adit) BUILD A ROBOTIC LAWN MOWER AUGUST 1990 ECHNOLOGY - VIDEO - STEREO - COMPUTERS - SERVICE apture any video imag /ith your computer! UILD A DIGITAL RESSURE GAUGE em i conductor sensi akes it practical niCROWAVE ECHNOLOGY "he world above 00 MHz C POWER MEASUREMEN back-to-basics primer UILD A SOLID-STATE ISK DRIVE asy plug-in board speed: our computer and reduce! nd tear on your hard dis* PUBLICATION! FLUKE AND PHILIPS - THE GLOBAL ALLIANCE IN TEST & MEASUREMEN High Resolution Digital Meter: 4000 count digital readout; 20,000 counl mode (Fluke 87) lor 4« digit resolution Backlit display: Mates il easy to read the DMM in dark, cramped quarters. Automatically shuts off after 66 seconds to save the battery. Recorder records minimums and maximums, plus true arithmetic average; and idle Mtn Max Alert; selectable response times— 1 second and 100 ms (all models) plus 1 ms Peak Min Max (Fluke 8?) Holster with Flex Stand"": Protects meter and provides test lead storage. Flexible leg allows meler to be hung from peg, bent around a pipe, or used almost anywhere. FLUKE 83 FLUKE 85 FLUKE 87 VoTls. otims. a rn&s. Oiode lest, aud b^cc"! nu! I ,-. I re ^ t jc r - y a ^ri -^ . J y cyr e capaciianee. mi tfi Hold* relai I've, protective bolster wild Flex-Eland 1_ _A $139' S229* s?er 0.3% basicdcaccuracj 01& basso do accuracy O.Pflbassdcaccuracy 5ktaatV 2CkHzacV 2QkHiicV Artalgg (airgraph dud ;;;'- three yea.' warranty Aiufog bargraoti and zoom ilveeyeu: w-j-|, HigftreiduIsM jnalr>gpotr.lfif In-.-" : , : . r ms PtAK MIN NAX 4V» digit mode BacK-ii d-s. ay Three year warranty •Suggested US. imp™* PHILIPS Analog Meter: High-speed analog display updates 40 times/ second-as last as the eye can (allow; X10 Zoom bargraph mode [Fluke 83 and 85) makes high resolution of (set measurements a snap Frequency counter: Accurate down to 0.5 Hz; also measures duty cycle Capacitance meter: Autoranging, with manual ranging at the touch oi a button I dti-Meter Meet the meter that brings an entire test bench to your job. The versatile Fluke 80 Series do-just-about- everything "Multi" Meter. It offers everything you'd expect from an advanced handheld DMM, plus a lot you'd find only in dedicated instruments. Plus Fluke-exclusive features you can't buy any- where else. All built with the most advanced surface mount design and single-chip ASIC technology for a thinner, tougher, more reli- able package. There's a fully annunciated display for clear operation. Duty cycle function. High-speed analog indicator. A protective holster with innovative Flex-Stand 1 " for easy, adaptable operation. Audible Input Alert'" to reduce the risk of damage to the meter, the user, and the unit being tested. Plus the strongest warranty in the business, All good reasons to move up to the truly- mufti Fluke 80 Series today You'll find 80 Series DMMs at your Fluke distributor. For immediate, off-the-shelf delivery. Call CIRCLE 121 ON FREE INFOF1MATION CARD 1-800-44-FLUKE, ext. 33 for the name of your nearest distributor. jam Fiuke Mlg. Co, Inc. PO. Bcb SOW WIS SSffiX Everett. WA 36206 US: 006) 347-54D0 CANADA 416-e90-7KO OTHER COUNTBIES M 356-5500 c Copyright '589- *h" Fto* **lj Co.- Inc. All uohls isssned ftiees aid spealiulians subject la change without notice AflraOXe-FflC FROM THE WORLD LEADER IN DIGITAL MULTIMETERS. FLUKI Aug USt 1 990 Electronics Vol. 61 No. 8 BUILD THIS 31 VIDEO FRAME GRABBER Add a vision system to your PC! Gene Toner 41 DIGITAL PRESSURE GAUGE Build a solid-state portable electronic pressure gauge. Anthony J. Caristi 45 THE LAWN RANGER: PART 3 Build the motherboard and the motor-control board. Raymond Rafaels Eran 51 AG POWER MEASUREMENT A refresher course on the principles of measuring power. Harry L. Trtetley 60 INTRODUCTION TO MICROWAVE TECHNOLOGY The terminology and technology of microwave electronics. Joseph J. Carr EUMM 73 BUILD A SOLID-STATE DISK DRIVE Construction details on the battery-backed RAM disk Mark Hatten EEZIffl 6 VIDEO NEWS What's new in this fast- changing field. David Lachenbruch 16 EQUIPMENT REPORTS Beckman Industrial RMS225 DMM. 18 DRAWING BOARD Video-scrambling techniques. Robert Grossblatt 67 HARDWARE HACKER Data compression. Don Lancaster 79 AUDIO UPDATE The High End Hi-Fi Show. Larry Klein 73 EDITOR'S WORKBENCH A low-cost logic analyzer Jeff Holtzman r^VwagpucTioN to C^UIJ/^I Df* V PAGE 60 ComputerDigest 96 Advertising and Sales Offices 96 Advertising Index 12 Ask R-E 97 Free Information Card 14 Letters 84 Market Center 25 New Lit 20 New Products 82 PC Service 4 What's News o c CO I co o o S t- o 111 _J W o a < fX If the idea of capturing video im- ages on a computer grabs you, take a look at our Video Frame Grabber. The inexpensive, half-length card plugs into any PC expansion slot, and accepts standard NTSC black- and-white or color input. Once you've captured the shot from your video camera, you can manipulate the image — to create line drawings or negative images, for example — and store or print it. Put actual pho- tographic images in your desktop- published newsletters or brochures, or use the frame grabber for elec- tronic photography, security sys- tems, computer "slide" presenta- tions, or automatic inspection. For all the details, turn to page 31. THE SEPTEMBER ISSUE GOES ON SALE AUGUST 2. R-E's VOCAL ZAPPER Filter out the vocal tracks from recordings — then dub in your own voice! BUILD THE LAWN RANGER Ourconcluding installment. THE AGONY OF AIM What does the future hold for the AM band? BUILD A 100-MHz FREQUENCY COUNTER Based on the Intersil 7216, it's accurate and easy to build. BUILD R-E's DIGITAL DASHBOARD Part 2 will return with complete construction details. As a service to readers. RADIO-ELECTRONICS publishes available plans or information relating to newsworthy products, techniques and scientific and technological developments. Because of possible variances in the quality and condition of materials and woricmanship used by readers, RADIO-ELECTRONICS disclaims any responsibility for the safe 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 0D33-7B621 August 1 990. Published monthly by Gemsback Publications. Inc.. 500-B Bi-County Boulevard. Farmingda I e. NY 1 1735 Second-Class Postage paid at Farmjngdale, NY and additional mailing offices. Second-Class mail registration No. 9242 authorized at Toronto, Canada. One-year subscription rale U.S.A. and possessions $17-97, 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. h a n k . Sing [e co p i es $2 . 50 . ■- 1 990 by Gemsback Publications , Inc. All rights reserved . Printed in U.S A POSTMASTER: Please send address changes to RADIO-ELECTRONICS, Subscription Dept.. Bo* 55115. Boulder. CO 30321-5115. 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 Gemsback (1884- 1 9G7) founder M. Harvey Gemsback, editor-in-chief, emeritus Larry Steckler, EHF. GET. editor-in-chief end publisher EDITORIAL DEPARTMENT Brinn C. Fen tan. editor Marc Spiwak, associate editor Denial Goodman, technical editor Kim Diinleavy, assistant technical editor Ten Scsduto, assistant editor Jeffrey K. Holtzmjn computer editor Robert Grossblatt. circuits editor Larry Klein, audio editor David Lachenbruch contributing editor Don Lancaster contributing editor Richard D. Fitch contributing editor Kathy Campbell, editorial assistant ART DEPARTMENT Andre Duiant, art director Injae Lee, illustrator Russell C. Truelson, illustrator PRODUCTION DEPARTMENT Ruby M. Yee, production director Janice Box, editorial production Karen S. Tucker advertising production Mareetla Amoroso production assistant CIRCULATION DEPARTMENT Jacqueline P. Cheeseboro circulation director Wendy Alanko circulation analyst Theresa Lombardo circulation assistant Michele Torrillo, reprint bookstore Typography by Mates Graphics Cover photo by Diversified Photo Services Radio-Electronics is indexed in Applied Science 4 Technology Index and Readers Guide to Periodical Liter- ature. Microfilm & Microfiche editions are available. Contact circulation depart- ment for details. Advertising Sales Offices listed on page 96. Radio- Electronics Executive and Administrative Offices: 1 516 293 3000. Subscriber Customer Service: 1 800 288-0652. Order Entry for New Subscribers: 1 800 999 7139. COAX ADAPTER KIT • Create any adapter in seconds ■ Make all combinations of BNC, TNC, SMA. N, UHF, Mini-UHF, F and RCA The TPI 3000 A kit contains male and female connectors of all 8 types, and 6 universal inter- faces. Simply screw any combination of 24 con- nectors to one of the interfaces to create the desired adapter. $ 1 50. TEST PROBES INC. 9178 Brown Deer.San Diego, California 92121. Call toll-free for cata- log: 1-800-368-57 19. CIRCLE 225 ON FHEE INFORMATION CARD DELUXE TEST LEAD KIT Users call TPI test leads The Absolute Best. The TLS2000 features the highest quality cable in the industry — with spring-loaded safety-sleeved plugs, U.L. listed (file E79581). Kit: $29. Leads & probes only: $19. Satisfaction guaranteed. TEST PROBES INC. Call toll-free for catalog: 1-800-368-5719. CIRCLE 226 ON FREE INFORMATION CARD ■m * Ji' V !►' 1 TT'I T 1 I^^H 1 BNC ATTENUATOR KIT Contains 4 attenuators — 3dB, 6dB, lOdB, 2QdB; 1 feedthrough and 1 termination. Thick- film circuitry for low reactances. Rugged de- sign resists shock and lasts longer. Rectangular shape stays put on the bench. Impedance: 50ft Frequency: 1GHz. Maximum Power: IkW peak, 1W avg, VSWR 1.2:1. Attenuator Accuracy:±0.2dB. Terminations Resistance Tolerance: ±1%. $150. TEST PROBES INC. Call toll-free for catalog: 1-800-368-5719. CIRCLE 227 ON FREE INFORMATION CARD ECONOMICAL SILICON RUBBER TEST LEADS Best value in moderately priced leads. High quality, soft, silicon rubber cable. Banana plug on measuring tip accepts push-on accessories. Plugs have spring-loaded safety sleeves. Model TL1000 $14. Satisfaction guaranteed. TEST PROBES INC. Call toll-free for catalog: 1-800-368-5719. CIRCLE 228 ON FREE INFORMATION CARD No Better Probe Ever at This Price! Shown here Model SP 150 Switchable lx-lOx 49 CIRCLE 180 ON FREE INFORMATION CARD Risetime less than 1.5 nsec. • Universal - works with all oscilloscopes • Removable Ground Lead • Excludes External Interference - even on scope's most sensitive range • Rugged - withstands harsh environments including high temperature and humidity • Advanced Strain Relief - cables last longer • Available in lOx, lx and switchable lx-lOx Call for free catalog and 10 day return policy - performance and satisfaction guaranteed PROBES, INC. 9178 Brown Deer Road San Diego, CA 92121 Toll Free 1-800-368-5719 Distributor in your area CIRCLE 123 ON FREE INFORMATION CARD > C o c Co CO CO o WHAT'S N EWS o z o EC o o □ < CL Individual atoms as building blocks Scientists at IBM's Almaden Re- search Center (San Jose, CA) have managed to position individual atoms on a surface, and have used that technique to build structures one atom at a time. Besides helping scientists to better understand the fundamental behavior of atoms on surfaces — knowledge that is crucial to many industrial processes — the achievement opens the door for a broad range of future applications. Some of the possibilities are build- ing custom molecules, making ul- tra-small electrical circuits, storing data on an atomic scale at densities more than a million times greater than is now possible, and perhaps even duplicating structures atom- for-atom. The technique might one day be adapted to reduce the size of semiconductor chips by a factor of more than 500. The process, which demonstrates that atoms can be moved across a surface and accurately positioned where desired, was first used to create the letters "IBM" in xenon atoms. Next, a chain of seven xenon atoms bound together — the first atomic cluster built one atom at a time — was created. Both demon- strations required the atoms to be cooled to -269°C (-453°F), which is only slightly higher than absolute zero. Physicists Donald M. Eigler and Erhard K, Schweizer (a visiting scien- tist at Almaden, on leave from the Fritz-Haber-lnstitut in Berlin) used a special scanning tunneling micro- scope (STM) to move the atoms into place and to view their progress. STM's can image individual atoms "IBM" IS SPELLED OUT IN INDIVIDUAL atoms. IBM scientists used a scanning tunneling microscope to move single xenon atoms across a surface and pre- cisely position them one at a time to form the letters. The distance between the atoms in the pattern is about 50 billionths of an inch; the image has been magnified approximately 2.9 million times. on a metal or semiconductor sur- face by scanning the tip of a needle over the surface at a height of only a few atomic diameters. To study how atoms and molecules interact with surfaces, Eigler built an STM that could operate with extraordinary sensitivity and precision. He placed the STM in a high vacuum, cooled it with liquid helium, and isolated it from vibrations. In a process similar to using the motion of a nearby magnet to move another magnet, a xenon atom can be "dragged" across a surface by placing the STM's needle tip close to the atom and moving the tip parallel to the surface. At the desired posi- tion, the tip is lifted, leaving the atom fixed in its new location. The exacting process — atoms are moved at a rate of 16 billionths of an inch per second — requires the STM operator to maintain a delicate balance of several attractive forces between the atoms. It took 22 hours to move the xenon atoms to form the letters "IBM." Lightning forecaster A system that predicts lightning before it strikes was developed by Dimensions, a French firm, in the course of research conducted at the French Matinal Institute of Aero- space Research. It is hoped that the new lightning-detection system will help to eliminate lightning-caused damage and related fatalities. The SAFIR system — which has been suc- cessfully tested at several sites, in- cluding the Kennedy Space Cen- ter — monitors storm activities in THE SAFIR SYSTEM MAPS STORMS IN REAL TIME AND FORECASTS LIGHT- NING danger zones up to a half hour be- fore it strikes. real time and issues lightning warn- ings through the use of radioelectric interferometry. Potential applica- tions for the lightning-detection sys- tem are at rocket-launching sites, flight- testing centers, air bases, ci- vilian airports, and air-navigation centers. As soon as it begins developing, a thunderstorm produces changes in the atmospheric electric field. The SAFIR system monitors those changes at their inception. One type of sensor detects and traces high-frequency radiating sources from the heart of a cloud to light- ning discharges that strike the ground, and a second sensor mea- sures the electrostatic field on the ground. Together, the two sensors detect the phenomena that precede a strike. A typical SAFIR installation con- sists of three detection stations, lo- cated 12-62 miles apart, that feed data to a central station where it is processed and displayed in real time. That setup covers 186 square miles, with a locating accuracy rang- ing from a few hundred yards to three miles. The system can monitor storms as they develop, producing maps that indicate "lightning dis- charge danger zones" on the ground and in the air. Danger zones are detected and located up to 30 minutes before the first lightning bolts strike the ground lessening the chances of a strike. R-E ]fe no fluke. Feature Fluke Model 77 Beckman Industrial RMS225 Digits 3-V2 Digits 4 Digits Resolution 3,200 Counts 10,000 Counts Accuracy 0.3% 0.25% Automatic Reading Hold Touch Hold* Probe Hold™ Analog Bar Graph 31 Segments 41 Segments Battery Life 2,000 Hrs 1,000 Hrs 10A Range / (Fused) v^ (Unfused) Protective Holster S / 3 Year Warranty s / True RMS / Auto Min Max™ / Relative Mode / Self-Resetting Fuse / (40mA Input) Price $159* $149 Made in the U.S.A. * Touch Hold is a registered trademark of the John Ruke Mfg. Co, , Inc. * 1990 Fluke and Philips Catalog ► RANGE ►HOLD > HEL Your best auto-ranging multimeter for the money It doesn't happen by accident. It takes expertise, painstaking R&D, and a solid commit- ment to provide you with the features you've asked for at a price you can afford. When you add it all up, the new Beckman Industrial RMS225 simply outperforms any meter in its class. And like all the Beckman other multimeters we've built over the years, it's designed for long lasting and trouble-free use. So, go visit your local dis- tributor todav and check out the new RMS225 digital multimeter Once you compare^ it to the others, the choice will be obvious. An Affiliate of Emerson Electric Co. Instrumentation Products Division 3883 Ruffin Road, San Diego, CA 92123-1898 (619) 495-3200 • FAX (619) 268-0172 * TLX 249031 Outside California 1-800-854-2708 Within California 1-800-227-9781 © 1990 Beckman Industrial Corporation. Specifications subject to change without notice Fluke is a CIRCLE 98 ON FREE INFORMATION CARD trademark of John Fluke M/g. Ca, Inc. JN189 01 0890 > c o c s Video News DAVID LAGHENBB.UGH, CONTRIBUTING EDITOR o m o H o o < rr • Video goes "wireless." In a little-noted change in its "part 15" rules on RF interference, the FCC last year voted to allow wireless electronic products with increased frequencies and no restrictions on usage, bandwidth, or type of modulation, as long as the uses are non- interfering. That will permit such limited-area uses as wireless loudspeakers. One of the most interesting new products permitted under the new regulations is the "home TV station." The first such station actually to be tested and approved by the FCC is the Videocaster by accessory manufacturer Gemini Industries. The Videocaster consists of a small transmitter and receiver, and its principal purpose will be to connect such devices as VCR's to TVs without using cables. Thus one VCR can feed all the TVs in a home, as long as each TV is equipped with a receiver. Another suggested use is monitoring a baby-sitting camera while visiting next-door neighbors. Transmissions are in the 900- MHz frequencies. The Videocaster will sell for about $100, including one transmitter and one receiver. Approvals of competing systems are expected soon. • Cardboard cassette. Video junk man has arrived — in the form of the throw-away cassette. The VHS-compatible (though not approved) cassette is made of cardboard, and in large quantities can sell for about $1.00, including tape, duplicating, and four-color label. Developed by Philmax, a Baltimore company, it's designed for premium, catalog, and give-away uses where durability isn't required. The tape is designed to be played five to ten times, although tested copies have lasted for as many as 150 plays. The developers say that the throw-away tapes won't damage VCR's. The tape stops playing when it no longer tracks correctly. • NEC "shakes out." Plagued with chronic overproductions and cutthroat competition that are bringing prices below the profit level in many instances, the consumer-electronics industry saw the first victim of a widely anticipated "shakeout of the '90's" in NEC, the American subsidiary of Japan's Nippon Electric Company. NEC, which has been offering televisions, VCR's, and audio systems on the American market for nine years, has decided to abandon those traditional consumer-electronics lines. Instead, it will concentrate on such things as its sophisticated TurboGrafx video-game system, personal computers, and custom "home theaters," including the Improved-Definition- TV {IDTV) two-piece projection system it has developed. Its color-television factory in McDonough, GA, is being converted to the production of laptop computers and monitors. In a move also related to the worldwide competitive situation in consumer electronics, the European giant Philips (which produces Philips, Magnavox, Sylvania, and Philco products in the United States) is buying a 25% interest in the audio-video operations of Denmark's Bang & Olufsen, noted for its high-styled (and high- priced) audio and video components. Both companies that are involved said the move would help them compete in the high-priced high-end market. • 8mm winning camcorder war. Sony, whose Beta system lost the competition for home VCR's to JVC's VHS, is winning a victory in the struggle for format supremacy in mini camcorders, as more brands begin to move to Sony's 8mm format over JVC's VHS-C (for "compact") system. The first major consumer- electronics brand name in the VHS camp to move to 8mm will be Zenith, which will add an 8mm camcorder to their line this fall. The fact that Zenith is defecting is particularly significant. Zenith was the first traditional American brand to enter the VCR market, in 1977, when it chose the Beta format (its recorders were made by Sony). As Beta lost the race, Zenith switched to VHS machines (supplied by JVC). Zenith's new 8mm camcorder will be made by Sanyo. Full-size VHS is still the leading camcorder format in the United States. In the first quarter of 1990, 57.5% of camcorders sold here used standard VHS cassettes. For all of 1989, the figure for VHS was 63%. R-E U 20MHz Frequency Counter □ Capacitance Meter □ Logic Probe □ Transistor Tester n Continuity Tester D LED Tester □ £fcde G&ecl D 7{M Ammeter D Voltmeter D Ohmmeter Functions With more uses and features than most other hand-held multimeters, the DM27xl and DM2 5xl really pack a punch; especially when you've got to troubleshoot or analyze a variety of components and circuits. Standard functions include capacitance measurement to 20>f, logic probe to 20MHz, transistor tester and resistance ranges to 20O0M12. The DM27xl further adds 20MHz frequency counting capability with selectable trigger sensitivity, plus an LED tester Both meters feature an enhanced display including a large, easy-to-read LCD, a full set of function annunciators and a battery-saving Auto Power Off. Grab a DM25xl for just $109.95, or a DM27xl for just $129.95 (suggested retail price) at your local Beckman Industrial dis- tributor After using one, you won't be able to function without it. Beckman Industrial ™ An Affiliate of Emerson Electric Co. Instrumentation Products Division 3883 Ruffin Road, San Diego, CA 92123-1898 (619) 495-3200 • FAX (619) 268-0172 • TLX 249031 Outside California 1-800-854-2708 Within California 1-800-227-9781 © 1990 Beckman Industrial Corporation All specifications subject to change without notice. CIRCLE 195 ON FREE INFORMATION CARD > C o o JN 193-01 -0890 w o z o (L o LU o o < DC REASONS FOR SELECTING CIE I Approved for educational benefits under the G.l. Bill for Veterans and other eligible persons. I CIE provides printed job resumes, letters of recom- mendation, and lifetime Employment Service for all graduates at no extra charge I State -ol-t he- Art laboratory equipment is yours to keep and it comes assembled, ready for hands-on- experiments, I Only CIE offers an Associate Degree program based on actual study time used. The faster you complete your degree, the less your overall tuition. I Upon graduation, CIE offere you free preparation to pass the Certified Elec- tronics Technician Exam CIE J CLEVELAND INSTITUTE OF ELECTRONICS 1776 East 17th Street • Cleveland Ohio 44114 PHONE TOLL FREE 1-800-321-2155 / In Ohio 1-800-523-9109 TXitt ELECTRONICS STARTS WITH For the last few years, the elec- tronics field and related indus- tries have been growing at an Incredible pace And today, a career In electronics offers more opportunities and greater rewards than ever before Just ask any of the many graduates of the Cleveland Insti- tute of Electronics who have landed high -paying positions with aero- space computer, medical and communications firms. They'll tell you success didn't come easy, , . but that CIE made it all worthwhile. SPECIALIZED TRAINING CIE isn^just another be-everythlng-to-everybody correspondence school. We're accredited by the National Home Study Council. And with more than 1100 graduates each year, we're the largest independent home study school specializing exclusively in electronics. CIE has been training career- minded students like your- self for over 50 years and we know the business inside and out. Some courses teature the CIE Microprocessor Training Inboratory, an integral part of com- puters. You'll gain all the practical experience needed to work with shte-of-the-art equip- ment of today and tomorrow. PRACTICAL TRAINING CIE students learn by doing, using sophisticated elec- tronic learning toots that weVe designed and developed. One such tool, our4K RAM Microproces- sor Training laboratory, teaches programming, interfacing and lets you work with a broad range of computers in a way that working with a single, stock computer simply can't. We combine that valuable hands- on training with our unique Auto Programmed e lessons, designed to teach you step-by-step and prin- ciple-by-princlple. The result is practical training. . .the kind of experience you can put to work in the marketplace P ERSONAUZED TRAINING While some of our students have a working know- ledge of electronics others are Just getting started. That's why we have 10 career course levels from Basic to Advanced. They let you start where you want. Learn at your own pace. And learn as much as you like You can even earn an Associate in Applied Science Degree In Electronics And when you need help, our trained profes- sionals are on hand to assist you by phone or mail. Learning electronics isn't easy, but getting started is. For a CIE catalog and enrollment Informa- tion, just mail the coupon below. Or call toll-free 1-800-321-2155. In Ohio, call 1-800-523-9109. Accredited by the Accrediting Commission of the National Homo Study Council, Washington, DC. Print Name Address City I want to get started. Send me my CIE school catalog including details about the Associate Degree program. Apt. .State Zip. Age. Area Code / Phone No. Check box for G,t. Bulletin on Educational Benefits □ Veteran D Active Duty CIE MAIL TODAY! CLEVELAND INSTITUTE OF ELECTRONICS 1776 East 17th Street, Cleveland, Ohio 44114 ARE-172 > c o CO O 11 Ask R-E WRITE TO: ASK R-E Radio-Electronics 500-B Bi-County Blvd. Farmingdale, NY 11735 o o s o 111 o < EC DTMF CONTROLLER I'm trying to build a circuit that uses the telephone DTMF (Dual Tone Afulti Frequency) tones as the basis to con- trol several different devices. My problem is that I'm having a hard time finding out exactly what frequencies are used for all the rows and columns. The books I've looked through list only the twelve telephone keys, but I thought there were more that. Could you tell me how many there are? — F. Geof, Hunter, NY You're right that there are more than twelve standard DTMF tone combinations available, and I'm sur- prised how few people are aware of that. Most of the books that talk about telephones only refer to the tones produced by the standard keypad, but that's because they're only dealing with telephones, not DTMF in general. Even though the standard tele- phone uses only twelve tone com- binations, there are really sixteen available. There are actually eight of- ficial DTMF tones, organized as shown in Table 1. Seven of them are in everyday use with telephones, but the eighth one, the last member of the high group, isn't used in any of the common consumer tele- phone devices although I've heard that it has some applications in mili- tary and industrial equipment. It used to be a real pain in the neck to build a DTMF receiver be- cause it had to be done with lots of filters, decoders, and so on. These days, the decoding methods have become almost completely digital (as has just about everything else), and semiconductor manufacturers have produced a wide variety of chips to both generate and decode the tones with an accuracy that's way beyond the earlier circuits made with acres of discreet components. The official list of tone combina- DTMF S7XMDAJS.D2. G/^OU^ FM^tpt/e/vc. y d-&W e,9 7 ffz^ J-t?W 7T& //^ s-otf 552 /- 7-C>jV ?j£-///z. W&& /JZ c -f//^_ &/&/¥ /J5-3& /¥*- /*/&/* /#77 f/jz- Ats&tf /^53/fe tions is shown in Table 2, and you can see that the last four digits all use the 1633-Hz tone as one of their components. Most of the available IC's that produce and read DTMF tones will let you handle all sixteen tones but, if you want to do that, you won't be able to use a regular telephone keypad in the design. That shouldn't be much of a prob- lem since just about all the IC's that generate DTMF will accept either a row-and-column or binary input. That means you can use any one of the commercially available matrix keyboards — or even make your own. If your circuit can deal with straight binary, the design is even easier because chips like National Semiconductor's 5088 converts bin- ary directly to DTMF and has an out- put level that will directly drive the telephone line. How things have changed! DIY VOR GENERATOR We would like to build a VOR gen- erator in order for us to test IN-38 course indicators, part of the naviga- tion system in Cessna aircraft. Accord- ing to the service manual, a standard VOR input is defined as an audio sig- nal consisting of 30 Hz and 9960 Hz at 0.5-VRMS ± 0.05 VRMS. Can you of- fer any help? — P. Jamison, Sutter Creek, CA Your letter isn't really clear about the form of the output signal but it seems to me that you're looking for a pair of simple oscillators. If that's the case, there's a wide variety of circuits you can use to get the job done. Probably the easiest way to gener- ate the frequencies you need at the required level and degree of ac- curacy is to build the circuit with a pair of 555 timers. The design is shown in Fig, 1. There's not much to explain about the circuit since it's one of the simplest 555 layouts you can build. Because you're looking for a pair of particular frequencies, the trimmers will let you tweak the output to get to the exact values you need. The 555 is extremely stable and TELSPWCWE. OTM/= ^SS/GAMENr /-/*. /JLO? /^^S& 7-¥7 / /<£3T_3 & 97 / Z 3 A 7 7 a 4- 5" 6 3 &<5-JL 7 <3 '?■ C ?#/ Tk o # z> 12 + V*-* 1 R1 30K ; tL ci ' 4.7nF X " ^V*" GND R2 5K 555 30Hl R5 600il Q R4 > 1.5K> R3 30K 7k C2 .05yF 555 R7 5K R6 600Q 9600H7. -VA- -OVRO OUT R8 5K FIG. t the output frequency is relatively immune to changes in voltage. Un- fortunately the output voltage is go- ing to depend on the supply voltage so it's a good idea to use a regulated supply. You can either buy one ready made or, since you're going to be laying out the circuit anyway it's not much more work to add a three- terminal voltage regulator and pair of capacitors to the board. That will give you a stable supply voltage and peace of mind as well. Sounds like a good deal to me. I don't know if the two frequen- cies have to be mixed together and, if so, whether they have to be of equal amplitude. In any case, you can use the simple resistor sum- ming circuit shown in the schematic to combine the two frequencies or add a mixing amplifier. If you do decide to use an amp, be careful about the one you use since adding more electronics to a circuit always introduces the possibility of more distortion. As for the circuit itself, you don't have to make a PC board to do the job. A breadboard can be used as a temporary solution, or you can build it on a piece of perforated con- struction board and wirewrap the connections between components. There's nothing critical about the parts layout and, since there are trimmers to adjust both the output frequencies and the amplitude, you can get the exact signal you want with standard-tolerance parts. It's still a good idea, however, to stay away from ceramic disc capacitors; use something like mica or tan- talum. The actual value of a ceramic disc can be as much as 100% off, and even though the circuit is tolerant, there are limits to everything. R-E ■- MAIL THIS COUPON -^ FOR FREE FACTS! TRAIN AT HOME FOR A BETTER CAREER 42 ways ICS can help you improve your life Rush free (acts and color brochure on how I can tram at home for the career I have chosen. I understand I am under no obligation and no salesman will visit me. CHECK ONE BOX ONLY! ASSOCIATE IN ASSOCIATE IN SPECIALIZED SPECIALIZED BUSINESS TECHNOLOGY DEGREE DEGREE PROGRAMS PROGRAMS □ Business Management D Civil Engineering Teen. □ Accounting □ Mechanical Engineering l '.Business Management Technology _ with oplion in Finance n Electrical Engineering LBusinessManagement Technology with oplion in Marteting rj Electronics Technology CAREER DIPLOMA PROGRAMS . Computer U Legal Assistant n Wildlife. Programming □ TV/VCR Repair Forestry D Personal □ Surveying S Conservation Computer Mapping L Veterinary Specialist C Catering/Gourmet Assistant n High School Conking D Diesel □ Bookkeeping i_ Fitness & _ Mechanics D Secretarial Nutrition □ Electrician H G Medical/Dental □ Small Business □ Interior 2 Office Assistant Management Decorating □ Legal Secretary LJ Drafting Q Motorcycle D Fashion ; j Air Conditioning & Repair Merchandising Refrigeration □ Gun Repair LI An to Mechanics G Microcomputer □Photography G Hotel' Repair □ Journalism' Restaurant □ Electronics Short Story Management □ Travel Agent Writing C Child Day Care C] Police Sciences □ Dressmaking & Management □ Art Design Name Address _ City/State . Phone ( Age_ . Apt. #- . Zip_ ■S515 Rl A Subsidiary of National Education Corporation CIRCLE 191 ON FREE INFORMATION CARD Cable TV Descrnmbler Article Farts We stock the exact parts, PC Board and AC Adaptor for two articles published in Radio-Electronics magazine on building your own CABLE TV DESC RAMBLER February 1984 issue #701 Parts 19.00 Includes all original parts. #702 PC Board 7.95 Original 3x4 etched, drilled and silk-screened pc board. #704 AC Adaptor 7.95 Original IB Voll DC 9 200me. #701, 702 &. 704 29.00 I February 1987 issue #301 Parts 29.00 Includes all original parts. #302 PC Board 7.95 Original 5x9 etched, drilled and silk-screened pc board. #304 AC Adaptor 7.95 Original 10 Volt DC 9 200mo. #301, 302 & 304 39.00 Free article reprint with purchase. Snooper Stopper 39.00 Cable TV dBscramblers can be detected, protect your privacy with the Snooper Stopper Free article on Cable Snooping. Macrovision Kit 29.00 flacroviston.now you see it, now you don't with our macroscrubber kit. Article was published in Radio Electronics 1987 issue. CALL TOLL FREE 1-800-332-3557 Out side USA 1-508-699-6935 Visa, Master Card and COD Add S3. 