.765,5 32,765il 32.765,H 65.536,6 65.536,1 65.536,5 131,07211 9192i9 8152,1 450115 ;25V! . 450m <25V>_ 450n5(12.5V|, 450ns <25V> 450ns(5V, .5V,.I2VJ.„ 2K|1 M s) __ 450ns |25V) .4% ,595 -525 -5.95 -.6,49 -4.25 .. 6.95 45C.« I2.SVJ CMOS 450ns 135V) 200ns 121V) 450ns I25V) CMOS 250ns [31V1 200ns 112 5V), 250m [126V], — l50nsil35VICMOS- 200ns 171V) — 250ns (2 m 150ns (12.5VI 200ns r! 2.5V) 250ns (21 V| CMOS. . . 150ns(l2.5V| 200ns (12.5V) 3 45 -395 3 55 .4 25 335 4.19 ;45 435 595 .525 6-95 250ns (12.5V), . 150ns(l2.SVICMD$. 25Qns;12 5V)CMOS 30ns .'12 5V: 150ns|12 5V|CMOS 250ns 112 5V) CMOS iMniiUiViCMOSMMesi 64K 450ns I35V| (CHi(iEnW<),. 64K 350ns |3V| (Oulpul Enitttl 4 75 595 ,1.49 . 5.49 .4.95 725 .549 7 35 .995 7 49 1995 14.95 1595 EEPROMS 201 6A-25 2040*0 250ri£ l. 9V- 1 S V 1 5V ftftadWrtlf ..... 6.49 2017A 2DtB*fi 350ns 5V ftftadiTV rttt 6.9S 20O4A S 3 B2 1 B 250ns 5V RMfl-Wrl I* ;f .r 1 . No ft B) 1 0,95 2BS5A 819?*B 250ns 5V R«»d, r WtHo 10.95 SOW SERIES Continue PlrtNo. PrtM 8286 ,..229 8748 125V) S748H (HMOSK2IV 8749 7,95 ... 9.95 995 8751 H (3.5- 1 2MH£) . . . .34.95 8755 1355 80296 1 ( 1 0MHi)iCC 29.95 80287-3 (5MHI) 109.95 80287,8 (SMHz) 209.95 80287-10 (10MHJ)... .239-95 80386-16 PGA 259.95 80387-16 (16MHI) ,.349,95 80387-20 (20UHI). -399-95 80387-25 (25MHi) -499-95 82284 ISMHiJ 5,49 82288 IBMHl) 6.95 DATA ACOUtSmON *DCQMSCCN ADC1205CCJ.1 3.75 -19-9S DAC0B08LCN AY-3-10150 1.49 -4.9S AV-5-1013A 2.95 6500/6800 68000 Series Pn« 6402 6502 6502A ...3.75 ...5.19 -.259 65C02 (CMOS) ... 6520 6.95 1.59 6522 . 65C22 6532 6551 6SC602ICMOS) ... 6800 6602 6808 , 6610 , 6820 6821 -.-..__., 68B21 6840 6845 — 6850 , 6852 MC6SO00L8 MC&30OOL1O MC68008P8 MC6S010L.10 MC6S020HC12B, MC68450L10 UC6S701 MC68705P3S MC68705U3S WC66861HC16A . WO68881PC20A .2.95 .425 .4.95 .269 ,..15.95 .,..1.75 2,95 2.49 125 .,2.75 1.75 225 ...3.49 ...2.75 1.75 .75 .... 9.95 ...11.95 849 ..19.95 ...59.95 .29.95 .1995 ...15.95 ...17.95 .129.95 159.95 Commodore WC11 770 S13052P — 8.95 99 6504* 1 19 6626 6S26A 1396 14.95 3.95 6567 24.95 6572 6581 (12V) 695 12.95 ... 7.95 5566 9701 5722 •B2S100PLA". 696 9.95 895 1596 325572 01 901225-01 901226331 90122702 901227 03 90122905 1795 15.95 1595 4% 1595 15-35 1.95 901486-06 295 'No specs available "No»«2Sl00PLA-LilJ|C64) 74C/CMOS 74CO0-. 74C02 . 74C04.. „ 74C08.. 74CI0.- 74CI4. 74C32.., 74C7'— 71C15 74C16 74C69. 74C90 74CI51 74C154 . 740 157 . 74CI60 74C161 74C162 74C173 74C174. 74C175- 74C1S3. 74C194. 74C221 . 74C240,. 74C344,. 74C373... 74(374 74C91I 740912 . 74C915- 74C917-, 74C930- 74C921 .. 74C922 740923... 74C925. 74C92E. MISC. COMPONENTS TANTALUM CAPACITORS TM.1 1|jT®35V. 19 I TM4.7 4.7ul@ 35V... .45 TM1 liit@35V. 19 TM6.1 6.8)11 «? 35V... J9 TM22 22n1@35V-. 25 I TM10 10uli3 35V 69 POTENTIOMETERS Valyes available (insert ennns mlo space marked ~X>T): 50011. 1 K. £K 5K. 10K. 20K, 50K. 100k. 200K. 1MEG 43PXX3,'4Wnn,T5Turn .99 i63PXXl*2Watl. ITurn .89 TRANSISTORS AND DIODES PN2222 _ .13 2N2222A 29 2N3055 69 2N3904 12 PN2907 13 2N4401 15 1N270 .25 1N7S1 15 ■',-1351 1N4I49 ".J73:, C106B1.. . .10 . ,07 25 . .49 SWtTCHES JMT123 SPOT. Dn.On 1.25 I 206-8 SPST. 14 pm DIP MPC12I SPCT.OiQiO 1.25 I M5102SPS'. 1.19 39 D-SUB CONNECTORS 0BJ5P Mate, 25pun .69 I OB26E FemaB. 25-pn )!C209FlTs,Red XC556BI1". Red. LEOS .151 XC556G Tl», Oreen .13 1 XC556Y Tl", Yallinv IC SOCKETS 8LP 14LP-. 16LP... 24LP 40LP.. wii»Wrop(Gc4tn l»v«i ia 49 £5 14WW I6WW... 24WW ..... 26WW... 4DWW .1.19 .1.39 .1.89 74HC HI-SPEED CMOS Pen ho. 74HC00 19 74HO02 19 74HC04 19 74HC08 19 74HC10 19 74HC14 SS 74HC30 25 74HC32 25 74HC74 23 74HC75 35 74HC76 35 74HC85 55 74HC86 _.2» 71HC123 59 74rtC125 — 49 74HC132 49 74HC138 45 74HC139 39 74HC154 1.49 74HC163 29 74MC174 59 partNn. Prim 74HC175 74HC221 59 89 74HC240 69 74HC244 74HC245 _.... 79 79 74HC259 49 74HC273 49 74HC374 74HC595 .69 129 74HC688 149 74HC943 6.95 74HC4O40 74HC4049 ... 74HC4050 79 29 29 74HC40W) 74HC4511 . 74HC4514 74HC4538 74HC4543 ... .99 .179 . 1.19 l 19 74HCT-CMOS TIL 74HCTO0 74HCT02 74HCT04. 74HCT08 74HCT14- 74HCT32 74HCT74 ... 74HCT66. . 74HCTI38 74HCTI39.. 74HCT157 74HCT174 74HCT175 74HCT240. 74HC1244 74HCT245 74HCT373 74HCT374 39 29 29 29 . 69 49 .49 49 39 LINEAR P"1 "o. t-s io, T1.071CP £9 T1072CP .79 T1.074CN 39 TL0S1CP m TL082CP _ 59 TL0S4CN _. .99 LM3Q7N .45 LM309N 65 LM309K,,.... 1.49 125 LW310N 1.49 125 LM311N 49 .39 LM317T 69 .59 LM318N 1.09 .99 LM319N 1.29 1.19 LM323K 3.49 3,25 LM324N 39 ,35 LM335Z .1.49 125 LM336Z 1.09 .99 UM337T -,__.129 1.09 LM33SK 4.49 4.25 LM339N __ 49 39 LF347N- 149 1.25 LU34BN _ .69 .59 LF351N- .49 LF353N -59 LF356N ^9 LF357N - .99 LM358N .59 LM380N .89 LM38521.2 — 1.75 LM386N 3 69 LM393N 45 LF396W 1.95 1.75 LF411CN 79 .69 LF412CN 1.29 1.19 NE555V J5 .29 XHL555 75 .65 LH656N 49 .39 LM565M 99 89 LM566CN 1.29 1.19 U4567V _. .75 LM723CN 49 LM741CN 25 LM747CN ^9 LM1458N — J9 LM1468N 49 Part II 0. ■■9 ID- DS14C88N LM1489N DS14C89N LW1496N LM1871N . LM1872N ULN20O3A ULM20O4* 26LS29 26LS31 26LS32 26LS33 - ULN2803A LM290IN LM2907N LM2917NI8P") MC3470P MC3479P MC3486P MC3487P LM3900N LM3905H LM3909N LM3914N... . NE5532 NE5534 7805K 7612K. 7S15K 7BD5T 7B12T 7815T 7SLOS _ 7905K 7905T 7S113 75150. . 75154 75174 75175 75176 75451 75452 75492 MCHS406P 1.19 1 09 49 45 1 19 109 69 -59 195 1.75 1.95 1.75 .79 .69 79 .69 2 95 275 1.19 .99 1.19 .99 175 1.49 1.19 .99 .39 .29 129 1.19 1.75 149 1.29 1.19 3.95 3.7S 1.29 1 19 129 1 19 49 45 129 1.19 89 79 1 95 1 75 .89 79 .89 79 1.29 1.19 1 29 1.19 1.29 1.19 .49 45 .49 45 .49 .45 35 .29 149 125 .55 .49 1 39 1.19 1.29 1.19 129 I 19 295 275 2 95 2.75 2 25 155 45 39 45 39 89 .79 295 2.75 PARTIAL LISTING • OVER 4000 COMPONENTS AND ACCESSORIES IN STOCK! • CALL FOR QUANTITY DISCOUNTS BAMs ARE SUBJECT TO FREQUENT PRICE CHANGES 90 CIRCLE 114 ON FREE INFORMATION CARD Now Available... Jameco *s NEW 1990 Catalog with 80 pages of Computer Peripherals, Components & More! Oscilloscope Probes Attenuation: x1 / x Capacitance .F180): 180pF j- **^*-** F180 40MHz Oscilloscope Probe $19.95 F210 100MHz Oscilloscope Prate $29.95 TEST EQUIPMENT latdStar 20MHz Oscilloscope and 1GHi Frequency Counter ■High 087020 Large 6" rectangular display ensilivity: 1 mV/div 5S7020 Oscilloscope $399.95 Wide measuring range • Measured alue hold function : C7102 Frequency Counter $299.95 Prototype Design Stations WM2 WM 1 & WM2 Features: • Removable solderless bread- board ■ Variable and fixed DC power supply * Multi- frequency signal generator ■ Analog multimeter ■ 8 bicoi- or LEDs (red & green) • 8 logic switches ■ Logic probe ■ Lighted power switch • Fuse overload protected * Sturdy ruggedized case WM1 Special Features: ■ 4 potentiometers • Built-in speaker WM2 Special Features: • Pulse Generator • Binary coded decimal (BCD} to 7 -segment decoder/driver - DB25 connector - Frequency counter (1Hz to 1 MHz) WM1 Analog Prototype Station .... $1 99.95 WM2 Digital Prototype Station $249.95 SPECIALS JE1061 OHS2005 DMS200S Mfflist *0nvtr £ Gup* Star. ! Pa ... $49.95 JE104S Hini DufcrFiopm CuniniDji [An $129.95 JE1061 BS232 imk caul (XT) $24.95 JE1079A wjiiiWSJMKbcofflnsrinn $59.95 JE1 198 Umarul Frlrnar sons $7.95 JE2Q1Q VemoiC«««'!50wrDwtrSupaV..$249.95 SCAN200 LooflKtizmffiPiSarmr $159.95 SMGC Moflochromt Giaphca Cud .$34.95 2012WR Mm verba! Case «.m™ sl-pbi .... $1 29.95 Prometheus 9600 Baud dodem I BOO E Eaenmaooam).... $7 49 .95 200B H«nal 1200 Baud $49.95 J :4O0B -mTOBK $99.95 IBM Compatible JEa) , 2 Cases and Power Supplies O JEIO'.O JE1D11 JE1018 JE1B30 JE1032 JE2Q11 JEM 12 JE2014 JEM1S Ftp- To? Straw! PGKTCaa - S39.95 SMtStanariPCWTCin S33.95 SxtB»y*1Ca» $5995 ISO mc PCKI n»« Su»> ,. J5I.95 203 «M Baby AT Power Stud S8955 vmai C4se«3tnw tv> Supy $279.95 MrtVirm Cue nOOOW Or Site*/.... II 4995 Flp-Tce Baby XT Tub) Can _ S6995 Ftp-Tool** 4TCBB B995 Display Monitors and Packages AMBER 12" Amber Monochrome $99.95 HD55H 14" RGB 640 x 240 $249,95 M9070S 16" Multiscan Monilor 1280 x 800 $1099.95 TM5154 14" EGA 720 x 350 $369.95 JE1059 TM51S4 EGA Monilor & EGA Card $459.95 TM5156 14- VGA 720 x 4B0 $399.95 JE2060 TM5156 VGA Monitor A VGA Card $529.95 TM5157 14" Multiscan 800 x 600 $469.95 JE2057 TM5157Mulliscan Monitor* EGA Card -.$559.95 M907DS Metex Digital Multimeters Vetex Genera/ Sipecs: ^^^ i Handheld, high accuracy AC/DC Voltage, ACrOC Current. Resistance. Diodes. >oni!nuity, Transistor hFE Manual ranging w/overload election ' wa&so ■- ' - ' V36S0. 3SSBB t M4B50 only: Also measure frequency and capacitance •JUS50 only; • Data Hold Switch ■ 4.5 Digit V13610 35 Don Muthmelw $49.95 3.5 Drgit Mullimerer w/Frequency £ Capaolance $59 .95 Bare m M365Dw,'Bargrapti....$79.95 4.5 Digit #rFrequency, Capadlance and Data Hold Switch $99.95 W3650 W3650B ',14650 Jameco IBM PC/XT/ AT Compatible Keyboards ART*. EPROM Programmer • Programs all current EPROMs in the 271 S lo 27512 range plus the X2864 EEPROM • May be operated by any RS232 port w/termina) emulation • Fully intelligent ■ ASCII command driven • Menu driven software included EPP $179.95 UVP EPROM Eraser «r. ■ Erases all EPROM's • Erases 1 chip In 15 Min. and 8 chips in 21 rnin. • Maintains constant exposure distance of 1" * Special conductive foam liner eliminates static build- up • Built-in safety lock ■ UV intensity: 6800 UVWCM2 DE4 $69.95 JE2017 JE2015 84 Koy Standard AT style Layout $59.95 | JE1016 101-Key rriM-L-i (I L-LV-..1- with 12 Function Keys .....$69.95 | JE2016 ' 1 1 ■ * e , F r,l ■ it Ml .v, I ■ : Be l.v i'(i»n...l Calculator $79.95 | JE2017 1 04 Key Enhances m\ti Trackball IHicrosoti compalibiel ....