50 S & H. S6.00 outside USA. D fi. Electronics, Inc., PO Box 3310, N Attleboro, Ma. 02761 Visa MC CIRCLE 186 ON FREE INFORMATION CARD > C o c: in to CD o 13 Letters POWER SUPPLY BOARDS For those interested in build- ing our "Generic Linear Power Supply," (Radio- Electronics, June 1990): Etched and drilled PC boards are available from the au- thor. Two boards cost $12.50 postpaid. Orders from Canada should include an additional $.25, and orders from South Car- olina should include 5% sales tax. Write to John Wanamaker, Rt. 4, Box 550, Orangeburg, SC 29115. TAKING IT TO THE LIMIT I'm writing to thank you for an excellent magazine. Radio-Elec- tronics always presents the latest in technology, such as your coverage in What's News (May 1990) of the world's first true digital optical pro- cessor. In particular, I enjoyed Don Lan- caster's Hardware Hacker. His arti- cle on op-amp noise is the first I have seen in any magazine that ex- plains what those parameters (cur- rent noise and voltage noise) are, and how to optimize a circuit for them. I have been an electronics engineer for nine years, and they don't teach those details in school. I recently went through several days of optimizing a circuit for drift in which I learned a lot about a similar set of parameters involving offset current drift and offset voltage drift. It isn't often that you have to push a part to the edge of its specifications, but when you do, there aren't many good places to turn to for the neces- sary information. I would really en- joy a tutorial series by Don Lancaster on op amps that exam- ined those parameters used when pushing the edge of technology. On another note, I was equally unimpressed with the article in the same issue concerning how to choose the right transistor for your next design. In that article, Josef Bernard explained that as long as your design does not "push the lim- its," and "sticks to middle ground," it's hard to go wrong! Ofcourseitis! I read the article in the first place to jBtaw Ktsn AA0/O- £L £CT*OMCS soo-a 3f-coovry aoui£YARD FA *M/A/G HAL £, At Y // 73 S learn what types were best for high- power, high-frequency (RF) ampli- fier, and other specialized applica- tions. We know how to use a general-purpose switching tran- sistor — now show us how to use a transistor to build a UHF amplifier. JOHN BURGAN NORTH PALM BEACH, FL DONT ARGUE WITH NYQUIST! The excellent article "Inside Dig- ital Oscilloscopes," which appeared in the May 1990 issue of Radio-Elec- tronics, presented some interesting and useful information about os- cilloscope technology. While I en- joyed the article, I must quibble on one point. The article states: "... sampling rate must be at least dou- ble the bandwidth ..." of the sampled signal. The term "band- width" is a bit vague. As I recall, the correct application of the double- frequency law tor sampled signals requires sampling at double the highest frequency component in the signal. That distinction is impor- tant. For example, a pure sine wave, say 1 MHz, has a very narrow band- width, although the sampling rate must be twice the frequency (not bandwidth), or 2 MHz, to recon- stitute the 1-MHz signal. That requirement is easily under- stood in consideration of, first, the need to detect both positive and negative signal excursions and, sec- ond, the assumption that the signal is a perfect sine wave. Given the sine-wave definition, and given (as Fourier proved) that any complex wave is composed of sine waves, then the sampling rate of twice the highest component f re- 14 CORRECTION In our "Softd State Wiper Control" construction article (Radio-Elec- tronics, April 1990), we regret that there were several editorial errors that need correcting: • In Fig. 1 on page 47, Zener diode D1 is backward. Also, RY1 should be connected as shown in the partial re- print of Fig. 1 shown here. The center terminal ot the switch in RY1 goes jointly to the low side of the motor (mot) and the low terminal on S2, The left terminal of the switch on RY1 goes jointly to the pole terminal on S2 and the hot input accessory + 12VDC from the battery, • In Fig. 2 on page 47, RY1 should be connected as shown in (he reprint of Fig. 2 shown here. Also, the last sen- tence of the original caption is incor- rect, switch 1 of RY1 goes in parallel across S2-b; the center terminal of switch 1 goes to the pulse terminal on S2-b, while the top terminal of switch 1 goes to (he pole terminal on S2-b. • The parts-placement diagram of Fig, 3 on page 48 was improperly reg- istered, and was reprinted on page 35 of the May 1990 issue. However, the power and ground leads need to be revised. quency provides information suffi- cient to reconstitute the signal. DAVE SWEENEY SOMERS POINT, NJ You are, of course, quite right. The article should have said either "absolute bandwidth" or "max- imum bandwidth, " instead of sim- ply "bandwidth." Thanks for the clarification. — Editor KEEP 'EM COMING! I'm writing to show my support for Robert Crossblatt's Drawing Board series dealing with the gener- ation of video signals. I am a student at the University of Miami, studying electrical engineering. After being inspired by the first article in the series, I went to the library to get more information on the subject. Although those sources covered the video signal, timing, etc., none of them discussed the hardware needed to create those signals. I would like to compliment Radio- Electronics on doing just that- enabling me to get first-hand expe- + 12- TOR10 HOT input ACCESSORY + WDCFRQM_ BATTERY ** SW1TCH1 | L0WO HOT INPUT ACCESSORY + 12V FROM BATTERY rience in a subject not covered elsewhere. Keep 'em coming! DAVID C. BURD MIAMI, FL DRAMA ON THE AIRWAVES Radio-Electronics readers might want to tune into a high-tech, futur- istic techno-drama, RUBY 3, that is being produced for radio by theZBS Foundation. The story, set in the 21st century, follows the adventures of two women: Ruby is a tough, witty detective who is hired to find the source that is causing a buying frenzy in the City of Malls on the planet Summa Nulla and Inanaison a spiritual mission in which she faces a series of life-threatening tests. The two characters create a drama that is at once comic, action- packed, mythical, and spiritual. The series of 20 self-contained half-hour shows will be broadcast on various public-radio stations beginning on October 1, 1990. KATHY CRONAU ZBS FOUNDATION FORT EDWARD, NY Put Professional Knowledge and a COLLEGE DEGREE in your Technical Career through HOME STUDY * 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 GRANTHAM > College of Engineering § 250 Frontage Road " Slidell, LA 70460 1 15 Equipment Reports o s o o < Beckman Industrial RMS225 Professional Digital Multimeter A feature-packed true-RMS meter that's easy to use. CIRCLE 35 ON FREE INFORMATION CARD AS MUCH AS WE APPRECIATE THE STRIDES that manufacturers have made in packing more and more features into handheld multimeters, we real- ize that it's not always appreciated by the professional user. If your job calls for making accurate voltage measurements, then a meter's abil- ity to measure capacitance, for ex- ample, is just excess baggage. That seems to be the philosophy behind the RM5225, the newest ad- dition to the professional line of Beckman Industrial Corporation (Instrumentation Products Division, 3883 Ruff in Road, San Diego, CA 92123-1898) The RMS225 measures resistance, and DC and AC voltage and current. It can also test continuity and diode junctions. A host of special features add versatility to the meter without making it more difficult to use. The RMS225 offers five DC volt- age ranges (1.0-1000 volts full scale) with a rated accuracy of 0.25%. Three AC voltage ranges (10, 100, and 750 volts) offer a rated accuracy of 1.0% for sinewaves from 45 Hz to 2 kHz. The accuracy for the true RMS measurements decreases slightly for other waveforms. Six resistance ranges (1K-4Q megohms) and three AC and DC current ranges (10 mA, 40 mA, and 10 amps) are also of- fered. The meter is housed in a gray, high-impact thermoplastic case that measures about 6 3 /tx 2YaX VA inches and weighs less than 12 ounces. The front panel sports a 4- digit LCD readout with analog bar- graph, three pushbuttons, a rotary function selector, and four input jacks. The meter fits easily in one hand, and all controls can be oper- ated by the thumb of that one hand— something that can't be said for many other "handhelds." Menu-selected features Three pushbuttons below the LCD readout are used to access the meter's special functions. Hitting the menu button calls up the menu, and allows you to scroll through the selections. Range lock is the first feature that is menu selectable. Although the meter is in an auto-ranging mode when it is first powered up, it is pos- sible to lock the meter scale to a given range. Like all other menu se- lected features, range lock can be de-selected with the clear button. Probe Hold is a convenience fea- ture that allows the user to take a reading without looking at the meter's display — a stable reading is held in the display for later viewing. The meter beeps to indicate that it has captured a stable reading. A relative mode is also accessed from the menu. That mode allows the user to set a reference value, and all other readings display with respect to that reference. Auto Min Max is a mode in which the meter measures and stores the minimum and maximum values, while displaying real-time readings. It's ideal for unattended monitoring. Using the meter The RMS225 is very easy to use. Although we were initially skeptical about the presence of a menu on a DMM, we were happy to find that Beckman's implementation was in- tuitively easy to use — even without reading the manual. Of course, we do encourage users to read operat- ing manuals; this meter's manual was well written. Unlike many other 4-digit multi- meters, the RMS225 offers a 10,000- count resolution — In other words, it's maximum reading is 9999, which results in a higher measurement res- olution. For example, you can re- solve 0.1-volt changes even when measuring a 500-volt signal. A 3 1 /2- digit meter would be able to resolve changes of 1 volt on the same signal. We didn't have the opportunity to overload the meter, but we know that accidents can happen. That's why we like the seif-resetting fuse that protects the low-current (40 mA) input jack. We also liked the continuous tone that warns when measurements exceed the meter's input ratings, and the lightning-bolt annunciator that warns the user of a potential hazard when measured signals exceed 25 volts. We also did not have the oppor- tunity to try the protective holster with Flex Strap that is normally sup- plied with the meter. (Ours was an early production model.) Besides of- fering protection, the holster, with its probe holders and strap, can make many measurements more convenient. The RMS22S carries a suggested retail price of $149. That competitive pricing should get the meter into a lot of hands rather quickly. R-E 16 PLUG IN. TURN ON. GET DATA. FAST. FREE SOFTWARE. NO PROGRAMMING. SB* 1 - ■^ Turnkey ProtoKey™ 8-channel data acquisition system. ..the accu rate, low cost solution to real time data collection from your IBM compatible PC. ..with user friendly software included Sophisticated, without being frightening. Truly functional. Amazing accuracy. More than mere hardware. Requires no programming skills. And, truly affordable at only $395 -- <_ All describe the hot, new Global Specialties American-made ProtoKey'" 8-channel data acquisition system, which includes ■ 8 A/D input channels with 12 Bit resolution ■ selectable con- version times of 7 Hz or 30 Hz ■ 3 input ranges from 5 Volts to 50mV ■ 100 uv resolution ■ ther- mocouple linearization ■ interfaces to a variety of transducers ■ plus, operating software and a complete users manual. Now you can create daring experiments as fast as you think of them,., store them indefinitely... expand or modify them as needed. Best of all, you don't have to be a pro- grammer, because you get an unlimited data window with Global's menu-driven software package... the power of a programmable package, without the hassle.. .simplified operation with every- thing you ever need to know right fCE J >J(y there on the screen in pop-up menu formats. Plus, on-line help, with interfaces to popular spreadsheet or analysis programs... with just a single keystroke. Get the facts today. Just say, "Data. ..fast!" We'll understand. That's ProtoKey /6^[i^9call toll-free for details ©LOBAL MJiJ 1-800-572-1028 SPECIALTIES Global Specialties. An Interplex Eleclronics Company, 70 Fulton Terrace. New Haven, CT 06512. Telephone: (203) 624-3103. P Interplex Electronics 1989. All Global Specialties breadboarding products made in USA. CIRCLE 188 ON FREE INFORMATION CAHD A0012 Drawing Board Video-scrambling techniques TRUST ME, PEOPLE, THIS IS THE LAST thing I'm going to have to say about video — at least for a while. You know enough now to make a pil- grimage to your local library and get a lot more information than I can squeeze into this column. And, in any event, my bench has been cov- ered with video junk for a few months now and I'm getting the itch to start messing around with some- thing else. Video-signal scrambling is the only basic subject we haven't really looked at. Scrambling methods go from the simple to the ridiculous, and the ones you're likely to encounter lo- cally depend entirely on who you happen to be getting the signal from. Small cable companies use relatively simple methods, but the people running the satellite systems go much further because they have less control over who can get the signal. Last 1 heard, there's no law against owning a satellite dish, but hook into the cable without autho- rization and you're in really deep... trouble. Most of the current scrambling methods fall into one or more of the following four categories: 1. Screwing around with the sync signals. 2. Screwing around with the picture. 3. Screwing around with everything. 4. Screwing around with something else. While I'm the first to admit that it's not the most informative list in the world, it's really what's going on. It's also impossible to describe every method there is because new ones are being devised as fast as old ones get beaten. But let's look at a few of them. Screwing up the sync The most common method of scrambling, and one of the oldest, is to mess up the horizontal sync. If your TV can't find it, there's no way for it to lock its horizontal oscillator to the beginning of each line of vid- eo. The result will be a weirdly col- ored, wavy bar somewhere in the middle of the screen and a totally unwatchable picture. As you proba- bly realize, the vertical bar is the sync portion of each line that really belongs off to the right and left of the screen. A line of video using this method looks something like Fig. 1. It takes only a simple twist of a knob for the broadcaster to remove the horizontal signal but, since he wants to put it back in later, there has to be some way to put it back — at the right time and the right level. The information used to be buried in the IF but that's been largely re- placed with encoding the informa- tion and sticking it in the vertical interval. Since the FCC eased their control of what can and can't be done during vertical retrace, people have found all sorts of uses for it. One of the newer wrinkles in the wonderful world of sync suppres- sion is to change the transmitted sync level in each field of video. The amount of gain needed to put things back is encoded in the ver- tical interval. The descrambler hard- ware knows how to get that information and, consequently, how much gain to use to restore horizontal sync. Screwing up the picture One method that my cable com- pany is starting to use now messes up both sync and picture. The basic scrambling technique is simple and ROBERT GROSSBLATT, CIRCUITS EDITOR makes the picture even worse than just suppressing sync. What's also interesting is that, even though it's newer, it's theoretically much easier to beat than suppressed sync. All that's done is to inver the en- tire video line using IRE as the center point. As you can see in Fig. 2, horizontal sync gets stuck in the picture area (positive IRE numbers) and picture information winds up in the control-signal area (negative IRE numbers). The TV can't find the horizontal sync and, since picture luminance and chroma are upside down, the colors are backward. You might think that all that has to be done to clean everything up is to put the whole signal through a wideband, inverting amp — and you would be right — except for one thing. If you look carefully at Fig. 2, you'll see a positive-going pulse im- mediately following the sync area. If you invert the line, that spike will be negative-going, and look some- thing like a delayed version of hori- zontal sync. The bottom line is that it's going to confuse the horizontal circuitry in the TV and the picture will still be messed up. The way to beat the system is to invert the picture and then run it through a circuit that does two things: First it watches for horizon- tal sync, and then, during the period that the spike is being trans- mitted, it adds a version of the spike that's 180 degrees out of phase. That will null out the spike and leave a restored picture. The circuitry needed to beat this is simple. As a matter of fact, you already know enough to design it. You'll need an amp that can handle video frequencies (top around 6 MHz), a sync separator, a counter, 18 hHplt/ZONTAL 1 'A >m 'AVAL J vo&za/vrAL mnwAL- J £t/PP/>£3Z£.D SYAC FIG. 1 FIG. 2 and finally, a mixing amp. Screwing up everything else All the methods we've looked at so far are the kinds of things you find done by cable companies. They're all fairly easy to implement, and the circuitry to do the job (on both ends) can be produced at man- ageable economic levels. Satellite systems don't have the luxury of an exclusive client list. Anyone who has a dish can get their signal so they need some sort of scrambling that's going to be more difficult to beat. Most of these guys use scrambling methods that realty tear the video apart. A system like this is much more difficult to break. It's not impossible, just much more difficult. If you look at some of them on a scope, you'll see things that don't even look like video. Sync (both horizontal and vertical) seems to be nonexistent and the video is strange as well. That's understandable since a lot of satellite scramblers change the order of lines and sometimes even superimpose miscellaneous waveforms on top of the whole mess. The initial stage of designing any circuitry to decode scrambled sig- nals is to look at the waveform. Be- cause there are so many ways that the signal can be screwed up, the only piece of advice I can give you is to use a dual-trace scope. Put a line of plain video on one channel and the scrambled signal on the other. By triggering off real video, you may be able to see a pattern. Breaking scrambled video is not something you can toss off between breakfast and lunch. It takes a lot of analysis and design. And, of course, depending on what you do with your new knowledge, you may be risking a paid vacation in the slam- mer. That isn't to say that digging into a scrambling technique is not fun to do — I'm a firm believer in having a good time at the bench. If you do have an urge to try it, re- member that there's always some pattern to the scrambled signal. Keep an eye out for a horizontal and vertical interval. A good rule of thumb is that no matter what's done to the signal, it has to be put back together, and the numbers we worked out a few months ago re- garding field- and frame-repetition rates should give you a starting point. R-E evaluating an ANTENNA (MATCH) FIG. 9 SETUP. ANTENNA VSWP 10dB per DIV 100 FIG. 10 I J 100MHz frequency The degree of match between a 50 SI source and an antenna is obtained with the set-up illustrated in fig. 9. The tuning, Q, and reflection loss are available. The CPL output with either an open or direct short on IN is plotted as the fwd line in fig. 1 0. Then the cable to the antenna is attached, and the scope photo of fig. 10 results. The difference between these lines is desired. The scope indication of "37 dB" forward, "12 dB" reverse, indicates the reflected loss is down 25 dB at 68 MHz; (1 .1 VSWR) 1/320=0.3% of the applied power is reflected or about 99.7% of the available power is radiated (or at least absorbed) by the antenna. Conversely, 99.7% of the received power is applied to a 50 SI receiver. Since the probe can "see" a low tevei, only a low radiated signal is required. The discrete lines are signals received by the antenna. The logarithmic response allows evaluation of good matches. to* SPECTRUM PROBE converts your scope into a 100MHz spectrum analyzer >) 1 y i/ direct Smith Design Dresher, PA 19025 1324 Harris > © c: (215)643-6340 - CIRCLE 193 ON FREE INFORMATION CARD o 19 N ew Products to o z o DC F o LU _1 LU Q o < DEVELOPMENT SYSTEM. De- signers who are developing systems based on Motorola's popular family of 68HC05 Customer Specified /ntegrated Grcuit (CSIC) mi- crocontrollers can debug hardware and software faster and easier than ever before, using the CD58/05 develop- ment system. The first entry in Motorola's "Jewel box Fam- ily," the affordable CDSS/05 provides a complete profes- sional development environ- ment in a portable 11x12 x 2- inch package. The system provides real- time, non-invasive emula- tion of the microcontroller. Time-saving features include a window-oriented user in- terface, menu-driven com- mands, single-step execu- tion, symbolic debugging, software breakpoints, con- tinuous run mode, and memory mapping. As the system is the first commer- cial product based on Motorola's 68332, which re- places the equivalent of nine CIRCLE 10 ON FREE INFORMATION CARD peripheral chips, the CDS8/05 takes advantage of the 32-bit microcontroller's advanced integration. To make it completely por- table, the CDSS/05 was de- signed with alternate power sources: either a universal 85-265-volts AC, 50-60- Hz power supply or a 9-18-volts DC converter. The system also features a bus analyzer that contains an 8K-by-80 real-time trace buffer. The bus analyzer can connect to on-board non-volatile RAM that stores macros loaded in the lab for use in the field. The included software-de- velopment package runs on an IBM PC, XT, AT, or com- patible computer, which also serves as the host computer for the CDS8/05. PC inter- connect software and a mac- ro assembler/linker are in- cluded with the software. The interface features sym- bolic debugging of assem- bly-language programs, macro definition and state collection, help screens and escape to DOS. The CDS8/05 development system costs $2950.00.— Motorola Inc., Micro- processor Products Croup, 6501 William Cannon Drive West, Austin, TX 78735-8598; Tel. 512-891-3184. THREE-CHANNEL OS- CILLOSCOPE. For easy analy- sis of low-level and high- speed signals, Leader Instru- ment's model 7700100-MHz, three-channel, dual-time- base oscilloscope features six-trace capability with 500-u.V maximum sensitivity and 5-ns maximum sweep speed. Other features in- clude alternate triggering, al- ternate time base, and varia- ble holdoff. The 7700's high- intensity CRT and extensive triggering controls provide a CIRCLE 1 1 ON FREE INFORMATION CARD bright, stable display, even of complex signals, TV- VI, TV- V2, and TV-H sync-separator circuits allow optimum trig- gering of video signals, and alternate timebase allows si- multaneous observation of vertical and horizontal TV signals. The model 7700 os- cilloscope costs $1545.00. — Leader Instruments Corpora- tion, 380 Oser Avenue, Hauppauge, NY 11788; Tel. 800-645-5104 (in NY, 516-231-6900). SURGE- PROTECTED TRIPLE OUTLET. Designed for situa- tions where electrostatic dis- charge (ESD) is a concern, Plastic Systems' model SP-0301 has three surge-pro- tected outlets configured in one unit, and also provides assurance that the electrical '«r CIRCLE 12 ON FREE INFORMATION CARD ground is accurate. Two highly visible LED's allow quick verification of surge protection and ground suit- ability. The monitor also pro- vides a plug-in ground point for a standard 0.175-inch ba- nana plug that is grounded for safety through a one- megohm resistor. The model SP-0301 spike- and-ground-alert outlet costs $29.50.— Plastic Sys- tems, Inc., 261 Cedar Hill Street, Marlboro, MA 01752; Tel. 508-485-7390. FILTER-SUBSTITUTION BOXES. With the Krohn-Hite 3000 Series Flexi-Filters, the response can be changed to fit many applications— with- out purchasing additional fil- ter cards. As many as four filterchannels have indepen- dently variable parameters to allow tailoring of their re- sponse. With the push of a button, the user selects But- terworth, Bessel, Cheby- shev, or RC responses with attenuation slopes from 6-48 dB/octave in 6-dB/octave steps. Each channel can be independently set to be low- pass, high-pass, band-pass, band-reject, amplifier only, or any combination (such as low-pass with band-reject). Cutoff frequencies are tuna- CIRCLE 13 ON FREE INFORMATION CARD ble from 0.001 Hz to 200 kHz. The filter boxes, which have differential or single-ended- inputs, separately adjustable input-output gains of up to 10,000, and output gain ad- justable in 0.1-dB steps, can be fine-tuned to suit the user's application. Additional features include up to two oscillator outputs, battery power, and IEEE-488 control of all parameters. The 3000 Series filter-sub- stitution boxes range in price from $1995.00 to $3600.00.— Krohn-Hite Corporation, Avon Industrial Park, Bod- well Street, Avon, MA 02322; Tel. 508-580-1660, ext. 31. THREADED BANANA |ACKS. To solve the problem of "not enough hands" while han- dling test equipment and making multiple test contact points on terminal blocks 20 CIRCLE 14 0N FREE INFORMATION CARD and strips, ITT Pomona Elec- tronics has introduced a threaded banana jack. Avail- able in three standard thread sizes, each unit is an inte- grally machined banana-jack receptacle and screw, with an insulated hex-head hous- ing. The terminal strip jacks thread directly into industry- standard barrier and termi- nal strips. The integral threaded studs, which are nickei- plated for corrosion resis- tance and low contact resis- tance, meet or exceed the torque specifications for the screws that they replace in the terminal strips. The insu- lated heads are 5 /i6 hex, to match the most common hex drivers. Models 5699, 5700, and 5701 are 6-32, 8-32, and 10-32 thread, respectively. Each is available in seven colors for easy recognition. The list price is $2.75 each, with quantity discounts avail- able. — ITT Pomona Elec- tronics, 1500 East Ninth Street, P.O. Box 2767, Pomona, CA 91769; Tel. 714-623-3463. TELEPHONE-NETWORK SIM- ULATORS. Two additions have been made to Telecom Analysis Systems' popular TAS 100 family of telephone- network simulators. De- signed for testing modems, fax machines, voice/data ter- minals, transmission test sets, and telephone sets, models TAS 121 and TAS 122 are compact tools for de- CIRCLE 15 ON FREE INFORMATION CARD velopment, reliability test- ing, manufacturing, field support, and maintenance. The TAS 122 provides si- multaneous bi-directional simulations of trunk impair- ments, and the TAS 121 pro- vides uni-directional impair- ments. On both units, im- pairment features include attenuation and noise; gain and group-delay distortion; phase jitter and frequency offset; nonlinear distortion; gain hits, phase hits, and im- pulses; and satellite delay and echo. Simulation of cen- tral office (exchange) varia- bles is also provided, includ- ing loop current, ring volt- age, ring frequency, and signaling frequencies and ca- dences. Both models simu- late 4- and 2-wire private lines and 2-wire switched lines. Automatic calibration and diagnostics assure test integrity. Standard GP1B and RS-232C remote-control in- terfaces are provided. Prices for the TAS 121 and TAS 122 telephone-network simulators start at $11,950.00.— Telecom Analy- sis Systems, Inc., 34 Industrial Way East, Eatontown, N) 07724; Tel. 201-544-8700. ELECTROMAGNATIC-RADI- ATION MONITOR. Designed to meet the rising concern about the potential hazards of low-level electromagnetic radiation, Walker Scientific's ELF-50D field monitor is a hand-held instrument that provides accurate readings instantly on a digital display. CIRCLE 16 ON FREE INFORMATION CARD The ELF-50D measures the extra-/ow-frequency (ELF) electromagnetic radiation that is generated from power lines, TV's, video displays, home appliances, and other I OPTOELECTRONICS The only name in HANDI-COUNTERS Model I ]< nun. 260011 2210A 1 "!«■ El A Fund Eon Frpq, Period Rnua.lnlrrvdl. Frcquvrtrv E-'n ,|...-n, ■. Vnil LKrney ftanjic lOKi- ■2AGHr. lOMBl- 2.4(1 Kz IIJUi- 1 K'rKj JMHi- I.JJGHi ftiaplay li> Midi LCD w'Fu net lan Anmineifllor* 10 Dtjtil LCD « Dipt LED SDiltit LED RF KijfftpJ ; .i, 1 1. .. ; . -i- 1 6 .Si^lllirnl Aii;.i--:.ii> " Bflrj.Taph |i^S-i;iv,ii- Adj .: - : .i ' i ' ■ E1;ir>:r;i|ih • ■ Pric* S-'iTij. «ns. si in. S1T9. SenaiEivilv^i lo^lUrnV ivplral Timp Bfl^n-'i 1 ppm ^ j^nn *dd S LED Model*: _* 2ppm Add S«Q. - W'tl Mhk^I> Xi*ad> k ai adapter indudi'd. Carry Cn*?, AnU-nnciN .incf Prritia* culm. One year pari* &lrthmrw^i , r.in". . Check These Incredible Features On The All New UTC3000 • I MM/ to 2.4GHz Range. Simply amazing! * 10 Digit LCD Display. H?. rusulution to over 15ti MHje direct. Readable in bright sunlight. ■ RF Signal Strength Bargraph* 16 Segment. Zero. & Full Scn!e ndjustmeint- SEE the input signal! • Supersensitivity. al&* lax. Kill I -Sim- Printim-i .mfJ Am-^fitv ('iituliiLj .n.ill.ibk- un rcqUGAL > c C CO CD O 21 CIRCLE 187 ON FREE INFORMATION CARD equipment. By simply switching the unit on and holding it where radiation is suspected, a reading is in- stantly provided on the 3 1 /2- digit display. The ELF-50D is calibrated to measure with ±1% ac- curacy the electromagnetic radiation generated from any 50- or 60-Hz device. It has two switch-selectable mea- surement ranges: a low range from 1 milligauss to 2 Causs, and a high range up to 20 Causs. The ELF-50D electromag- netic-radiation monitor has a suggested list price of $225.00.— Walker Scientific, Inc., Rockdale Street, Wor- cester, MA 01606; Tel. 800-%2-4638. CAPACITANCE METER. Boonton Electronics' model 7200 capacitance meter accu- rately measures 1-MHz ca- pacitance in the presence of loss — and measures the par- allel conductance loss as well. The unit will compute and display on command the parallel resistance, dissipa- CIRCLE17 0N FREE INFORMATION CARD tion, quality factor (Q), the equivalent series capaci- tance and resistance, AC, and A%. It features a 0-2000- pF capacitance range and a conductance range of to 2000 u.S. Test levels are pro- grammable from 15 to TOO mV. The 7200 accepts, mea- sures, and displays external bias voltages to ± 200 V. an optional internal supply pro- vides programmable bias voltages to ±100 V. That, to- gether with fast analog C, G, and V outputs, make the in- strument useful for C-V and G-V plots of semiconductor devices. When operated on theGPIB bus, the C,G, arid V information is available si- multaneously for rapid data transfer. The model 7200 capaci- tance meter costs $4,495.00.— Boonton Elec- tronics Corp., 791 Route 10, Randolph, NJ 07869; Tel. 201-584-1077. PORTABLE FUNCTION GEN- ERATOR. A versatile general- purpose signal source, Beckman Industrial's model FC2A function generator performs over seven fre- quency ranges (0.2 Hz through 2 MHz) and a very large array of signal outputs, including both TTL pulse outputs and adjustable low- distortion sine-, square- or triangle-wave signals. The in- strument offers the con- venience of push-button CIRCLE 18 ON FREE INFORMATION CARD selection of power, frequen- cy range, and wave form. It is housed in a durable case that has a cushioned handle/tilt stand and recessed areas in the top cover for easy stack- ing of multiple units. Ap- plications for the portable field-test instrument include such things as testing vibra- tion, servo systems, audio systems, and ultrasonic de- vices, as well as in R&D and in teaching electronics. Various controls provide flexibility. The duty-cycle control allows users to change the nominal 50% duty cycle of the signal to any desired value, and the DC offset control adds a variable DC-offset voltage to the sig- nal. The VCF input, which permits the frequency to be controlled with an external DC control voltage, is useful for generating 1000.1 or 1.1000 sweep signals. The model FC2A function generator has a suggested list price of $215.00.— Beck- man industrial Corporation, Industrial Products Division, 3883 Ruff in Road, San Diego, CABLE - TV SICNAL RC/H€VCR§ •FOR ELIMINATION OF SEVERE INTERFERENCE •FOR -CENSORING' OF ADULT BROADCASTS ■as _.«■; <4|A) 15(B) 16(C) 17(D) 50-<00 MHz SOT 1B22 144174 MHz 1«(E) 13(F) 10(G) 21 (H)2Z|I) 50-400 MHl 130 713 i.'j :■■■'-. mhz 713.10.11 1213 S0-40O MM; $30 o z O DC O Q < 22 3 for $75 - 10 for $200 - mix or match CALL TOLL FREE FOR COD ORSEND CHECKTO ORDER FAST DELIVERY 30 DAY MONEY BACK GUARANTEE (3 FILTERLIMIT) Star Circuits P.O. Box 94917 Las Vegas, NV 89193-4917 1-800-433-6319 KENWOOD OSCILLOSCOPES WULOG OSCILLOSCOPE H/0 RIADOUT HOCO. CS-5135 40 II:. Dual Channel . Delayed Sweep. REG. $895.00 SALE 1719.95 MODEL CS-5155 SO Nil, 3 Channel, 6-Trace. Delayed Sweep. REG. $995.00 SALE $819.95 MODEL CS-516S 60 HHz. 3 Channel, 6- Tract. Delayed Sweep. REG. 11095. 0C SALE S899.9S MOOEL CS-2350 ISO HHi, « Channel, 6- Trace, Delayed Sweep. REG. $7395.00 SALE $1495.95 AKAL06 OSCILLOSCOPES M/REAiXWl/alRSffiS MOEL C5-5130 40 MHz. Dual Channel. 4-Trace, Delayed Sweep. REG, $1095.00 SALE IB99.95 MOEL CS-51J0 100 HHi, Dual Channel, 4-Trace, Delayed Sweep. REG. $1695.00 SALE $1399. 