$99.95 1 PROTOTYPING PRODUCTS Jameco Solderless Breadboards } I*""" \^ -V24 JE27 L- J. 0* JE21 4j J 623 pin No. Dim. i ■■ < ■«■■ corned Polnti Blnalnn JE21 JE23 JE24 JE25 JE26 JE27 3.25x2.125 6.5x2.125 6.5x3.125 6.5x4,25 6.875x5.75 7.25 1 7 5 400 830 1,360 1,660 2,390 3,220 $4.95 $6.95 2 $12.95 3 $17.95 4 $22.95 4 $32.95 3.5" and 5.25" Floppy Disk Drives MPF11 Pictured Sony MPF1 1 3 6" 720KB Internal Drive.... $69.95 SMK 5.25' Installation Kit WFaceplale,. $14.95 Toshiba 356KU 3 5' 1 44 MB Inter™! Di« $1 09.95 TEAC FD55B 5.2s- asoKb Hail m. $99.95 FD55G s.25- 1 2Mb h s ii hi $119.95 Jameco JE1 020 5 25- 360Kb Hall HI. Black $89.95 JE1021 S.SS" 360Kb Half Ht. Guy $89.95 ■JE1022 5 25-1.jtMbH.il HI. Gray $99.95 Soldering and ~^0 Q Desoldering Stations 1^ ^ 60 Wall Digital Display Soldering Station ■ Electronic temperature control Irom 200 e to a7!5 e 'F ' Temperalure displayed on easy to read .560"H 3-digit LEO readout ■ Nlchrcfne heating element XY96Q... $99.95 60 Watt Analog Display Soldering Station • Electronic temperature conirol from 200° to 878°F • Cartridge healing element tor a longer life of the soldering tip XY1683 $59.95 60 Watt Analog Display Soldering Station - Electronic temparature control from 200° to 87B"F ■ Ceramic heating element for a steady temperature and long life XY2660 $89.95 30 Watt Electronic Temperature Controlled Desoldering Station * Electronic temperature control from 212° to 842° F • Self-contained high rotary vacuum pump XY999 $279.95 Hard & Hard/Floppy Disk Controller Cards MFMHuaWom RLL HantTltfifiy Computer Type »lPCIT)gl:1 WatHtTVtWaM Wj I'ryato m nm in ■ Pan No. . Price 1CC3VMMVS.ta.S5 igggiMHt«l4M9 Part No. I Prlea , Q06VSfl'„S'«5 9S Pan Kin. I Price trxuvUMiS'Jsss ICIMVMU2.J169M Part No. I Price l003VSmai69s6 ■XT.=F-s-ii;i 355 Shorewey Road iclmont, CA 94002 UHour Order Hotline (415) 592-8097 : AX'S (415) 592-2503 or (415) 595-2664 Telex 176043 - Ans. Back: Jameco Blmt )ata Sheets - 50c each itfKI $2.00 Poslig* lor a FREE 80-Page Catalog 3 19S0 Jameco Electronics 2/90 8M is a registered trademark of ntarnalional Business Machines I//S4* ■ 1..^.— H,.,!,,, ameco ELECTRONICS 125.00 Minimum Order- U.S. Funds Only L CA Residents Add 6%, 6.5% or 7% Sales Tax I Shipping ■ Add 5% plus $1 .50 Insurance I (May vary according lo weight and shipping method) I Terms: Prices subject to change without notice, i We are not responsible lor typographical errors. We reserve the right to substitute manufacturers. Items subjecl to availability and prior sale. Products pictured may only be representative. Complete Use of lerms/warraniies is available upon request. 24-Hour Order Hotline (415) 592-8097 - The Following Services Are Also Available Through (415) 592-8097 From 7AM - 5PM P.S.T.: ■ Customer Service ■ Technical Assistance • Credit Department • All Other Inquiries CIRCLE 114 ON FREE INFORMATION CARD m 33 C > < 8 91 AK, Puerto Rico - 218-681-6674 1-800-344-4539, FAX — 218 681 3380 TWX - 9103508382 DIGI KEV CORP INTEGRATED CIRCUITS O0 O o MJ7.II j43rN 7431* nuju. NJih ^CJ .'Jinn. 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I ,H-VAC P*513 odi to P45U tjrj.j'M P4$lft (tlS 50 f45«..iOji: , 90 WtVf 023 W H01I 027 S) «5l9 EMM P4JU0 Q7J9'50 HBJ LKiJB PA5S2 6.0M to P4523 OW 50 H534 0«'5O tffi» 5 74 ■ B K r, /.; :. v to 1 Bi Oaij . ipr> 1 31 0015-100 00 IB ■!« 1 11 C.232 1K _LB pg37 ICC 1JJ1 0033 ioa COM 103 0047.' 100 ? 03 QJSS.1W )H 3Q5i 100 323 3 OS? 100 0.1. '100 330 0.12.100 2.57 fj ';■ ]« 7 I': :. ji IS 7 !•: 22.' 100 3.94 27.100 334 O.TO'IOO 1*1 39.100 4V. t«:i _AJJ 92 CIRCLE 82 ON FREE INFORMATION CARD EQUALITY PARTS ^DISCOUNT PRICES &FAST SHIPPING ALL ELKTROniCS CORP. 3 to 6 Vdc MOTOR with GEARBOX Probably designed for childs toy. Lever selects 2 forward and one reve rse speed, 1 st gear aprox . 120rpnV6vdc, 2nd gear aprox. 300 rpnV6vdc, Reverse aprox. l20rpnV6vdc. 3.35" X 1.75" X 3.25" CAT« DCM-10 $6.00 4 AA BATTERY PACK (USED) Four AA nickel cadmium batteries connected in series to make a 4.8 volt pack. Batteries are in a 2X2 configuration with a 2 pin connector attached. The lour batteries can be separated into single AA size solder tab nickel cadmium batteries or rasolderod into other configurations. SPECIAL SALE PRICE - W ERE M l t>0 par pooh MOW $3.00 per pack CAT# NCB-41AAU STEPPER MOTOR Airpax* A82743-M4 Brand new 12 volt dc stepper motor. 35 ohm coil. 7.5 degrees per step. 2.25* diameter, 0.93" long excluding shaft. 0.22" diameter shaft is 0.75" long. 2 hole mounting flange, 2.675" mounting centers. 6 wire leads. CAT* SMT-5 $10.00 each 12 VOLT DC MINI FAM Howard Induslnes* 3-15-STQ, Operation 12Vtic. O.lOomp, 1.D Compact plastic touting., 35" square X 1 J7S - thk*- 9 Wade Ian. Two V pigtal lesfli. CAT# CF-1J1 S3 .00 each 115 VAC COOLING FAN STANDARD SIZE COOLING FAN. Feature! die cut irwtiJ housing lor strength and durability. IMPEDANCE PROTECTED 4 11/119" square XI 1/2" deep. FacKxy new 120 Vac tans. CF1-N $950 each WALL ^TRANSFORMERS ALL PLUG aRECWr INTO 120 VAC OUTLET Vet 9 K» mi CAT* DCTI.SM K3S SVdc0 2»mn. CATS DOTX-eM SI.50 18 V« O < "TO- CAT! ACTX-1S1S S3 So 24VuBSSfink CAT* ACTX-24S2 flSS SWITCHES ITT PUSH BUTTON _^~ rrruuH,M*»». vrx £§!§^ WT gray reetamgular ^*^"T he* ces. S.P-5.T. NO. Pueh to daee. RATH): 0. 1 ajrp wnoMng, 025 tfrc wurr eymrt. p.c. mc^jrx. CAT* PU SSeaacti • 10I-* MOO ■ Its lorSSMB 10 POSITION MINI-ROTARY GnyhiM 56F*£1-l-lON-C WW rotary SMtoh. Msn^horllna. 1 dK*. 10 portions. ,12S* die. >hrf X .J7S- bug. .3R-bJi,nd the panel depth. PC. p». CATS MRS-IO WAS S2.50 NOW 11 j50 each SPDT PUSHBUTTON u*rqu*idi* lata Hated e bhp> t> isstJW Vug. Btach plHtjo puvMhAml Srwilth bail- .tliTK .65". CATS PB-1S Sl.&5*»ch - 10!orS1.»i PUSHBUTTON SWITCH Qc/Thomtens 35-420 S.P.S.T., nonnark; open momentary push- button twitch. Red pbuHcaccuttor .67" dl*. Chrome bezel .GS' dimtir. Threaded bxnhlng rrounti En ,50" dlam. cheat It hole. flaled 3 ini>e2» Vac. Solder loop lerrriruls. CATS PB -20 $1.00 trash LED'S STANDARD JUMBO ^ DIFFUSED T1 -2/4 vim RED CAT* LED.l 101«*..M " 1W Iwt 13.00 OtiE£fi CATfLEIM 1 lor JZOO '100 lOf 11 ?jOO VEilC'iV CAT* LEO" 10 For 12.00 ■ lO0r O rl17,CC FLASHING LED -l buit ill liaihing CfTOlft ^J apaa-aiaa on 5 vofti.. . RED ILOOaach A CAT! LED-* tO far *3.M f Pff t rJN J 1 TO aach | CAT* LED-4Q 10 (w |fl.50 ^ BI-POLAR LE0[_ L»g M» RED on* draction, Spf GREEN if* cthaf. Two tavdi, [ CAT* LED-4 2 for (1,70 LEO HOLDER _ " TPrtpe»r,:-5«. " ffj CAT* HLED tQ tor S5a RELAYS 12 VOLT D.C. COIL S.P.D.T. t>mniG»-l84P 335ohfficoLL Sugjtr cutwiLt*. .61* X .4? X .44" hgh. >J P.C. rrojrtl *nLTi pn» on DIP ..paring. CAT* RLY-717 |1 .50 twh S-C VDC SIP REED RELAY GbcM 'BluaBoyt sas:AoSAio 5^Vdc,ButiohMcol. S.P.S.T, nwmally optn r**d ratty. 0,5 amp 0Onlac(i. SIP omligwiIJon. TXJ3I7S"X.3*. CAT* RHi.r-SIP5 Jt.t0«eh * lOrOTJlOOO ^ PHOTO FLASH CAPACITOR Rubicon* FKX 200 mid, 330 volts. 0.79" Piameter X 1 . 1 1" Noh Solder loop terminals. CAT# PPC-200 $3,25 each 10 for $30.00 ■ 100 for $275.00 a MMtU WHAT 1 1 MO WILL II UV /*-, /™1 200 ASSORTED 1« WATT RESISTORS B*fiE tMdi, c»rtKo cofrp. and cwtxMi Tim, CAT* ORES (l.oo par euorUTwm /-CO^ ,CI0-\ 200 ASSORTED 1/J WATT RESISTORS 9 fl CAT I GRABPE SI .00 p#f M«ftm*n! 50 ASSORTED DISC CAPACITORS Motr «."• an {p.c. bede>. Some 10 500 vadi CATS QRABDC 11.00 pel utsmei* TS VALUES OF - ELECTROLVTICS ConuM bah txkl tAd ndu utfm Imm1 nid. CATS CPASCP 11.00 pe f 10 AMP SOLID STATE RELAY ELECTfWL* S21S1 OOWTFtOL: Ral«J5.5l9lOVfc (will op*nr* &n 3-32 Vdc}.'' LOAD: lOanve 240 Vie Z lrt' X 1 3r4* X 7AT CAT* S8RLY-1O0 (ft-Sfl hA QiMNlTTVC*SCOUrVT HOKXH^QO - 23faf*t7SJl0 501wlXC.CC ■1001^*WO.O0 22/44 PIN CONNECTOR ^" I IIIJMiP 5 .156" pin spacing. 200" between double rows, gold contacts. P.C, mounting, SPECIAL Same as AMP# 2-530655-6. QfkTM E8C-1 G SI 00 each ■ 10 for $6.00 0-30 MINUTE AUTG- SHUTOFF TIMER SJuikyo Saike M1g.» TMCF35MYB9 120 Vac 60 hz. 10 amp conncu. " UL raldd. Tucn state to turn on lights, or othar fllectricaJ dflvtcst. 6«ll ringa and drcuct breaks after apecifiKf amouni of lima, Meal for any device shai needs to shut off automaAcaily. 2.32* x 1 .9" x zw behind face plate. iiU'hallWuunclihafL CAT# TMC-30 $3.00 each LED CHASER KIT Build ihls variable \ w\\i*itj.^^f^} speed led chaHf. lOtadtaaati sequeniially alwhatovof s|Xfed yo-j &0E LlwiTt for. Easy to build kit Includes pc boand,, pans ana inilructtons. Operates on 3 to 9 voftt. PC ■ board ti 5" X 2 25", A great one hour projoct. CAT# AEC $6,50 each XENON TUBE r bnfi lUlMub* pf«pc*3 with S MT f*d ind b**i kwta. UmI lor •tocironb i!iuh or nrotw proj*cti. CATJ FLT-3 2fof n«3 1/4 WATT RESISTOR KIT lo*d for [rw -weriahep. I'm 1M» 1G pt*c** Nctn at 42 of ihw moti popular valuta (420 placaa lo- laTj. LkJlxSm a drvkM box and iparU locator. VALUES In Ma kit an: 1 ohm. lOohrrv 30. grim, 47 ohm, 51 Otiffl, AS oiim. 100 ohm, 130 ohm. ISOphrrv IPJOetKAj 220ohfTV 3^ 0IVTV 470 Ohm. 560 CfifTt AM OflrPL, tK. 1^K, L5K, ZK.2.2K.2.7K, 3K.4.7K. &1K. S^K, 10K 1 &X, 2K, 3QK. 33K„ 36K. 47K, UK, 68K. 100K, 120K. 150K. 220K.470K, hUEaS.1UEQ.10UEQ Tha r*4Lttori bmYw would tall lor 121.00- kH*CAT#REKIT-14 $17.00 B PIEZO WARNING DEVICE MuntiErieSPKOS-JAO High pilehed «ydw« eUnn. Op- enlH wi 3 - 2D Vds © M rre. T high x 7IC die. PXX boenl mount, CATS PSZ44 11 .75 *Kh NICKEL-CAD BATTERIES (RECHARGEABLE) SPECIAL!! AAA SIZE 1.2vckd>1SOUAh CATe hcb-aaax tl^Oeecn iciai13.» ■ 1O0"c.. I1E3M AA5CE SZODevh 1^5»IUKOmM CAT* MCB-AA AASIZE S220«Kh WITH SOLDER TABS CATC hCB-SAA CSKE H44EACH 1 .2 ^h» 1200 rT*h CATJ MCB-S DSiZE S4.S0«Hdi 1 3 vein 1!00 rMh CATS NCB-0 TRANSISTORS ORDER BY PART ■ PN2222 KPN TO-92 5for75e PN2907 PNP TO-92 5lbr75« 2N3055 NPN TCW S1 .00 each MJ2955 PNP T03 $1.50 each MJE2955T PNP TO-220 7S* each HJE3055T NPN TO-220 75* each TIP31 NPN TO-220 75* each T1P32 PNP TO-220 75eB«*i T1P121 NPN TO-220 75* each TIP126 PNP TO-220 75c each TIL-99 PHOTO TRANSISTOfl TQ- 1 cau WKh vrindow. For wida ■ ang w vwiriing applcalioni . Spadrally and mocha.