95 WOEL CS-M10 100 HHi, 4 Channel, 10-Trace, Delayed Sweep. REG. 11995,00 SALE (1699.95 MODEL CS-W20 15D KHz. 4 Channel , 10-trace, Decayed Sweep. REG $2395.00 SALE $1999.95 MODEL CS-4n25 2(1 MHz, Dual Channel Oscilloscope. REG. I49S.O0 SALE $349.95 INT Products International S931 Brookville Rd. Silver Spring, NO 20910 (800)638-2020 (301)587-7824 FAX* 301-585-5402 EAST ORDER FA* LINE (800)545-0058 800-638-2020 CIRCLE 192 ON FREE INFORMATION CARD CA 92123-1898; 619^95-3240. Tel. NTSC-PAL-SECAM TV/ MONITOR/VCR. Incompati- ble TV-broadcasting sys- tems— NTSC, PAL, SECAM— have created problems in in- ternational communications for years. The Multicombo and Super Multicombo TV/ monitor/VHS VCR's allow PAL tapes to be enjoyed with no loss of quality. Ten-Lab describes the units as the first "built-in, up-dated American (NTSC) video cen- ters that have foreign sys- tems capabilities." CIRCLE 19 ON FREE INFORMATION CARD Both cable- ready sets are available in either 20- or 27- inch sizes, and feature 155 channels, wireless remote controls, double multi-func- tion on-screen color display, hi-fi stereo sound, MTS broadcast stereo decoder, and two built-in full-range speakers. The Multicombos provide play-back of NTSC and PAL videotapes in color, and SECAM playback in black-and-white. The Super Multicombos also allow PAL and SECAM recording (in full color), as well as PAL and SECAM monitoring (PAL in color, SECAM in B&W). For the proper color, video quali- ty, sound linearity, and syn- chronism, the sets provide 525 lines, 60 Hz for NTSC and 625 lines, 50 Hz for PAL. The 20- and 27-inch Multicombos cost $1345.00 and $2495.00 and the 20- and 27-inch Super Multicombos cost $2100.00 and $3200.00, respectively. — Ten -Lab Multi- system Video Products, 11064 Mississippi Avenue, Los An- geles, CA 90025; Tel. 213-473-66551. CIRCLE 20 ON FREE INFORMATION CARD SYNTHESIZER/CLOCK GEN- ERATOR. Designed for engi- neers who require an afford- able, basic frequency source, Novatech's 2901A synthesizer/clock generator offers 10-ppm accuracy, sta- bility, good spectral purity, and low harmonic distor- tion. The instrument's out- put frequency is adjustable from 200 kHz to over 32 MHz with 5-digit resolution. Sine- wave and TTL-compatible outputs are available on the front panel. The sinewave output amplitude is adjusta- ble from 100 mV to 1.1 volts peak-to-peak. The 2901A also has an auxiliary sinewave- tracking output on the rear panel that is equal to the front-panel sinewave output plus 128 MHz. The unit is housed in a convenient bench-top case with tilt-up bail. The Novatech 2901A fre- quency synthesizer/clock generator costs $750.00. — Novatech Instruments, Inc., 1530 Eastlake Avenue East, Suite 303, Seattle, WA 98102; Tel. 206-328-6902. THREE-WIRE CIRCUIT ANA- LYZER. A.W. Sperry's easy-to- use, hand-held circuit ana- lyzer, model CA-300A, warns against faulty wiring in 3-wire receptacles. As soon as the ■ Hi H.W.BKRRY , ■ ■/■^r+Mtzt "*t tit* m si. o@o y SVOOO wamQOO » %£fo@ f """ ooo MLH CIRCLE 21 ON FREE INFORMATION CARD Cut Your Video Servicing Time by 54%* $3,495 Patented *Qu MP S& With The Market Proven VA62A Universal Video Analyzer Are you finding it tough to service today's hi-tech VCR and TV circuits? Successful video servicers have told us that, to them, the new technology meant lost profit and troubleshooting grief until they tried the VA62A's time tested, functional analyzing methods. 'The VA62A cuts servicing time and increases profits ..." "Based on a nationwide survey of users who reported an average time savings of 54% compared to their previous test equipment. You can prove it to yourself, in your shop, absolutely risk free — and share in the profits successful video servicing can bring. Call 1-800-SENCORE t73e-seT3) and ask about our exclusive VA62A instrument evaluation program. Tech-Tape Video Preview and FREE full line color catalog are also available. 3200 Sencore Drive, Sioux Falls, SO 57107 100% American Made CIRCLE 185 ON FREE INFORMATION CARD > C o c CO to o 23 H» MAXTEC INTERNATIONAL CORP. SUMMER Syfmrt MODEL 560 Programmable In/Out of Circuit IC Tester. REG. $3500.00 SALE $2940.95 FREE AK-560 SOFTWARE!!! FREE 1541A or 2520 Scope!!! MODEL 2120 Oscilloscope, 20 MHz, Dual Trace. RES. $549.00 SALE $374.95 MODEL 154 LA Oscilloscope, 40 KHz, Dual Trace. REG. (845.00 SALE $597,95 MODEL 2! 60 Oscilloscope, SO Ml. Dual- Trace M/Oelayed Sweep. RES. $1099.00 SALE $874.95 MODEL 388-HD "Test Bench," 41 Barge, l\ Digit, Multifunction DMM. RES. $129.00 SALE $99.95! COMPLETE BAK LINE AVAILABLE "CALL FOR YOUR PRICE QUOTES" MODEL 2522 Oscilloscope, 2D MHi, 10 MS/S. Oual Trace, DSO, OLD LIST $1495. NEW LIST $995. ONLY $ 835 INT 95 Products International 3931 Brook.il le Rd. Silver Spring, HD 20910 (800)638-2020 (301)587-7824 FAX (301)585-5402 E Z Order Fax Line 1-800-545-0058 C«rti _ A: 800-638-2020 CIRCLE 200 ON FREE INFORM ATfON CARD unit is plugged in, a succes- sion of yellow and red indica- tors signal exactly which wire in the receptacle is the defec- tive one. The CA-300A will not nor- mally trip a GFC1 (Ground- Fault Circuit Interrupter). It is intended for use on 110- to 125- VAC circuits. The CA-300A 3-wire circuit analyzer costs $4.50. — A.W. Sperry Instruments, Inc., 245 Marcus Blvd., Hauppauge, NY 11788; Tel . 516-231-7050. REMOTE/WALL SWITCH ON/ OFF CONTROL. For security purposes, or just for the sake of convenience, (he versatile model 72-320 from Midland CIRCLE 22 ON FREE INFORMATION CARD can be used manually or re- motely to control on/off functions as well as to dim tights. A keychain-size transmit- ter controls both functions from a dstance of up to 50 feet away. The transmitter, which uses UHF radio technology on coded channels, can han- dle up to 400-watt incandes- cent bulbs in indoor or outdoor settings. (For exam- ple, a porch or garage light can be controlled from with- in a car.) All kinds of household de- vices can also be manually turned on and off, and lights dimmed, using the perma- nently installed wall switch. The model 72-320 remote control/wall switch with the included light-dimmer func- tion fits in a standard-sized electrical box. It has a sug- gested retail price of $39.95,— Midland Interna- tional Corporation, Consum- er Communications Divi- sion, 1690 North Topping, Kansas City, MO 64120; Tel. 816-241-8500. CO y z o it£rm, Ii\l Use the keyboard to ask for information SET key allows you so change previous settings SENSOR ON/OFF key chooses the functions to report ONLY $129.95 Dials Out In Alert Conditions Set the unit to call out to your office, neighbors' and rela- tives" to announce any alert conditions that are outside preset limits. Up to four numbers can be programmed. Order Toll Free 1-800-253-0570 The SD-6230 House Sitter is yours for only $129.95*. To order, call toll-free 1-8OO-253-0570. VISA, MasterCard, American Express or your Heath Revolving Charge card accepted. Use order code 601-015. See our full line of electronic products for your home in the Heath kit catalog -call 1-80O-14-HEATH for your FREE copy. Heath Benton Harbor, MI *Pi M- ilo.-M-.nt in. lu.Lr shipping and hflTMlhng. US ippljcafclf ulr> HE. > c o c o 25 CIRCLE 86 ON FREE INFORMATION CARD Electronics DTfflDi]0 LOW COST PC LOGIC ANALYZER. De- signed for students and hobbyists working with 5V TTI/CMOS signals in the Khz range. 36" data cable— eight channels, external clock, ground. Selectable trigger & clock edge, internal clock (1Hz-100Khz). Full-fea- tured software, state table graphics, file/print utilities, etc. Over 100,000 samples/sec on 12 Mhz AT. LA1— $99.95. PHOTRONICS, INC. 109 Camille St., Amite, LA 70422 (504) 222-4146. CIRCLE 201 ON FREE INFORMATION CARD A VIDEOPHONE CHIP, ORAM, A/D etc. (6 chips & discretes), capture any NTSC video picture and sends it over the phone in 12 seconds. It displays on any composite monitor or TV (VIA VCR). It is offered, pres- ently in KIT form. The CONTROL chip ONLY, and schematic are available for $59.95. from: PMC ELECTRONICS, Box 11148, Marina Del Rey, Calif. 90292. CIRCLE 184 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 ft 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 SIMPLY SNAP THE WAT-50 MINIATURE FM TRANSMITTER on top of a 9v battery and hear every sound in an entire house up to 1 mile away! Adjustable from 70-130 MHZ. Use with any FM radio. Complete kit $29.95 + $1.50 S + H. Free shipping on 2 or more! COD add $4. Call or send VISA, MC, MO. DECO INDUSTRIES, Box 607, Bedford Hills, NY 10507. (914) 232-3878. CIRCLE 127 ON FREE INFORMATION CARD CABLE TV CONVERTERS AND DE- SCRAMBLERS SB-3 $79.00 TRI-BI $95.00 MLD-$79.00 M35B $69.00 DRZ-DIC $149.00. Special combos available. We ship COD. Quantity discounts. Call for pricing on other products. Dealers wanted. FREE CATA- LOG. We stand behind our products where others fail. One year warranty. ACE PROD- UCTS. P.O. Box 582, Saco, ME 04072 1 (800) 234-0726. CIRCLE 75 ON FHEE 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. □ ANALOG DEVICES 1990 CIRCLE 29 ON FREE INFORMATION CARD log provides complete prod- uct descriptions, configura- tion charts, block diagrams, specifications, and pricing for sensor-fo-host sub- systems. Featured are prod- ucts such as modular signal controllers, PC -compatible data-acquisition adapter boards, distributed data-ac- quisition and -control hard- ware, and a variety of applications software. A helpful tutorial and refer- ence section guides users through the selection and configuration process. DATA CONVERSION PROD- UCTS SHORT FORM CATA- LOG 1990. Micro Networks/ Unitrode, 324 Clark Street, Worcester, MA 01606; 508-852-5400; free. This 12-page booklet pro- vides an overview of data- conversion products for high-end-industrial and mili- tary/aerospace applications. It contains more than 75 product groups, organized CIRCLE 30 ON FREE INFORMATION CARD into easy- to- read specifica- tions tables. It includes dig- itai-to-analog converters, analog-to-digttat — including sampling and multi-chan- nel — converters, and data- acquisition systems. A broad selection of trackyhold ampli- fiers is highlighted. R-E Get hands-on training for a high-paying career in today's booming electronic information industry as you build your own complete data ^_ communications system NRI's new Data Communications training gives you the high-tech, hands-on skills in demand in today's explosive new electronic information industry. Now with NRi, you actually build and go on-line with your own powerful data communications system, complete with IBM PC/XT-compatible computer, 2400 baud modem, communications software, breakout panel, test instruments, and more! It's a fact: The hot jobs in electronics today are in the electronic information industry. An explosion in new technologies is turning desktop computers into high-powered, high- speed data communications systems — making it possible for computers to talk to computers the world over. Already, electronics technicians trained to install and service the new data com- munications equipment demand and get S25,000, 830,000, 535,000 a year and more. Now with NRI, you get hands-on data communications know-how, so you too can cash in on today's multibillion-dollar elec- tronic information industry. NRI's ready to help you succeed now with new at-home training featuring a powerful data com- munications system you build, program, operate, and keep! NRI trains you from the basics on up- giving you everything you need to get a fast start in data communications Your NRI training starts with the electronics fundamentals you need to understand and service all data communications equipment. As you assemble your NRI Discovery Lab 9 , a complete breadboarding system included in your course, you perform experiments and demonstrations that show you electronics principles at work firsthand. Quickly moving on, you use NRI's pro- fessional digital multimeter to take voltage, current, and resistance measurements, testing a variety of circuits you build on your Discover)' Lab— circuits just like those in today's data communications equipment. And that's just the beginning. With a solid foundation in electronics behind you, you're ready to build your own powerful data communications system. Breakthrough training includes 51 2K computer, 2400 baud modem, communications software, breakout panel, much more At this point in your training, you're sent the new IBM PC/XT compatible Packard Bell VX88 computer. Following NRI's clearcut in- structions, you easily master your computer's powerful operating functions, then move on to build your own complete data communica- tions system. You begin by programming the RS-232C communications interface built into your computer, giving the Packard Bell the power to transmit data over serial lines. Next you construct a high-quality breakout panel, an indis- pensable diagnostic too) you use to examine and test the interna] workings of your interface. Then, completing your state-of-the-art system, you power up the 2400 baud modem included in your course and take it through a series of comprehensive tests and demonstrations. In no time, you have a firm understanding of the data conversion system built into | your modem, and you're ready to put your system on-line with a world of elec- tronic information. Go on-line with the exclusive NRI network Your NRI training continues by giving you exciting real- world experience in data communications. Having completed your data communications system, you actually take it on-line to "talk" to your instructor and other NRI students, complete a finaJ project by computer link, and leave messages on the NRI Bulletin Board, Step by step, NRI gives you a complete hands-on understanding of the technology that's powering today's booming electronic information industry. Step by step, you get what it takes to start a high-paying career as today's in-demand data communications technician! FREE 100-page catalog tells more Send today for NRI's big, 100-page, full-color catalog describing every aspect of NRI's hands-on training in data communications, as well as at-home training in other fast- growing, high-tech career fields. If the coupon is missing, write to NRI School of Electronics, McGraw-Hill Continuing Education Center, 4401 Connecticut Avenue, NW, Washington, DC 20008. School of Electronics McGraw-Hill Continuing Education Center 4401 Connecticut Avenue, NW ■/, j| Washington, DC 20008 pjjC H Check one catalog only D Data Communications □ Computers and Microprocessors D Robotics D TV/Vrico/Audiu Servicing For career courses approved under CI bill [] check for details 1} Computer Programming " Electronic Music Technology □ Cellular Telephone Servicing Q Security Electronics □ Digital Electronics Servicing Q Basic Electronics > C o Name iplciv: prim) Age _l in Address to CO O QxffSURUSp Acendtod Member National Home Sltidy Council 3QS0 29 Radio Shack Parts Place YOUR NEARBY SOURCE FOR HOBBY AND REPAIR ELECTRONICS over 7000 Locations in the usa— nobody compares! Try Our Special-Order "Hotline" jj i ICs, Crystals, Tubes, Lots More Your Radio Shack store manager can special- order a wide variety of parts and accessories from our warehouse — vacuum tubes, ICs, mi- croprocessors, phono cartridges and styli, crystals, even SAMS Photofacts* manuals. There are no handling charges or minimum order requirements — just fast delivery to our store near you. Plug-in Board Resistor Buys (1) 72- Position Board. Great lor a variety of projects. Popular .100" contact centers. 4lfoc5"/l«? #276-192 4.99 (2) Socket tor Above. #276-1452 . 4.58 m (2) (3) (1) Thermistor. *271 -110 . 1.99 (2) 0.1W Trimmers. Ik, #271-280: 4.7k. #271-281; 10k, #271-282: 47k. #271-283: 100k, K271-284 Each 490 (3) Color-Code Decoder. •(271-1210. 69 e Car connectors Tran and Choke (1) Solderless Motorola-Type Plug, fits car radios and many scanners. #274-709 (2) Solderless Jack. #274-710 (3) Lighter Outlet DC Plug. #274-335 (1) Power Transformer. 120VAC primary Secondary is 18VAC. 2.0 amps, center- lapped. 2*1 X 2V< X 2: #273-1515 (2) 0.1 mH RF Choke. #273-102 Prewired Temperature Module Just Add Battery You can use it "as-is" for a thermom- eter. Or, add switches to select F or C display and simple circuits to control a buzzer. LED, fan or heater at preset temperatures. Automatic attic ex- haust fan controller is just one possi- ble application, 'fa" digits. Range: -40 to +120° F E'Vi6x13fax1VB:' Requires "AA" battery. Low current drain. With complete data. #277-123 Battery special-Order service Hundreds of Types Available Now In addition to our large in-store stock, Radio Shack can now supply almost any currently manufactured battery— even special communications bat- teries for walkie-talkies and pagers. Batteries are sent from our main warehouse to the Radio Shack near you. Never a postage charge! Hookup Tools Cooling Fan (2) (1) D-Sub Pin Crimper. Crimps #20. #24 and #28 pins. (276-1595 9.95 (2) IDC Tool. Ail aches IDC-type plugs to (lal cables, #276-1596 12.95 Project Box 95 18 Quiet and Efficient Protect yggf equipment! This 4" Ian oper- ates an 12DVAC and provides about 65 cu- bic ?eei per minute airflow U's easy to mount and ;ated 11 watts. #273-241 security Switches Transmitter Case. Ideal lor an RF or infra- red control, beeper or portable device. Du- rable molded case has a removable end panel and compartment for 9V battery. 3*x2^BXtr #270-293 (1) UL Listed (3) (2) I 0) Normally Closed. #49-513 ...... 1,29 {2) Tamper Switch. For alarm panel or si- ren. Normally open, #49-526 1.59 (3) Panic Switch. NO. #49-517 . . M9 Connectors for Test Equipment (1) Solderless Male BMC. For RG 58 ca- ble. #278-1B5 3,59 (2) 90- BNC Adapter. #276-116 . . 3.99 ( 3 ) Stackab le Ban ana Plugs. B u i 1 1 - in jack for "chain" hookups. Solder type. One red, one black. #274-734 Set ol Z/1.59 (4) Flei Banana Plugs. #274-730. Set 91 2/1.69 IS) 'Gator Adapters. * 270-354 .... PilrJ1.B9 (6) Mini-Hook Adapters. Fil lest probe lips. #270-334 Pair/2,59 (7) Micro Flat Test Clips, 1 red, 1 black. J270-336 Set of 2/1,19 Crimp D-Sub connectors o z o IT r- o UJ o D < rr 30 Gold-Plated Contacts Pos Type Cal. No. Each Pos Type Cat. No. Each 9 Male Female 275-1427 276-1428 ,99 1.19 25 25 Male Female 276-1429 276-1430 2.49 299 Autoranging Probe dvm 39 95 Great for Tight Spaces Data-hold button freezes display and lets you re- move tester for easy reading. Has continuity sounder, low-battery indicator and overload pro- tection. Measures to 400 volts AC/DC and resist- ance. Includes batteries, manual, case. #22-165 4-in-i Soldering Tool Provides up to 60 minutes of operation and refills with butane lighter tual #64-2161 29.95 2,4 mm Replacement Ttp. *64-2162 9.95 1.0 mm Replacement Tip. 064-2163 9.95 Slow Torch Tip, #64-2166. Heat Blower Tip, #64-2169, and Hoi Knife Tip, *64-2i70 are available on special CMC order Each 9.95 Over 1000 items in stock! Binding Posts, Books, Breadboards, Buzzers, Capacitors, Chokes, Clips, Coax, Connectors, Fuses. Hardware, ICs, Jacks, Knobs, Lamps, Multitesters, PC Boards, Plugs, Rectifiers, Resistors, Switches, Tools, Transformers, Transistors, Wire, Zeners, More! Prices apply at participating Radio Shack stores and dealers. Radio Shack is a division of Tandy Corporation. M Radio /hack Americas technology CIRCLE 73 ON FREE INFORMATION CARD ision — probably the ultimate r computer enhancement. What's the big deal? Once an Im- age is digitized, applications are limited only by the imagination. Such as? How about electronic photography, automatic inspec- tion, security systems, pattern recognition, image processing/ enhancement, desktop publish- ing — to name just a few. Yeslerday, adding vision to a PC was expensive; today it's not. These clays you can add a capable vision system to any standard PC for well under S150, depending on the stale of your junk box. Our frame grabber is a hah- length card thai plugs into any 8- or 16-bit expansion slot. The card accepts standard NTSC black- and-white or color video input, and digitizes it at a resolution h watt R19, R20 SlOOohms Capacitors ^^^hm^^^^^^b Cl, C2 150 pF C3, CS 0.22 |i.E metal Mm C4.CS 0.1 jjlK metaijilm C7 68pF. disk CIO O.liii: disk C6. C9, Cll I pj-' C12-C22 0,01 jiF.disk C23 22 pF Semiconductors ^^mh^^h^^m ICl, IC4 LF353N dual bi- FET op-amp IC2 LM1881N video syne separator TC3 LF398NFET sample/hold amplifier ICS 741^04 hex Invener 1C6 74LS00qaad two-input NAND gate IC7, IC19 74LS74 dual-D Jlipjlop (National Semiconductor) ICS 74HC74 dual-D Jlip-Jlop IC9-IC12 74LS193 synchronous up/down binary counter IC13 MP7682JN 6-bit Jlash A/D converter IC14, IC15 43256-J5 32K x 8 static RAM. 150 ns IC16 74LS244 trt-slate octal buffer IC17 74HC688 8-bit magnitude comparator IC1S .74HC4075 triple three-input OR gate Dl, D2 ,.... AN4148 switching diode D3 1N5226B. 3.3-vott Zcner diode Other components hib^hh Jl PC-mount RCA video connector JU1, JU2 not used JU3-JU8 single-row 2-pin header XTAL1 20-MHv. crystal VIDEO SOURCE -;> input VIDEO AMPLIFIER \ ^£ ODD/EVEN FRAME V SYNC SEPARATOR 20-MHr GATED OSCILLATOR DIVIDE BY A \ Mi HORIZONTAL SYNC BURST GATE BLACK LEVEL REFERENCE I/O PORT SELECT I/O ADDRESS BUS PC BUS ;> £_ PIXEL CLOCK CONTROL \ * FLASH 6-BIT A/D CONVERTER A ADDRESS DECODE "\ CARD SELECT CONTROL BUS \> COMMAND LATCH DATA BUS Fig. 1. BLOCK DIAGRAM. Thejrame grabber consists of a video circuit, a clock/counter circuit, a bus interface. theAJD converter, and 64K of static RAM. clock signal (via pin 6 of IC6) also to stop. The circuit remains dis- drives the pixel counters abled until the black-level refer- (IC9-IC12) when the second bit ence signal (at the start of the (pin 9 of IC19) of the command next horizontal scan line) goes latch is high. low and then high, which clocks At this point, the A/D convert- a high into nip-flop IC8-b, and er's output is enabled and the thereby allows the gated os- outputs of the capture memories dilator to resume, are disabled, thereby giving the The output of the pixel counter D/A converter control of the local is differentiated by the network data bus. When a high from the consisting of D2, C8, and R17. pixel clock is presented to the A/D converter, a conversion is com- ^^^^^^^^^^^^^^^^^^^^ pleted. Then, when the pixel clock goes low. the data is trans- The following are available from ferred to the output buffers of the IDEC, Inc. A/D and presented to the capture P.O. Box 69 memories. When the pixel clock Fountainville, PA 18923 again goes high, the rising edge (215) 249-0673 of that signal Strobes the data on Assembled and tested board, software, the local" bus into the capture and User ' s Manual with one-year war- memories, and simultaneously ram y • — ■ • • si99 starts another conversion Complete kit including PC board, all siarts anoLner conversion. s software, and User's Manual That cycle proceeds until 256 $140 samples have been taken. Then Partial kit including PC board. IC2, IC6. the output of the second pixel !C7. ice. IC13. ICW. ji, XTAbi. D3. counter (pin 13 of IC10) goes low. brackets, screws, jumpers, software. and that signal resets IC8-b. and User ' s Manual $75 which causes the gated oscillator Otherwise a continuous low would be presented to the reset input of IC8-b, thus causing con- tinuous reset and system lockup after one video line had been cap- tured. The diode prevents the voltage at pin 10 of IC8 from ex- ceeding V cc + 0.7. The IC spec- ified for IC8 is a 74HC74, which can take a voltage exceeding V cc by 1.5 volts, as opposed to a 74LS74, which can only take V cc + 0.5 volts. When the next black-level refer- ence pulse is encountered, the line-capture cycle is repeated. The cycle repeats until 256 lines have been captured, at which point the output of the second line counter (pin 13 of 1C12) goes low. That action resets the enable- capture flip-flop (IC8-a) as well as the command latch (IC19-a, lC19-b). The software can read the contents of the command latch, so that reset provides a convenient means of signalling end-of-capture. > c a c CO so to o 33 RADIO-ELECTRONICS Fig. 2. COMPLETE SCHEMATIC. The full circuit is shown here Read mode The next step is for the soft- ware to read the captured data into main memory. This is done by setting bit of the command latch low, which enables the cap- ture memories and disables the A/D converter. The counters are again reset by a write to base plus one, and the data read at the data port. Only the lower six bits of the data port are of interest, as the upper two bits reflect the con- tents of the command latch, and must be masked off by the soft- ware. The pixel counters are ad- vanced to the next pixel by strobing bit two of the command latch first low and then high. That sequence must be repeated until all pixels have been read into memory, from where they can be processed, saved to disk, etc. ^ T lcr ^ m.£?a ', c , 19 > -Tdft JJU8 M 1JU3 R21 W n'Jr-Tl 2EEE ^R30- ifei L CQMPQNEfct RIG£ w r y »- jj i' a r. ■ MM ■ i- *■' M ■ H >< 1 i illllililllUlUllitUI Fig. 3. PARTS LAYOUT. Mount all components as shown here. Note the connections/or C23. \ Construction Due to the high frequencies in- volved, we recommend that you build the frame grabber on a PC board. Patterns are shown in PC Service: if you make your own PC board, remember that you'll have to solder many lands on both sides of the PC board. As an alter- native, you may want to pur- chase a PC board from the source mentioned in the parts list. Kits and assembled versions are also available. Construction of the board is straightforward and should pres- ent no problems. Figure 3 shows where all parts are mounted. When mounting parts, observe the polarities of all diodes, ICs, and electrolytic capacitors. On the PC board, pads for C23 are shown just above IC7. Mount the capacitor instead between the pad above pin 1 and directly to pin 3 of IC7, as shown in Fig. 4. Doing so lets C23 provide a stable load for the crystal oscillator. Check all solder joints after mounting the components, and then remove all flux residue. Installation First install jumpers as follows: • JU3: If installed, the computer is the last device on the video ca- ble. Normally installed. • JU4/JU5: Set both jumpers the same way, installed for sources TABLE 1—1/0 PORT SETTINGS I/O Port JU6 JU7 Fig. 4. C23 MOUNTING. Connect one teg oj C23 to the pad directly above pin 1 of IC7. and the other leg directly to pin 3 of 1C7. with a strong video carrier, un in- stalled for normal sources. Nor- mally uninstalled. • JU6/JU7: Selects I/O port ad- dress according to Table 1. • JU8: Install to ground input cable shield. Normally installed. Then install the board in an empty 8- or 16-bit expansion slot. Copy the software to a subdirec- tory of your working disk and then run VSETUR The program asks you to specify your PC's vid- eo adapter and printer. Then you can run the main program, VGRAB. 03F0 Oft On 03E0 On Off 02FO Off Off 02E0 On On In bringing up the board for the first time, feed a good, clean RS-170 video signal to the card — not a signal from an inexpensive video modulator. If you have a problem, be sure that there is valid output from pin 1 of IC4, especially if you have to reset the computer to regain control. The signal there should resemble a standard video signal, with the end of the horizontal- sync pulse at ground and the white level at about 3.3 volts. The LM1881 is very sensitive to the value of R8 (680K). If solder with water-soluble flux is used, be sure that the area around this resistor is clean, as the flux is conductive and may alter the effective value of the resistor. Using VGRAB As shown in Fig, 5, the soft- ware has a friendly user interface with drop-down menus and sta- tus panels. The software is avail- c able on the RE-BBS (516) c 293-2283; download the file h called VGRAB. ARC. Going from 5 left to right, the first menu allows ° 35 Electronics Hobbyists . . . SELECT 5 BOOKS W $495 when you join the Electronics BqqkCljb 5 ■\2t7P 124.95 SMTP 1 18.95 n MUP (21.95 Counls as 1 PRACTICAL ANTENNA I<2J 1 Alport Infill . EI.fXTRu:,:' > n \u book 29S3P S17.95 2A3TP SlS.&S Mj,b 2613P $17.95 31 4S SI 9.95 For 25 years, your most complete source for electronics books. 3170 MI-95 Count* u 2 2925P 19.95 Battery- powered Two-]C Projects IIKiOrlK mSm,. \*,a Ml* P if X* 3219 527.95 Counts u 2 1B97P 514.95 3157 525.95 Count! u 2 3155 (17.95 2724P $16.95 STOT J26-95 3259 519,95 2S80P 514.95 TheHMlir \\ t JSJWWWW 1 ?j * ti •^ I^p _._ 1 3275 (22.95 32GQ 522.95 4290 (35.00 Counts bi 2 2941P 515.95 2972 (23-95 If card is missing, write to: Eleclronics Book Ciub, Blue Ridge Summit, PA 17294-0810. All books are hardcover unless number is followed by a "P lor paperback. (Publishers' Prices Shown) HOW THE CLUBS BIG SAVINGS: In addition to this introductory offer, you keep saving substantially with members' prices of up to 50% off the publishers' prices. BONUS BOOKS: Starting imme- diately, you will be eligible for our Bonus Book Plan, with savings of up to 80% off publishers' prices. SHOP-AT-HOME CONVENIENCE: Every 3-4 weeks, you will receive the Book Club News, describing the Main Selections and Alternates, as well as bonus offers and special sales, with scores of titles to choose from. AUTOMATIC ORDER: If you want the Main Selection, do nothing and it will be sent to you auto- matically. If you prefer another 36 the club that suits your needs . . . Electronics Engineers & Designers Take any 3 PROFESSIONAL BOOKS £° r |y $ 4 95 when you join the ELECTRONICS ENGINEERS & DESIGNERS BOOK CLUB ! WORK FOR YOU! selection, or no book at all, simply indicate your choice on the reply form provided. You will have at least 10 days to decide. As a member, you agree to purchase at least 3 books within the next 2 years and may resign at any time thereafter. Books purchased for professional purposes may be a tax-deductible expense. IRONCLAD NO-RISK GUARANTEE: If not satisfied with your books, return them within 10 days without obligation! EXCEPTIONAL QUALITY: Alt books are quality editions from the leading publishers and experts in both the electronics and engineer- ing fields, especially selected by our Editorial Board for timeliness and accuracy to members. 3199 $52.00 Count* as 2 9731 SES. 95 SB2S 549,95 9305 359.50 3375 329.95 3241 P 516.95 101 SOLDE8LESS BKEADEOARDIKG raojicrs 1 IN1X STRIA] Essentia! Omuls Rtjttmce Hade ituimi use 2985 S24.95 2962P $17.95 3203 144.50 Count! u 2 9319 $59.50 Count* » 2 332 1 524.95 9a 13 339.95 3429 529.95 3297 539.95 Counts as 2 9220 $46.25 Counts as 2 9246 $33.95 Counts ss 2 9245 545.95 Counts ii 2 II card is missing, write to: Electronics Engineers & Designers Book Club, Blue Ridge Summit, PA 17294-0860. All books are hardcover unless number is followed by a "P" for paperback. (Publishers' Prices Shown) > C Q c m H to O THESE SCREEN SHOTS HINT at the versatility of the VGRAB software. Clockwise from the top left, the same image is shown in; VGA mode with 64 shades of gray; EGA mode with 4 gray levels; CGA mode with 2 gray levels; a negative image; a line drawing; and a horizontally flipped image with a black.' white threshold condition applied. UMII FliflrTURABIIER o z O az 1- o < Grab the IMAGE ^^^^^■■j SUIG Card Installed : MO Inage Loaded ■ MO BRIGHTftESSf= 9 ♦5 Iaage Saved : NO Working Directory : DaTXvREvUIDG System Resolution : USA L Ualue: 9 Display Mode ! UGA 61 GRAY ! Printer Installed : HP LASERJET Picture Size : 3.25 x 2.fi& in \'r ICOHTRftST | -5 o +3 Left Margin : 1.63 in. 1" Top Margin : 1.63 in. Ualue: 9 ^w == - "~= - : - - Use the AKK0D REVS to CHftlffiE SELECTION, ENTER to SELECT, and ESC to EXIT. 5UPERMISIDH UJideo Frarae Grabber Copyright (c) 1989 imc, inc. version 2.21 Fig. 5. VGRAB SOFTWARE. The menu bar across the lop line provides access to the capture, file, image-manipulation, and print Junctions. you to capture the currently dis- [save, load, etc,}. The third menu played image from the board. The contains functions for manip- next menu contains file utilities ulating the image. You can re- verse it horizontally and ver- tically, turn it into a negative or line drawing, adjust contrast and brightness, change the display resolution, etc. (The box above shows some examples.) The last menu allows you to set print pa- rameters and print the image. Images are saved in the TIFF file format, which is just right for importing into desktop pub- lishers (Ventura, PageMaker}, and modern word processors (Word, WordStar, etc.) that sup- port the format. Idee has developed software that interacts with database pro- grams such as Ashton-Tates dBASE III. These programs allow dBASE III to capture, display, and print images from normal dBASE III record fields, allowing the construction and mainte- nance of image databases. Con- tact Idee at the address in the "Ordering Information" box for more information. R-E 40 DIGITAL PRESSURE GAUGE Now you can take pressure readings the modern way using our electronic pressure gauge. ANTHONY J. CARtSTI MOST OF US ARE FAMILIAR WITH AN ORD1- nary pressure gauge, such as that used for tires that measures pressure in pounds per square inch (psi). They are usually analog devices with an indica- tor bar or a moving needle whose movements depend on the specific pressure. However, with the advance of solid-state technology, it is possible to construct an accurate electronic pressure gauge with a resolution as low as 0.1 psi. Our digital pressure gauge operates from a 9-volt battery, so it is com- pletely portable. The circuit uses only 4 milliamperes, so battery life will be extremely long. A large two-digit LCD is used to display pressure read- ings, but we'll also show you how to build it with a 31/2-digit display. The full-scale range of the pressure gauge is determined by the selection of the pressure sensor; in this case we have used a 0-100 psi semiconductor sensor, manufactured by Sensym (1255 Reamwood Ave, Sunnyvale CA 94089). Other sensors are available in full-scale ranges of 1, 5, 15, 30, 100, and 150 psi. Using a 15-psi sensor, for example, would result in a display resolution of 0.1 psi with a two-digit readout. Pressure is measured by connecting a flexible hose between the sensor and source of pressure. If the project is to be used for differential pressure mea- surements, two hoses must be con- nected to the sensor and the device under test. Vacuum measurements re- quire only one hose connection. The circuit The sensor is a differential device, which allows two pressure connec- tions, and it measures the difference between the two. The sensor also per- mits vacuum measurements when one side of the sensor is exposed to the atmosphere and vacuum applied to the other. Pressure and vacuum mea- surements may be taken on any non- corrosive and non-toxic media such as air, dry gases, etc. The portable nature of the unit allows it to be used almost anywhere, such as for check- ing tire pressure or a compressed air tank. The heart of this project is a dif- ferential piezoresistive pressure sen- sor which is constructed using integrated-circuit technology. It con- sists of four resistors connected in a Wheatstone bridge configuration, which are deposited on a silicon di- aphragm that separates two chambers of the sensor housing. Each side of the diaphragm can be exposed to a pressure source by means of "ports" called PI and P2. Any pressure dif- ference between port P! and port P2 will be detected by the sensor, provid- ing a differential pressure reading. Figure 1 shows a cioseup of the sen- sor. The common pressure gauge which many people are familiar with is, in reality, a differential pressure gauge, with atmospheric pressure (14.7 psi) being the reference pressure. Thus, when no pressure is applied to the sensing port of the common gauge, the reading is zero. The same goes for our gauge; pressure is applied to P2 while PI is exposed to the atmo- sphere. When the pressure sensor is at rest, there is no stress on the silicon di- aphragm and the values of the re- sistors are essentially equal. The Wheatstone bridge is thus balanced and its output voltage is virtually zero. During a pressure measure- ment, any difference in pressure be- tween the two ports of the sensor result in mechanical stress of the sil- icon diaphragm and a change in the values of the four resistors. Two re- sistors increase in value and two dc- FIG. 1— HERE IS A CLOSEUP of the semi- -digit LCD (we've used only a two-digit display, DSP I). It is driven by the voltage be- tween pins 7 and 8 of op-amp ICL The sensitivity of the A/D converter is set by the reference voltage applied between pins 35 and 36. The refer- ence voltage, which is about 238 mil- livolts, is set by the divider composed of R2, R3, and R4. In this project only two digits are required since the resolution of the project is 1 psi and full scale is 100 psi. However, note that if you measure exactly 100 psi, the readout will dis- play 00, since the hundreds digit is not present. Note that for readings greater than 99 psi, or for 0.1 psi resolution, the circuit can modified to use the most significant and least significant digits of the A to D chip. In this case you'd need to use a 3'/2-digit readout, and its decimal place would be illuminated as required. If you wish to use a V/i- digit LCD, Fig. 3 shows the addi- tional connections to the A/D con- verter that are required. However, note that the 3!A-digit display is a 40-pin device that won't fit on the provided PC board . You must either hardwire it or design your own board. Because of the characteristics of the pressure sensor, the display will read up- scale regardless of which port of the sensor is pressurized. However, you should use the same port for which the project was calibrated. If the project is to be used for vacuum or differential pressure measurements, the display will indicate the pressure difference in psi, with no polarity in- dication. The A to D converter used in this circuit does have an output termi- nal to indicate polarity, but it is not used. Construction The project is constructed on a sin- gle-sided PC board. A foil pattern is provided in PC Service. The circuit can also be hard wired on a perforated construction board if you wish. The parts-placement diagram is shown in Fig. 4. Note that the LCD readout is mounted on the copper side of the 42 3V2-DIGST DISPLAY HALF DIGIT I 1 !