-: tail y oompat- ibl* wil h TIL-3 1 S. CAT* TtL-*fi ^ si.cn B *:h - iofo.fg.oo M -^ — TIL-31B PHOTO DIODE TO- 1 8 oaio w.lh wr fKto*>r. Inlrarad omitLTfl phola dk»d*. CAr*tpL-3lB ll.OOaa. ^ iQftf S*,50 N-CHANNEL MOSFET RF-S11 TO-220 (ttt CATJflflF S.11 5!. DO each- IOIdtSOOO LARGE QUANTITY AVAILABLE % L.E,D. FLASHER KIT Two LE.0l* ILtah in ^1/> ^|v untaon whan a 9 voi "If^sdja***^^^. baaaryaBlaehad, £Z_**Vy Jl Trwi M Mbsal a jgj ^ -^^ p.c board, al !h* ^--^ part* and iftsUucliani to maha a limpJa \'m>.o' cr- euiL A quick and aaay pTojad for any/QfwwIh bat* totdying afcila- CAT* LEDKIT 11.75 p*x tt TELEPHONE COUPLING TRANSFORMER Uutl Producta L-.t^naSkxiaii A1BN-HO-1&1 PilmaryeOOohm Sacondarr: 600/600 ohm .TTXjsi'XAarhlgK fl- p,t, pin* on ,1 87" carmtt. Primary Inductano*: 300 mH min. at ikHl. 1 VOR, CATJTCT3t-1 J!.?5*ac:h - .OMrftl.DD OPTO SENSOR U thap#d pachaO* wdh mc-riring aara. 1/9* opening. 3/4* mounUrg hola*. CAT* OSU-B 00c ««ch trjlorM.50 ■ 10O1of 140.00 OPTO ISOLATOR Slgmai 3C1 T1-120L Serial applad lo ihe Snptrt b Couph>d by maanB ol light IP koWad photo oOn- dudiva call. HHJh r«J Utility ■wfechlng, 12 wjfl Input, CAT* OP-301 tl.SOaaCrl AC, LINE CORDS 8hKh art. 18^, »pt-2 HON POLARIZED PLUG CATJLCAC 2^11.00 - lHJltfW5.G0 POLARIZED PLUG CAT*LCP-1 OQa aaoh - 1 00 (of 150.00 14.7 VOLT TRANSFORMER SpHie Induturieif CS-S1CA. 14.7 wM, 60 hz r 8.82 Vd. TfilV:ighX:.3§7X 1 .47-. Mtxini&ng hoiea on ?^2" oenion. CAT# TX-147 $3.00 each 10 for 527.00 * 100 far $250.00 CALL OR WRITE FOR OUR FREE CATALOG OVER 4000 PARTS! Now 60 pages MAIL ORDERS TO: ALL ELECTRONICS P.O. BOX 567 VAN NUYS, CA 91408 TWX-5101010163 (ALL ELECTRONIC) OUTSIDE THE U.S.A. SEND $2.00 POSTAGE FOR A CATALOG!! ORDER TOLL FREE 800-826-5432 INFO: (818)904-0524 FAX: (818)781-2653 MINIMUM ORDER $10.00 QUANTITIES LIMITED CALIF. ADD SALES TAX USA: $3.00 SHIPPING FOREIGN ORDERS INCLUDE SUFFICIENT SHIPPING. NO C.O.D. m DO J3 C > ■< _L (O CO o CIRCLE 107 ON FREE INFORMATION CARD 93 MARKET IMG COU.hK JDR Microdevices 30 DAY MONEY BACK GUARANTEE ' 1 YEAR WARRANTY ON ALL PRODUCTS - TOLL-FREE TECHNICAL SUPPORT DYNAMIC RAMS 7> s X 2 < PART# 4164-150 4164-120 .ntii-lOO TUS4464-15 TMS4464-12 TUS4464-10 -11256-150 41255-120 41256-100 41256-80 41266-60 414256-100 414266-60 1 MB-120 1 MB-100 SIZE 6553611 65536k 1 6553611 65536x4 6553EI4 65536x-l 262:44,1 262144x1 £6214411 252144X1 262144x1 262144x4 262144x4 1048576x1 1046576x1 1 046576X1 SPEED 150ns 1 20ns 100ns 150ns 120m 100ns 150ns 120ns 100ns 00ns 60ns 100ns 80ns 120ns lOOrvs 80ns Depict '$ HIGH-TECH SPOTLIGHT ,fll.m,m,imMHI!IHIH.-IIJIUJ!flMJ,M SIMM/SIP MODULES PART* 412S6A9B-12 4125SA9B-60 4 21 000 ABB- 10 4Z1000A9B-10 421Q00A9B-90 256KX6SIP-80 256KX9SIP-60 1MB MS IP- B0 PARTI HM61I6LP-2 NM6264LP-15 HM6264LP-12 HM43256LP-12 HM43256LP-10 SS2E 256Kx9 256Kx9 IMBxB (M3x 9 !MBx9 2S6Kx9 256Kx9 1MB* 9 SPEED 120ns 60ns 100ns 100rre 60ns BOns 60ns BOns TYPE SIMM'PC 36.95 5IMMVPC 44.95 SIMM/MAC 1 09,95 SIMMJPC 113 95 SIMM/PC 119.95 SIP/PC SIP/PC SIP/PC 54.95 64.95 124.95 STATIC RAMS SIZE 204&xS $192x3 ai92xS 32768x8 32768*8 SPEED 1 20ns 1 SOrts .2.0ns 120ns 100ns I *topp*d r*cCnTVTT*nd*rig CGA dlibkjy lyitonu to my frtondi about 4 y*on ogo. Th*n. lh* ectf p*r p&*f wen town for CGA than EGA, and my Hjgg*ttton wot ft equtntly lgrtor#d. How. hawuvar, VGA not a low*( coil p*r pixiri ihon *tth*r CGA or EGA. In foci, *xp*Ct 1o g*t obbut 40% mor* rviOlurkHi ror /our dollar wtth VGA at compor*d to CGA. ThU IhiI Juit a numb*u gam*. Qp*rotor comfort ood display pr*»ntaflon or* In* roal koy luue*. Wish mas and mcjo proa. -rami using a GUI (graphical usor interface). Ih* n**d far high roioJirtron color Irvc [H»t. Hftochfi'O l*xt on a CGA altploy tt no) particularly *a»y tor any tongth of time TTw Hn*i **«. to run togvth*f and during tcfoimg lh* Ant tow Urwt on Ih* scr**n fUekar. Wltti VGA, Ofld lo 10m* *xtont EGA. that* complalnii dhapp*ar. Th*y or* r*ptac*d wtth cemmtntj about th* imoorh ihn* *dg*t, rwiitftc ihoding. rapid icr**n updat**, and Ufttlfc* colon. In 2b£> color mod*, liom a patotl* of 256 1tic-u;arnd CODOft. Ih* abllHy Of VGA dttpkry to (*nO** n*ar photographic Imagoi muil b* hhui la bo approclaltd. It th* mov* to lull eater VGA bn't In your pockvrbook, ptoaw l*i tr# tuggwt o monochroni* VGA tytttm a i an oflemct* ehote*. Wtth 1* or 64 tovtb of gray icato, H b porttculorly uwful Eor d**Kiop py&Uihing wh*r« your print™ down't do eater anyway. Dartck Moor*. Dtr*etar of Engtna*rtrig EPROMS MATH COPRt PARTI SIZE SPEED Vpp PINS PRICE a-etr coprocessors inhJ 5 YEAR 1 2716-1 I 2732A 2046*8 350ns 4036x6 250ns 26V 21V 24 3.3:. 