——] I I a, b, c, d, e, t, g, a 2 b 2 c 2 d 2 e 2 f 2 g? a, b 3 c 3 d 3 e 3 f } 3 30 19 23 15 to BACKPLANE 21 IC2 ICL7106CPL FIG. 3— HERE ARE THE ADDITIONAL CONNECTIONS to the A/D converter that are required for a 3V2-digit display. Note that the 40-pin display won't fit on the PC board — you'll have to hardwire It or design your own board. PIN1 FIG. 4— PARTS-PLACEMENT DIAGRAM. Note that the LCD readout is mounted on the copper side of the board. board. That allows the relatively flat side of the PC board to be mounted next to the side of a suitable enclosure containing a cutout or window to ex- pose the readout for viewing. You should use sockets for both of the IC's. Especially for IC2, which is a 40-pin chip and not inexpensive. The cost of a socket is minor com- pared to the IC itself, and you can never predict when an IC will have to be removed from a PC board. Once the sockets are in place, continue in- stalling components, but do not insert the IC's yet. The 5-volt regulator, IC3, looks like a small transistor; simply solder it directly to the board, and be sure to watch its orientation. Also be sure that the diodes are properly oriented. The circuit requires four jumpers; the short jumper wire between pins 2 and 6 of the LCD can be a piece of bare wire, but the other three should be insulated to avoid shorts. Many of the resistors specified in the parts list are metal-film types which exhibit excellent temperature stability. Since we want the project's calibration to remain stable with vary- ing temperature, you should not sub- stitute other types of resistors. The LCD and the pressure sensor are fragile and must be handled care- fully to avoid breakage. It is sug- gested that the readout be mounted to the board last. You may wish to use a socket for the readout, and you can make one by taking an ordinary 18- pin DIP socket and cutting it in half lengthwise. Remember, the socket (and readout) will be placed on the copper side of the board, so you must allow some space between the plastic of the socket and the board itself to allow room for soldering. Before mounting the LCD, take note of where pin 1 is. If you look at Fig. 5, the black border around it has a marking on one side. Looking at that marking, pin I is where you'd nor- mally see it on any ordinary IC. The pressure sensor may be fas- tened to the board using two #4 ma- chine screws and nuts, but be very careful not to over-tighten them; it could result in a cracked plastic as- sembly. Note that one of the terminals PARTS LIST All resistors are Vi-watt, 5%, car- bon, unless otherwise indicated. R1 — 51 ohms R2, R4, R8-R10, R12— 100,000 ohms, 1% metal film R3, R15, R1 7— 10,000 ohms, 1% metal film R5— 100,000 ohms R6— 200,000 ohms, PC-mount po- tentiometer R7, R14 — 41,200 ohms, 1% metal film R11 — 1 megohm R13— 221 ohms, 1% metal film R16— -100,000 ohms, PC-mount po- tentiometer R1 8— 47,000 ohms Capacitors C1-C3, C5 — 0.1 u.F, ceramic disc C4 — 100 pF, ceramic disc C6 — 0.01 (j.F, ceramic disc C7 — 0.47 ixF, ceramic disc C8 — 0.22 u.F, ceramic disc Semiconductors IC1 — LM324N quad op-amp IC2— ICL7106CPL 3 1 /a-digit A/D con- verter (Intersil) IC3— AN78L05 5-volt regulator IC4 — differential semiconductor pressure sensor, SX01DN for 1 psi full scale SX05DN for 5 psi full scale SX15DN for 15 psi full scale SX30DN for 30 psi full scale SX100DN for 100 psi full scale SX150DN for 150 psi full scale (Sensym, 1255 Reamwood Ave, Sunnyvale CA 94089) D1-D4— 1N4148 silicon diode DSP1— two-digit LCD module (Di- giKey LCD001) Optional — 3'/2-digit module (Digikey LCD002) Other components S1— SPST toggle or slide switch, N.O. B1— 9-volt battery Miscellaneous: battery clip, en- closure, IC sockets, hose w/fitting, clamps, wire, solder, etc. Note: A PC board is available for $14.95 and a pressure sensor for S35.00 from A. Caristi. 69 White Pond Road, Waldwick, NJ 07463. Add $2.50 postage and handling per order. of the sensor is marked with a small dot. That is pin l , so be sure to mount it as shown in Fig. 4. The four termi- nals of the sensor are very fragile, and ; must be carefully bent into position < using a needle-nose pliers to support ! the leads next to the body of the part. ; If you attempt to bend the leads with- ! 18 17 16 15 14 13 12 11 10 nnnn.nnnnri uuuuuuuuu 123456789 FIG. 5— THE BLACK BORDER around the display has a marking on one side. Using the marking as a reference, pin 1 is where you'd normally see it on any ordinary IC. out such support, you risk breaking the wires. A suitable pressure hose must be connected to port P2 of the sensor, and secured with a small metal clamp that has been designed to handle high pressures. Such clamps can be ob- tained from automotive supply out- lets. It cannot be over-stressed that pressures greater than 10 psi are sub- stantia!, and the hose and clamp must be able to withstand such force. If you want to use the project to measure tire pressure, you need a hose from a bicycle shop with a fitting at the end that depresses the valve stem during a pressure measurement. You might be able to take an o!d tire pressure gauge and modify it for use with our digital pressure gauge. As with the pressure-sensor connection, you will need to clamp the valve fit- ting to the hose. \ou may wish to use a normally open pushbutton switch for your proj- ect. That will prevent accidentally leaving the power on and depleting the battery. Be sure to use a connector clip for the battery to ease replacement when necessary. The battery should be se- curely mounted in the project's en- closure so that it does not rattle around and break anything. When you have completed assem- bly, examine the circuit board very carefully for bad solder connections and inadvertent short circuits, es- pecially between adjacent IC termi- nals. Bad solder joints often arc dull, rough blobs of solder. Correct any problems that you find. Figure 6 shows both sides of the completed unit. Checkout To check out the project you will need a DC voltmeter, as well as a source of air pressure such as a porta- ble air tank. Be sure tank pressure is not over 100 psi. For the preliminary checkout it is not necessary to know the precise pressure of the source, but it should be in the range near the maximum measurement capability of the project. Before putting ICl and IC2 in their sockets, set the calibration potenti- ometers to mid-position. Connect a 9- volt battery, and turn on power. Measure the voltage across C2; you should obtain a reading between 4.8 and 5.2 volts DC. If you do not obtain the correct reading, do not proceed with the checkout until you trou- bleshoot the problem. Check IC3 for proper orientation. Check the termi- nal voltage of the battery to verify that it is delivering at least 7 volts. Discon- nect the battery and measure the resis- tance across C2 to verify that you do not have a short circuit between the 5- volt bus and ground. When you are satisfied that the 5- volt regulator is operating properly, disconnect the battery from the proj- ect and insert the IC's into their sock- ets. Be sure to follow the orientation as indicated in Fig. 4. Reconnect the battery to the project and turn the power switch on. No pressure is to be applied to the sensor at this time. The display should indi- cate a two digit reading, and adjust- ment of R16 should allow you to set the reading to 00. If you don't get any display, check that the LCD is properly mounted on the copper side of the board. Check IC2 to be sure that it is properly ori- ented in its socket. Check the 5- volt regulator to verify that power is being applied the circuit. If your meter is capable of measuring DC current, you can check the current draw from the battery to determine if it is approxi- mately 4 milliamperes, which is the normal current draw of the project. If you obtain a display but the il- luminated segments of the digits are not entirely correct, the most likely cause is open or short circuits at the output connections of IC2 which drive the readout. Disconnect IC2 and the battery from the project and locate the fault using an ohmmeter. Note that the display may, on occa- sion, indicate 01 instead of 00. This is not to be construed as a defect in the circuit; it merely means that your zero adjustment is not centered exactly. When you are satisfied that the zero adjustment of the display is correct, you may apply full pressure to the P2 port of the sensor. When that is done, the readout will indicate some number. Adjust R6 for a display equal to the pressure of the source, if known. continued on page 83 WD CONVERTER t/3 o z O cc r- O ul _i UJ 6 2-D1GIT DISPLAY § FIG. 6— HERE ARE BOTH SIDES of the completed unit, notice how the display goes on the en foil side. 44 LAST MONTH WE DIDN'T GET A CHANCE TO FINISH THE MOTHERBOARD and the motor-controller board. So let's finish up those two boards now, and then continue with the story. Construction Assemble the motherboard by soldering the three edge connectors onto the PC board with the connector pins protruding through the circuit side of the PC board. The schematic is shown in Fig. I. The circuit side of the board contains the large ground plane. Figure 2 shows the parts-placement diagram for the motor-controller board. First, solder the IC sockets to the PC board (one can be obtained from TSI or you can make one from the foil pattern provided in PC Service). Next, solder in all remaining components except for the following com- ponents that require special installation: R71, R76, R85, R88, R93. C6, C17, C46.C48-C5I, D20, and D22, Capacitors C6, CI7, and C46 are tall and have radial leads (both This month we discuss the motor-controller board. leads stick out of the bottom). In order to keep the height of the motor-controller board at a min- imum, we need to mount those capacitors on their side. That can be accomplished by adding !s-inch of insulating plastic sleeving to each of the leads before the capacitor is in- stalled. Then solder, trim leads, and bend the capacitor over on its side. A small drop of RTV or epoxy can be added to secure the capacitors to the PC hoard. Diodes D20 and D22 mast be sol- dered in series, and then installed as a single component in the location indicat- ed in Fig, 2. Resistors R93 and Rl consists of two 16-ohin, '/j-watt resistors connected in parallel. The resistors arc then installed as a single component as indicated in Fit;. 10. Re- sistors R71. R76, R85, and R88 should have 0. 1 p.F capacitors soldered in parallel with them before installa- tion. The capacitors are identified in Fig. 2 as C48, C49 C50. C51, respectively. There arc some jumpers that must be installed on the solder si the board. The First one goes from J22 pin 41 to EC! pin 4. Another from J22 pin 47 to IC2 pin ft. Next, two twisted pairs of junipers. eaeh"|SS consisting of a length red and black wire twisted together, must also be installed on the solder side of the board. 'Hie red wire of the first pair must go from J22 42 to R8 1 . and the black wire goes from J22 pin 45 to R82, The red wire from the second twisted pair goes from .122 pin 3tt to R63, and the black wire noes from J 22 pin 39 to R64. ' Alignment Alignment of the motor-controller hoard consists of adjusting potentiometers R20CR2(>2, and R203. R20! and R202 are used to adjust the Speed of the left and right drive motors, respectively, and R203 adjusts the offset voltage to the D/ A circuit. First adjust R201 and R202 to their center position. R203 should be adjusted until the D/A output (pin 7 of [C-4-bj is t) volts when the D'A input is as follows: DAO = 0. DA I = I , DA2 - 1 . DA 3 = 1 , DA4 f 1 . and DA5 = 0. The D/A input can be set by temporarily apply i ng + 5 volts for a " I" and ground for a "0" when the Build the Lawn IZanger w o z O IT H O LU Q Q < P21 POWER BOARD P22 MOTOR CONTROLLER BOARD P23 DIGITAL BOARD I 2 3 4 5 a 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 l 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 IS 19 20 21 LF0R2 1 2 3 4 5 6 7 B 9 10 11 12 13 14 15 16 17 18 19 20 _2J_ START/STOP PROG eoi BD1 BD2 BD2 BD3 BD3 BD4 B04 BD5 BD5 BDB BD6 BD7 BD7 BOS BD8 BD9 BD9 BO10 ECHO BD11 BD11 BD12 BD12 BD13 BD13 BD14 BD14 BD15 BD15 SiiJI 1 L TACH + 10V + 10V STOP + 5V *-5V + 5V + 5V i 5V + 5V DAO DAO 22 23 24 25 26 27 23 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 43 49 50 DAI 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 DAI GND GND GND GND GND GND L. FOR L FOR L REV L, REV DAS R. FOR R. FOR DAS R. REV R, REV DA10 FULL STOP DA2 DA2 -10V -10V DA5 + 40V DA3 DA3 J- 24V ' 24V DA4 FULL STOP L. REV 2 +10V L FOR 2 GATE PULSE GATE PULSE L. REV 2 L TURN R. FOR 2 START START R. REV 2 MON SIG FULL STOP LC i LC4 DA11 LC- LC- CUT SIGNAL CUT SIGNAL STOP MOVE STOP MOVE POWER ON/OFF L. TACH POWER ON/OFF RC + RC + KILL RC- R. FOR 2 MON SIG POWER START R. REV 2 POWER START RC- + 40V L TURN DA4 DA5 FIG. 1— ALL OF THE INTER-BOARD CONNECTIONS are made via the motherboard. PC board is disconnected from the motherboard. The same D/A inputs couid be established by temporarily blocking (with electrical tape) grass sensors 1-8 after the Lawn Ranger is completely assembled. Motor controller test The best way to test the motor-con- troller board is after the Lawn Ranger is completely assembled. By block- ing grass sensors with your fingers or electrical tape, you can "simulate a grass border that the Lawn Ranger can track. As you block different grass sensors, you can verify that the motor controller is working properly by observing the drive wheels as they change speed and direction. However, that will have to wait until next month, when we will discuss the construction and operation of the power board. We'll also discuss the manual controller and mechanical frame. Start building your own Lawn Ranger now so you can have fun learning valuable electronic skills and, at the same time, produce a per- sonal robot that can perform useful work while amazing your friends Power board The power board is responsible for providing regulated DC voltages, controlling the power on/off function, switching -r-24-volts DC to the motors (ibr forward and reverse rota- tion), and stopping the cutting motors after power is turned off. Figure 3 shows a photograph of an assembled power board. Figure 4 shows the biock diagram of the power board. The + 24- volt DC input power is supplied by two I2-volt lead-acid batteries that are connected in series. The batteries are rechargea- ble and can be purchased from sup- pliers of electric wheel chair batteries for about $35-$45 a piece. Three DC/DC converters are used to efficiently convert the + 24-volt in- put to ±10-, +5-, and +30-volts DC. The DC/ DC converters can be purchased from Power General di- rectly (see parts list). The left and right motor power drive circuits energize the drive motors. The circuitry contains a se- ries of power MOSFET's that act as low-resistance (0.035 ohm) switches. The MOSFET switches can turn the motors on and off, as well as apply a reverse voltage to make the drive wheels spin in reverse. The cutting-motor drive circuitry controls the rate at which the cutting disks spin when they are initially turned on. The amount of ctirrent that is sent to the cutting motors is monitored and limited to 15 amps (peak) or approximately 10 amps (average). The circuitry is also used to quickly stop the cutting motors when power is turned off by shorting the motor leads together. That technique is typically referred to as dynamic braking. The shorting of the motor leads causes a reverse magnetic field to be generated inside the motors causing the cutting blades to stop within 3 seconds. A 0.01-ohm re- sistor (R32) is used to limit the motor current to a safe level during dynamic braking. Circuit description Figure 5 shows a detailed sche- matic of the power board. The + 24- volt battery power is routed through Jll pins 4 and 5 and fuse Fl, Relay RY1 is used to connect and disconnect power from the entire robot. Power is switched on by the operator when the ignition key is turned. The momen- tary ignition switch grounds J21 pin 46 j>Oxr_ iiriyCx^x^'^'j.j FIG. 2— PARTS-PLACEMENT DIAGRAM for the motor-controller board. FIG. 3— AN ASSEMBLED POWER BOARD should look similar to this one. 44 and energizes the relay. When the relay switches, the three DC/DC con- verters will begin to produce the ap- propriate voltages and the CPU board will come alive. The CPU board will begin to run diagnostic checks and then place + 5 volts on J21 pin 41 in order to turn Qll on; that keeps the relay energized after the operator re- moves the key. Forward/reverse motor drive Transistors Q3-Q6 and Q7-Q10 are power MOSFET's that are used to control the left and right drive motors, respectively. When the left drive motor spins in the forward direction, Q3 and Q5 are turned on and Q4 and Q6 are turned off. Figure 6-a shows the path that current follows when the left drive motor is going forward. On the other hand, if Q3 and Q5 are turned off and Q4 and Q6 are turned on, the current will flow through the motor in the opposite direction caus- ing the motor to spin in reverse (see Fig. 6-b). Cutting-motor control The cutting motor circuitry con- tains power MOSFET's (Q13 and Q14) for switching, as well as a feed- back control system for current limit- ing. Current limiting allows the cutting motors to come up to speed in a controlled manner by limiting large current spikes when the cut button is pushed. The MOSFET's are con- > c Q C CO 47 J11-4 7 12V BATTERY 12V BATTERY #2 FRONT PANEL CONTROLS STOP RUN • • • CUT POWER | relayI^-cld-*- J11-5 jn-3 J11-8 + 24 DC/DC CONVERTERS (3) HGND + 5V + 10V -10V + 30V RIGHT MOTOR POWER DRIVE LEFT MOTOR POWER DRIVE CUTTING MOTOR DRIVE SWITCH CONTROL RIGHT MOTOR BLACK LEFT MOTOR GLACK FIG. 4— HERE IS A BLOCK DIAGRAM of the power board. PARTS LIST- POWER BOARD All resistors are Vis-watt, 5%, un- D1, D2, D11-D13, D30. D31— not less otherwise indicated. used D3, D4, D16, D17, D20-D24, R1-R10, R13-R15, R17, R18, D33-D38— 1N4001 diode R20-R28, R45-R49— not used D5, D14, D18, D19, D32— 1N4148 R11, R44. R50— 3300 ohms diode R12— 680,000 ohms. 6-pin, Vj-watf, D6, D1 5—1 N5402 diode SIP resistor network D7-D10— 1N5256B 30-volt Zener R16, R19, R32, R43— 0.01 ohm, diode 5 watts D25-D29— 1N4740 10- volt Zener R29— 150,000 ohms diode R30, R31, R34, R35— 270,000 ohms Q1.Q2, Q12— not used R33, R36— 1 megohm Q3-Q10, Q13, Q14— IRFZ42 R37— 147,000 ohms. Vi-watt. 1% MOSFET R33— 10,000 ohms, potentiometer Q11, Q15, Q1 6— 293904 NPN R39— 82,000 ohms transistor R40— 100,000 ohms R41— 27,000 ohms Other components R42— 22,000 ohms J11 — terminal strip R51-R54— 560,000 ohms RY1— T90N1D12-24 relay (Potter Brumfield) Capacitors RY2— 68P-111P-US-DC24 relay C1-C5, C7-C13, C16, C17— not (Omran) used F1— 3AG 30-amp fast-blow fuse C6— 1000 ixR 35 volts, axial F2— 2AG 0.5-amp fast-blow fuse electrolytic MOD1— Model DC2- 2-24/1 2, ± 12- CI 4, C15, C23-C26— 0.1 p.F, 50 volts volt DC converter {Power General) C18, C21— 100 ji.F, 50 volts, radial MOD2— Model DC2-2-24/15, ± 15- electrolytic volt DC converter (Power General) C19, C20— 100 m-F, 16 volts, radial MOD1— Model 710, 5-volt DC con- o electrolytic verter (Power Genera!) C22— 220 p.R 16 volts, radial DC electrolytic Miscellaneous: 3AG fuse holder. O 2AG fuse holder, solder posts for _l Semiconductors the "E" terminals, 18-gauge solid n IC1, (C2— not used insulated wire, 18-gauge stranded 5 < rr IC3— LF412N op amp insulated wire, solder, etc. PARTS LIST— CONTROL PANEL S1— S4 — momentary pushbutton switch S5— SPOT switch LED1 — red light-emitting diode Wire and sheet metal for the panel itself Note: The following equipment can be purchased from Tech- nical Solutions, Inc., P.O. Box 284, Damascus, MD 20872 (301-253-4933): etched and drilled PC boards for CPU Board, Motor Controller Board, Power Board, and Motherboard, $39 each; programmed EPROM, S39; grass sensors, $8,99 each; hand-held manual controller kit, $39; full kit for CPU Board, $129 (PC board, EPROM, all parts); full kit for Motor Controller Board, $169 (PC board and all parts); full kit for Motherboard, $69 (PC board and all parts); Power Board kit (PC board, and all parts except DC/DC convert- ers), $149; Detailed drawing package, $59; Lawn Ranger demo videotape and information package, $19; complete elec- tronic kit with everything men- tioned above, $757. Please add $8.00 for S/H. Maryland resi- dents add sales tax. nected in parallel in order to share the switching load. They are turned on by pull-up resistor R42 and turned off by Ql6. After the MOSFET's are turned on, the +24-volt power supply will be routed to through R32 to pin 5 of relay RY2. As the operator presses the cut button, +5 volts will be applied to J2J pin 41 and Q15 will turn on; that grounds pin 4 of RY2 causing it to switch the + 24- volt battery power to the cutting motors. The cutting motors will begin to spin, and as they begin to, the current through resistor R32 will rise sharply; R32 is used as a current monitor and the voltage across it will rise in proportion to the current flow. Differential amplifier IC3-a ampli- fies the voltage drop across R32 and feeds it to pin 5 of IC3-b, which is a comparator circuit that compares the current flow with a preset value of 15 amps. When the current through R32 reaches 15 amps, the comparator out- put (JC3-b pin 7) will swing positive and Q16 will turn on. The power MOSFET's will turn off and the cur- rent will stop flowing through the cut- 48 FIG. 5— DETAILED SCHEMATIC of the power board. High-current jumpers have to be installed on the solder side of this board. S 066i±snonv CO o z o en i- o LU _l LU 6 Q < LEFT /^\\ DRIVE ( J ) FORWARD MOTOR v Q5 ft V I Q4 D^S -&*i-o^ r_^Tj + 24V POWER fTTTT FIG. 6— LOOKING AT a, YOU CAN SEE the path that current follows when the left drive motor is going forward. However, in order for the motor to spin in reverse, b shows the path that the current must take. FIG. 7— THE HAND-HELD CONTROLLER allows you to "walk" the mower around the yard to cut a perimeter for it to follow. J4 MAN 12 STOP < < < <: <: <: 4 10 f-EMALE MALE DB 25 OB 25 J12 9 P011 MANUAL 8 DRIVE 12 JO P0T2 1t MAN 7 START AUTO 2 DRIVE 15 GND 6 MON 13 + 10V 6 MAN REV -10V 14 1! FASTI 3 10 12 15 13 14 ELECTRONIC CONTROL FRONT PANEL R1 240K J * J VvV-f R3 10K SI I— Q O— t I J R2 56K S3 REVERSE ci ; 47nF S2 nr FIG. 8— HERE'S THE SCHEMATIC DIAGRAM of the hand-held controller. BUMPER SWITCH FIG. 9— THE ELECTRONIC CONTROL PANEL must be wired as shown. PARTS LIST HAND CONTROLLER R1— 240,000-ohm resistor R2— 56,000-ohm resistor R3 — 10,000-ohm potentiometer C1 — 47 wF electrolytic S1— SPDT switch S2— DPDT slide switch S3 — momentary pushbutton switch Male and female DB-25 connectors, ribbon cable, suitable enclosure ting motors and R32. That causes the comparator output to swing negative and the MOSFETs wiii again turn on causing the current to be applied to the cutting motors. The process is re- peated until the cutting motors have reached their maximum velocity. Be- cause the MOSFET's are turning on and off, instead of supplying full power all at once, the cutting motors will slowly come up to speed in a well-controlled manner. {Continued on page 80) 50 Hi® po^sr wmmmmm Learn the principles of measuring power. HARRY L. TRIETLEY AC POWER MEASUREMENT: YOU PROBABLY don't think about it very much. Most engineers and technicians normally don't even give it a second thought. Nonetheless, it's an extremely impor- tant and pervasive area of electronics, used in a wide variety of fields, in- clude determining RF transmitter power and field strength, radar, motor and generator testing, sonar, stereo, and acoustics, and one area that af- fects all our daily lives, commercial AC power distribution. We're all billed using a kilowatt- hour (kWh) meter, and obviously want it to be accurate. Utilities need to measure true usage, because it affects generator loading and fuel consump- tion. Consumers likewise need to control operating efficiency, peak load usage, and billing. With rising fuel costs and the need for con- servation, the subject has become in- creasingly relevant. AC power isn't always easy to measure, because it's affected by such factors as phase shift and waveform distortion. This article discusses techniques of measuring AC power, using some special IC's designed for this purpose. True power and RMS voltage Let's review DC power; the power law, P=ExI, and Ohm's law, E = I xR, produce the 12 equations in Fig. I. They're for DC only, and omit capacitive and inductive reactances. They're valid for AC if the load is FIG. 1— OHM'S LAW AND THE POWER EQUATION combine to form 12 basic equations for resistive circuits. purely resistive (causing no phase shift), and if E and I are true Root Mean .Square (RMS) values. RMS means the square root of the average of the squares of a series of voltages or currents. The RMS concept is neces- sary, because the time-average value of a sinusoidal voltage or current with no DC component is zero. Let's see why, and how this relates to power. Figure 2-a shows a sinusoidal volt- age sampled 16 times, applied across Rl in Fig. 2-b. As each sample varies, the dissipated power is P(t) = e 2 (t)/ Rl . To find the approximate RMS co- efficient for time-average power, the power is found for each sample, and the average of the values is deter- mined. Increasing the number of in- tervals increases resolution, and improves accuracy. Table I shows the calculations; the average sampled instantaneous power is 0.503 x V2 pK /R| (0.709 XV PK )2/R1. The letters A-P in Fig. 2 correspond to the same let- ters in parentheses in the left-hand column of Table I . The RMS value for > c a c 00 CO '■£• O 53 o z o I 6 Q < output, and 5% inputs produce 0.25% output, and so on. Thus, this method isn't suited to voltages varying over a wide range, or waveforms with high crest factors. Implicit computation Implicit computation as shown in Fig. 8 may seem less direct than ex- plicit computation, but it's simpler. There's no square-root needed, and this approach has better dynamic range than is the case in direct RMS computation. Here, A and B in the multiplier/divider are V A , and C is V OUT . Thus Vl = (V [N )2/V OUT . This voltage is filtered (averaged) to be- come the outrrut, so V GUT =Avg[(V 1N )2/V OUT ], or 'OUT = VAvg[ c Q C CO O 59 INTRODUCTION TO JCROWAVE TECHNOLOGY [■[KSTINASt.kIl.S01 ARTICl dealing with microwave electronics. The word microwave stems from " micro, V meaning very small, and "wave," for electromagnetic oscilla- tions; thus, microwaves are very short- wavelength electromagnetic os- cillations. The electro magnetic spec- trum shown in Hg. 1. is broken into such bands lor purposes of both con- venience and identification. Rigorously defined, the microwave region begins above 300 MHz, oc- cupying an upper part of the UHF (300 MHz-3 GHz) band, ail of the SHFband (3 GHz-30GHz), all of the EHF band (30 GHz-300 GHz), and a lower pail of the infrared OR) region. However, there's considerable overlap in physical properties between! the UHF and microwave regions. The Get to know basic microwave terminology and technology. JOSEPH J. CARR !> UHF region is nominally from 300 MHz-3 GHz, hut above about 900 MHz or 1 (ill/., UHF and microwave propagation and scattering are very similar. The definition of exactly where the microwave region begins is further complicated a great deal by bodi his- torical precedent, and depends on both the application and the user. For example, the original military defini- tion of the microwave bands for radar and communication systems (circa World War II), used letter designa- tions to define them, as shown in Ta- ble I. Those definitions used the letters P. L, S. C, X, K. Q, V, and W, in dial order, and were originally defined for security and technical reasons. There was no sensible partitioning of the actual frequencies involved. Whatever rationale was orig- inally used to select these bands and labels, both arc really of historical interest only. For that reason, the Wept. Of Defense (DOD) issued updated hand designations on May 24, 1970, as shown in Table 2, that used a some- what less chaotic approach. The band labels went in strict alphabetical order, from A-M. although there were still considerable jumps in the actual frequencies assigned to each. Thus, almost the same entire frequency re- gion is considered microwave, al- though the new scheme reduces the lower bound by 125 MHz. As if this weren't ambiguous enough, the /nstitute of Electrical and Electronics Engineers illTFi. the major U.S. and international elec- trical engineering society, has its own designation scheme, as shown in Ta- ble 3, now almost universally accept- ed, although older designations still persist out of habit. 'Hie IEEE desig- nations use a combination of some of the original World War II band desig- nations, and then add their own letter- ing. They maintain the HF, VHF, and UHF designations, but above that, use the designations L, S, C, X, Ku, K, Ka, Millimeter, and Sub- millimeter. For purposes of this series, the high end of the UHF region will be consid- ered part of the microwave region, since there's no sharp transition in properties from the shortest non-mi- crowave UHF wavelengths to the lon- gest microwave wavelengths. Also, certain applications usually consid- ered strictly in the microwave region sometimes also use UHF (such as long-range radar). For present pur- poses, our definition includes all fre- quencies above 500 MHz but below the IR region. No doubt you're wondering how microwaves differ sufficiently from other frequency ranges of electromag- netic waves to warrant a separate se- ries of articles. Microwave wave- lengths approximate the physical size of ordinary electronic components, so components tend to behave dif- ferently when this is the case. At mi- crowave frequencies, a half-watt metal film resistor is a complex RLC network with distributed inductance and capacitance, and a much different resistance. Certain characteristics ir- relevant at lower frequencies become significant in the microwave region. Components and conductors act in- creasingly like transmission lines, with reflection, transmission, and cross-talk becoming critical to circuit function. Microwave history Microwave technology was rela- tively undeveloped until World War II, when huge investments in research and development led to rapid develop- ments in radar and other electronics technologies used in the war. Vacuum tubes of the 1920's and I930's wouldn't work at the UHF or micro- wave frequency ranges. The main problems were interelectrode capaci- tance and electron transit time from cathode to anode. Attempts to reduce electrode size and spacing caused other problems that proved unaccep- table in practical circuits. Interelectrode capacitance was re- duced using clever geometries and closer interelectrode spacing (also a factor in transit time). By World War II, operation at 200 MHz was possi- TABLE 1— OLD U.S. MILITARY MICROWAVE FREQUENCY BANDS BAND DESIGNATION FREQUENCY RANGE P 225 MHz-390 MHz L 390 MHz-1 .55 GHz s 1.55 GHz-3.9GHz c 3.9 GHz-6.2 GHz x 6.2GHz-10.9GHz K 10.9 GHz-36 GHz Q 36 GHz-46 GHz v 46 GHz-56 GHz w 56 GHz-100 GHz TABLE 2— NEW U.S. MILITARY MICROWAVE FREQUENCY BANDS BAND DESIGNATION FREQUENCY RANGE A 100 MHz-250 MHz 250 MHz-500 MHz 500 MHz-1 GHz c D 1 GHz-2 GHz E 2 GHz-3 GHz F 3 GHz-4 GHz G 4 GHz-6 GHz H I 6 GHz-8 GHz 8 GHz-10 GHz J 10GHz-20 GHz K 20 GHz^tO GHz L 40 GHz-60 GHz M 60 GHz-100 GHz TABLE 3— IEEE/JNDUSTRY STANDARD MICROWAVE FREQUENCY BANDS BAND DESIGNATION FREQUENCY RANGE HF 3 MHz-30 MHz VHF 30 MHz-300 MHz UHF 300 MHz-1 GHz L 1 GHz-2 GHz S 2 GHz-4 GHz C 4 GHz-8 GHz X 8GHz-12GHz Ku 12GHz-18GHz K 18 GHz-27 GHz Ka 27 GHz-10 GHz Millimeter 40 GHz-300 GHz Submillimeter >300 GHz ble, 500-800 MHz was achieved by the end of the war, and 800 MHz by the early 1950*s. In 1920, Barkhausen and Kurz of Germany achieved os- cillation at 700 MHz by manipulating electron transit time. Although the Barkhausen-Kurz Oscillator achieved UHF/microwave oscillations, it was inefficient. Overheating was also a problem, because the grid glowed white hot at high power. One solution in 1921 by A.W. Hull replaced the grid with a magnetic field, which later evolved into the magnetron, the first practical high- power microwave generator, still used in some radars and microwave ovens today. Unfortunately, it's a narrow- band device, often requiring the de- signer to make a trade-off, regarding available output power versus fre- quency agility. > c o c 61 z O H o LU _l LU 9 D < VLF LF MF HF VHF UHF II SHF || EHF INFRARED i MICROWAVES 0,03MHz 0.3MHz 3MHz 3MHz 30MHz 300MHz 3GHz 30GHz 300GHz VISIBLE LIGHT ULTRA-VIOLET fUVt LIGHT □ GAMMA(y)RAVS X-RAYS 1 COSMIC RAYS 1C'«Hz 10 ,s Hz 10"Hz 10'°Hz 10?«Hz FIG. 1— THE ELECTROMAGNETIC SPECTRUM; the upper end of UHF is considered microwave. Bath regions have common properties, and certain microwave applications, like long-range radar, are often UHF. Here, microwaves include all frequencies above 500 MHz and below IR. The power- vs-frequency dilemma seemed insoluble until 1935, when W.W. Hansen of Stanford Univ., and A. A. Heil and O. Heil exploited tran- sit time by velocity modulating an electron beam. In 1939, W.C. Hariri and G.F. Metca If proposed the theory of velocity modulation for microwave tubes. A few months later, Russell H. and Sigurd F. Varian extended Dr. Hansen's work, producing the first two-cavity microwave vacuum tube using velocity modulation, known as a reflex klystron. And, in 1944, R. Kompfner invented the helical Travel- ing-Wave Tube. Much of the really critical micro- wave development work during World War II was performed at the Massa- chusetts Institute of Technology Radi- ation Laboratory, known as the RadLab. Their reports are still ac- tively used today by many working microwave engineers as references, and can be found — over 45 years later — as standard items in many technical bookstores. In the 1950's vacuum tubes began to be replaced with bipolar tran- sistors. Although P-N junction semi- conductor diodes like the IN 23 were made for low- frequency microwaves during World War II, other solid-state devices simply refused to function at these frequencies. Semiconductor materials exhibit a phenomenon anal- ogous to vacuum tube transit time, called electron saturation velocity. B.K. Ridley and T.B. Watkins in 1961 and C. Hilsum in 1962 indepen- dently predicted that gallimum-arse- nide (GaAs) would exhibit the transferred-electron effect. In 1963, John B. Gunn of IBM experimented with N-type gallium-arsenide (GaAs), and noted current instability that was due to negative resistance. That observation evolved into the Transferred-Electron Device, or Gunn diode. Other solid-state microwave de- vices soon followed. You can now buy DC-to-2-GHz Monolithic Microwave /ntegrated Circuits (MMIC's) that FIG. 2— THE RELEVANT PARAMETERS IN A sinusoidal wave. Microwaves, like all elec- tromagnetic waves, exhibit the characteristics of amplitude, propagation in free space at the speed of light, frequency, wavelength, period, and phase. produce about 13-20 dB of gain for about $1 . Other solid-state microwave devices operate at 20 GHz or more. All such microwave solid-state de- vices exploit negative resistance for oscillation and amplification. Modern electronics designers have a wide variety of solid-state devices to select from, and microwave tech- nology is no longer the poor orphan of electronics. Radar, communications, electronic navigation, and satellite TV links all operate at microwave fre- quencies. Also, modern medical di- athermy, or tissue heating, long ago moved from the II -meter band to mi- crowave frequencies. Wavelength and frequency Microwaves, like all other elec- tromagnetic waves, exhibit the characteristics of amplitude, propaga- tion at i he speed of light in free space, frequency, wavelength, period, and phase (see Fig. 2). Amplitude is the measure of intensity, expressed in electric or magnetic field (volts/meter or amps/ meter). The speed of light in free space is c = 3x I0 B meters/sec- ond = 186,200 miles/ second. Frequency is the number of indi- vidual oscillations per unit time, as measured in Hertz (Hz), or cycles per second. Figure 2 shows a cycle as one complete reversal of the waveform, e.g., either T1-T3 or T3-T5. The GHz, or I0 y Hz, is the frequency unit most commonly used in microwaves. Wavelength is the interval in dis- tance between identical points on suc- cessive cycles of a wave (see Fig, 2). It's measured between identical peaks or zero crossings in a given direction. For all propagating waves, the prod- uct of frequency and wavelength is the propagation speed , or v = X x/v^. Here, k is the wavelength in meters/cycle, f is the frequency in Hz. e r is the magnitude of the complex relative permittivity or dielectric con- stant of the propagation medium rela- tive to vacuum (unitless), and v is the propagation speed. Solving for wavelength: X = c//Ve or frequency: /=c/XVi. For microwave signals in air, wave- lengths vary from 10 centimeters at 3 GHz to 1 millimeter at 300 GHz. Mi- crowave frequencies above 20 GHz are also called millimeter waves due to their extremely short wavelengths (under 1.5 centimeters). In media 62 other than dry air or vacuum , propa- gation speed decreases. To maintain constant propagation speed, the wavelength must decrease if frequen- cy is held constant. The only characteristic quantity that remains perfectly constant in a propaga- ting wave is frequency. When micro- wave energy passes through a piece of plastic, for example, its speed decreases because e> I, but \ must also decrease to produce the same number of cycles in a given time interval. Any waveform can be described ei- ther temporally (in time) or angularly. As is shown in Fig. 3-«, period is shown to be the reciprocal of frequen- cy T= I//', where T is the period (in s/ eye), and /is frequency (in Hz). The angular description of a sin- usoid stems from the fact that it's mathematically generated from a cir- cle, arbitrarily defined as containing 360°. The true, non-arbitrary angular unit is the radian (or rad); to define it, consider a circle. If, as is shown in Fig. 3-b, you bend a line segment one radius long to fit along a sector of the corresponding circle, it subtends a 57.3° angle. If you repeat this as many times as possible over the entire circumference, you'll fit 6.28 radii on the circle in all, or 3.14 radii along a semicircle. By definition, the number 6.28 is twice the constant pi (ji), or 2xji radians = 6.28 rad, soji = 3.14. Since 2xjt radians = 360°, then k radi- ans = 180°, or 1 radian = 57.3°. The term phase denotes cither Absolute or Relative Phase Angle (APA or RPA). The APA refers to the number of de- grees or radians into a given cycle where the instantaneous point of inter- est is located. In Fig. 3-a, for exam- ple, point A' has an APA of ji/2 radians or 90°. Relative phase angle (RPA) refers to the phase angle between two sig- nals, whether two voltage signals, two current signals, or voltage and current signals. The waveforms of Fig. 4 aren't coincident (phase angle isn't 0°). In this example waveform A is a cosine function, while wave- form B is a sine function). These wave fo mis are of the same frequency, but 90" out of phase with each other. This condition is called a quadrature phase relationship. Skin effect There are several reasons why ordi- nary lumped components don't work FIG. 3— WAVEFORMS ARE DESCRIBED EITHER temporally or angularly. In (a), the Abso- lute Phase Angle at A' is 90° or n/2 rads. In (b), a radius bent to fit on its circle subtends a 57.3° angle, so 6.28 radii fit in ail. Or 2 x jT rads = 360' = 6.28 rads, n rads = 3.14 rads = 180°, or 1 rad = 57.3°, the most basic angular unit. FIG. 4— RELATIVE PHASE ANGLE REFERS TO the phase angle between two signals, whether two voltage signals, two current signals, or voltage and current signals. Here, waveform A is a cosine function, while waveform B is a sine function. They have the same frequency, but are 90° out of phase, called a quadrature phase relationship. well at microwave frequencies. As mentioned earlier, component size and lead lengths approximate micro- wave wavelengths. Also, distributed values of inductance and capacitance become significant here. Finally, there's the skin effect, which occurs when AC tends to flow on the surface of a conductor. While DC flows throughout the en- > c o c (D o 63 R-E Engineering Admart 1 Surface Mount Chip Component — - Prototyping Kits — \ Only CD i Capacitor Ki! contains 365 pieces, bea. of every 10% value from 1 pi to .33^1. Cfi-1 Resistor Kil contains 1540 pieces; 10ea. oteven/5%veJug(rom IQftlQ lOmagn Sizes are 0SC5 and -.206. Each hit is ONLY $49-95 and available tor Immediate One Day Delivery I Order by toll-free phone, FAX, or mail We accept VtSA, MC, AMEX. COD, or Pre-paid orders. Company P.O. s accepled with approved credit. Call lor free detailed brochure. 'COMMUNICATIONS SPECIALISTS. INC. 426 Wesl Tafl Aire. ■ Orange. CA 92665-4236 Local (714) 996-3021 ■ FAX (714) 974-3420 Entire USA 1 -800-854-0547 CIRCLE 176 ON FREE INFORMATION CARD Rates: Ads are 2V4" x 2W. One insertion $950. Six insertions $925. each Twelve rtiorts $895. each. Closing date same as regular rate card. Send order with ittance to Engineering Admart, Radio Electronics Magazine, 50D-B Bi-County I., Farmingdale, NY 11735. Direct telephone inquiries to Arline Fishman, area code-516-293-3000. Only 100% Engineering ads are accepted fat this Admart. FCC LICENSE PREPARATION The FCC has revised and updated the commercial license exam. The NEW EXAM covers updated marine and aviation rules and regulations, transistor and digital circuitry. THE GENERAL RADIOTELEPHONE OPERATOR LICENSE - STUDY GUIDE contains vital information, VIDEO SEMINAR KITS ARE NOW AVAILABLE, WPT PUBLICATION 979 Young Street, Suite A Woodburn, Oregon 97071 Phone (503) 981-5159 CIRCLE 183 ON FREE INFORMATION CARD 6805 MICROCOMPUTER DEVELOPMENT SYSTEM The MCPM-1 system allows the IBfvt PC and compatibles to be used as a complete development system (or the Motorola MC68705P3. PS. U3. US. R3 and PS single chip microcomputers. The system includes a cross assembler program, a simulator/debugger program and a programming board that connects to a serial port. Pnce— $449 .00 VISA and MASTERCARD accepted 'the Ehsiheess ' COltiBBSATIft. IMC. RR#3, BOX 8C Barton, Vermont 05822 Phone (802) 525-3458 FAX (802] 525-3451 CIRCLE 190 ON FREE INFORMATION CARD I O o DC o Q Q < or tire cross-section of a conductor, AC flows only near the surface, in a nar- row cross-sectional band that gets thinner as frequency increases. Cur- rent density falls off exponentially from the surface of the conductor to- wards the center, as shown in Fig. 5. At the critical depth 5. called the skin depth, the current density is I/ FIG. 5— THE SKIN EFFECT CAUSES AC TO flow near the surface of a conductor. While DC flows through the cross-section, AC flows only in a narrow band near the surface (a). Current density falls off expo- nentially toward the center; at the critical (skin) depth 5, the current density is 1^ e = 36,8%, of thai of the surface (b). e = 1/2.718 = 0.368 = 36.8%, that of the surface. Skin depth is defined as 5 = 1/Vji X/X |xo\ where 5 is skin depth (in meters), /is frequency (in Hz), p. is permeability (in henries/m), rj is conductivity (in Siemens/ meter). Microwave components Because current only flows in a small part of the cross-section of a microwave conductor, instead of through its entire cross-section as at lower frequencies, the AC resistance of a microwave conductor is consider- ably higher than its DC resistance. Because skin effect is a function of frequency, conductors will perform as they do at DC for very low frequency AC, but may be useless in the micro- wave range. For these reasons, microwave cir- cuit design must consider the dis- tributed resistance, inductance, and capacitance for components. In addi- lion, specially designed lumped con- stant components like thin-film in- ductors, and chip resistors and capacitors, are necessary. For exam- ple. Fig. 6 shows how an inductor FIG. 6— MICROWAVE CIRCUIT DESIGN MUST consider distributed resistance, in- ductance, and capacitance of compo- nents. Also, special lumped-parameter parts are used, like thin-film inductors, and chip resistors and capacitors. Here's how an inductor might appear in a micro- wave circuit on a PC board. Capacitors are similar, but the conductors are separated from one another. might be formed in a microwave cir- cuit built onto a PC board. Capacitors are also made similarly, but with the conductors separated from one an- other. In our next installment, we'll con- sider traditional methods of generat- ing RF power. While not specifically microwave technology, that little his- tory lesson will set the stage for your understanding of why vacuum tubes and other early generators fared so poorly at microwaves. R-E 64 PC Service flm T 12% INCHES- here's THE SOLDER SIDE of the RAM disk at haif the actual size. USE THIS PATTERN for the pressure gauge c Q C to 8 65 w o z O IT h- O uu 6 Q < 66 111 •Jjfflfil ;l Mi III "•? I : V 1)11 ■6 INCHES- THIS IS THE SOLDER SIDE of the frame grabber. HUS * i=^ » ■ m F ^ » ^^ > ? • *1 • • m, • • ■ \i i>«tnj t i >*■ • *% *m **\ ♦~ \ m - & + — ^i • ■ f xVt > i^ * ^ ■ ^x» « t » W -r COMPONENT SIDE ■6 INCHES THIS IS THE COMPONENT SIDE of the frame grabber. Hardware Hacker Data compression there's a pair of stupendous new high-end compaction break- throughs for this month, so I thought it might be a good time to go over some of the fundamentals of... Data and image compression You can compact data or an image whenever you want to store it in less space or else transmit it in less time. The process of compaction is some- times called compression, while the reverse process is called restoration, expansion, or regeneration. A compression scheme is noiseless if it does not add anything in the way of artifacts to the output data string. A scheme is lossless if nothing gets removed and if the re- covered data is exactly the same as the input data. Being both lossless and noiseless is obviously impor- tant if you're dealing with electronic funds transfer. On the other hand, slight video-image quality variations to that tapioca pudding scene in Godzilla versus the Night Nurses will usually not be noticeable. Even to the critical reviewers of this cross- genre classic. A data compression scheme func- tions in real time if it keeps up with TV frames or movie film, or else if less than one second of delay is needed for a user interaction. The compression is symmetric if the same amount of time and hardware is needed for either data compac- tion or regeneration. The compression ratio is simply how much compaction you gain. If you reduce a 100K textfile to 12.5K, your compression ratio is a big 8:1. Similarly, a 20 percent compression reduces your file size by 5:4. As you might suspect, a modest amount of compaction, say 30 per- cent, is easy to do. Things get sticky fast after that. The higher the com- pression ratio, the more time and effort that is required to do the job. Naturally, there is a fundamental limit to the ultimate achievable com- pression, based upon information theory and on entropy constraints. Because both the English language and typical pictures are extremely redundant, these limits are often surprisingly generous. But do note that the less redun- dant your information, the more in- tolerable any errors will become. Further, any simple errors tend to become far more destructive. For instance, any uncompressed error that misspells a single word can instead totally trash the entire message in your compacted file. This error intolerance, along with the long processing times, are the two serious tradeoffs that get in- volved in extreme compaction. Compression schemes which are content dependent are often (but not always) more effective than schemes that can accept anything as an input. In general, the more you know about what you want to com- press, the more you can squash it. For instance, the compacted data string alincgburgadd should not NEED HELP? Phone or write your Hardware Hacker questions directly to: Don Lancaster Synergetics Box 809 Thatcher, A2 85552 (602) 428-4073 DON LANCASTER take you four score and seven years to expand into its full text version, especially if you have got a library handy. Or, as a second example, you could use a city, state, and a zip code consisting of the single digit for your own town in a local mailing list. Several popular areas of compres- sion interest include ASCII text strings, fax printouts, delta modula- tion, disk data formats and full color HDTV video images. Text compression Eight-bit bytes of 256 states are a wasteful way of showing ASCII text letters, which at the most needs 127 characters, and often require only 26. Early Infocom text adventures used a scheme that crammed three ASCII characters into a pair of 8-bit bytes, a compression to 67 percent. Which also made snooping for hints real tough. The Adams adventures instead used character pairs. The most commonly used occurrences of two characters got placed in un- used code slots, again giving you something like a 3:2 compression on the average. In spelling checkers, the words are usually arranged alphabetically. Since each new word will share many of the initial characters with a previous one, you can provide a leading number instead. For in- stance, to get from fixation to fixative, the second word could be coded as 6ve. You can also use character pairs as well as a trailing byte that could represent the 256 most popular combined ways of <=■ ending words, s, ing, ly r ed, and so c on. When all is said and done, it h takes only slightly over 9 bits to rep- » resent an average English word in a ° 67 spelling checker. Advanced data compaction schemes often are first described in the Communications of the ACM from the Association for Computer Machinery. Going to a non-ASCII interpretive code can also help you bunches. For instance, to describe a single curved portion of a PostScript character, six signed integers, seven spaces, and the word curveto get involved. For a total of around 42 characters. In Adobe's Type ! Fonts, a special character string code gets used, of which 32 entries are commands, and the rest signed numerics of one or two self-spacing bytes. Typically, only six bytes will be needed for the same curveto example, giving you a compaction of 6:1 or so. There are more details in Adobe's Type I Font black book. I do have a few of these in stock. The ASCII letter "e" usually needs eight bytes for transmission. So does an ASCII "z." But the "e" gets used far more often. So, why not set up a code where an "e" needs four bits, while a "z" needs fourteen? On Symbol "A" that is 20% likely codes as 10 Symbol "B" that is 18% likely codes as 000 Symbol "C" that is 10% iikely codes as 011 Symbof "0" that is 10% iikely codes as 110 Syrribo; "E" that is 10% likely codes as 111 NEW FROM DON LANCASTER HANDS-ON BOOKS Hardware Hacker Reprints II 24.50 Ask The Guru Reprints I or II 24.50 CMOS Cnokbook 18.50 TTL Cookbook 16.50 Aclive Filler Cookbook 15.50 Micro Cookbook vol l or II 16.50 Enna icing your Apple I Or II 17.50 AppleWniei Cookbook 19.50 Apple Assembly Cookbook 21.50 Incredible Secret Money Machine 10.50 LaserWriter Reference (Apple) 19.50 PostScript Cookbook (Adobe) 15.50 PostScript Ref. Man. (Adobe) 22.50 PostScript Prog. Design (Adobe) 22.50 Type I Font Format (Adobe) 15.50 Real World Posiseripl (Roth) 22.50 UNLOCKED SOFTWARE LaserWriter Secrels (lie Mac PC) 29.50 PoslScripl Show & Tell 39.50 Inlro to PostScript VHS Video 39.50 PoslScripl Beginner Stulf 39.50 PoslScripl Perspective Draw 39.50 PostScript Technical Illustrations 39,50 PostScript BBS stuff 19.50 Absolute Reset lie & lie 19.50 CO AppleWriler LaserWriter Utilities 49.50 o Enhance I or II Companion Disk 19.50 2 o AppleWriler C8 or Assy CB Disk 24.50 h- o FREE VOICE HELPLINE VISAiMC LU SYNERGETICS LL 6 Box 809-RE Thatcher, AZ 85552 < EC (602) 428-4073 CIRCLE 63 ON FREE INFORMATION CARD Symbol "K" inai is 4% likely codes as 00110. Symbol "L" thai is 3% likely codes as 001110 Symbol "M" thai is 1% likely codes as 001111 FIG. 1— A HUFFMAN COMPRESSION USES SHORT CODES for often-occurring letters or symbols, and longer codes for those less often used. On the average, your overall message will end up shorter. Here's a simple example code which in- volves thirteen symbols. the average, all of your text mes- sages will end up somewhat shorter. Such a scheme is called Huffman coding. The original horse's mouth document is A Method for the Con- struction of Minimum-Redundancy codes, as found in the September 1952 Proceedings of the IRE. An ex- ample of a Huffman code appears in Fig. 1- Huffman codes are based upon making the length of a character code inversely proportional to the popularity of that character's use. The good news here is that a Huffman coding is fairly fast and simple, and often can be applied in combination with other compaction techniques. The bad news is that a variable bit length word can be awk- ward to handle in an 8-bit or 16-bit micro, and that the total compaction you get is often rather modest and typically in the 20-percent range. Worse, errors under a Huffman cod- ing do tend to trash the entire mes- sage, rather than a single word or two. Variations and improvements on this scheme are known as modified Huffman codes. These are in no way limited to ASCI I. Any place you have symbols with different probabilities, you can use variable-length codes to your advantage. Often, your mes- sage will first get analyzed, and a set of rules in dictionary form will get sent as a prolog. Matching the cod- ing to the message usually gives you the optimum compaction. Fax and the printed page Most fax images and most printer output consists of little bits of black buried in a sea of white. Obviously, a bitmap that sets aside one bit for each black or white dot is horren- dously inefficient most of the time. One popular way around that which works exceptionally well with black-and-white images is called run length encoding. With run length encoding, each successive byte represents how many black dots or how many white dots are to follow. For instance, four bytes in a bitmap could only represent 32 pix- els. But those same four bytes co- ded -18- -56- -9- -143- could now represent a string of 226 pixels, a 7:1 compaction. In this case, the first 18 pixels would be black, followed by 56 white ones, followed by 9 black ones, and a final 143 white ones. Figure 2 shows you a simple exam- ple of run length encoding. Should you have lots of picture detail, popular run length encoding schemes will automatically switch back to a bitmap whenever bitmaps are more efficient. The code can also be extended to allow for identi- cal sequential lines. In PostScript, the first time your descriptive font character is used, that character gets converted into a bitmap and placed into a font cache. Repeated use of the same character becomes much faster, since you are now only moving a bitmap using a BitBlt operator, rather than generat- ing fancy paths. On up to a certain size, "real" bitmaps are used. Above that size, run length encoding is used to minimize the storage needs. While run length encoding in PostScript is typically six times slower than using a real bitmap, the method is still many hundreds of times faster than using the original character description. Most modern fax machines use what is known as a Croup III com- pression, which is based largely upon run length encoding. One source of circuits and information on Croup 111 compression is American Micro Devices, especially their AM95C71 video compression- expansion chip set. But the best way to compress a fax image is to flush it and use PostScript instead. Besides offering you a ridiculously better image quality, most PostScript supertax im- ages transmit in one-tenth the time and will store in one-tenth the space. 68 DIN HUN LENGTH ENCC 3: D7 CC 8C B9 CA 9C 8A C9 BC 8C C8 CC 75 17 C6 52 7C 55 37 C5 53 7C 45 47 C3 55 7C 26 57 C2 65 7C 15 7 7 CO FO A6 OF 09 70 FO 97 01 FO 78 D8 CD 8C D3 C9 DB 9D B9 DB 9D BO (A zero value means "don'i change" unless at She line end.) FIG. 2— RUN LENGTH ENCODING IS AN EFFECTIVE compression scheme for black-and- white images. In this example, four-bit bytes representing how many white or black pixels replace the bitmap for a^:1 compaction. Doing the obvious One obvious way to compress files is to not send what you don't need. Eliminating all comments and REM statements from programs at run time is a typical example. So is getting rid of any extra spaces used for pretty printing. In PostScript, careful use of persistent downloads and common dictionaries will very much reduce your individual file sizes. Another way to really compact certain types of images goes by the name of delta modulation. With de- lta modulation, you transmit only the changes between what you have now and what went by previously. Animation is one obvious exam- ple. I've had one of my students do some incredible 4-stroke engine an- imation on the Apple lie simply by brute force coding only frame-by- frame changes in successive pic- tures. But delta modulation really shines in sound synthesizers. To compact voice or music, you try to anticipate where the sound is going to be in the next sample, and then transmit only the difference between the predicted and exact value. This is known as linear predictive coding, and the sound toolkits on the Macintosh and the Apple llgs include lots more detail. A typical compression is 2:1 or 8:3, depend- ing on the acceptable quality, I use an even sneakier form of delta modulation to speed up PostScript. Say you have a shipping label or a business letter with a fancy letterhead and a digitized signature. Instead of retransmitting the entire image each time, you simply place the total image into your PostScript printer once and then print the first name and address. You then erase only the name and address, and then print up your second name and address, repeating the process until your entire mail list or what- ever is finished. The same idea works well with forms, or anywhere else a long makeready time can be shared among many different out- put copies. The disk breakthrough Most floppy- and hard-disk for- mats are surprisingly wasteful of space. So there are lots of pos- sibilities here, over and above the obvious of trying to increase the number of tracks or the number of bytes per track. Knowing exactly how your disk space is organized can often save AMATEUR RADIO ASTRONOMY RESOURCES Amateur Radio Astronomers 247 North Linden Street Massapequa, NY 11758 (516) 798-8459 CIRCLE 230 ON FREE INFORMATION CARD Nasa Tech Briefs 41 East 42nd Street Ste 921 New York, NY 10017 (212) 490-3999 CIRCLE 234 ON FREE INFORMATION CARD Astrophysical Journal NRAO Observatory PO Box 37005 PO Box 2 Chicago, IL 60637 Greenbank, WV 24944 (317) 753-3347 (304)456-2011 CIRCLE 231 ON FREE INFORMATION CARD CIRCLE 235 ON FREE INFORMATION CARD Bob's Electronic Service Science/AAAS 7605 Deland Avenue 1333 H Street North West Fort Pierce, FL 34951 Washington, DC 20005 (407) 464-2118 (202) 326-6400 CIRCLE 232 ON FREE INFORMATION CARD CIRCLE 236 ON FREE INFORMATION CARD Jeff Lichtman VLA Astronomy Site > 1425 Parkmont Drive P.O. Box O C Q Roswell, GA 30076 Socorro, NM 87801 c (404) 992-4959 (505) 772-4011 -I CIRCLE 233 ON FREE INFORMATION CARD CIRCLE 237 ON FREE INFORMATION CARD O 69 g z o cc I- o LU you bunches of room. As one an- cient example, leaving off those last eight invisible bytes of an Apple II HIRES image saved you an entire DOS disk sector per picture. In ProDOS, a5T1-charactertextfile needs only one sector, while a 513- character one needs fhree sectors; one for the first 512 characters, a second for the new index block now required in your switch from a seedling to a sapling file, and a third for the final data byte. In fact, you can save at least one sector anytime you can get your file size just under a multiple of 512. Full details in the Beneath Apple Pro- DOS from Quality Software. On the Mac, removing unused re- sources from your System files can often free up surprising amounts of disk space. This becomes especially critical on earlier Mac versions with limited RAM. Similarly, knowing how your disk files are arranged and stored on any system can sometimes save you quite a bit of space. Especially on a disk that is nearly full and needs room for one or two more short files. Our first major compression chip breakthrough for this month is the 1C-105 co-processor from Infochip Systems. This one is initially intend- ed for the MS/DOS world and gives you an average of a 3:1 or higher compaction of disk files. And does so while remaining fully noiseless and lossless, and still allowing a full random access. Compression is real time up to 2 megabytes per second, and the decompression blazes along at a 5-megabyte per second rate. An adaptive algorithm is used that senses the type of data and creates optimum data dictionaries for each type. A Markoff scheme is used. Interestingly enough, you do not have to store these data diction- aries. They will automatically build themselves up during the de- compression process. Image com- pression can go as high as 15:1. The initial cost is in the $200 range. The obvious first use for this chip is for tripling the amount of disk storage space on any laptop com- puter. It will be interesting to see how error-tolerable this new tech- nique is. It should be a real winner if it works reliably enough under real- world noise conditions. NAMES AND NUMBERS Advanced Micro Devices PO Box 3453 Sunnyvale, CA 94088 (800) 538-8450 CIRCLE 238 ON FREE INFORMATION CARD Association for Computer Machin- ery 11 West 42nd Street New York. NY 10036 (212) 869-7440 CIRCLE 239 ON FREE INFORMATION CARD Bourns 1200 Columbia Avenue Riverside, CA 92507 (714) 781-5050 CIRCLE 240 ON FREE INFORMATION CARD C-Cube Microsystems 399-A West Trimble Road San Jose, CA 95131 (408) 944-6300 CIRCLE 241 ON FREE INFORMATION CARD Cryptosy stems Journal 9755 Oatley Lane Burke. VA 22015 (703) 451-6664 CIRCLE 242 ON FREE INFORMATION CARD IEEE 445 Hoes Lane Piscataway, NJ 08885 (201) 981-0060 CIRCLE 243 ON FREE INFORMATION CARD infoChip Systems 2840 San Tomas Expressway Santa Clara, CA 95054 (408) 727-0514 CIRCLE 244 ON FREE INFORMATION CARD Maxim 120 San Gabriel Drive Sunnyvale. CA 94086 (408) 737-7600 CIRCLE 245 ON FREE INFORMATION CARD OKI Semiconductor 785 North Mary Avenue Sunnyvale, CA 94086 (408) 720-1900 CIRCLE 246 ON FREE INFORMATION CARD Phillips 2001 West Blue Heron Blvd Riviera Beach, FL 33404 (407) 881-3200 CIRCLE 247 ON FREE INFORMATION CARD PowerTech 0-02 Fair Lawn Avenue Fair Lawn, NJ 07410 (201) 791-5050 CIRCLE 248 ON FREE INFORMATION CARD Quality Software 21601 Manila Street Chatsworth, CA 91311 (818) 709-1721 CIRCLE 249 ON FREE INFORMATION CARD Rochester Electronics 10 Malcolm Hoyt Drive Newburyport, MA 01950 (508) 462-9332 CIRCLE 250 ON FREE INFORMATION CARD Rogers One Technology Drive Rogers, CT 06263 (203) 774-9605 CIRCLE 251 ON FREE INFORMATION CARD Samsung 3725 North First Street San Jose, CA 95134 (408) 954-7000 CIRCLE 252 ON FREE INFORMATION CARD Sony 10833 Valley View Street Cypress. CA 90630 (714)229-4195 CIRCLE 253 ON FREE INFORMATION CARD Slock well Rubber 4749 Tolbut Street Philadelphia, PA 19136 (800) 523-0123 CIRCLE 254 ON FREE INFORMATION CARD Synergetics Box 809 Thatcher, AZ 85552 (602) 428-4073 CIRCLE 255 ON FREE INFORMATION CARD TecSpec 3 Mine Mountian Road Cornwall Bridge, CT 06754 (203) 672-0123 CIRCLE 256 ON FREE INFORMATION CARD Tektronix P.O. Box 500 Beaverton, OR 97077 (800) 835-9433 CIRCLE 257 ON FREE INFORMATION CARD Testa Coil Builders Assoc 3 Amy Lane Queensbury, NY 12804 (518) 792-1003 CIRCLE 258 ON FREE INFORMATION CARD Texas Instruments P.O. Box 809066 Dallas, TX 75380 (800) 232-3200 CIRCLE 259 ON FREE INFORMAnON CARD 70 The image breakthrough But the really big development this month is the CL550A chip by C- Cube. This beauty does a full-color video compression from any source to 33:1 and beyond in real time, up to and including 60-frame-per-sec- ond HDTV! A massive 300:1 parallel pipelining is provided through an unusual architecture. The action in this chip takes place at a previously unheard of ten billion operations per second. The compression is done by mak- ing what are known as Discrete Cos- ine Transforms, that involve blocks of 64 pixels. It turns out that certain spatial frequencies and some color shifts are nearly invisible to the human eye, so a careful filtering throws out anything that you aren't going to be able to see anyway. Best of all, this chip implements what is soon to be an international JPEG (/oint Photographic fxperts Croup) image standard, so it is in no way proprietary. The obvious uses include gen- uine multimedia on personal com- puters, compact full animation on CD-ROM and for squashing the bandwidths needed for HDTV broadcasts to well under those cur- rently being used for plain old TV. C-Cube does have a free technical information packet for you on their products, along with demo boards and software emulators. Projected pricing of their chip is in the $95 range. Video distribution amplifiers There are lots of times when you Open Circuit Termination Open Circuit Termination it ft T might like to drive more than one video monitor from a single source. Unless you are very careful, you will get disappointing results. For- tunately, there's a brand-new low- cost MAX457 chip from Maxim which greatly simplifies this task. Video is normally routed through shielded cables with a characteristic impedance, of 75 ohms or so. If you do intentionally open or short-circuit a cable, whenever a pulse or other signal gets to the end, it will reflect and bounce back to the source and cause standing waves — unless the cable is terminated at both ends by a load equal to its characteristic impedance. At baseband video frequencies, reflections off a short cable may not be all that bad. As a crude rule, if the cable is ten feet long or less, you can often get away without terminating it. Longer than that, and you will want resistive terminations at both ends, or you will get character smearing and other loss of quality. Figure 3 shows you the correct way to tie several monitors to a sin- gle source. You can use a daisy- chain connection. The monitors in- side the chain should all be set to their high impedance termination stage. The last monitor in the string should get load terminated. Note that you cannot simply put a bunch of monitors in parallel, since all their loads will gang up and swamp your source, leaving you with a very washed out picture, poor sync, or even nothing at all. Figure 4 shows you a dual video driver using the MAX457. Each out- 75 Ohm Terminano-'i ...J 7511 Video Source FIG. 3 — THE CORRECT WAY TO CONNECT several video monitors to a single source is to daisy chain them. Only the last monitor input should be terminated with a 75-ohm resistor. Never connect cables in parallel! DIGITAL VIDEO STABILIZER ELIMINATES ALL VIDEO COPY PROTECTIONS Whlla watching rental mcnriss, you wilt notice an* noylng periodic color darkflnFng, color sMH, un- wanted: lines, flashing or Jagged edges. This is caused by the copy prelec- tion jamming sfgnsJs em- bedded in the video tape, such es Mac revision copy pro tec- ion. Digital Video Stabilizer: RXff completely ell ml nates all copy protec- tions and jamming signals and brings you crystal clear pictures. FEATURES: • Easy lo use and a snap to install • State-of-the-art In- tegrated circuit technot- • 100% automatic - no need for any troublesome adjust- ments • Compatible to all types of VCR? and TVs • The best and most excit- ing Video Stabilizer In the market • Light weight {Bounces) and Compact (1x3, 5xtV} • Beautiful deluxe gift box • Uses a standard 9 Volt battery which will East 1- 2 years. WARNING : SCO Electronics and RXII dealers do not encourage people to use the Digital Video Stabilizer to duplicate rental movies or copyrighted video tapes. RXII is in- tended to stabi- lize and restore crystal clear picture quality for private home use only. ( Dealers Welcome ) To Order; $49.95 ea + $4 for FAST UPS SHIPPING 1-800-445-9285 or 516-694-1240 Visa, M/C, COD M-F: 9-6 (baticry not Included) SCO ELECTRONICS INC. Dept. CB4S 581 W. Merrick Rd. Valley Stream NY 115S0 Unconditional 30 days Monty Back Guarantee CIRCLE 196 ON FREE INFORMATION CARD CABLE TV DESCRAMBLER lUnit 10 + JerroldS.B $74 $55 Jerrold SB w/Trimode $90 $70 Oak N-12 (w/VS) $89 $65 Scientific Atlanta $109....