3.95 6087 5 MHz 89.95 1 2784 8192x8 450ns 12.5V ?fl 3.49 6097-2 9MH1 129.95 \ IIAI WARRANTY 1 1 2764-250 9192x6 250ns I2.5V 29 3.69 806"/- 1 10 MHz 189.95 W 1 2784-200 8192x6 200ns 12.5V 28 4.25 IB-BIT COPROCESSORS ^ 1 27C64 8192x6 250ns 12.5V 28 4.95 80287 6 MHz 139.95 1 27128 16384x6 250ns 12.5V 28 4.25 80287-B 8 MHZ 209.95 1 27128A-200 16384x3 200ns 12.5V 28 5.95 90287-10 !0MHz 239.95 lix 1 1 27256 32768x8 250ns 12.5V 28 4.95 80C287 12 MHz 299.95 1 27256-290 32766x9 200ns 12.5V 28 5.95 ^B <>. *» I 1 27C256 32768x8 250ns 12.5V 28 £.95 32-BIT COPROCESSORS INCLUDES MANUAL 1 SOFTWARE GUIDE J 1 27512 65536x8 250ra 12.5V 26 7,95 80367-16 16 MHz 359.95 1 27C512 65536x8 250ns 12.5V K 8.95 80387-SX 16MHz 319.95 1 27C 101-20 131072x8 200ns 12.5V 32 24.95 80367-20 20 MHz 399.95 60387-25 25 MHz 499.95 80367-33 33MHz 649.95 f £VW)M FBAfSFBG 74 SERIES LOGIC 7400 74LS00 74LS02 7404 74LS04 74S04 7406 7408 74LS08 7432 C.P.U 'S BOO0 80S2AH BASIC 34.95 9066 5.99 8250 5.95 6261A 1.69 6253-5 1.95 62S4 9.95 5255-5 2.49 6741 9.95 6748 7.95 9749 9.95 9755 14.95 «5O0 65C02- 7.95 6522 2-95 V-20 V29 5.95 V20-S 9.95 V20-10 11.95 1 V3Q 13.95 74LS32 74LS73 7474 74LS74 74S74 74LS136 74LS155 74LS163 74LS240 7415244 MISC DAC08O0 3.29 1793 9.95 COM8116 8.95 MC146813 5.95 MM58167 9.95 INS6Z50 6.95 NS 16450 10.65 LM317T .69 NE555 .29 LM741 .29 7805T .49 781 2T .49 75150 1.95 75154 1.95 14411 9-95 CRYSTAL OSCILLATORS 1.0MHz 5.95 1.3432 5.95 29.0 4.95 24.0 4.95 74LS245 74LS273 74S268 74LS322 74LS367 74LS373 '■■4 L S3 74 74LS393 74LS682 74LS583 DATARASEII $ 39.95 -SHIRT POCKET SIZE 1 • ALL SIZES UP TO 4 AT A TIME - ERASES MOST EPROMS IN 3 MINUTES OATARASE II SPCCTROMICS Model Tlnur '<" Intensity Uni1 CORPORATION Chips (uW;Cirfl| Coil PE-140 NO 9 3.000 > 89.95 *i^ PE-110T YES 9 8,000 *1 39.95 PE-240T YES 12 9.600 1189.95 PL-265T YES 30 9,600 {255.95 PALS 16LB 2.9 16R4 2.95 16R6 2.96 16R8 2.95 20L9 J.95 20H4A 4.95 20R6 4.95 20R8 4.95 20X9 4.95 PAL KIT AN ENTRY-LEVEL | COMPLETE PAL DEVELOPMENT KIT FROM CUPL. FULL SUPPORT" FOR16L6, 16R4, 16R6. 16R8. 20LS. 20R4, 20H6, 20R8. AND 20X9. MOB-MPL-SOFT 999.95 POWER SUPPLIES ■Rl MflMTT • XT-COMPATIBLE- UL APPROVED '110-220VSWITCH • +5V@15A.+12V@4.2A. -5V® 5A,-12V@.5A PS-t3S J59.95 PS-1S0 150WSUPPLY ,. (69,95 PS-200X 200W SUPPLY S89.95 200 WATT • AT COMPATIBLE • UL APPROVED ■ 110-220V SWITCH ■ t5V»20A, »12V®7A -SV iS SA. 12V @ 5A *}J- PS-200 $89.95 PS-250 250W SUPPLY *129.95 PROTOTYPE CARDS FR-4 EPOXY GLASS LAMINATE WITH GOLD PLATED EDCECARD FINGERS AND SILK SCREENED LEGENDS FOR XT JDR-PR1 WITH »5VANDGROUNDPLANE 27.95 JDR-PR2 ABOVE WITH HO DECODING LAYOUT . 29.95 JDR-PR2-PK PARTS KIT FOR JOR-PR2 ABOVE 0.95 FOR AT JDR-PR10 BIT WITH l(0 DECODING LAYOUT 34.95 JDR-PH 10-PK PARTS KIT f OH JDR-PR10 ABOVE 12.95 FOR PS/2 JDR-PR32 32 BIT PROTOTYPE CARD 69J3 JDR-PR1S 16 BIT WITH I/O DECODING LAYOUT 49.95 JDR-PR16-PK PARTS KIT FOR JDR-PR1 6 ABOVE 15.9S JDB-PR16V 16 BIT FOR VIDEO APPLICATIONS 39190 EXTENDER CARDS SIMPLIFY PROTOTYPING AND TESTING EXT-806B 6-BIT FOR 80S6 MOTHERBOARDS 29.95 EXT-S0286 16-BIT FOR 266/386 MOTHERBOARDS ..39.95 EXT-1S MICROCHANNEL 16-BIT 69.95 EXT-32 MICROCHANNEL 32-BfT 99JJ5 PC BREADBOARD-ONA-CARD • 52 BUSLINES - USE UPTO24 14-PIN ICS - 1940 TIE POINTS • DB25 D-SUB CONNECT PDS-6M $49.95 SOLDER STATION • UL APPROVED - ADJUSTABLE HEAT SETTING. ■ TIP TEMPERATURE READOUT • REPLACEMENT TIPS # $2 95 1 68-3C $59.95 IC SOCKETS/DIP CONNECTORS SOLDERTAIL WtREWRAP ZIF SOCKETS 8 PIN ST .1 1 14 PIN ST .11 16 PIN ST .12 19 PIN ST .15 20 PIN ST .15 24 PIN ST .20 24 PIN WW 1.49 6 PIN WW .59 ZIF-14 14 PIN WW .69 ZIF-16 16 PIN WW .69 18 PIN WW .99 ZIF-20 ZIF-24 40 PIN ST 640 X 480 IN 16 COLORS, 528 X 480 RESOLUTION IN 256 COLORS • IBM STYLE MONITOR ■ VGA. EGA. CGA, AND MGA COMPATIBLE VG A-PKG (INCLUDES VGA CARD AND MONITOR) VGA MONITOR • 14- ANALOG VGA • GLARE RESISTANT SCREEN • 720 X 480 ■ TILT/SWIVEL BASE • FRONT MOUNTED POWER SWITCH VGA-MONITOR *1Vesljky5 multisynch $429.95 • FULL FEATURED MULTISCAN MONITOR WITH UNLIMITED COLORS ■ 1024 X 768 RESOLUTION. 14' NON-GLARE DISPLAY ■ AUTO SWITCHING • TTUANALOG VIDEO INPUT JDR- MULTI $359.95 ES^P£C!A^CAR^^ONfTQ^USTS47S^ EGA-MONITOR 14' RGB MONITOR $339.95 HEC-MULTI-3D DIGITAL 1 024X768 RESOLUTION ..