$75 Pioneer $109....$75 Panasonic converter $98 .$79 73 channel converter $79 $59 We Beat Anyone's Price! 30 Days Money Back Quaranty Free Catalog Visa, M/C, COD or send money order to: US Cable TV Inc. Dept.KCTB 4100 N.Powertine Rd., Suite F-4 Pompano Beach, Fl 33073 1-800-445-9285 Piease have make and model number of the equipment used in your area ready. No Florida Sales! It's not the intent of US Cable TV Inc. to defraud any pay TV operator and we will not assist any company or individual in doing so. CIRCLE 197 ON FREE INFORMATION CARD > C c. c v. It O 7" Be an FCC LICENSED ELECTRONIC TECHNICIAN! Lrc»V| Learn at home in spun! ■ -r ^>| No previous experience needed! 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! You don't need a college degree to qualify, but you do need an FCC License, No Need to Quit Your Job or Go To School This proven course is easy, fast and low cost! GUARANTEED PASS — You get your FCC License or money refunded. Send for FREE facts now. MAIL COUPON TODAY! T VdmmdiiD VRODJcfiofi i" " I FCC LICENSE TRAINING, Dept. 90 • P.O. Box 2824, San Francisco, CA 94126 Please rush FREE details immediately! NAME ADDRESS CITY STATE I I \K> VIII CLEANJNG/MAINTENANCE/REPAIR EARN UP TO $1000 A WEEK, WORKING PART TIME FROM YOUR OWN HOME! c/3 O 2 o H o LU — I LU I o □ < fX 72 THE MONEY MAKING OPPORTUNITY OF THE 1990S IF you are able to work with common small hand tools , and are famillarwlth 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! Viejo's 480 PAGE TRAINING MANUAL (over 500 pho- tos and illustrations) and AWARD-WINNING VIDEO TRAINING TAPE reveals the SECRETS of VCR mainte- nance and repair — "real world" information that is NOT available elsewhere! Also includes ail the info you'll need regarding the BUSINESS-SIDE of running a successful service op- eration! FREE IHF0RMflT1OM CALL TOLL-FREE 1-800-537-0589 Or write lo: Vieio Publications Inc. 3540 Wilshire BL. STE, 310 Los Angeles, CA 90010 Dept. RE FIG. 4 — THIS DUAL VIDEO DRIVER is handy any time you want to use more than one monitor with a VCR or a computer, especially with long cables. put is an independent 75-ohm source. You can cascade as many of these as you need to. To make up for the drop across the 75-ohm source resistance, the video gain is set to precisely two. Half of that develops across the source, and half across your termi- nating load. At a gain of two, the bandwidth is around 30 megahertz, so high-definition stuff can be han- dled as well as ordinary video. A split +5, -5 supply is required. Sorry about that, but you do have to somehow suck out current on all your grounded sync tips. Supply current is under 40 mils for the pair of drivers. The normal output level is adjusted to a white level of 2 volts and grounded sync tips. That be- comes a standard one-volt video signal after the drop across the source resistor. Radio astronomy resources For our resource sidebar this month, i have chosen to round up some stuff for amateur radio astron- omers. Two of the foremost resources are Bob Sickels and Jeff Lichtman. Bob runs Bob's Electronic Service and publishes the Radio Observer mag- azine. He also stocks parts and kits for low-noise amplifiers, microwave electronics, chart recorders, and lots of similar stuff. His free catalog also has a good no-nonsense intro. Jeff has published three classics in the field which include his fine Radio Astronomy Handbook, his Solar Radio Astronomy, and his Microwave Radio Astronomy. A leading amateur astronomy club is apparently the Society of Am- ateur Radio Astronomers. Their $20 yearly membership includes a newsletter. Publications providing radio as- tronomy information in them in- clude Science, the Astrophysical Journal, NASA Tech Briefs, and thei r discontinued IEEE Transactions on Radio Astronomy. Two radio astronomy sites which welcome visitors are the NRAO ob- servatory located in Creenbank, West Virginia, and that VIA site in New Mexico, New tech literature Useful new data books for this month include a Voice Synthesis LSI and Telecom LSI volumes from OKI; Microwave Transistors from Phillips, High Speed CMOS Logic from Samsung; Optoelectronics and Im- age Sensors from Texas Instru- ments; and A/D & D/A Converters from Sony. Toni Patti of the Cryptosystems journal offers some newly revised free Lorenz attractor "Owl's Mask" chaos theory programs when you send him a formatted IBM disk. In- cluded is a powerful set of new 3-D graphics routines. Other free soft- ware includes a Selectrim trim pot selector from Bourns, and a continued on page 90 CIRCLE 182 ON FREE INFORMATION CARD ComputerDicesi Last time we outlined the hardware and software com- prising the static RAM disk. Un- like a RAM disk allocated from system memory (whether con- ventional, extended, or ex- panded), our RAM disk occupies only a few I/O port addresses. And because it contains its own CMOS memory subsystem, our RAM disk can be immunized against power failures. Now let's talk about how the cir- cuit works, and about how to build and use the SRAM disk. Hardware details The circuit consists of three main sections: a bus interface, a battery backup circuit, and the static RAM array. Figure 1 shows the complete schematic diagram. The PC bus interface consists of 1C3, IC4, and IC5. The latter are a pair of 74LS244s (three- state octal bus drivers) that buff- er the address lines. A bi-direc- tional three-state octal buffer (1C3, a 74LS245) buffers the data lines. The ior (I/O Read) line from the expansion bus drives the data di- rection input of IC3; the decod- ing circuitry discussed below drives IC3's gate input (pin 19). The decoding circuitry con- sists of IC6, IC7, and several gates in IC9 and IC10. Two out- puts from IC6, a 74LS138 3-to-8 line decoder, drive the cs inputs of the parallel ports (IC1 and IC2). In a multi-board system, the first board uses the two low-order out- puts (yo, yi) of IC6; subsequent boards use higher-order outputs. Address lines AO and Al select one of four registers (three data ports and one control port) in the selected port (IC1 or IC2). Address lines A2— A4 drive IC6, which pro- vides an output select every four addresses. For IC6 to be enabled, its g5a must be driven low. For that to happen, several conditions must be met. First, aen from the bus EDITOR'S WORK- Bench Low-cost Logic Analyzer Logic analyzers can inspire fear. They're usually expen- sive, conceptually difficult, and hard to use. To counteract that trend, Photronics has intro- duced the LAI Logic Analyzer, a $100 device that plugs into your PC. The LAI is not going to put Tektronix out of business, but it's not even trying to compete. The LAI is really an educational tool that provides a low-cost, easy-to- use introduction to logic ana- lyzers. It keeps cost down by lim- iting operating speed to about 100 kHz, and by relying on the PC for its intelligence. The LAI consists of a half- length card that plugs into any 8- or 16-bit slot. As shown in Fig. 1, A connector is accessible to the user through the rear bracket; a supplied ten-conductor ribbon cable plugs into the connector. The cable is terminated with color-coded mini -clips that you attach to the circuit under test. Eight lines are for data, one is ground, and the other is for an external clock. (Continued on page 78} > c D c CD s 73 RADIO-ELECTRONICS C5 g 01 to ?! to o I I to 1 I g i*£im 6 6 60 666 6 2$ must be low. If it is not low, a DMA operation is taking place. Sec- ond, either Tor or Tow must be ac- tive (low). When those conditions are met, pin 3 of IC10 will go high. Another necessary condition is that the a=b output of IC7 be high. That IC is a four-bit magni- tude comparator; it has three outputs that reflect the state of two four-bit, sets of inputs. If the binary-weighted A inputs are less than the binary-weighted B in- puts, the a=b output goes high. The a = b and ab outputs function similarly. To compare more than four bits, you can cascade ICs by connecting outputs of one stage to corresponding inputs of the next. The lowest-order stage re- quires its a=b input to be high. In our circuit, A9 from the bus drives the a=b input, and A5— A8 drive the comparison inputs. DIP switch SI is connected to the other group of comparison in- puts. The A5 and A8 address lines actually drive the A3 and ao inputs, and A6 and A7 drive the B2 and bi inputs respectively. The other A and B inputs are con- nected to the poles of SI, The net effect is that pin 6 goes high when A9 is high and when A5-A8 match the DIP-switch settings. Tkble 1 shows the switch set- tings for various I/O port ad- dresses. In each line of the table, the address shown is 512 more than the sum of the binary switch weights. The reason is that A9 is also decoded, so the minimum address is 512. When pin 6 of IC7 and pin 3 of IC10 go high, pin 8 of IC9 goes low, thus enabling IC6-d, one of the port ICs. In addition, after inversion by IClO-b, the pin-8 output also enables IC3, the data-bus buffer. At that point a byte will be read or written (de- pending on the states of Tor and Tow) to the appropriate port of the selected port IC. SRAM array Each SRAM has fifteen address lines, eight data lines, an output- enable (oe) line, a write-enable (WE) line, and a read/write (r/w) line. Port A of IC1 drives the low- order address lines of all SRAM's ; the lower seven bits of port B > c Q c (a CD o 75 TABLE 1 —I/O PORT ADDRESSES Sl-d S1-c S1-a sirb Address (256) (128) (64) (32) (decimal) ON ON ON ON 512 ON ON ON OFF 544 ON ON OFF ON 576 ON ON OFF OFF 608 ON OFF ON ON 640 ON OFF ON OFF 672 ON OFF OFF ON 704 ON OFF OFF OFF 736 OFF ON ON ON 768 OFF ON ON OFF 800 OFF ON OFF ON 832 OFF ON OFF OFF 864 OFF OFF ON ON 896 OFF OFF ON OFF 928 OFF OFF OFF ON 960 OFF OFF OFF OFF 992 drive the high-order address lines; and port C drives the data lines. The high bit of port B (PB7) functions as a pseudo read/write line that drives the oe lines, and, after inversion by IC8-a and IC8- b, also the we lines. Last, the A and B ports of IC2 drive the chip- select inputs of the SRAM's, one bit per SRAM. Port C of IC2 is not used in the present design; you could modify our circuit to de- code an additional 8 SRAM's or use the port for other things. Data retention The battery-backup circuitry is quite simple. Five volts from the bus feeds all of the logic and par- allel ports. In addition, bus power also feeds the SRAM's and associated chip-select pull-up re- sistors (R6-R21) via diode Dl. When bus power is off, the back- up battery feeds the SRAM's and pull-ups via D2. The author successfully used several types of batteries for backup, including a 0. 1- Far ad ca- pacitor formerly sold by Radio Shack, four AA cells, and a re- chargeable cordless phone bat- tery (Radio Shack number 32-173). If you use a rechargeable battery, install a jumper in D2's position. Construction You can build the circuit on a prototype board with an XT-type bus interface, or you can build it on a PC board. Foil patterns are shown in PC Service; a drilled and etched board with plated- through holes is also available from the source mentioned in the parts list. As shown in Fig. 2, on the front side of the board install all re- sistors, then IC sockets, then ca- pacitors, then the DIP switch and the two header blocks for the backup battery and the decoding block. Then, on the back side of the board, install the six jumpers shown in Fig, 2. Connect a pair of wire-wrap wires to each pin of a two-pin female header; connect the other ends of the two wires to the pads by the cs inputs of IC1 and IC2 (pin 6). Then connect the female header to the desired pair of pins on PI. Choose A + B, C + D, E + F, or G + h. and make sure that the wire from IC2 goes to the lower-order pin (A, C, E, or G). In a multi -board system, use the jumper settings shown in Table 2. TABLE 2— BOARD SELECT Board IC2, Pin 6 IC1,Pin6 1 A B 2 C D 3 E F 4 G H The board is a little too tall to fit in an XT-style case. Either use an AT case, or trim the board to a height of about four inches. Doing so will cut through several traces, which can then be re- placed by jumper wires. Make sure you don't remove any more than the top eight traces to keep the additional jumpers to a mini- mum. If you trim the board, the addi- tional jumpers should be added between the correspondingly numbered pads J1...J8. For ex- cn o I H LU Q D < DC -C1- ■xj— IC18 RJ3 T-7 ■ -1017 -C3-> """ *-X4"-T~ i-C5-' PXT— 1. ITT? IC16 J ■IC15 T7 ". iC14 IC13 1012 1 nto ~ C9— " J1 J -C10 J J2 -C11-J3 -C12-'-J4 *-C13— J5 «-C14-= J6 -C15 TT ; IC19*-; IC20 7 V [C21- -C12- J4 —C13- { U : u ! i— — — *■ > r — ~~i 1 i '"" J 1C22 • IC23 ; f — •-V ■ fcr— ' T *""~ H * 1 I— — *7™** fc=r^^2 U J IC24 i. U 1 JUS IC2 IC7 □ SEL-B TT-T- ; .*. JR2|R4 ^cis- J7 ~ci6- J. bf-CjfessH...** 1 - 3 hr rr-r 1 , E , J r Ji ' U "1 m — I D'lT ■ ' -.•-• ' i • . . . '. "ABCPFG H > ■ : - r " ■ ■" ,|l, i [i'iIiu \ rn — *-— • ; ' b.lCS. jut ■. yiVO •. > JC6- !G25 R19 R14 R15 R16 R17 R1B FIG. 2. MOUNT ALL PARTS AS SHOWN HERE. MAKE SURE THE FOLLOWING VERSION OF THE PARTS LIST RUNS. THERE ARE A FEW DIFFERENCES FROM PART 1. •:• i R20 b JC6 • 1C26 • ' i - ■ ' i"."~ ^T • • * ; . (J..V..AII U . u ., i . . , u . a ; ,Mi.(...i.| R21 tC17* JU2 L^LM 111 wy.t..:l,^i'.. ! IVii. 1 1 1 i 1 11 1 1 JI i 1 1 1 . t 76 Parts List All resistors are 'A-watt. 5% unless otherwise noted, Rl-RS 4700ohms R6-R21 22.000 ohms Capacitors hhh^^^^ C1-C16 0.01 pJ-* polyester C17 10 pF, 10 volts, electrolytic Semiconductors ^paHM*^^ D1.D2 IN914 switching diode IC1.IC2 8255 Programmable peripheral interface IC3 .74LS245 Bidirectional bus buffer IC4.ICS 74LS244 Octal bus driver IC6 74LS138 Three- to-eight line decoder IC7 74LS85 Four-bit comparator IC8 74LS04Hex inverter IC9 74LSOOguad NAND gate IC10 74LS08Quad AND gate IC11-IC26 43256-10 Static RAM Other Components ^b^m^^h SWl Four-position DIP switch Bl , Four AA cells (with holder) I optional) Jl 2-posltlon. single- row, 0.1" Jemale header J2 2-positlon. single- row, 0,1" Jemale header PI , 8'posltton. single- row. O.r male header P2 , 2-posltton, single- row. 0,1" male header Ordering Information The following are available from Hatronics 145 Lincoln Street Montclair, NJ 07042 (201) 783-7264 (201) 245-6614 (BBS, join tne Hatronics conference) Bare PC board $50 Kit with 0KRAM ....$90 Kit with 128KRAM $155 Kit with 256K RAM $220 Kit with512KRAM $322 Assembled and tested untt. OK $135 Assembled and tested unit, 256K $255 Assembled and tested unit. 512K $395 Ail orders add $10.00 Jar shipping and handling. New Jersey orders add sales tax (6% ), 5 CLS 10 PRINT"************************************************** 20 PRINT"* * 30 PRINT"* SRAM INITIALIZATION PROGRAM * 40 PRINT"* * 50 PRINT"* COPYRIGHT HATRONICS * 60 PRINT"* * 70 PRINT"************************************************** 80 PRINT" THIS PROGRAM WILL INITIALIZE THE FIRST 32K " 90 PRINT" THIS WILL SET UP THE FAT AND DIRECTORY AREAS " 95 PRINT 97 INPUT" WHAT PORT ADDRESS " ; PO% 99 IF P0%=0 THEN GOTO 130 100 PRINT" ARE YOU SURE YOU WANT TO DO THIS ??? Y or N " 110 AS=INKEY$; IF A$="Y" OR A$*"y" THEN GOTO 140 120 IF A$= n " GOTO 110 130 PRINT" ABORTED !!!": END 140 DIM S2{16) 150 S2{ 1) =254:82(2 )=253 : S2(3)=251 :S2( 4 ) = 247 160 S2(5)=239:S2(6)=223:S2(7)=191:S2(8}=127 170 F1A=PO%:F2A=PO%+16:F1B=PO%+1;P2B=PO%+17 175 PlC=PO%+2:P2C=PO%-t-18:PlD = PO%+3:P2D=PO%+19 180 OUT P1D,128 190 OUT P2D,128 200 OUT P2B.255 210 OUT P2A,255 220 P%=P2A 230 PRINT" INITIALIZING FIRST 32K" 240 IF BA =2 THEN P%=P2B 250 FOR S = TO 127 260 FOR T = TO 255 270 OUT P1A,T:0UT P1B,S+128 280 OUT P1C,0 290 OUT P%,S2(S3):OUT P%,255 300 NEXT T 310 NEXT S 320 PRINT " END INITIALIZATION" : END ample, run a jumper from Jl un- der the DIP switch to Jl by C9, from J2 under the DIP switch to J2 by C10, etc. If you're not going to install all sixteen SRAM's, install the SRAM's in part-number order (IC11. IC12,...IC26). Check your work carefully for solder bridges and cold solder joints. Fix any problems, and then set SI to a value unused by any other adapter in your system. Try 768 if you're not sure; that address is reserved by IBM for prototype boards. Then power down your PC and insert the board into a vacant ex- pansion slot. Initialization Power your PC up; if it doesn't boot normally, power down quickly, check the board again, and correct any mistakes. Before you can use the board, you must initialize it. Run the BASIC program shown in Listing 1 ; that program performs a func- tion similar to DOSs FORMAT command. If you don't keep a battery attached to the board, you'll have to run the BASIC pro- gram each time you boot. In that case, you may want to modify the program so that it automatically uses the correct port address and so that it returns to DOS after it finishes executing. In other words, change all END state- ments to SYSTEM statements. Then you could execute the pro- gram from your AUTOEXEC .BAT like this: GWBASIC SFORMAT The author is working on an enhancement that will allow the driver to optionally initialize the board each time you boot. Both the initialization program and the device driver are available from the RE-BBS, 516-293-2283, 300/1200, 8N1. The file called SRAMDISK.EXE is a self-extrac- ting ZIP file that contains the BASIC program, the executable version of the device driver, and the source for the device driver. Run SRAMDISK.EXE on a disk with at least 150K of free disk space. Check with the author at £ the address given in the parts list g for the latest version of the ini- ^ tialization program and device ^ (Continued on page 80) g 77 O z e g LU _l UJ 6 Q < EDITOR'S WORKBENCH (Continued Jrom page 73) The card has several jumper blocks for specifying the I/O ad- dress through which data is passed to the host PC, and for selecting the clock type and rate of the clock. If you use the inter- nal clock, you can specify a clock frequency of 1, 10, 100, 1,000, 10,000, or 100.000 Hz. The board is laid out well, has a solder mask and a silk screen indicating all component positions, and all IC's are installed using socketed con- nectors. The software consists of a sin- gle executable file that uses a drop-down menu system for load- ing and saving files, configuring defaults, capturing data, print- ing the results, etc. lb capture data, you first specify capture pa- rameters using the dialog box shown in Fig. 2. The trigger byte lets you specify the byte with which capture will begin. You can specify 0, 1, or X for each bit. For capture to begin, you must re- ceive a byte that matches the pat- tern of Is and O's in the trigger byte. (X matches either a 1 or a 0.) The Edge Select field in the di- alog box allows you to specify whether each byte will be cap- tured on the leading ( + ) or the trailing ( - ) edge of the clock. Sampling Count specifies the number of bytes to capture: 16, 32, 64. 128, or 256. Timeout specifies the max- imum period of time to wait for the trigger byte. If it is not re- ceived in that amount of time. the capture process terminates. You can specify an infinite wait by specifying a value of 0; how- ever, your computer will lock up if the desired byte is not received. After capturing data, you can view a graph of the state of each of the eight captured bits at each clock cycle. The software switch- es to a graphics mode for this dis- play; all standard IBM adapters (CGA, EGA, VGA, 8514, 3270) are supported, as are several others. The program will also print the graph; most common dot-matrix and laser printers are supported. Figure 3 shows a LaserJet II printout of one sample run. l,IM,Ml l | .^.. l JI ',ilJ.lJ 1 JIMJm4T'J l T ; ^.H FIG. 2 sPORTt, (C) Copyright 1989 WHS Fort: C0I11 of I Options: %G8 Baud, 8 Data, Ha Parity, 1 Stop Sena Status; recelue) CTS USB CD BI Fl-Help FZ-Port FH-Options F4-RTS F5-DTB ni-fiscn F7-Send FB-Capture F9-liandshakiiHj Fie-Quft Commit i cat ion Display his type oF text is typed in locally. Typed characters seem to follow the currEsor post ion by one. Stff inreverse uideo comes from the rettole channel 971151001IS23232323232323Z3Z3Z3Z3Z3232323232323Z3Z32323Z3 ?21H2434«546474B'l9Ol.iee9Gl9ll0Q0lGOllOeeilOll»ieieil00i. ^lODli30ilieiiaiO0G011QlGG1911OiOlO I? You can also cahnge the display to show hex, decimal and, 'fbinary characters J jUihhhhhhhhhhlilihhhhhhhhhlthli FIG. 3 The LAI also has a special "Log- ic Probe" mode, in which a bit- mapped display is constantly up- dated to reflect the state of the input probes. For demonstration purposes, you can run the soft- ware without the card in a ran- dom mode, in which data is not captured but created by a ran- dom-number generator. Documentation consists of a 20-page pamphlet that does a good job of explaining how to set up and use the LAI, but is weak on background information and examples. That's a weakness, be- cause I doubt that anyone famil- iar with logic-analyzer operation would be interested in a product like this. Its low speed and 8-bit operation simply aren't sufficient for real-world use. For educational use, the easy- to-use interface has a distinct ad- vantage, but the documentation should have some sort of tutorial information. All in all, though, the LAI would be valuable in con- junction with a beginning course in digital electron ics.|(D+ 78 RE Computer Admart GETTING THE MOST FROM YOUR PRINTER Getting The Most From Your Printer PL 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 unlock 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 2V<" * 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 Arline Fishman, area code-516-293-3000. Only 100% Computer ads are accepted for this Admart. ' SECRETS OF THE 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, graph ics-co I o r-and sim- ple animation, and even a chapter on ma- chine code. Get your copy today. Send S5.00 plus $1.25 tor shipping in the U.S. to Electronic Techology Today Inc., P.O. Box 240, Massapequa Park, NY 11762-0240. IC. PROMPT DELIVERY!!! SAME DAY SHIPPING (USUALLY) QUANTITY ONI PB.CfS SHOWN to, MAY tf. TWO DYNAMIC RAM 1MB COMPDe5kPni3B6.'20 S295.00 I SIMM AST Pl8m38G-33 Mill 225 .00 1 SIMM imx9 eons 88.00 1 SIMM 25eK*9 100 ns 30.00 1 ] 1Mb it if.ki 80 ns 8.25 1 141256 256Kx1 60 ns 4.151 1 41256 256KX1 80 ns 3.10 1 1 41256 2S«Kxi 100 ns 2.50 1 141256 2S6Kxi 120ns 2.251 14464 c-ikjj tOO ns 3.00 1 141264* $4Kki 100 ns 5.95 1 EPROM I27C100Q i2SKx6 200 ns SI S.00 1 127512 .mk.sii 200 ns 7.80 1 [27258 32KxS 150 ns 6.50 1 |2712B 16K18 250 ns 3.75 STATIC RAM I62256P-10 32Kk« 100 ns 58.251 I6264P-12 skkS 120 ns 4.50 1 I6116AP-T2 2Kx8 120 ns 4.25 1 OPEN 5 DAYS. 7 JOA1I IOpu SHIP VIA FED-EX ON SAT MICROPROCESSORS UNLIMITED. INC '^JoTZl? (918)267-4961 Hs* ml v&K» « c^fr-u* 1 AEC LIVtD M Fn p ■ 11U01 Pj CIRCLE 61 ON FREE INFORMATION CARD Serial port setup with sFORTt You can never have enough weapons In the never-ending battle with RS-232 interfaces. sPORTt is a software-only serial port tester that aids determining correct port settings for PC com- patibles. It provides an interac- tive screen, shown in Fig. 4, in which you can change settings at will, as well as send and receive data. Whatever you type at the keyboard is sent out the current port at the current settings. You can also send a disk file, and re- ceive to a disk file. The nice things about sPORTt are that you can quickly and easi- ly change settings, and that the Photromcs LAI Logic Analyzer Binary Counter Test CLK DD 01 dj i 02 03 04 05 D6 07 jimjuuLnjui^^ jumiirLJiJLJiJinmji^iJTTmj JUU~LJlJ IB o FLfU ruLTUiriajirTni UUUL uiiiiiiirinjiJiij^^ MUUL Riuinj "UUU1 JU ITLiLRilTL Limjuuinnnuuinnr LI1I1IUJlJ~lJL 16 2+ 32 40 Byte Campled 48 56 64 FIG, 4 current settings are always visi- ble. For example, if you wonder whether that plotter requires a high on RTS, press F4 to make it high, and then send some data. If that doesn't work, press F4 to turn it back off, and try again. You can follow the same pro- cedure with DTR. The states of the receive signals (CTS, DSR, CD, RI) are constantly displayed as well. The central portion of the screen contains the Communica- tion Display, in which all sent and received characters are dis- played. Each character is dis- played according to the current display mode (ASCII, hex, deci- mal, binary), which you set with F6. Unfortunately, the numeric display modes are a little raw, with no spaces between adjacent characters, which makes the val- ues difficult to read. I'd like to see the display formatted in a DE- BUG style, with numbers on the left and ASCII on the right. A "chat" mode, in which keyboard characters (Backspace, Tab, etc.) were interpreted intelligently would also be nice. The program currently sup- ports COM1 and COM2; it would be nice if the user could specify a port address, because the "stan- dards" for COM3 and COM4 are > c a c 03 CO CD O 79 in o z o ot I— o LU I LU 6 Q < not universally adhered to, and multi-port serial boards use al- together different addresses. Using the program is easy, be- cause the single screen is self-ex- planatory. Printed documenta- tion includes a 40-page three- ring notebook with background information on serial communi- cations. 9-pin, 25-pin, and null- modem wiring diagrams, etc. At bottom, sPORTt is a handy, easy-to-use diagnostic for PC's. It won't substitute for a fancy exter- nal serial-port analyzer, but at $90, it costs 10% of one of those devices.^CD^ j C: The Complete Reference C -language aficionados will appreciate McGraw-Hill's comprehensive new reference by the prolific Herbert Schildt. The book is divided into five parts. Part one includes an introduc- tion to C that is as good as some textbooks. Part two includes complete descriptions of all stan- dard library functions. Part three discusses data structures and al- gorithms common to all types of programming (searching and sorting; stacks, queues, and linked lists; arrays; etc.). Part four discusses programming problems from a higher level, and includes discussions of interfac- ing with assembly language; porting and debugging, and soft- ware engineering. Part five dis- cusses C++, ANSI C, and how the latter differs from the classic K&R version of the language. At 800 pages, the book is about two inches thick, and it's filled with code examples, all of which are available on-disk directly from the author for about $25. If you're thinking about switching to C, this book will help you get up to speed quickly. If you're al- ready there, it will serve as a valu- able reference. |CD| ITEMS DISCUSSED • LAI Logic Analyzer ($99.95). Photronics, Inc., 109 Camille St., Amite, LA 70422. (504) 748-7090. CIRCLE 260 ON FREE INFORMATION CARD • sPORTt ($90). Western Hy- drologic Systems, 3037 Grass Valley Hwy. , #8201, Auburn, CA 95603. (916) 885-2480. CIRCLE 261 ON FREE INFORMATION CARD • C; The Complete Reference. 2nd ed. {$28. 95). Herbert Schildt, Osborne McGraw-Hill, 2600 Tenth Street, Berkeley, CA 94710. CIRCLE 262 ON FREE INFORMATION CARD RAM DISK DRIVE continued from page 77 driver. The next task is to add the de- vice driver to your CONFIG.SYS file. Until you are sure things are working the way you want, you may want to boot from floppy, not your hard disk. Later, after you arrive at the correct configura- tion, copy the device driver to your hard disk and edit its CON- FIG.SYS, The device driver line in CON- FIG.SYS takes the form: device = a:ramdev.sys /768 #16 $016 %2 The first parameter specifies the board's base address, in this case 768. Next comes the number of SRAM's installed (16), followed by the number of directory entries (016), and last by the number of sectors per allocation unit (2). Each parameter must contain the number of digits shown (three, two, three, and one. re- spectively). Add a leading zero (or leading zeros) if necessary. In ad- dition, you must prefix the base address with a slash, the number of IC's with a pound sign, the number of directory entries with a dollar sign, and sector number with a percent sign. Edit the CONFIG.SYS of your boot disk to add the appropriate values, and then reboot. If all is working well, you should be able to use the static ram disk just like any other kind of drive in your computer, |CD| LAWN RANGER continued from page 50 Hand-held controller The hand-held controller allows the operator to manually steer the robot forward and backward. It contains a potentiometer and switches that inter- face with the electronic control sys- tem. The cable from the controller plugs into the electronic control panel located at the rear of the Lawn Ranger. Figure 7 shows a photograph of the hand-held controller, and Fig. 8 shows the schematic diagram. Potentiometer R3 is used to steer the robot to the left or right. Micro- switch SI is hand- activated and stops and starts the forward motion of the Lawn Ranger. As the operator squeezes the hand control, SI closes and allows the robot to move. If the operator opens his hand or drops the controller, the robot will automat- ically turn itself off. Switch S3 is a momentary pushbutton that is used to activate the cutting motors. An RC delay circuit formed by R2 and CI slows the Lawn Ranger down before it goes into reverse after the operator pushes the reverse button. DPDT slide switch S2 allows the operator to choose either a slow or fast driving speed. As far as the contruction of the controller goes, simply install the components as shown in Fig. 8 in a suitable enclosure. Electronic control panel The electronic control panel is lo- cated at the rear of the Lawn Ranger. The control panel consists of a DB-25 female connector (for the manual controller), three momentary push- button switches, a power switch (ig- nition), and a flashing power-on LED indicator. The schematic diagram of the control panel is shown in Fig. 9. The power switch is a key-operated ignition switch that supplies power to the robot. The stop button cuts the power and stops the cutting blades. The cut button is used to energize the cutting motors. The start button is used to start the automatic cutting op- eration after the hand-held controller is disconnected. Next month the Lawn Ranger story will continue. We will be covering the power board and the mechanical as- sembly. We'll also show you how to thoroughly test each section of the mower. R-E 80 Audio U PDATE The High End Hi-Fi Show LARRY KLEIN, AUDIO EDITOR MY BIG EVENT OF THE SEASON IN THE Iate1950's was the annual Institute of High Fidelity Music Show at the New Yorker Hotel. Along with hun- dreds of other early audio philes, l elbowed my way through crowded corridors for the chance to meet face-to-face such audio luminaries as Vic Brociner, Sol Marantz, Avery Fisher, Rudy Bozak, Gilbert Briggs, and Paul Klipsch. I remember a fel- low audiophile who, impressed by the imposing physical and sonic presence of a dozen Klipschorns, asked timidly, "Mr. Klipsh, what would happen if you turned up all these speakers to full volume?" Without missing a beat, Klipsch re- plied in his characteristic drawl, "My boy, it would permanently damage the structure of the building!" I encountered no such claims at the recent High End Hi-Fi Show sponsored by Stereophile maga- zine, a publication that caters to the needs, rational and otherwise, of dedicated audiophiles. What I did hear at the High End Show was ex- cellent sound produced by the products of scores of high-end man- ufacturers. Touring the show A $25 admission fee covered all three days of the High End Show and included admission to the vari- ous panels, discussions, demon- strations, and live music events. I must admit that my tour of the show was far from definitive. Other com- mitments had limited the time I had available, but part of the blame has to be placed on the show's sprawl- ing layout. Manufacturers' displays were scattered throughout two TWO B&W MATRIX 800 SPEAKER sys- tems are shown side by side, with and without their grill covers. Their brilliant sound, impressive size, and distinctive shape are matched only by their $18,000 price tag. floors and two mezzanines, and close study of the show directory was required to locate the ex- hibitors of interest. It turned out that the show organizers had delib- erately spaced the exhibitor's rooms both to expedite traffic flow and to prevent sonic conflicts. The products Near the entrance to the show floor was the B&W room, featuring thei r new Matrix 800 speaker system pictured elsewhere on this page. Note that the photo shows fwo com- plete systems side by side, one with its grille cloth on, the other with it off. I was rather startled by the ap- pearance of the speakers, each of which stands more than 6-feet tall. But I have enough confidence in B&W's engineering integrity to know that the design configuration was neither arbitrary nor specifically designed to impress by its sheer size and strange shape. How did it sound? In a word: magnificent! Small musical groups came across with a natural quality and balance and an impressive sense of depth and space around the performers. Large orchestral performances were handled at real- istic (loud!) concert-hall volumes with no sense of strain and a substantial bottom end. The free- field frequency-response specifica- tions of the system are given as 23 Hz to 20 kHz ±2 dB, and I don't doubt it for a minute. Few of us would be willing to fit a pair of Matrix 800's into our listening rooms (or to accommodate their $18,000' cost) but they're a good example of how good a speaker can be when its manu- facturer makes an all-out effort. An interesting contrast to the enormous and expensive B&W Ma- trix 800 was provided by the dimin- utive Atlantic Technology Pattern woofer/satellite speaker system. The Pattern system has separate 15- watt amplifiers for each of its two satellites and a single 30-watt ampli- fier for the dual bass drivers. Each satellite measures 4 inches square and 7 inches high, and consists of two black cubes joined together by a pivot that allows one cube to be rotated 360 degrees relative to the other. The amplifiers are housed in- side the bass module, which mea- sures 19 inches long, 12fi inches high, and 8% inches deep. > c Q C O 81 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. rvw if Banner Technical Books, Inc. 1203 Grant Ave. Rockford, IL 61103 CIRCLE 67 ON FREE INFORMATION CARD The Pattern's amplifiers do more than simply feed a chosen signal to its drivers. The bass amplifier in- cludes a dynamic equalizer that en- hances the low-base output at reasonable volume levels, but turns it down about 5 dB when a combina- tion of low bass and high volume would tax the 6 1 /2-inch woofers' ex- cursion capabilities. The Pattern's highly flexible input arrangement accepts connections from up to three stereo program sources plus wires from the speaker outputs of a separate amplifier or receiver. The sound from the Pattern system was very good, although not quite up to the standard set by B&W's $18,000 Matrix 800. But for $500— built-in amplifiers and all — most people would probably consider the Pat- tern a better buy. Accessories In the past decade, the audio business has been "accessorized" to a fare-thee-well. For the dealer, accessories answer the question of what to sell the audio consumer once he's bought his basic compo- nents; for the audiophile, accesso- ries provide an opportunity to be consistently involved in what he perceives as an evolving system. For example, for quite a while it has been possible to buy shock mounts for every component in your sys- tem — even the amplifier. Following an opposing theory, "spiking" de- vices are also available to ensure a firm connection between the com- ponents and the surface they are resting upon. I don't know how many au- diophiles are losing sleep over the question of whether to shock mount or to spike, or whether to apply the various clamps, weights, preservatives, and enhancing fluids, but there is one category of accesso- ry seen at the High End Show that I can heartily endorse. Several man- ufacturers are selling gold-plated RCA-type phono plugs that have been redesigned and machined to provide a constant ground during insertion and withdrawal and to have a clamping action once in- stalled. A great idea. Over the years I've probably blown hundreds of dollars worth of midranges and tweeters because of carelessness and cable problems that would have been prevented by proper plugs. Very expensive special speaker leads and interconnect cables (we used to call them "phono" cables) were seen in profusion at the show. The manufacturer's claims and quasi-technical explanations for the superior performance of their prod- ucts ranged from the vaguely possi- ble to the definitely ridiculous — as did the prices. I was told of one speaker cable that sells for approxi- mately $200 per foot! I didn't get a chance to check out the Wadia line of outboard digital decoders meant to be connected to CD and DAT players with digital out- puts. I must admit that the technical content of the impressive Wadia lit- erature lost me in the section about LaCrangian and Spline decoding polynomials, but their basic claim is simple enough: Critical amounts of information are lost (and displeas- ing artifacts added) in the D/A-con- version sections of all current CD and DAT players. The Wadia 2000 decoding computer purports to re- store the sound to the quality in- tended by the recording engineers. It's possible, but my CD players sound just fine to me as is. It would seem that I lack both the aural sen- sitivity and financial wherewithal ($7,700) to ever be a customer for their top-of-the-line decoder. The final word Consumer hi-fi shows have ap- parently fallen out of favor in the past decade. Whether the reason is lack of manufacturer support or loss of public interest I can't say, but the Stereophile Show is the only one currently scheduled. Perhaps it's just as well, because the hi-fi shows generally had deteriorated to SPL (Sound-Pressure Level) contests where it was difficult to find anyone really knowledgeable about the products shown and impossible to make critical sonic judgments be- cause of the noise leakage from ad- jacent rooms. I would guess that the 7,000-or-so attendees at the High End Show were mostly critical music listeners, and the exhibitors, by and large, re- spected their serious interest both by the choices of the program mate- rial and the reasonable levels at which it was played. I regret that I didn't get a chance to cover all the products played and displayed. Maybe next time, R-E CIRCLE 108 ON FREE INFORMATION CARD DIGITAL PRESSURE GAUGE continued from page 44 PRESSURE SOURCE HOSE CLAMP i PC BOARD f^B ACCURATE PRESSURE GAUGf BATTERY Jt HOSE TEE FIG. 7— TO CALIBRATE THE GAUGE, use this setup. Remember that all hose connections must be securely clamped. Final calibration The best way to calibrate your pres- sure gauge is to compare it to the reading ol* a known, accurate gauge. Additionally, if you plan to use the gauge 10 measure pressure which is normally less than full-scale ca- pability, it would be prudent to cali- brate it at this pressure level rather than at lull scale. Use the setup in Fig. 7, remembering that all hose connec- tions must be securely clamped. The setup allows the pressure source to be applied simultaneously to both gauges. Adjust R6 so that the digital read- out agrees with the reference gauge. After adjustment of R6, remove the pressure from the sensor and check the display, which should read zero. If there is some offset from zero, repeat the adjustment for R16 and R6. Battery life should be as long as 1 or 2 years if the project is used intermit- tently. The display will change in ap- pearance when the battery needs to be replaced, and it will disappear al- together when the battery is totally exhausted. R-E ARE YOU IN DEFAULT on a student loan? If you're in default on a guaranteed student loan (FISL, GSL, Stafford, SLS, or PLUS loan), you may be eligible to pay it back without penalty or collection charges. For information about this special program, call the guarantee agency that holds your loan, or call the U.S . Department of Education's toll-free number: (800) 333-INFO Assembly Power! Healh provides an alternative for computer buyers who want to do more than just plug in a ready-made computer. Heath computer kits offer superior per- formance - and the satisfaction and pride of building a high-power laptop or desktop computer yourself. Our expert team of computer sales consultants will give you a special price that's sure lo fit your budget. Simply call I -800-753-5454 and ask about any of these unbeatable systems: • HS-3286 SupersPort 386 SX laptop • HS-2862 1 2 MHz 80286 laptop • HS-3629 32-bit. 25 MHz 80386 desktop Heath 1-800-753-5454 (M-F, 8:00 a.m. - 4:30 p.m., EST) EARN YOUR BaWitat ■ DEGREE THROUGH HOME STUDY Our New and Highly Effective Advanced-Place- ment Program for experienced Electronic Tech- nicians grants credit for previous Schooling and Professional Experience, and can greatly re- duce the time required to complete Program and reach graduation. Mo residence schooling re- quired for qualified Electronic Technicians. Through this Special Program you can pull all of the loose ends of your electronics background together and earn your B.S.E.E. Degree. Up- grade your status and pay to the Engineering Level. Advance Rapidly! Many finish in 12 montre or less. Students and graduates In all 50 States and throughout the World. Established Over 40 Years! Write for free Descriptive Lit- erature. COOK'S INSTITUTE OF ELECTRONICS ENGINEERING *SHY*1 4251 CYPHESS DRIVE *^-*- E JACKSON, MISSISSIPPI 39212 CIRCLE 58 ON FREE INFORMATION CARD ORDER FROM JAN FOR CRYSTAL CLEAR COMMUNICATION • YOUR RELIABLE SOURCE SINCE 1965 • QUICK DELIVERY - PRICED RIGHT • EMERGENCY ORDER SERVICE AVAILABLE FOR FREE CATALOG, CALL OR WRITE: JAN CRYSTALS P.O. BOX 06017 FORT MYERS, FL 33906 CIRCLE 199 ON FREE INFORMATION CARD (813) 936-2397 TOLL-FREE: 1-800- JAN-XTAL (526-9825) FAX ORD ERS: 1-813-936-3750 ^ / CIRCLE 104 ON FREE INFORMATION CARD MARKET CENTER FOR SALE GREAT buys! Surplus prices, ICs, linears, transfor- mers, PS, stepping motors, vacuum pump, phototransistor, meters, LSASE, FERTIK'S, 5400 Ella, Phila.. PA 19120. DESCRAMBLERS. All brands. Special: Combo Jerrold 400 and SB3 $165.00. Complete cable de- scrambler kit $39,00. Complete satellite de- scrambler kit $45.00. Free catalog. MJM INDUSTRY, Box 531, Bronx, MY 10461-02OB. T.V. notch filters, surveillance equipment, brochure $1.00. D.K. VIDEO, Box 63/6025, Margate, FL 33063. (305) 752-9202. TUBES: "oldest," "latest." Parts components sche- matics. SASE for list. STEINMETZ, 7519 Mapiewood Ave., RE, Hammond, IN 46324. CABLE TV DESCRAMBLERS! ZENITH descrambler test device. Authorizes all channels for full service. Sold as test aid only! $69.95 each for info call (407) 76B-Q278, DESCRAMBLERS: dealers! We have new Z-Tac descramblers. only $185.00 in 10 lots, with other systems available. 1 (800) 695-CABL, CO CJ z O rr t- o UJ o Q < BARGAIN HEADQUARTERS! ■ JERROLD • TOCOM ■ HAMLIN • SCIENTIFIC ATLANTA ■ ZENITH 0*k M35B ONLY 160 6 month wamnty! We •hipC.O.D.I Lowed reteil'wholeul* pricuf FREE CATALOG: Global Cib+e Network 1032 Irving St. Suite tos S.F., C A 94122 ORDER TODAY! 800-327-8544 ENGINEERING software, PC/MSDOS. Hob- byists — students — engineers. Circuit de- sign $49.00, PCB layout $99.00, Logic simulation $29.00, FFT analysis S69.00, Mathematics $39.00, Circuit analysis $29.00. Call or write for free catalog. (614) 491-0832. BS0FT SOFTWARE, 444 Colton Rd., Columbus, OH 43207. RESTRICTED technical information: Electronic sur- veillance, schematics, locksmi thing, covert sci- ences, hacking, etc. Huge selection. Free brochures. MENTOR-Z, Drawer 1549, Asbury Park, NJ 07712. RENTAL movie stabilizer. Connect between VCRs or to monitor Satisfaction guaranteed. $69.95, $4.00 handling. 1 (800) 367-7909. Quality Microwave TV Antennas wmELESS CABLE-1 .9 to 2 . 7 Ghz. «d& Gain ( I ) 36-Ctiannel System Complete $149.95 12-Ctianne! System Complete S114.9S Call or Write (or "FREE" Catalog Phillips-Tech Electronics P.O. Soi 8533 * Scottsdale, AZ 85252 , E (602 ) 947-77D0 IHM Credit ill pro™ infers!) WARRANTY MlUerCiri • Vlll • CMS QujntitY Piking LASERS. Imw to 2kw, worlds largest selection of new & used surplus. Free catalog. MWK INDUS- TRIES, 1269 Pomona Road, Corona, CA 91720. (714) 27S-0563. LOTTERY - IBM computer disk for all lotteries $10.00. ROBERTS, Box 63/6025, Margate, FL 33063. MAGNET wire 18-38 gauge sotderable. Send SASE to SMW DIST., PO Box 1015. Huntington. IN 46750. CATALOGS you can get free over 200. Send $3,50 to ERIC LIVELY, 3982 Stuart, Bossier. LA 71112. CLASSIFIED AD ORDER FORM To run your own classified ad, put one word on each of the lines below and send this form along with your check to: Radio- Electronics Classified Ads, 500-B Bi-County Boulevard. Farmingdale, NY 11735 PLEASE INDICATE in which category of classified advertising you wish your ad to appear. For special headings, there is a surcharge of $25.00, ( ) Plans/Kits ( } Business Opportunities ( ) For Sate ) Education/Instruction ( ) Wanted ( ) Sate I file Television ( ) Special Category: $25.00 PLEASE PRINT EACH WORD SEPARATELY, IN BLOCK LETTERS. (No refunds or credits for typesetting errors can be made unless you clearly print or type your copy.) Rates indicated are for standard style classified ads only. See below for additional charges for special ads. Minimum: 15 words. 1 6 11 16 ($49.60) 21 ($65.10) 26 ($80.60) 2 7 12 17 ($52.70) 22 ($68.20) 27 ($83.70) 3 8 13 18 ($55.80) 23 ($71 .30) 28 ($86.80) 4 9 14 19 ($58.90) 24 ($74.40) 29 ($89.90) 5 10 15 ($46.50) 20 ($62.00) 25 ($77.50) 30 ($93.00) 31 ($96.10) 32 ($99.20) 33 ($102.30) 34 ($105.40) 35 ($108.50) We accept MasterCard and Visa for payment of orders. If you wish to use your credit card to pay tor your ad til in the following additional information (Sorry, no telephone orders can be accepted.): Card Number Expiration Date Please Print Name Signature IF YOU USE A BOX NUMBER YOU MUST INCLUDE YOUR PERMANENT ADDRESS AND PHONE NUMBER FOR OUR FILES. ADS SUBMITTED WITHOUT THIS INFORMATION WILL NOT BE ACCEPTED. CLASSIFIED COMMERCIAL RATE: (for firms or individuals offering commercial products or services) S3.10 per word prepaid (no charge for zip code).. .MINIMUM 15 WORDS. 5% discount for same ad in 6 issues; 10% discount for same ad in 12 issues within one year; if prepaid. NON-COMMERCIAL RATE: (for individuals who want to buy or sell a personal item) $2.50 per word, prepaid, no minimum. ONLY FIRST WORD AND NAME set in bold caps at no extra charge. Additional bold face (not available as all caps) 55e per word additional. Entire ad in boldface, $3.70 per word. TINT SCREEN BEHIND ENTIRE AD : S3.85 per word. TINT SCREEN BEHIND ENTIRE AD PLUS ALL BOLD FACE AD: $4.50 per word. EXPANDED TYPE AD: S4.70 per word prepaid. Entire ad in boldface, $5.60 per word. TINT SCREEN BEHIND ENTIRE EXPANDED TYPE AD: $5.90 per word. TINT SCREEN BEHIND ENTIRE EXPANDED TYPE AD PLUS ALL BOLD FACE AD: $6.80 per word. DISPLAY ADS: 1" x 2H"— $410.00: 2" x 2W— $820.00; 3" x 2Vt" — $1230.00 General Information: Frequency rates and prepayment discounts are available. ALL COPY SUBJECT TO PUBLISHERS APPROVAL. ADVERTISEMENTS USING P.O. BOX ADDRESS WILL NOT BE ACCEPTED UNTIL ADVERTISER SUPPLIES PUBLISHER WITH PERMANENT ADDRESS AND PHONE NUMBER. Copy to be in our hands on the 10th of the third month preceding the date of the issue, (i.e., Aug, Issue copy must be received by May 10th). When normal closing date falls on Saturday, Sunday or Holiday, issue closes on preceding working day Send for the classified brochure. Circle Number 49 on the Free Information Card. 84 CB RADIO OWNERS! We specialize in a wide variety of technical information, parts and services for CB radios. 10-Meter and FM conversion kits, repair books, plans, high-performance accessories. Thousands of satisfied customers since 1976! Catalog $2. CBC INTERNATIONAL P.O. BOX 315D0HE. PHOENIX. AZ 85046 CA8LE TV converters descram biers, remote con- trol Tocom $199.00 new, RTC-56 with remote $150.00. Jerrold with remote $125-00, SA-3- Tri-8i $89.95, Zenith Z-Tac $225.00, Hamlin MLD-1200 $45.00, Hamlin 6600 $150.00, M35-B $45.00, quantity price available, COD ok. MOUNT HOOD ELECTRONICS (206) 896-6837. SURVEILLANCE privacy- control-debugging-pro- tection. (Kits assembled). Large new catalog $5.00. TRI-TRON. 2209F Lapalco, Harvey, LA 70058. WIRELESS CABLE RECEIVERS 1.9 TO 2.7 GHz 30 CH PARABOLIC DISH STSTl M 8173.90 30 CM ROD ANTENNA SYSTEM 5193.90 30 CH CRYSTAL C0NT ROl LED SYSTEM S291 ,S5 SUN MICFtOWWE IKT1. «. SEKO Slot FOB P . BOX #MS22 CATALOG H THE 5 E PHOEM AZ. ISW7 MID li I MEi; FINE mi 1 230-051 t VIDEO PHDDUCTS BUINTTT1' D1SC0UIII3 UFWME MPBUNr T xixsis of mums msmiss itmao CABLE TV converters: Jerrold, Oak, Scientific At- lantic, Zenith & many others. "New MTS" stereo add-on; mute & volume. Ideal for 400 and 450 owners! 1 (800) 826-7623, Annex, Visa. M/C accept- ed. B & B INC., 4030 Beau-D-Rue Drive, Eagan, MN 55122. TUBES, new, up to 90% off. SASE, KIRBY, 298 West Carmel Drive, Carmel, IN 46032. TJ SERVICES is here to serve you! Our quality products, quick courteous service, knowledgeable sales people and rock bottom prices prove it! Not sure what you need? Call (313) 979-8356 well help! We specialize in Jerrold, Hamlin, interference fil- ters and most SA equipment. PROGRAMMABLE stepper motor drive & control for under $100, IBM PC/XT compatible, Com- modore 64, or other with 25 pin parallel port. PCB, interface, & software. Send for detailed literature to: MASE, R.D. #2 Box 166, tvtohrsville, PA 19541. COMMUNICATIONS electronic equipment, sales, service, FCC licensed, free catalog, RAYS, PO Box 14862, Fort Worth, TX 76117-0862. FREE CATALOG FAMOUS "FIRESTIK" BRAND CB ANTENNAS AND ACCESSORIES. QUALITY PRODUCTS FOR THE SERIOUS CB'er. SINCE 1962 FIRESTIK ANTENNA COMPANY 2614 EAST ADAMS PHOENIX, ARIZONA 85034 FREE catalog. Interfaces for IBM compatibles. Dig- ital I/O and analog input. Control relays, motors, lights, measure temperature, voltage. JOHN BELL ENGINEERING, INC., 400 Oxford Way, Belmont. CA 94002. (415) 592-8411 . __ CABLE descrambters (Jerrold) from $40.00. Tocom VIP test chip. Fully activates unit. $50.00. Call (213) 867-0081, PR I N TED ci rcuit board s etched & dri I led . Free d eliv- ery. K & F ELECTRONICS, INC., 33041 Groesbeck, Fraser, Ml 48026. (313) 294-8720. ___ STUN guns: The ultimate self protection device for non-violent people. Low prices. Write: PROTEC- TION, Box 24762-RE, Nashville, TN 37202-4762. (615) 226-8930. CABLE-TV Scientific Atlanta 8580 QTY/price each 1/289 5/249 10/239 6PM to 10PM EDT week- days (301) 791-5019. No Maryland orders accepted. CABLE-TV BONANZA! •CALL FOR AVAILABILITY Name Address State D Cashier's Check Acct # Signature Zip □ Money Order City .Phone Number ( ) □ COD Q Visa Exp. Date ITEM 1 UNIT 10 OH MORE HAMLIN Nice JOOtJ 3SCORO60 HEMOTE CONVERTER 1CI1 Irmly, 29 00 18 00 PANASONIC WIRELESS CONVEJ1TER lour Mcsr D„y, 9SO0 79 00 STAR GATE 2000 BB DO 69 00 ■JERROLD 300 COMBO 169 00 H9 00 JERHOLD 40O HAND REMOTE CONTROL 29 00 ■ii .;'. 'JERROLD ISO COMBO 1*9 00 139 00 ■JERROLD JSO HAND REMOTE CONTROL ;.:<■ |)(| 1S00 !-■>■< SiJ-AL.:)- .!N 99 00 63 00 ■JERROLD SB-ADD-ON WITH TRIMODE 109 00 75 :■:.' •M-35 B COMBO UNIT iCn 3 0lilp»l only) 99 00 7000 ■M-35 B COMBO UNIT WITH VARISVNC 109 00 7600 MINICODE IN- 121 9S «■ 62 00 ■MINICOCi'.- '. '. V,i ■■. VAHISYNC 1D9O0 66 00 MINICODE VAHISVNC WITH AUTO ON-OFF MS 00 105 00 ECONOCODE Ifnimcodc subslilnliri 69 90 a?O0 ECONOCODE WITH VADISYNC r9 00 ■16 00 MLD-1200-3,n wuyi 11900 66 00 "SCIENTIFIC ATLANTA ADD-ON REPLACEMENT DE SCRAMBLER 11900 65 00 Quantity Item Output Channel Price Each TOTAL PRICE SUBTOTAL from shipping any cable descram tiling unit to anyone residing in the state of California. Prices subject to change without notice. Shipping Add $3.00 per unit COD & Credit Cards — Add 5% PLEASE PRINT TOTAL 3 3 ■ □ Mastercard o 8 FOR OUR RECORDS: DECLARATION OF AUTHORIZED USE — I. the undersigned, do hetebv declare under penalty ot penury thai all products purchased, now and in the future, will only be used on cable TV systems witfi proper authorization from local officials or cable company officials in accordance with all applicable federal and State laws. FEDERAL AND VARIOUS STATE LAWS PftOVtD€ FOR SUBSTANTIAL CRIMINAL AND CJWL PENALTIES FOR UNAUTHORIZED USE. Dated:. .Signed:. Pacific Cable Company, Inc 7325V2 RESEDA BLVD., DEPT. R-8 • RESEDA, CA 91335 (818)716-5914 ■ No Collect Calls • (818)716-5140 ! IMPORTANT: WHEN CALLING FOR INFORMATION I Please have the make and model # of the equipment used in your area. Thank You > c o c to o 85 CABLE TV DESCRAMBLERS 10 Lot „ Ml JERROLD™ Tri-Bi Mocfc.SlOS.OO JS5.00 W Ti JKRKOLD™ SB-3 OR 2 S89.0O $65.00 O ^_ ^ UJ HsmlinMLD-1200 S99.M 162,00 2 Z ? — 0«kN-I2W/V^ $99.95 S6Z0O Q < ^ Oalc-M-35-B W/V.5 599.00 I7B.0O C J D < OAKE-13 J99.95 158.00 I— Q LU CJ 2enilhSSAV[ $185.00 SI4S.00 O |— !2 S Eagle PD-3 S120.00 SS5.00 LU < j— .2 Sdcmifc AUnntt- $129.93 $105.00 [n 2 ff- H? SA-C«nW». CALL $CI1 . _l ^ I Tocom , $350.00 $295.00 D ^ g H Oik N-12W/ Auto S140.00 5105.00 "g 3 < Z Jeirctd Smtom CSV.... SI 39.95 GUI *NEW STARGATE 2000 CABLE CONVERTER 1-S89.00 10-S69.00 100-Call Last channel recall-Favorite channel select- 75 channel -Channel scan-Manual line tune- One year warranty-surge protection-HRC a Stand- ard swiichabie- and much more. Cnll Todav! INFORMATION(402)554-041 7 Orders Call Toll Free 1-800-624-1150 M.D. ELECTRONICS 115 NEW YORK MALL SUITE 133E OMAHA. NE. 68114 M.C. VISA CIRCLE 53 ON FREE INFORMATION CARD REMOVE VOCALS FROM RECORDS AND CDs'. 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 yet connects easily to a home component stereo. This unique product is manufactured and sold Exclusively by LT Sound - Nut sold through dealers* Call or write for a Free Brochure and Demo Record. LT Sound, Dept.R L-3 ,7980 LT Parkway Lithonia, GA 30058 (404) 482-4724 Manufactured and Sold Exclusively by LT Sound ■ tmM.j.n/.uu*,nm).t=MCJ'£.ii.-)-r-«:) PHOTOFACT folders, under #1400 $4.00. Others $6.00. Postpaid. LOEB, 414 Chestnut Lane, East Meadow. MY 11554. TROUBLESHOOT Solid-state relays. Easy to un- derstand guide with diagrams and instructions. Send $3.00 to: REMCO TECHNOLOGIES, PO BOX 428, Henrietta, NY 14467. NINTENDO service manuals. Schematics, wave- forms, parts lists, troubleshooting tips. Untapped markets nationwide. $30.00. SPIEL ELEC- TRONICS, PO Box 50941, Amarillo, TX 79159. O o tr 5 UJ O Q < EC CABLE TV TB-3 (Tri-Bi) or SA-3 Quantity Prices 10 20 $48. $43 Each 50 Each 100 xpvl^a $a9i Each Each Hours open 10:00 am to 4:00 pm Eastern time Minimum order 5 units 55.00 ea. Dealers wanted. We ship COD. King Wholesale 1-800-729-0036 Fax number 6173400053 'Wo one beats the King's prices!" DESCRAMBLERS One tree can make 3,000,000 matches. One match can burn 3,000000 trees. STOP the electronic thieves! Techniques, equip- ment, laws. Free information. SVS, 198 N. 2nd St., Suite 6, Porterville, CA 93257. (209) 781-2634. 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 $1.00 for catalog, refund on 1st order. J.B, ELECTRONICS, 3446 De- mpster, Skokie, IL 60076. (70S) 982-1973. T.V. cable descramblers converters. Zenilh. Tocom. SA-3. Tri-Bi, Jerrold-400, Hamlin, Oak, wholesale prices to all, examples Tocom $125.00, Oak RTC-56 with remote $150.00. COD orders ok, no catalog just greal prices. S.A.C., information (702) 647-3799, orders only 1 (800) 622-3799. SURVEILLANCE countersurveillance equipment catalog $5.00. EAVESDROPPING DETECTION EQUIPMENT, PO Box 1087, Williamsviile, NY 14231 TOCOM 5503 V.I. P. shutdown? Descramble "all channels" perfectly with deluxe "furnon" module. Easy hookup. $39.00. MIKE, Box 743, Oldsmar, FL 34677. $ NUTS & VOLTS ti M A B A Z p,o. Box tm-e tia, ca 9es?o GIVE YOURSELF A BREAK —A PRICE BACAM I NUTS & U0LTS will Sir* you MONEY ON ELECTRONIC PARTS fi EQUIPMENT PJtll SHOW YDU WHERE TO FIND UNIOUE. UNUSUAL AND HARB-TO-F1NU ITEMS. k A HtHmlPiMlaliui fn Tk fliyftj Wi% OfBtetmit Equprtnt OAK Sigma descrambler. channel 3 output, rare hard-to-find factory equipment, with free documen- tation, $150.00. Oak Sigma mod ili cation documen- tation $20.00 postpaid. Oak VN12-4 (or Hamlin) descramblers with free remote control converter, $85.00. Eagle remote control converter de- scrambler combos, $100.00, Send moneyorder, ship postpaid within 3 days. SURPLUS ELEC- TRONICS, POB 10009, Colorado Springs, CO 80932. 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 06430. MINIATURE FM transmitters! Tracking transmitters! Voice disguisers! Bug detectors! Phone Devices! More! Available in kits or assembled! Catalog $2.00: XANDI ELECTRONICS, Box 25647, Depl. 60G, Tempe, AZ 85285-5647. CATALOG: hobby'broadcasting.HAM.'CB: Cable TV, transmitters, amplifiers, surveillance devices, computers, more! PAN AXIS, Box 130-F8, Para- dise, C A 95967. REMOTE CONTROL KEYCHAIN Complete w/mini-transmitter and +5 vdc RF receiver Fully assembled Including plans to build your own auto alarm Quantify discounts available frs-iA nc Check, Visa or MIC Ctxi'+.yo Add $ 3 shipping VISITECTINC/Dept, R (415) 872-0123 PO BOX 5442, SO, SAN f=RAN,,CA 94O80 SURVEILLANCE transmitter kits! Four models of each; telephone, room, combination telephone/ room transmitters tune from 65 to 305 MHz. Catalog with Popular Communications book review of "Electronics Eavesdropping Equipment De- sign," $1.00, SHEFFIELD ELECTRONICS, 7223 Stony Island Ave.. Chicago. IL 60649-2806. INVESTIGATORS, experimenters — Quality plans. Micro and restricted devices. Free catalog. Self ad- dressed stamped envelope required KELLEY SE- CURITY INC., Suite 90, 2531 Sawtelle Blvd.. Los Angeles, CA 90064. CB Tricks II book. Power amplifier design and theo- ry, UHF CB tune ups. Send $19.95 MEDICINE MAN CB, PO Box 37, Clarksville, AR 72830. 86 NEWHENE LASER TUBES $35 Dealer inquiries invited. Free Catalog! MEREDITH INSTRUMENTS: 6403 N. 59th Ave. Glcndnle, AZ 35301 • (602) 934-9387 ' 'The Soum for tnstr Surplus ' ' X LASERS Build gunsights, pointers, liteshow, nitelite, lab. Blueprints and instructions $9.00 each, 3 for $20.00. Free list. NIGHTWRITER, POB 44188, Phoenix, AZ 85064. FM wireless microphone, 3 mile range, plans S4.00. FM. PO Box 4383, Bloomington, IL 61702-4383. STRANGE stuff. Get the advantage! Laser listener. surveillance, descrambling. underground informa- tion. Plans, kits, complete items. Informational package $3.00 refundable DIRI JO/BOND, Box 212, Lowell, N.C. 28098. LASER lighting entertainment systems. Create your own 3-dimensional laser light shows. Detailed mechanical and electrical schematics, scanning and control operations. $20.00. MILLENNIUM, 877 Saint Charles #5, Thousand Oaks. CA 91360. DETECTION — Surveillance, debugging, plans, kits, assembled devices. Latest high-tech catalog $5. OETECTION SYSTEMS, 2S1S E. Thomas. #16-B64F, Phoenix, AZ 85016 DESCRAMBLING, new secret manual. Build your own descram biers lor cable and subscription TV. Instructions, schematics for SSAVI, gated sync, sinewave, (HBO, Cinemax, Showtime, UHF, adult) $8.95. $2.00 postage. CABLETRONICS, Box 305Q2R, Bethesda, MP 20824. BUILD robot from outer space! Pfans $11.95, de- tails Iree. ROBOT WORKS, Box 1979, Colorado Springs. CO 80901. DIGITAL V.O.M./D.P.M. SALES— SERVICE— PARTS FLUKE-BECKMAN-SIMPSON-ETC. U.S. MADE ONLY, QUOTATION PRIOR TO WORK. FAST SERVICE. 90 DAY WARRANTY. STANDARDS TRACEABLE TO UBS. SINCE 1948. CALIBRATION CERTIFICATE AVAILABLE. INDUSTRIAL INSTRUMENT WKS. INC. 5745 SALMEN, HARAHAN. LA 70123 504(733-8355 TRANSFORMERS. Learn to build your own. Easy Smart. Send $1.00 (refundable). W. CHARLES TECHNOLOGIES, 28740 S.W. Parkway #A1, Wilsonville, OR 97070. ETCH your own printed circuit boards using the photographic method. The only inexpensive step- by-step process that guarantees professional re- sults. A book that every serious electronics hobbiest should have. Send $12.95 to ETCHING INFO, F>0 Box 8064, Westfield. MA 01086-8064. Computer Kits 6026G-i2m.ru. 1.2 ot 1.4*1 fsoppj..^ 1 n I iCeyfioDrd, 512k. Uono Monitor. Pnmiltl Port, 5 Drlvi Co™, 200 ' P0w«r Supply. T>OT Wor-ranrj, 'QW., ,Q.M CorripciHh<«, Frie SqUmot* Free Catalog General Technics OualEly Compulse Syilema Post Office gox 2 576 Lake Rortkonkomo, NY 11779 Lake Koftkonkoina, NT 11^9 yr: (51 5) 981 9475 £— BUILD working 68000 single board computer under S1 00.00! Complete slep-by-step manual includes schematic, circuit board, layout, parts lisl. Plans incorporate same CPU chip as Macintosh, Amiga. Atari ST; $24.95. Catalog of robotic and varied CPU projects, $1.00. HTC TECHNOLOGIES, 9 Union Square, Ste 129, Southbury, CT 064B8. (203) 263-3958. ^PftOttPU Vidtopkottt in a Chip STILL FRAME TV PICTURE TELEPHONE TRANCEIVER KIT San-LJti Slow Scan TV pictures ovir Tho phono lino In Twelvs ^oconHiy Cuplum VCR. NTSC Video output and hold. ihd -rJi -* r p>\i\y and sends on command Auto Mods ei and racBlve IC Chip R«ptncoe t BO SS C IS to 50 Levels of Grey Scale Serves as: TV FAX llowo hands froo Bond Displays on any TV P»P» | Camera PhDMVU Lii'H." *— Us. VCR Med E VEdtophoni Chip ind Schematic A/0, DRAM, D-R-g. PC Board (BARE] 50 Rtft. Cap, Dlorfa Cabin*!, (uncut) Powor Pack TV Camera ! M r..-: j ■:..-;. r p. uioae 4BP DIP (56.95 $21.00 518.95 $29.75 si:. 7 5 S9.75 $189.50 5113-7 5 Visa ana FAX Order (213) BS7-1B52 nil f\ Electronics Box 1 1 14B rIVILr Marina OqI Ray, CA 90292 FM transmitter 88-108 MHZ kit $12.95; Flyback test- er assembled $95.99; S & H 4%. SIERRA ELEC- TRONICS, Box 709, Elfers, FL 34680-0709. RECEIVE all cordless telephones on your police scanner. $5.00 and SASE gels frequencies FRE- QUENCIES, TO Box 550, Tiverton, Ri 02878. VCR amplifier. Transmits to any TV in the house. Complete unit only $49.95. Miniature FM transmit- ter-size of postage stamp, up to 1 mile range, $29.95. Free into. CAS ELECTRONICS, 1525 Avia- tion Blvd., Suite 136, Redondo Beach, CA 90278. COLLIMATOR PEN (INFRA-RED) LASER DIODE (VISIBLE-RED! UNICORN - YOUR IX. SOURCE ! • Output: 2.5 mW (max.) •Current: 90-150 mA ■ Operating Voltage: 2.2-2.5V • wavelength: 820nm ■ Collimation: .18mrad (typ.) ■Size: 11 mm diameter STOCK# PRICE SB1052 $39.99 LASER DIODE (INFRA-RED) •Output: 10 mW (max.) •Current: 90-1 50 mA • Operating Voltage: 2.2-2.5V • Wavelength: 820 nm ^^^A STOCK* PRICE ^N^ SB1053 $9.99 LASER DIODE (VISIBLE-RED) ■ Output: 5 mW (max.) •Current: 65-100 mA • Operating Voltage: 1.75-2.2V • Wavelength: 780nm STOCK* PRICE LS022 S19.99 • Output: 5 mW (max.) • Current: 20 mA • Operating Voltage: 2.2-3.0V • Wavelength: 665 nm STOCK* PRICE LS3200 $129.99 EPROMS SIOCK, PINS DESCRIPTION! 1.24 25 39 100* 1702 24 256 * 4 1 us 3 99 3.79 3.41 2708 24 1024 s 8 450ns 6.49 6.17 5.55 2758 24 1024KB 450ns 3.99 3.79 341 2716 24 2048x6 450ns (25v) 3.29 3.13 2.62 2716-1 24 2048 « 6 350ns (25*) 3.79 3.60 3 24 THS2716 24 2048 X 6 450ns 6.29 5.93 5.38 27C16 24 204818 450ns (25* -CMOS) 3.99 3,79 3.41 2732 24 4096 KB 450ns (25v) 3.79 3.60 3.24 2T32A-2 24 4096 k 6 200ns (21 v) 3.79 3.60 3.24 2732A 24 4096x8 250ns (2 W) 369 3.51 3.16 2732A-1 24 4096x8 *50ns (21 v) 3.19 3.03 2,73 TM52532 24 4096x8 450ns (25*) 5.79 5.50 4.95 TMS2532P 24 4096 x 8 450ns (25v-One Time Program mable'l 1 .99 1,89 1.70 27C32 24 4096x8 450ns (25V-CMOS) 4.19 3 98 3,58 2764-20 28 S192xS 200ns (21 v) 3.99 3.79 341 2764 28 8192x8 250ns (21V) 3.79 3.60 3.24 2764A-20 28 8192x8 200ns|12-5v) 3.99 3.79 341 2764A 28 8192x8 250ns (12.5v) 3.29 3.13 282 TMS2564 28 8192x8 250ns (25v) 6.79 6.45 5.81 27C64 28 8192 x B 250ns (2W-CMOS) 4,19 3.96 3.53 27128-20 28 16,384x8 200ns (21 V) 5.79 5.50 4.95 27128 2B 16.3B4XB 250ns (2 W) 5.09 4.84 4.35 271 28A 26 16.384x8 250ns (21V) 5.79 5.50 4.95 27C12B 28 16,384x8 250ns (2 1v) 5.79 5.50 4.95 27258-20 20 32,728 xB 200ns (12,5V) 5.29 S.03 4.53 27256 28 32.768 k 8 250ns (12.5v) 4.79 4.55 4.09 27C2S6 28 32.768 x 3 250ns ( 1 2.5Y-C MOS) 5.29 5.03 4 53 27512-20 28 65.536x8200ns(12.5v) 7,49 7.12 6,41 27512 28 65.536 x 8 250ns (125v) 6.99 664 S9B 27C512 28 65.536 x 3 250ns (12.5v-CMOS) 6.99 6.64 5.98 27C1Q24 32 1 3 1 ,072 x 8 2O0ns < 1 2 5v- CMOS) 17.99 17.09 15.36 68764 24 8192 xB 450ns 13.99 13.29 11.96 6B766 24 8192x8 450ns ^H!" f. \ lM(OIt\ '-jJ ELECTRONICS 14,99 14.24 12.82 1001 Canoga Ave., Unil B-8 • Chatswortk CA 91 31 1 OUTSIDE CALIFORNIA: (800) 824-3432 {Orders Only) IN CALIFORNIA: (818) 341-8833 ORDER BY FAX: (818) 998-7975 Minimum Order: SI 5.00 > o c: to o 87 CIRCLE 181 ON FREE INFORMATION CARD COMPUTERS FOR LE$$ 1 MHz 8088 System $369 > 4.77/10 MHz 6088 Motherboard . 256 KB RAM (640KB max) • 150 Watt Power Supply • Floppy Disk Controller . One 5.25" 360 KB Floppy Drive • MonoGraphics Card w/ Parallel Port • 101 Key Enhanced Keyboard • Case (3 LEDs ,2 Buttons , Key-Lock) • 12" Amber Monochrome Monitor 12 MHz 80286 System $669 . 12 MHz 80286 Motherboard > Wait State . 512 KB RAM (4 MB max) • 200 Watt Power Supply • Floppy Disk Controller • One 5.25" 1 .2 MB Floppy Drive • MonoGraphics Card w/ Parallel Port • 101 Key Enhanced Keyboard . Case (3 LEDs ,2 Buttons , Key-Lock) • 12" Amber Monochrome Monitor One Year Parts & Labor Warranty 30 Day Satisfaction Guarantee Shipping & Handling Extra VISA & M/C add 3% Amex add 4% Price & Availability subject to change without prior notice JINCO COMPUTERS INC. 5122 Walnut Grove Avenue San Gabriel, CA 91776 Tel: (818) 309-1108 CIRCLE 179 ON FREE INFORMATION CARD CONSOLIDATED £ C O H I ^wsr w^ttfB UI W M . flig.T.y; . THE ULTIMATE ELECTRONICS CATALOG Order your 260 page catalog and price lilt with over 14,000 money laying electronic parti and equipment! Send $3.00 in a check or money order, or call 1-800-643-3668 today and me your Maitercard or Vtaa. Conjolidatod Elearonicj, Incorporated 706 Wstervliet Aye., Dayton, Ohio 45420-2699 Name Addrwt_ City -State K.D. VIDEO FOR ALL YOUR CABLE TV NEEDS WE SPECIALIZE IN DEALER PRICING QTY Jerrold (Type) SB-3 Jerrold (Type) Tri-Bi Scientific Atlanta SA-3 Hamlin MLD-1200 OakN-12 Vari-Sync Jerrold 550 Converter Jerrold 400 DRX-3DIC (With Built in SB-3) 1 10 20 89.00 56.00 48.00 119.00 69.00 65.00 129.00 8000 75.00 99.00 59.00 45.00 99.00 59.00 58.00 99.00 75.00 68.00 69.00 109.00 100.00 1-800-327-3407 Call us lor prices on large quantities K.D. Video PO Box 29533. Mpls. F WIN 55429 PLANS! Remote control tester S9.95. Zener diode tester (plug into DMM) $9,95. Electronic Stethoscope S9.95. D.E. STENGER, Box 1136, Brooks, Alberta TO J 0J0. IMAGINE That, is a collection of new ideas and product concepts that have been only partially de- veloped. Innovative, thought-provoking. For design- ers and hobbyists alike. $5.35. N1FFTY CON- CEPTS, BOX 1323. Sheboygan, Wl 53082-1323. GARAGE alarm system. AC or battery operated. Detailed installation instructions control panel, key- pad, siren, switch, wire $135.00. Write to: JM IN- DUSTRIES, 2840 W. Southland Drive, Franklin, Wl 53154. BUSINESS OPPORTUNITIES EASY work! Excellent pay! Assemble products at home. Call for information. (504) 641-8003 Ext. 5192. MAKE $50/hr working evenings or weekends in your own electronics business. Send for free facts. INDUSTRY, Box 531, Bronx, NY 10461. YOUR own radio station! AM, FM, TV, cable. Li- censed I unlicensed , BROADCASTING, Box 130- F8, Paradise, CA 95967. MAKE S75.000 to $250,000 yearly or more fixing IBM color monitors (and most brands). No invest- ment. Start doing it from your home. (A telephone required.) Information. USA, Canada $1.00 cash. US funds. Other countries $8.00 RANDALL DIS- PLAY, Box 2168-R, Van Nuys, CA 91404 USA- GET m AW ON THE SI I BILLION A YEAR COMPITKR SERVICE INDUSTRY UP TO LEARN HOW TO CLEAN/ MAINTAIN/REPAIR PRINTERS . viejc'S AW/n>a-wunnie hummc main mo CBHPXttWK THM1HNE hjhhmi {OVER 300 ACTION-PACKED P1GES) OTHIffKMFl ID OfJ*H INTER REPAIR WITH TOUR MIEaiOE MECHANICAL ABILITY WE CAN SHOW YOU HDW TO REPAIR UEI0 SSH0EALLPRIN1EBS START EAHKINS EI IRA CASH III DAYS! • HUGE UN WPP ED MAHKETI • se n i o Li s lack o rt n a i n e a t e c h n i c i a h s . . . OVER 37 MILLION PC'S IK USE . . APPH0XIMATELY !S% HAVE A PRINTER. ATTACHED . VHlMtl'MflY OrPRINTEflBREAKDDWHSAREOUETOSSMPLE MECHANICAL OR ELECTRO-MECHANICAL FAILURE OH WRITE TO: VIEJD PUtLICATIONS HitWUMHEILfM DE(TRE-2L.» CA SSDIO FREE INFO CALL 1-800-537-0589 EARN $10O0's extra as a part-time computer dealer. Where to buy products at big discounts. Who to sell to. Financing without cash. Obtaining free software. Exclusive dealer trade shows. Step-by- step check list. Industry inside knowledge. Written by industry pioneer. Order now, only $24.95 plus $4.00 shipping/handling, CA residents add $1.81 sales tax. CORNERSTONE PUBLICATIONS, Dept BD, PO Box 5151, San Jose, CA 95150. Allow 2-4 weeks. EASY! Moneytnaklng one man CRT rebuilding machinery. $6,500.00 — $11,900.00. CRT, 1909 Louise, Crystalake, IL 60014. (815) 459-0666. LEARN to clean'repair fax machines. Huge new market! Earn $85/hour. No experience necessary. Free details call 1 (800) 537-0589 or write to: VIEJO PUBLICATIONS, 3540 Wilshire Blvd. #310, Dept. FX200, LA. CA 90010. INVENTORS: We submit ideas to industry. Find out what we can do for you. Call 1 (800) 28 8- IDEA. LET the government finance your small business. Grants'loans to $500,000. Free recorded message: (707)449-8600, (KS1). WANTED INVENTIONS/new products/ideas wanted: Call TLCI for free information 1 (800) 468-720024 hours/ day - USA/Canada. ANTIQUE RADIO CLASSIFIED Free Sample! Antique Radio's Largest Circulation Monthly. Articles, Ads & Classifieds. 