$649.95 JDR-MONO 12- TTL MONOCHROME- GREEN $69,95 JDR-AMBEH 12-TTLMONOCHROME-AMBER $69.95 QUALITY KEYBOARDS STANDARD KEYBOARDS; BTC-5060 AUTOSENSE FOR XT/AT $59.95 MAX-5060 WITH TACTILE FEEDBACK $64.95 ENHANCED KEYBOARDS: BTC-5339 AUTOSENSE FOH XT/ AT. AUTOREPEAT .. $69.95 K103-A AUDIBLE "CLICK- STYLE $34.95 MAX-5339 MAXI-SWITCH WfTACTILE FEEDBACK $B4.95 MODULAR CIRCUIT TECHNOLOGY DRIVE CONTROLLERS; MCT-FDC FLOPPY DISK CONTROLLER $29.95 MCT-FOC-HD 144MB FLOPPY CONTROLLER $49.95 MCT-HDC HARD DISK CONTROLLER $79.95 MCT-HLL RLL CONTROLLER $69.95 MCT-FH FLOPPY/HARD CONTROLLER $139.95 MCT- AF H 2667386 FLOPPY/HAH D $149.95 MCT- AFH-R L L 286/386 RLL CONTROLLER $199.95 DISPLAY ADAPTOR CARDS: MCT-MGP MONOCHROME GRAPHICS $49.95 MCT-CG COLOR GRAPH ICS ADAPTOR $44,95 MCT-EGA ENHANCED GRAPHICS ADAPTOR $149.95 MCT-VGA-8 8-BIT VGA, ANALOG OUTPUT $169.95 MCT-VG A-1 6 1 6-BIT VGA, ANALOG OUTPUT $199.95 MCT-MGMIO MONOGRAPHICS MULTI 1(0 $119.75 MCT-MGAIO 288386 MONOGHAPHICS 1(0 $99.95 MULTIFUNCTION CARDS: MCT-HIO MULTI KO FLOPPY CONTROLLER $79.95 MCT-IO MULTI KO CARD S59.95 MCT-AMF 286(388 MULTIFUNCTION $139.95 MCT-AIO 286(388 MULTI i-'O CARD $59.95 MEMORY CARDS: MCT-RAM 576K RAM CARD $49.95 MCT-EMS EXPANDED MEMORY CARD $99.95 MCT-A EMS 288/386 EMS CARD $129.95 SeniSoan 400 dpi l jl ~ *vv $10095 Xj} • UP TO 400 DPI • 32 LEVELS OFGHAY SCALE- SPEED OVERRUN WARNING LIGHT - INCLUDES SCANED IT 1 AND DR. GENIUS SOFTWARE GS-4500 EPROM PROGRAMMER $129.95 ■ PHOGHAMS 27XX AND 27XXX EPROMS UP TO 27512 • SUPPORTS VARIOUS PROGRAMMING FORMATS I VOLTAGES ■ SPLIT OR ■ COMBINE CONTENTS OF SEVEHAL EPROMS OF DIFFERENT SIZES -READ, WRITE, COPY. BLANKCHECK& VERIFY - SOFTWARE FOR HEX AND INTEL HEX FORMATS MOD-EPROM HARD DISKS KITS 21.4 MB $ 199 21.4 MB $ 249 I 32.7MB $ 219 32.1 MB $ 279 \ 42.8MB $ 339 65.5 MB $ 389 80.2 MB $ 5( ays. ram mm SPt£B FACTOR ONLY 157.5MB ESDI DRIVE KIT $ U04i J-114- HARD DISK, FLOPPY/HARD COOTHOLLER, CABLES, MOUNTING HARDWARE 1 SOFTWARE 135S-PKQ 1.44MB 3-1/2" DRIVE w $99** ^ ■ ULTRA HIGH DENSrTY . REAOAVR1TE 720K DISKS. TOO •■ - .^1(^_ ' FDD-1.44X BLACK FACEPLATE POD- 1.44 A BEIGE FACEPLATE FDD-1.44 SOFT SOFTWARE DRIVEH $19.95 1/1 HEIGHT FLOPPY DISK DRIVES: FD-55B 5-1/4- TEAC DS/DD360K $99.95 FD-55G 5-1/4' TEAC DS7HD1.2M $129.95 FDD-360 5-1/4' DS/DD 360K $69.95 FDD-1 .2 51/4' DS/HD 1 2M $96.95 MOTHERBOARDS 20MHZ386 $Q29 ^ • 16/20 MHZ • 15 MB RAM CAPACITY -8MB ON BOAHD(BK). 8 MB RAM CARD ■ USES 256K OR 1MB SIP RAMS ■ a SLOTS: 1X32-BITRAM 2X 8-BIT S 5X 16-BIT ■ MEMORY INTERLEAVING - AMI BIOS ■ XT-S32E BOARD MCT-M386-20 MCT-C3S6-25 25MH2 MINI 386 W/CACHE .. $1 1 99.00 MCT-M386-M4 8MB RAM CARD (OK) $99.95 MCT-386MB20 10(20Mh: 386 $799.00 MCT-3B6MB25 10/25MHZ386 $999.00 10MHZ MINL2S6 189 ■ AT COMPATIBLE • KEYBOARD SELECTABLE 6(1 0MHZ - EXPANDABLE TO 4MB 0N-B0AHD WITH 1 MB DRAMS (OK) ■ SIX 16- BIT. TWO 8-BIT SLOTS • AMI BIOS - LED SUPPORT MCT-M2B6-10 MCT-M286-12 8/12MHZMINI.286 $199.95 MCT-M286-16N 8/16MHZ2BB $289.95 MCT-M2B6-20N 1 1X20MHZ 286 $389,95 MCT-XMB STANDARD 4.77MHZ 8088 $87,95 MCT-TUP.BO 4 77I8MHZS0SB $89.95 MCT-TURBO-10 4.77(10MHZ SINGLE CHIP 8088 $99.95 T&. LOGITECH MICE , B \ . THREE- BUTTON SERIES 9 infi'ttCU - 320 DPI RESOLUTION III VI Kllll -SERIAL PS/2 COMPATIBLE. \ LOGC9 SERIAL MOUSE Z. S98.95 LOGC9-C SERIAL (NOT PS(2 COMPATIBLE) $79.95 L0GC9-P SERIAL MOUSE WITH PAINTSH0W $109.95 LOGC9-PC SERIAL MOUSE WITH PAINT/CAD $154.95 LOGB9 BUS MOUSE $89.95 LOGB9-P BUSMQUSEWITHPAINTSHOW $1 04.95 LOGB9-PC BUS MOUSE WITH PAINT/CA0 $149.95 JDR MICRODEVICES. 2233 BRANHAM LANE. SAN JOSE 95124 LOCAL (408) 559-1200 FAX (408) 559-0250 TELEX 171-110 RETAIL STORE: 1256 S. BASCOM AVE.. SAN JOSE. CA (40B| 947-8881 HOURS: M-F 9-7 SAT. 9-5 SUN. 12-4 'SJ SO lor air Order's. O changes -please ccmiaci trie sales depflrimpni tor im? amount CA •• ■. dpi ,-■. m -,i incMfJo ii.n pi i c iJ6 li 1 SflltfS Ua Pjicei bubiect Id change wilhOul notice "*' fflllBglf ■dips A lull copy of Our ORDER TOLL FREE 800-538-5000 CUSTOMER SERVICE TOLL-FREE 800-538-5001 • TECHNICAL SUPPORT TOLL-FREE 800-538-5002 CIRCLE 113 ON FREE INFORMATION CARD DEALERS CIRCLE 170 ON FREE INFORMATION CARD 95 to o O EC F O LU _l HI 6 D < VALVE-PRICED TEST EQUIPMENT ALL WITH A 2 YEAR WARRANTY! '^* | # r $ 499 95 35 MHZ DUAL TRACE OSCILLOSCOPE • WIDE BANDWIDTH ■ VAHIABLE HOLDOFF MODEL-35O0 (SHOWN) 20 MHZ DUAL TRACE OSCILLOSCOPE '389.95 • TV SYNC FILTER ■ COMPONENTS TE5TEF MODEL 2000 79 95 THE ULTIMATE 3.S DIGIT DMM ■ BASIC DC ACCURACY •fi.lS:: • 3* RANGES ■ TEMP, TRANSISTOR &. RESISTANCE FEATUHES DMM-3M (SHOWN) 3.5 DIGIT FULL FUNCTION DMM "49.95 ■ BASIC DC ACCURACY ±0.2511 • 22 RANGES DMM-20Q $49.95 3.5 DIGIT POCKET SIZE DMM '29.95 ■ BASIC DC ACCURACY ±0.511 • t « RANGES DMM-100 3.5 DIGIT PROBE TYPE DMM ■ AUTORANGIWG • ACfDC 2V - 500V. • RESISTANCE: 2K-2M DPM-1000 (SHOWN I HIGH, LO W LOGIC PROSE * 1 7. 95 • DETECTS TTUCMOS LOGIC STATES • MEMORY FUNCTION FREEZES DATA FOR LATEH USE LP-2BOC PULSEH PROSE FDH QUICK DEBUGGING '19.95 \ ■ INJECTS PULSE INTO TEST CIRCUIT-VARIABLE WIDTH ■ TTL, DTL. TRL, HTL. HINIL. MOS. & CMOS COMPATIBLE LP-540 *54 95 JIM'S BARGAIN HUNTERS CORNER Jim Wharton JDR's VP Safes Vvl $9ff* REFURBISHED FULL SIZE AT MOTHERBOARD WAS $299.95 SAVE 6611 OFF THE ORIGINAL PRICE OF THIS FACTORY REFURBISHED 8MHZ AT-COMPATIBLE MOTHERBOARD' ■ 6/8MHZ KEYBOARD SELECTABLE SPEEDS ■ 256K TO 1MB ONBOARD RAM CAPACITY (OK INSTALLED) ■ B EXPANSION SLOTS (SIX 16- BIT & TWOB-B1T) ■ BATTERY BACKED CLOCK/CALENDAR ■ SET-UP ROUTINES BUILT IN TO BIOS ■ JUMPER FOR RESET SWITCH, SPEED INDICATORS AND KEYLOCK FUMCT-286 EXPIRES ■21151m JDR Microdevices 2233 BRANHflM LANE. SAN JOSE. CA 95124 ORDER TOLL-FREE 800-538-5000 LOCAL |408| 55S-1200 CUSTOMER SERVICE 800-538 500) TECH SUPPORT 800-538 5002 FAX (408) 599-0250 ADVERTISING INDEX 56 Parts Express 86 78 Radio Shack S — RE Bookstore 50 179 Sequoia Publishing 30 188,189 Sencore CV3, 23 — Star Circuits 22 83 Synergetics 68 193 TEC1 74 183 Video Repair School 30 64 Video-Link 84. 86 180 Viejo Publications 16 181 WPT Publications 74 RADIO-ELECTRONICS does not assume any responsibility for errors that may appear in the index below. Free Information Number Page 108 AMC Sales 73 75 Ace Products , 30 107 All Electronics 93 — Amazing Concepts 83 77 B&K Precision CV4 67 Banner Technical Books 71 109 C&SSales 13 70 CEI 89 — CIE 3, II 194 Cable Network Co 89 SO Caig Laboratories 21 190 Chenesko Products 30 — Command Productions 73 182 Communications Specialists 74 58 Cook's Institute 25 — Damark International 16 127 Deco Industries. 30 82 Digi-Key ..,.,.....„. 92 176 Electronic Goldmine 88 — Electronics Book Club 44 — Electronics Tech Today 82 192 Emulation Associates 30 121 Fluke Manufacturing CV2 184 Global Specialties 7 — Grantham College 14 86 Heathkit 19 185 ICS Computer Training 71 177 International Components Corp.. . 88 1 13. 170 JDR Microdevices 94, 96 1 14 Jameco 90 104 Jan Crystals 25 17S Jinco Computers 86 — King Wholesale 21 — Lindsay Publications 42 53 MD Electronics 87 93 Mark V. Electronics 87 — McGraw Hill Book Club 62 61 Microprocessors Unltd 82 191 Movie Time 12 — NRI Schools 26 186,187 Optoelectronics 15, 89 — Pacific Cable 85. 88 Gems back Publications, Inc. 500-B Bi County Blvd. Farmingdale, NY 11735 1-516-293-3000 Fax 1-516-293-3115 President: Larry Steckler Vice President: Cathy Steckler For Advertising ONLY 1-516-293-3000 Fa* 1-516-293-3115 Larry Steckler publisher Arline Fishman advertising director Lisa Strassman credit manager Christina Estrada advertising assistant SALES OFFICES EAST/SOUTHEAST Stanley Levitan Eastern Sales Manager Radio-Electronics 259-23 57th Avenue Little Neck, NY 11362 1-718-428-6037. 1-516-293-3000 MID WEST/Texas/ Arkansas/ Okla. Ralph Bergen Midwest Sales Manager Radio-Electronics 540 Frontage Road— Suite 339 Northfield, IL 60093 1-312-446-1444 Fan 1-312-446-B451 PACIFIC COAST/ Mountain States Marvin Groan Pacific Sales Manager Radio-Electronics 5430 Van Noys Blvd. Suite 316 Van Nuys. CA 91401 1-818-986-2001 Fax I -818-986-2009 CIRCLE 113 ON FREE INFORMATION CARD 96 Dealers Circle 170 on information card Introducing The SG80 AM Stereo-FM Stereo Analyzer TM Now For The First Time, A High-Performance AM Stereo (C-QUAM) - FM Stereo Analyzer Integrated Into One Unit, Allowing You To Performance Test Troubleshoot, And Align To Manufacturers' Requirements SG30 seisicone ft M STEREO- FHSTEMO *" MIM.YIM RHF UP X SIGNAL Iff * SU P FBEQUEHCf EXIEHOEOIWWSEFM vi..:- . PJMFWHCE Xl« *1W *fl jttai^... «^HB ffF ^t^-' w***"..** Bf .| F M« i'" 1 " >■ ouif" 1 865 &lW ,F*ER stGH * tS UJB iB Patented FM analyzing signals isolate any FM receiver defect. ► Exclusive integrated AM Stereo C-QUAM analyzer. • Digitally accurate performance tests meet EIA/IHF requirement • Exclusive, tuneable FM-IF Sweep and Markers-aligns all IF stages. » Expandable FM features for future service needs, plus SCA compatible, 1 Twice the capability for less than 1/2 the cost of stand-alone instruments. ---;'-."'■ ."■'"-'; C-DU AM is a registered trademark o ■ M.lJ J. -•'•■'■ ■■i ■■ 200 Sencore Drive, Siou* Falls. South Dakota 571 _ Caff 1-800-SENC 1736-2673} About A 10 Day Video Preview ffi IX: THINK OF IT AS AN ELECTRONIC SWISS ARMY KNIFE. CAPACITANCE METER What an idea the Swiss had . . . a hand-held device combining many different tools in one unit. The same inspiration is behind B&K-PRECISlON's new Model 38SHD Test Bench. It offers the capabilities of five popular instruments in one hand-held package. LOGIC PROBE This 41 range digital voltmeter, ammeter, ohmmeter, frequency counter, capacitance meter, logic probe, transistor and diode tester features an extra-large LCD display, rugged drop-resistant case and high-energy fusing. While you won't flip-out forks or knives, you will flip for the versatility of this low- priced wonder. For immediate delivery, see your local B&K-PRECISION distributor. TRANSISTOR TESTER B&K-PRECISION TEST BENCH 129 w MAXTEC INTERNATIONAL CORP. Domestic and International Sales 6470 W. Cortland St, • Chicago, IL 60635 312-BB9-144B • FAX; 312-794-974D Canadian Sales, Adas Electronics, Ontario. r mr\ FTTdii FRFF INFORMATION CARD