6-Month Trial: $13. 1-Yr: $24 ($36-1st Class). A.R.C., P.O. Box 802-L6, Carlisle, MA 01741 INVENTORS! Confused? Need help' Call IMPAC for free information package. In US and Canada: 1 (800) 225-5800. INVENTORS INVENTORS! Can you patent and profit from your idea? Call AMERICAN INVENTORS CORPORA- TION for free information. Over a decade of service 1 (800) 338-5656. In Massachusetts or Canada call (413) 568-3753, 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. 4080 Paradise Rd. #15 Dept. RE-90 Las Vegas. NV 89109 TEST EQUIPMENT ACCESSORIES LOW cost oscilloscope probes, multimeter test leads. Save over 50%. 1 (800) 772-1519 free cata- log. PROBEMASTER INC., 4898 Ronson Court, San Diego, CA 92111-5000. MASTERCARD AND VISA are now accepted for payment of your advertising. Simply complete the form on the first page of the Market Center and we will bill. SATELLITE TV VIDEOCIPHER II manuals. Volume 1 — hardware, Volume 2 — software. Either $34.95. Volume 3 — projects/software. Volume 5 Documentation or Vol- ume 6 — Experimentation $44.95 each. Volume 4 — Repair $99,95. Cable Hacker's Bible — £34.95. Clone Hacker's Bible — $34.95. Catalog — $3,00. CODs: (602) 782-2316. TELECODE, PO Box 6426- RE, Yuma, AZ 85366-6426. 88 CIRCLE 70 ON FREE INFORMATION CARD CABLE TV EQUIPMENT Converters, Remote Controls, Dcscramblcrs, CD Players. JERROLD-OAK-SCIENTIFIC ATLANTA-HAMLIN ZENITH MANY MORE CALL TODAY! V Only quality products sold V Easy to use YSiti&faction guaranteed V Knowledgeable sales staff V Most orders shipped within 24 hours CALL FOR YOUR FREE CATALOG 1-800-228-7404 MAKE THE CONNECTION WITH INL-TEK ELECTRONICS | 51 14 Balcones Wood Dr.#307 Dept.298 ^^^^Attstjn/rx^875?^^^^^ FREE catalog — Lowest prices worldwide, save 40 — 60%. Systems, upgrades, parts, all major brands factory fresh and warranted. SKYVISION, INC., 2009 Collegeway, Fergus Falls, MN 56537. 1 (800) 334-6455. MN & International (218) 739-5231. VIDEOCYPHER II descrambling manual. Sche- matics, video and audio. Explains DES. EPROM, CloneMaster, 3Musketeer, pay-per-view (HBO, Cin- emax, Showtime, adult, etc.) $13.95, S2.00 postage. Collection of software to copy and after EPROM codes, $25. CABLETRONICS, Box 30502R, Beth- esda, MD 20824. CABLE TV secrets — the outlaw publication the cable companies tried to ban. HBO, Movie Channel, Showtime, descramblers, converters, etc. Sup- pliers list included. $9 95. CABLE FACTS, Box 711- R, Pataskala. OH 43062. K.U. band satellite system. Perfect for R.V. or patio use. For information call (317) 742-6346 or write to NEW HORIZON ELECTRONICS, 345 Burnetl Road, West Lafayette, IN 47906. CABLE TV DESCRAMBLER LIQUIDATION! • Major Makes & Models! • Will match or beat anyone's prices! • Dealer discounts at 5 units! • Examples: HAMLIN COMBOS . $44 ea. {Min. 5) OAK ADD/ON $40 ea. (Min. 5) OAK M35B $60 ea. (Min. 5) WEST COAST ELECTRONICS For Information: 818-709-1758 Catalogs & Orders: 800-628-9656 DIGITAL ODOMETER REPAIR DIGITAL Odometer; Replacement chips for damaged odometers easy to install in GM, Ford, & Chrysler. All you need is year, model, & last known mileage. (Caution) You will break the law using this product to falsify odometer readings, this product is for repair only! For ordering information send $2.00 to CHIP. PO Box 3302, Saginaw, Ml 48605. 7 ***** PRESENTING ** -tt* * CABLE TV DESCRAMBLERS ***** STARRING ***** JERROLD, HAMLIN, OAK AND OTHER FAMOUS MANUFACTURERS * FriVEST WMFWJTY PROGFE^U AVAILABLE * LOWEST ftETAiL/WHCHESALE PRICES IN U.S. * ORDERS SHIPPED FROM STOCK WtTHJN H HOURS FOP I RJ.-F CATALOG ONd 1-BDO- 34 5- S92 7 t FORALLIfJFORMATfOW f-818-716-5914 j T PACIFIC CABLE CO. INC. CABLE T V "BOXES" Converters — Descramblers Remote Controls — Accessories * Guaranteed Best Prices * * 1 Year Warranty- CO D s * * Immediate Shipping * * FREE CATALOG • Call or Write TRANS-WORLD CABLE CO, 12062 Southwest 1 17th Court. Suile 126 Miami, Florida 33186 I 1 S0O 4 42 93 3 3 MARK V ELECTRONICS, INC. OLALH Y COMPONENTS * COMPETITIVE PRICES A indicates the level of difficulty in the assembling ofour Products. TA-1 2QMK2 CATALOG & INFORMATION (213) 888-8988 ORDER TOLL FREE 800-423-3483 IN CALIFORNIA 800-521 -MARK FAX (213) 888-6868 A Beginner A A Intermediate AAA Advanced * Fully Assembled MODEL TA-28MK2 TA-50A/B TA-50C TA-120MK2 TA-300 TA-302 TA-323A TA-377A TA-400 TA-477 TA-800 TA-802 TA-820A TA-1000A TA-1500 TA-2200 TA-2400A TA-2500 TA-2B00 TA-3000 TA-3600 ~ DESCRIPTION Digital Voice Recorder A A Multi-Purpose Melody Generalor A Multi-Purpose Melodi Generalor A 35W Class "A" Main Power Mono Amp AA. 30W Multi-Purposo Single Channel Amp A 60W Stereo Power Booster (w/case) AA 30Wx2 Stereo Pre-main Amp A. Hi-Quality FET Stereo Pre-Amp AAA 40W Solid State Mono Amp A 120W Mosfel Power Mono Amp AA BOW-.BOW DC Pre-Main & Power Amp AA 80W+80W DC Siereo Main Power Amp AA 60W+60WOCL DC Pre-Main Stereo Amp AA 100W Dynamic Class "A"Main Power Mono Amp AA 100W«2 Class "A" DC SterBo Pre- Main Amp AAA. ... FET Super class "A - DC Pre-Amp AAA Electronic Echo & Reverberation Amp AAA* HQ Pre-Amp. w/10 band graphic equalizer * — HI-FET IC Pre-Amp. w/3 way tone control AA Stereo SimuEalor (mono TV f any mono source} A A 30OW HO Hi-Fi Power Mono Amp ' ' 30.00 ,.11.84 12.65 .27.16 ..20.00 .. 60.00 ..29.50 69.95 . 20.00 .68.00 .60.92 46 94 ..40.39 ..59.69 ..7370 .47.70 48.90 .30-20 .79.00 16. SS 17.71 38.81 29.00 70.00 33.35 75.00 34.93 65.00 79.2D 59.72 49.37 80.58 9S.B1 58 24 116.00 90.80 63.57 41.36 103.00 KIT ASSMB: TR-100A 0-15V 2A Regulated DC Power Supply tc««/iwufniti] AAA* S 69.50 TR-355A CM 5V5A Regulated DC Power Supply A 14.55 20.76 TR-355B O-30V 3A Regulaled DC Power Supply A 14.55 20,76 TR-503 O-50V 3A Regulated DC Power Supply AA 15.75 22.65 SERB SM-48 SM-48A SM-49 SM-100 FC-t0O0A 3 1,'2MuI[i-l-unclional 4 1/2 Hi-Precision O.P.M.AAA -T333- (w/ABS plastic case) . 38.00 4 1/2 Hi-Prescision D.P.M. w/ABS plastic case AAA 41.20 3 1/2 Mulli-Functional LCD D.P.M. (wmold fnncliDn) AA 36.00 150 MC Digital Frequency Counter AAA 79.00 1 GHz Frequency Counter * 4W 48.00 52.00 44.50 90.00 179 00 ViSSSO, TfUKSlT cabinet SM-328 * taMform. ~ i - SM-49 .ANEOUS KIT ASfrHB. MODEL DESCRIPTION TY-23B 3 Channel Color Ligtil Controller AAA* $ 5604 $ 74.50 TY-25 Siereo Loudspeaker Protector A 12.65 19.88 TY-35 FM Wireless Microphone A 9J?2 TY-36 AC/DC Quartz Digital Clock A 18.00 25.20 TY-3H SounoVTouch Control Switch A. 12.00 TY-41MKV Infared Remote Control Unil w/case AAA 20.00 35.00 TY-42 Bar/Dot Level Meier AA 24.15 TY-43 3 1/2 Digital Panel Meter A 29.00 38.00 TY-45 20 Steps Bar/Dot Audio Level Display AA 38.45 46.14 TY-47 Superior Electronic Roulette AA 19.46 27.24 SM-222 7 Band HI-FI Graphic Equalizer AAA* 26.80 38.80 SM-328 4 Channel Professional Coloi Light Conirctier* 150.00 SM-333 Audio/Video Surround Sound Processor AAA* 62.00 83.00 SM-666 Dynamic Noise Reduction A 26.00 34.00 METAL CABINETS WITH ALUMINUM PANEL MODEL H" I W- I D" MATCHING PRICE LG-1273 3" 12" T TA-2800.TA-377A $ 20.16 LG-16B4 4" 16" 8" TA-322i, TA-323A, TA-377A 24.64 LG-1924 4" 19- 11(4 TA-802, TA-820A, TA-1500. TA-120MK2. TA-800 ..30.00 LG-1925 5" 19" 1114 TA-477, TA-800, TA-1500, TA-1000A 33.00 LG-1983 2»i 19" 8" TA-377A, TA-2800. TA-2200, TA-120MK 2 26.50 POWER TRANSFORMERS MODEL DESCRIPTION MATCHING PRICE 001 56VCT. 60VCT6A TA-BO0, TA-802. TA-820A, TA-1000A. TA-tSOO S 26.00 002 72VCT3A TA-3221, TR-503, TA-323A, TA-400 21.00 003 80VCT6A TA-477 27.00 004 48VCT6A TR-120MK2 21.00 005 52VCT3A TR-355B 15.00 006 36VCT5A TR-355A 14,50 007 112VCT8A TA-3600 42 00 VSA (CPU. SAT 10W*U bCT. MU :tnM3 S'QCOWK MARK V ELECTRONICS, INC. - 8019 E. Slauson Ave, Montebello, CA 90640 > c Q c CD o CIRCLE 93 ON FREE INFORMATION CARD 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 gob or school. Everything is explained In easy-to-understand language with plenty ol draw- ings, diagrams and photos We show you how to troubleshoot and repair video -cassette recorders and TV sets, how lo handle house calls and shop repairs for almost any make of television or VCR Tools are included with your course so you can get "hands-on" praclice as you follow your lessons step by step. Send lor Iree lads about the exciting opportunities in TV VCR Repair and find oul how you can start making money in this greauarm MA IL_COUPON TO DAY__ ™c ICS SCHOOL OF TV/VCR REPAIR, Dept. DEO70 IsseuhtJ 925 Oaik Street. Scrarrton, PA 18515 Please send me full inlormation and color brochure on how I can learn TV VCR Repair at home in my spare time I understand there is no obli gahon and no salesman will visit me. Age . Address Cily/SSate _Apl#_ .Zip ^Phrme [ ) __ ^ EDUCATION & INSTRUCTION MAGIC! Four illustrated lessons plus inside inlor- mation shews you how. We provide almost 50 tricks including equipment for four professional effects. You get a binder to keep the mate rials in, and a one- year membership in the Internationa! Performing Magicians with a plastic membership card that has your name gold-embossed. You get a one-year sur> scriplion to our quarterly newsletter "IT'S MAGIC! 1 ' Order now! S29.95 for each course + $3.50 postage and handling. (New York residents add applicable state and local sales tax). THE MAGIC COURSE, 500-B BiCounty Boulevard. Farmingdale, NY 11735. BASIC video cleaning and maintenance. TV one half hour, VCfl one hour. $38.00 each. JAMES BRADFORD, PO Box 38359, Detroit, Ml 48238. ELECTRONIC review Detailed electronics review- ing for bettering grades, interviews, and promotions. Over 300 pages $39.95 include $4.25 shipping. USER-GRAPHICS, Education Department, 7136 Everett, Boise. ID 83704-7415. LEARN IBM PC assembly language. 80 pro- grams. Disk $5.00. Book $18.00. ZIPFAST, Box 12238, Lexington, KY 40581-2238. CABLE T.V. CONVERTERS WHY PAY A HIGH MONTHLY FEE? All Jerrold, Oak, Hamlin, Zenith, Scientific Atlanta. Magnavox and all specialized cable equipment available tor shipment within 24 hours. For fast service MC/ VISA or CO. D. telephone orders accepted (800) 648-3030 60 Day Guarantee (Quantity Discounts) 8 A.M. to 5 RM, CS.T, CLOSED WEEK- ENDS. Send self-addressed Stamped enve- lope (60s postage) for Catalog. n po B015000 tniDujesT suit? miRi €L€CTROniC5tnC. ^™2le. IL SIM No Illinois Orders Accepted. HARDWARE HACKER continued from page 72 PowerMOS power transistor disk from Phillips. A free sample from Tektronix! Welcome to the nineties. They'll be happy to send you a free sample of their new SMT grabbers. Rounding out the free samples for today are those Bend-Flex flexi- ble printed circuits from Rogers and the Conpad el astomeric battery clip replacements from Stockwell. A High Current Transistor Design Guide wall chart is available through PowerTech, while Rochester Elec- tronics offers an inventory guide to discontinued semiconductors. Tec Spec is an outstanding hacker newsletter chock full of easy-to- build and hands-on stuff, including Van De Graff generators, visible lasers, and do-it-yourself vacuum pumps. A free sample copy of the newsletter is available. Another spe- cial-interest newsletter is the Tesla Coil Builder's Association quarterly. This one is $20 per year. R-E 9 z o pc h o LU o D < rr 90 I Parts (M) motorola Polydax fjFyMiMQf EMINENCE „;:z£r*sr ===== 1-800-338-0531 » pioneer- 3-WAY 100W CROSSOVER 12 dE'ocfave roUoft. BDOHz, SOOOHl crossover points. 8 ohm. 100 watts RMS. m #260-210 $12.50 (1-9) $9.95 (10-up) SPEAKER CONTROL PANEL Panel wittr 50 watt L -pads' for tweeter and midraiige and built-in LED power merer. S'i 3 VF 100 wan TertJOB available $1450 #260-235 {1-5) $12.90 (6-up) 12" POLY WOOFER Super duly, 40 oi. magnet. 100 warn RMS, 145 Wilts max. 4 and 8 ohm compat- ible (.6 ohm). 2' voice coil ts-2SHi.OTS^.166, VAS-lCBcuft. Response: 25-1500 Br. Nel weight: 9 lbs. Pioneer *A3OGU40-31D #290-125 $36.80 (1-3) $34.50 (4-UP) 15" WOOFER Original Sanyo woofar. Paper cone with vented dust cap and Irealeddoth J surround. 12 02. f**j magna!. 60 watts RMS. 85 watts ^ max. B ohm. Resonance: 26 Hi. Response: 25- 2,500 Hz* #291-155 $23« $21 90 (6-up) PIONEER HORN TWEETER Mylar dame. 2.93 ox. barium ferrite magnet J ohm. Response. 1B0D- 20000 Hi. 3SWRMS, SOWimu. fa- 2000 Hx, SPL «s 106 dB. Pioneer #AHE6Q-51F * #270-050 S6.S0 (1-9) $5.90 (10-up) II r Parts ycxpress 340 E. Ftii- St, Duytran. 02*0 45402 Loci]: !-5i3-£22-DiT3 FAX- 513-222-1644 * 15 day money b*dc guiraOM ' S [530 navmn order ' Wo accwpi kUswffaffd, Vm. Dt9onw, *rd COD. oidnx "24 hour EhifpLrg 'Shipping chUfgje- UPS Chin iWe *%UXi- 33-00 minimum ehirge) 'Hour* £30 in." 8:00 pm EST, Mondiy - Fndiy 'Mailorder c^jtomcus, ptautT ciH for alMcpixij wtimit.ii on ordcra ojcccodirrg 5Q». 12" SUB WOOFER Dual voice coil sub woofer. 30 oz, magnet, 2'" voice coils. 100 wans RMS, 145 watts mar. ts - 25 Hi. 6 ohm (4 and & ohm compatible). SPL-89dB 1W/1M. Response: 29-700 Hi, OTS .31, VflB I0.3cu. It.. Pioneer #A30CtJ30-S5D. Nel weight- 6 lbs. $39.80 (1-3) #290-145 15" THRUSTER WOOFER Thrusler by Eminence. Made in USA Poly loam surround, 56 oz. magnet. 2-1S*, 2 layer voice coil. 180 watts RMS. 210 watrs Text. 4 ohm. Is -23.5 Ht,QTS = .33, VAS=17.9 cull. £Pt-94.BdB 1W/ 1M Net weight: IS lbs. $43.50 #290-180 18" EMINENCE WOOFER MADE1NUSA 100 oi. magnet. 3" voice coil. 2S0 watts RMS, 3S0 watts max, 3 ohm, 30 Hz resonant frequency . 22- 2700 Hi response. Efficiency; 95 dB 1W/1M. Paper cone, treated accordian surround. Net weight: 29 lbs. #290-200 $98.90 (1-3) $89.50 (4-up) TITANIUM COMPOSITE TWEETER Tianum is depenud on a psJ/n* ■cScme to combine [he v&XMtiaxjm of both hud *nd Kft dame WdWrOicgiML Sohm- Fen Quid cooUd vote* «nl, Et = 1300H±, 5PL SJdB IW/1M. 50 wilti EMS, 70 vritu TDU- 4" round Fotydw put l>DTWIUTL25. #270-047 *(i-9) $24.80 {10-up) GRILL FRAME KIT With this Idl you can make speaker gull frames up to SO" i 4 Mm JE21 JE23 JE24 JE25 JE26 JE27 3.25 12.125 65x2-125 6.5x3.125 6.5x4.25 6.37515.75 7 .25 X 7.5 400 B30 1.360 1.660 2,39* 3,220 $4.95 $6.95 $12.95 $17.95 $22.95 4 $32.95 Oscitloscope Probes ■ Attenuation: xt / xli ■ Capacitance (LF1B0): 180pF /22pF:[LF210}: 40pF717pF LF1B0 40M Hz Oscilloscope Probe $19,95 LF21 1 00MHz Oscilloscope Probe $29.95 GoldStar 20MHz Oscilloscope and 1GHz Frequency Counter * Large 6" rectangular display * High sensitivity: 1 mV/div GS7020 osoiitaseope $399.95 » Wide measuring range * Measured value hold function FC7102 Frequency Counter $299.95 Metex Digital Multimeters General Specs: - Handheld, high accuracy ■ ACVOC voltage, AC/DC current resistance, diodes, continuity, transistor hFE ■ Manual ranging w/ overload prolection M3650, 3650B X M465U only: ■ Also measure frequency and capacitance M4650 only: • Data hold swilch ■ 4.5 digit M361 3.5 Digit Mullirneler $49,95 M3650 3.5 0*0*1 Multimeter mlFrequency 1 Capacitanca $69,95 M3650B Same as M!650w/Barorapli $74.95 M46 50 4 .5 Digit wVFrequency Capiatmce and Dan Hod Swilch $99.95 s 92 Multimeter Specials M80; * AC/DC voltage, ACfDC current* resistance, diodes, continuity & frequency ■ Full auto- ranging on DC voltage ♦ High/low semi- auEoranging for AC- DC currant and ohms ■ Data hoW switch ■ Extra-large display M&O 3.75 Digit Mtflimeler $59,95 M3000: « AC DC vrjliaga, AC/DC current , resistance, diodes, conlinuily, dwell angle and engine RPM ■ High surge voltage protection M39O0 3.5 Digit Multimeter $59,95 Prototype Design Stations WM2 WMi & WM2 Features: * Removable soldert&ss breadboard * Variable and fixed DC power supply ■ Multi-frequency sig- nal generator * Analog multimeter * 8 tricolor LEDs {red £ green) * 8 logic switches ■ Logic probe • Lighled power switch * Fuse overload protected * Sturdy rugged, zed case WMi 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 (1 Hz to 1MHz) WM1 Analog Prototype Station $199.95 WM2 Digital Prototype Station $249.95 A.R.I EPROM Programmer UVP EPROM Eraser i j • Programs all current EPROMs in the 2716 to 27512 range plus the X2864 EEPROM ■ RS232 port ■ Software included EPP • Erases all EPROM's • Erases 1 chip in 15 Min. and 8 chips in 21 min. • UV intensity; 6800 UW/CM^ .$179.95 DE4 $69.95 Soldering and Desoldering Stations 60 Watt Analog Display Soldering Station - Electronic temperature control from 200° to 878"F • Cartridge heating element for a longer hfe Ol the soldering lip XY1683 .$59.95 60 Wall Analog Display Soldering Station - Electronic temperature conirol from 200* to 97B*F - Ceramic healing elemeni for a steady temperature and long life XY2660.... ,.$aa.95 60 Watt Digital Display Soldering Station * Electronic temperature control Irom 200° to 878*F • Temperature displayed on easy (o read .5SO"H 3-digit LED readout ■ Nichrome heating element XY960 $99.95 30 Watt Electron ic Temperature Controlled Desoldering Station • Electronic temperature control Irom 212° lo 842°F * Self-contained high rolary vacuum pump XY999 $279.95 51-Piece Electronic Tool Kit The MS305 provides the tools needed tor building, repairing and general maintenance of most electronic equipment. A convenient and durable carry-along combination lock case safely protects and secures this 5i-piece tool kit. From the digital multimeter to the desoldering pump this kit Is the perfect item tor technicians and electronic enthusiasts. • 10" measuring tape ■ Electric tape • 6" long tweezers • 7" brush and scraper ■ 7" line point probe ■ 7" slotted probe - Rosin core solder • 30 watt soldering iron • Desoldering pump ■ Soldering stand Tools Included in Kit • Stainless steel scissors • Utility components box ■ 8 pes. hex key wrench • Digital Multimeter • Round needle file ■ Flat needle file • 8* adjustable wrench • Utility knife with extra blade ■ Bent needle nose pliers • Diagonal cutting pliers ■ 5.25" needle nose pliers ■ 6 piece precision screwdriver set ■ Brush ■ 10 piece screwdriver set: 5 Slotted & 5 Phillips ■ Flat nose pliers •Carrying case: 17.63"Wx12.5"Dx3.5"H MS305 $119.95 Partial Listing Over 4000 Components and Accessories in Stock! • Call for Quantity Discounts CIRCLE 1 14 ON FREE INFORMATION CARD J MbiI Order Electronics -Worldwide a me co ELECTRONICS Request Jameco's 1990 Catalog for a Complete Listing of Components, Test/Measurement Equipment and Computer Products Jameco 20MHz 80386 Desktop Computer Kit Fully IBM Compatible Free! Concurrent 386 (Disk Operating System) Software Included 4MB RAM Included, Expandable to 8MB on board, 16MB with optional expansion board 8/1 6'20MHz Keyboard Switohable Operation AMI BIOS ROMs Included Fliptop Case w/200 Wall Power Supply Conner High-Performance IDE 3.5" 40MB Hard Disk Drive Teac 1 2MB Floppy DSHD Disk Drive Multi I/O Card with Universal Floppy Controller Fujitsu 101 -Key (Enhanced) Keyboard Shown with VGA Option (not included) JE2Q5S Mulliscan Monitor and VGA Cafd....J6S9.9« (See Below) IE3551 20MHz 80386 Compatible Kit. .......$1 949.95 lameco IBM >C/XT/AT Compatible Cards IE 1043 360KB/720KB/1.2MB/1.44MB Floppy Disk Controller Card (PC/XT/AT).. $49.95 E1 050 Monochrome Graphics Card w/ParaHel Printer Port (PC/XT/AT) $49.95 IE1052 Color Graphics Card vtt Parallel Printer Port (PC/XT/AT) $49.95 IET055 EGA Card w/ 256KB Video RAM (PC/XT/AT) $139.95 IE1 057 8/16-Bit VGA Card w/ 256KB Video RAM [PC/XT/AT) $199.95 IE1 060 I/O Card w/ Serial, Game. Printer Port & Real Time Clock (PC/XT) ... $59.95 IE1062 RS232 Serial Half Card (PC/XT/AT) $29.95 IE1065 I/O Card w/ Serial. Game and Parallel Printer Port (AT) $59.95 IE1 077 Multi I/O Card w/ 360KB/720KB/1 .2MB/1 .44MB Floppy Controller (AT) .. $99.95 :G A, VGA & Multiscan Monitor Packages telisys 14" EGA monitor and EGA card package 540 x 350 max. resolution) IE1059 EGA Monitor & EGA Card $509.90 lelisys 14" Multiscan monitor and 16-bit VGA card lackage (640 x 480 max. resolution) IE2059 Multiscan Monitor & VGA Card... $669.90 teltsys 1 4" VGA monitor and 16-bit VGA card package 640 x 480 max. resolution) IE2061 VGA Monitor S VGA Card $629.90 JE2061 IBM PC/XT/AT Compatible Keyboards MEI 100-Key Micro type Keyboard FKB4700 JE201 5 84-Key Standard AT Style Layout $59.95 : K B4700 1 1 -Key E nhanced Layout will-. 12 Function Keys $69.95 • IBM PC/XT/ATOB6 Compatible * Saves an amazing 60% of the desk space used by equivalent standard keyboards MIRU.. $129.95 Jameco Digitizer Tablet ■ AutoCAD 10 template and four- button puck ■ Resolution: up to 1016 lines per inch ■ Accuracy: ±025" ■ Emulates Ihree of the worlds most popular formats: Summagraphics MM. Sum ma- graphics Bit Pad One. Calcomp 2000 • EEPROM allows custom configuration J CAD Digitizer Tablet $199.95 Stylus Two Button Stylus .... $39.95 Logitech Scan Man Plus Scanner • IBM PC/XT/AT Compatible ■ 4" Scanning Window • 400 dpi SCANP $219.95 Logitech Mice Serial Moose 1 MouseWare Sodware $89.95 Moose w/Bos Board & Mouse* Ware Software $99.95 PS/2 Mouse & MousoWare Softwifo $79.95 Modems External Modems 1200C ;aa™« ick dm $89.95 2400 C 0jtiironia!«0Siod $149.95 9600 E PrcmettausKooBaud $699.95 Internal Modems 1200B jimeniaDhua $49.95 2400B jj-ks: aoc B-oi $99.95 Modems listed abow Include Procomm Software IBM Compatible Cases and Power Supplies | JEtOM JE2012 JE1010 Ftp-Top SowWPOXT Cast 53955 JE1011 sweStjotedPCMtHs., $3955 JE1030 lawiPOOTft-wSu-o-i""" $59.95 JE1D32 JOOnaBaSjATPowSuppV $83.95 JE1035 OTwS ATRawSlH-V. $133.95 JE2Q11 Vmacaawxow PurSupriy $289.95 JE2012 tHtnjrMCWMaotlWF-ir.a-g-aj $169.95 JE2019 Pip-Too 6jt» AT Cjs*. Floppy Disk Drives MF3S3B Mitsubishi MF353B 3.5 - 720KB Intamal Drive $99.95 Toshiba 3 56K U 3. 5' 1 .44M B Internal Drive .. $ 1 09 .95 Teac FD55B 6.25- 3$0KB Internal Drive .. . $89.95 FD55G 5 ?. 5" l i M B Internal Dove ... . $99.95 MiniScribe Hard Drives MFM M8425 20MB (68ms) 3.5'HH $229.95 M8425XT 20MB (68ms) 35'HH (Kit) $289.95 M8425AT 20MB (68ms) 3.5'HH (Kit) $339.95 RLL [68ms) 3.5'HH $249.95 (68ms) 3.5'HH (Kit) $299.95 (68ms) 3.5'HH (Ki1( $389.95 (45ms) 3.5'HH $329.95 (45ms) 3.5'HH (Kil) $369.95 (46ms) 3.5'HH (Kit) $429.95 Disk Drive, Controller A Cables M8438 30MB M8438XT 30MB M8438AT 36MB M8450 40MB M8450XT 40MB M8450AT 40MB (Kit) includes Hard Colorado Memory Systems 40MB Tape Back-Up ■ IBM PC/XT/AT/386 Compall&le • Back-up 40MB In 40 minutes • Back-up 60 to 120MB with extended tapes and data compression software - Includes 40MB tape cartridge DJ10 40MB Tape Back-Up .. $329.95 KE1 External Enclosure Kit $149.95 TB40 J0MB Tape Cartridge $24.95 TB60 60MB Tape Cartridge $32.95 lameco ELECTRONICS 1355 Sho newsy Road, Belmont, CA 94002 24 Hour Order Hotline (415) 592-8097 $50.00 Minimum Order FAX'S (415) 592-2503 or (415) 595-2564 Telex 176043- Ans. Back: Jameco Bimt Data Sheets ■ 50e each For a FREE 46-Page Filer und $2.00 to cover First Class Postage and Handling : 1990 Jameco Electron cs 6790 CA Residents Add 6.25%. 6.75% or 7.25% Sales Tax Shipping - Add 5% plus $1 .50 Insurance (May vary according to weicr I and shipping method) Terms: Prices subject lo change without notice. Items subject to availability and prior sale. Complete list ol lerms/warrantkH is available opoo request. IBM ,B A rfrj-suwed vjdemnrt: at hltrnational Suunaii Mnchlntf visa* Miwic (£ iiw c*^S*^?JS Please refer to Mail Key 2 when ordering > C © c m O 93 Customer Service -Technical Assistance ■ Credit Department • All Other Inquiries • (415) 592-8097 • 7AM - 4PM P.S.T. CIRCLE 114 ON FREE INFORMATION CARD TiT JDR Microdevices • 30 DA K MONEY BACK GUARANTEE ■ 1 YEAR WARRANTY ON ALL PRODUCTS • TOLL-FREE TECHNICAL SUPPORT O WORLD JDR caters to We developer with a tuft fine of prototyping St programming products. Request oar catalog for the compiete fine! MODULAR PROGRAMMING SYSTEM MODULES USE A COMMON HOST ADAPTOR CARD- t SLOT PROGRAMS EPROMS, PROMS, PALS, MORE! HOST ADAPTOR CARD ■ UNIVERSAL INTERFACE FOR ALL - ROG PI A V.M IN G HO DO LE S' ■ SELECTABLE ADDRESSES PREVENTS CONFLICTS -MOLDED CABLE MOD-MAC *29.95 *Q '499.95 UNIVERSAL MODULE • PROGRAMS EPROHS, EEFfiOHS, PALS. Bl -POLAR PROHS. 6748 » 87S1 SERIES DEVICES- 1 6V8 AND 20VB GALS (GENERIC ARRAY LOG IC)FROM LATTICE, NS. SGS • TESTS TTL, CMOS. DYNAMIC & STATIC RAMS ■ LOAD DISK. SAVE DISK. EDIT. BLANK CHECK, PROGRAM, AUTO, HEAD MASTER, VERIFY AND COMPARE ■ TEXTOOL SOCKET FOF1 3" -6"W. ID'S [ 8-40 PINS) MOD-MUP MOD-MPL-SOFT CUPL SOFTWARE $99.95 EPROM MODULE ■ PROGRAMS 24-33 PIN EPROMS. CMOS EPROMS & EEPROMS FROM 16K TO 1024K • HEX TO OBJ CONVEHTER -AUTO, BLANK CHECK'PROGRAM'VERIFY -VF-PS. 12.5. 12.75. 13. 21 4 25 VOLTS • NORMAL, INTELLIGENT. INTERACTIVE & QUICK PULSE PROGRAMMING ALGORITHMS MOD-MEP OTHER MODULES: PAL PROGRAMMER, DIGITAL TESTER. BIPOLAR PROGRAMMER. MICROPROCESSOR PROGRAMMER ■ fflO* SI2S.SS TO K59.9J- CALL FOR INFORMATION *119.95 $ 129. 95 EPROM PROGRAMMER - PROGRAMS 27XX AND 27XXX EPROMS UP TO 27512 • SUPPORTS VARIOUS PROGRAMMING FORMATS I VOLTAGES - SPLIT OR COMBINE CONTENTS OF SEVERAL EPROMS OF DIFFERENT SEES • READ. WRFTE. COPY. BLANK CHECKS VERIFY ■SOFTWARE FOR HEX AND INTEL HEX FORMATS MOD-EPHOM EPROHS 271 28 18384x8 250ns 12.5V 28 4.28 imlMM 163S428 200ns 12.5V 28 5.95 PARTIAL LISTINGS ONLY- MANY OTHERS AVAILABLE! EPROM ERASERS DAI ABASE II * 39.95 ■SHIRT POCKET SIZE 1 • ALL SIZES UP TO 4 AT A TIME • ERASES MOST EPROHS IN 3 MINUTES DATARASE II PE-140T5PECTROMCS9 CHIP ERASER WlTIHER . $139.1 PROTOTYPE CARDS Ffl-J EPOXY GLASS LAMINA TE WfTH GOLD PLA TEJ> EDGECARD FINGERS AND SILK SCREENED LEGENDS FORXT JDR-PR1 WITH *5V AND GROUND PLANE 27J5 JDH-PH2 ABOVE WITH I/O DECODING LAYOUT ... 29 .95 JDR-PR2-PK PARTS KIT FOR JDR- PR2 ABOVE 8.95 rem at JDR-PR10 1 B-BIT WITH TO DECODING LAYOUT 34,94 JDR-PR10-PK PARTS KIT FOR JDR-PH10 ABOVE 12.95 EXTENDER CARDS SIMPUFY PROTOTYPING AND TESTING EXT-SOM 8-BIT FOR 8088 MOTHERBOARDS 29.S5 EXT-80288 16-BIT FOR 286*386 MOTHERBOARDS . 39.95 BUILD YOUR OWN 286 SYSTEM FOR UNDER $650 ITS A GREAT WAY TO LEARN AND A GREAT WAY TO SA VE! HERE'S JUST ONE OF OUR MOST POPULAR CONFIGURATIONS MCT-M2S6-12 8'1 2MHZ MINI 288 MOTHERBOARD MCT-MGP MONOCHHOME GRAPHICS ADAPT MCT-FDC- HO 350K 1 44MB FLOP PY CONTROLLER CASE-JR MINI FLIP-TOP CASE W/150W PS. FDD-3S0 360K 5-1W FLOPPY DISK DRIVE JDR-MONO MONOCHROME MONITOR [GREEN] BTC-SD60 STANDARD 84-KEY KEYBOARD 5199.55 $49.95 $49.95 $149.95 $69.95 $69.95 $59.95 TOTAL SYSTEM (0K INSTALLED) $649.85 OPTIONAL COMPONENTS MOTHERBOARDS MCT-TURBO-10 4 77i'IOMHZ SINGLE CHIP 8088... $99,95 M CT-M 286-1 6N 8/16HHZ 2B6 WJNEAT CHIPSET $289.95 MCT-M286-20N 1 0J20MHZ 286 wineaT Chipset $389,95 LitttefOOf" gg UPRIGHT CASE *249.95 SPACE SAVING DESIGN HOLDS ALL SIZES ! OF MOTHERBOARDS AND INCLUDES A 250 WATT POWER SUPPLY •MOUNTS FOR 3 FLOPPY AND 4 HARD DRIVES •TURBOS RESET SWITCH •LED SPEED DISPLAY CASE-100 CASE-FLIP FLIP TOP CASE FOB S088 MBS $39.95 POWER SUPPUES PS-150 1 50 WATT SUPPLY FOR BOSS'S $59.95 PS-200X 280 WATT SUPPLY FOR SOWS $89.95 PS-200 200 WATT SUPPLY FOR 28S/386'S $89.95 KEYBOARDS BTC-5339 101 KEY ENHANCED KEYBOARD , $69.95 MAX-5339 101 KEY W7TACTILE FEEDBACK (288) ... $69.95 DRIVE CONTROLLERS MCT-FDC-HD4 4-floppy disk CONTROLLER $59.95 MCT-HDC HARD DISK CONTROLLER $79.95 MCT- A FH 286(388 F LOPPY/HARD CONTROL $149.95 MEMORY/MULTIFUNCTION CARDS MCT-RAM 576K RAH CARD (OK) $49.95 MCT-IO HULTI 110 CARD $59.95 1 . 44MB FLOPPY DRIVE *99.95 <**•+& •ULTRAHIGH DENSITY ■READ.WRFTE 720K DISKS TOO •BLACK OR BEIGE FDD-1 .44X BLACK FDD-1 .44A BEIGE FDD-1.2 5-1 14 - DS/KD 1.2MB FLOPPY $95.95 SEAGATE HARD DRIVES 21.4MB KIT S 249 32.1MB KIT $ 279 65MSAVG- ACCESSORY KIT INCLUDES INSTRUCTIONS. XT-COMPATIBLE CONTROLLER AND CABLES. CALL FOR PRICES ON OTHER SEAGATE DRIVES 3SMHZ DUAL TRACE OSCILLOSCOPE $ 499 95 (KX^::^ VOI COMPATIBLE PACKAGE '499.95 -720 X 540 MAX RESOLUTION. 640 X 480 IN IS COLORS. 528 X 480 RESOLUTION IN 258 COLORS •IBM STYLE MONITOR -VGA. EGA, CGA, AND MGA COMPATIBLE i VGA-PKG 1 1 NCLUDES VGA CARD AND MONrfOR) JDR-RGB 14- rgb MONrroR $239,95 JDR-AMFJER 12- TTL MONOCHROME-AMBER .. $69,95 16-BIT VGA DISPLAY ADAPTOR *199.95 ■640 X 480 RESOLUTION ■256K VIDEO RAM. EXPANDABLE TO 51 2K | ■64 LEVELS OF GREY SCALE MCT-VGA-16 MCT-EGA ENHANCED GRAPHICS ADAPTOR .. $149.95 MCT-MGMIO ^SONOGRAPHICS MULTI VO $119.95 2400 BAUD MODEM S 89.95 •2400/l2O0nO0 BAUD HAYES COMPATIBLE •CONFIGURE AS COM1.2.3 OR 4 •BUILT-IN SPEAKER ■ PHOCOMH COMMUNICATIONS SOFTWARE MCT-241 DYNAMIC RAMS PART* sure speeo pins prjce 4164-150 65538*1 »50n» 18 240 4I2S6-1J0 282!44*1 (50ns 18 i-ss •issa-iM 252144.1 120« 1« US .i >."--. HM 2*2:44X1 lOOra tt *,15 41256-80 282!44*l «0nc 18 3,75 '- HMD IMSSTSHI SOni 18 UM m »M1 . WIDE BAND WIDTH ■ VARIABLE HOLDOFF - 1X/I0X PROBES ■ FULL 2 YEAR WARRANTY MODEL-3500 MODEL-2000 20MHZ VERSION $389,95 DMM-3B0 34 RANGES, i0.25%. TEMP 4 TRANS TEST $79.95 DMM-280 35DIGIT.22RANGES.i0.25SACCURACY $49.95 DMM-100 3 .5 DIGIT.14 RANGES, =0.51k ACCURACY $29.95 ALL JDR INSTRUMENTS PRODUCTS WARRANTEED 1 YEARS Jitn Whaflon JDR 3 VP Salts JIM'S BARGAIN HUNTERS CORNER 112 WATT SWITCHING POWER SUPPLY • OPEN-FRAMED POWER SUPPLY HADE BY DELTA - »5@10A. »12V@3.5A, «-12V gl 1. 5A, -12111200mA • MEASURES 5 X 8 5 XI 97' WEIGHS 2.3 LBS PS-DPS-110AP EXPIRES 7'1S«I UPGRADE YOUR OLD SYSTEM! REQUEST OUR HEW FLYER TO LEARN HOW! ORDER TOLL FREE 800-538-5000 KEY CODE 12 CUSTOMER SERVICE TOLL-FREE 800-538-5001 • TECHNICAL SUPPORT TOLL-FREE 800-538-5002 tn . ..:. ,v-:' U I :u Vfv are not *K5pcr>si&rirn«rit«iofi. Rotfllffl appro*. 140 dajgrtfla. Pot contacted lo motor wits torn 500 to 3 000 olvnt. 1.53"X0.B5"X 1.6SV 0.87" dimn*1*y rubber wheel mttadxd to motor ihatl can b* uc*d U a capalan or can be ea&ry removed. Prepped wrtti caparitori, dtokec and wir* leadi CAT* SV03 2 for Si 00 tltiffl PHOTO TfiANStSTQII^ TO-K cat* Wit, window. For o__ . vfld^anor* staffing appHcatior*. Sptcttaiy and fTHChanfcaJry compaiia* wUti til-31 B. CATiTlL-00 Si 00 each - 10 for tt.Oti TIL,31BPH0T0.D!0D£ TO-iacmv tnJrar *} X 6 1/4* deep. Choice o, three halghts. Include* non-skid rubber feet and hardware. Available In twig*, Ivory, black, and blue. **n* hi. CAT* 21/4' CAT* MB- A t7.S0a*oh 10kr$6&.00 2W CATfMI-ft t775**ch 10 kr 16750 y CATIM'r-C 19.00 aetf. 10 ftp 570.00 Please specify color. SOUND ACTIVATED SWITCH PC board with eiectrvt mke responds to sounds En immediate vicinity. Originally part of sound activated light organ. Shuts off whan sound is not present. Includes hook-up diagram. CAT*SAB-2 $2.50 each 0*6 HOUR "AUTO SHUT'OfF TIMER LEO'S M H Rhodes. Inc Mark-Time* 90007 Timer fits standard 3" deep wsllbox. Rated 20 amps @ 125 Vac. Turn knob lo desired lime Includes hardware, beige wallplate, and knob. UL and CSA listed. CAT* TMC-t 35.75 each • 10 for 350.00 I XENON TUBES:;!! 1- long iaihtube with 3 1/2" red and Hack leads Ideal for elec- tronic lath er eliobe projects. CATlFLT-3 2 for 31 00 : RELAYS £3 5-«VnCSIP REED RELAY Bectroi -Blue Bey* SaStAOSAtO 5-S Vdc 500 ohm coil. S.P.&.T. normally open reed relay. 0.S amp contacts. SIP con- tguronon t ■ X .375" X .3". CAT* BBLY-3IPS Sl-ioejch • tororiio.oo E VDC LATCHINQ RELAY AromaW RSL2D-SV Miristn SPDT. dual col niching istay. 3 Vdc, t70ahmcoML lamp.TTLoorrv petbie. UL and CSA recognized. 0.737- X0.3WX 0.»4- CATfLRLY-CDC S2 50 each 12 VOLT D.C. COIL S.P.O.T. Omror*G2E-1MP 4 imp contacts. 335 ohm colt. Sugar cube srzt.,Sf X .42- X .44 Ntfl. P.C. mouit with pan on DIP pacing. CAT*RLY-7S7 31. 50 each & © SPECIAL? PURCHASE 210 MFD 330 V PHOTOFLASH CAPACITOR Rubicon CE photoflash capacitor 0.79- eta. X 1 T high These are new capacitors thai have been propped with 1 .4' black and red wire leads soldered to the terminals. CAT* PPC-210 32.50 each 10 for 322.50 ■ 100 for 3200 00 Large quamiies atfaitable. Can lor pricing. 22/44 PIN CONNECTOR:;! I- Taj 1IIIIIIIIIIIIIIIIIIIIIITI " .154' pin spacing, 0.2OO" between double raws, gold contacts, P.C. mourning. SPECMf. Sam* as AMP* 2-530055-6. CAT* EBC- 10 $1.00 each • 10 fry 38 00 ELECTRONIC GAME BOARD The Inner workings of an electronic Scrabble game. Operates on E Vdc 8 digit alpha- numeric readout, 45 button keypad, 14 transis- tors. 2 1.C.'s, 1 piezo element and other good- ies. Top and bottom row d keypad buttons are fu nebbn keys, middle 3 rows are alphabet- ic. No instructions avalabkt. r X 4.45'. C AT* ST -4 $1.75 each 1Cllcrj15 00 :^S^PWHE:CQ.IJP.yf«:^AhSlsOIWIEfl: rvkili Products I ntemesbnaW A1SN-HO-1DV1 Primary: 600 ohm Secondary: 600/600 ohm 0.77" X 06f X 0.63" high 6 pc pins on O.I 37- centers. Primary inductance: 300 mH ruin., at 1 kHz. 1 vcfi CAT(TCTX-1 3l25oa. • 10 tor 31 1.00 STANDARD JUMBO DIFFUSED TlWra ■ RED CAT*LE0.1 10 for (1 50 • 100 lor 313.00 GREEN CAT* LED-3 10 tor 32.00- tOOforl17.00 YELLOW CAT* LED-] lObr 32.00 ■ 100 kr 31 7.00 FLASHING LED mfh buit in ieshkifl cirouit . opereleson Gvohi... '* RCO It .00 each I CATILEtM l0fort».5C • Gft££H SI .Worth || CAT* LED-40 10 tor 13.50 BI-POLARLED Q Lights RED one dreclan. TJ SHEEN the other. Two leads CATS LE 0-4 2 tor 31.70 \\ LEO HOLDER a Two pieoe hotter {£ *> CATiMLED lOforeN LED GRAB BAG Hiuorlad LED, - * Many dlnarant ■hipea,, odotii, ■ t*m. Round, rs*Ctangukr. Curved, «tO, CATHTQRUD . .M-00ft*ri siiORTQiSEtJSOR:!!! U shaped package with mounting ears. 1/1T opening. 3/4" mounting ears. CAT* OSU-S 50* each 10 for 34 50 • 100 tor 340.00 STEPPER MOTOR AirpaxP/rlCfc^ll-MI 17 Vdc dual 00), permanent magnet sleeper. 23.25 ohm coil. 7,5 degnses per step. CAT*SMT-S $8.00 each 10 for $50.00 L.E.D. FLASHER KIT Two L E D '• flash in unison when a vott -r£- Sj^^av canary is attached £. *&& J^ ThiskJlncludesa ( -jjx> p.e. board, all the parts and inst ructions to make a simp Is flasher circuit. A quick and easy protect for any- one with basic soldering skint. CAT*LEDIQT 31 .75 per kit kLEDCHASERKITS BuHd thtis va(iabl« ■pMd r«dcha»r. 10lada flash Saaquantialy al whatavar ipft*x. you aat them for. Eaiy to build kit imludaa po board, pan* $n$ instructions (dial lor apecial lighting affacta. costumw. ace Operataa on 3 to firolt PC boand b 5" X 2,25". A great one hour propel CATf AEC %6.SC aa. STEPPING; MOTOR CONTROLLER KIT Learn about stepping motor s white building this simple circuit. Includes circuit board and all parta except 12 Vdc power supply. CATN5MK1T Std.OOeacn RECHARGEABLE 8ATTERWgA<^USHpji| Four AA nickel cad- mi urn batteries oorv nected in aerie* to make a 4.S voR pack EJati&ri-wj aia in a 2X2 configuration with a 2 pin CJOnnpctor attached. The fou r batter iet can be leparated inioaingla AA aize iplderiab nickel cadmium balteriee or reeoldered into other conliou ration a. SPECIAL SALE PRICE NOW $3JX1 per pack - 1 packs lor $25,00 CAT* MC&41MU ORDER TOLL FREE 1-800-826-5432 *. 1 .VK^SE CALL OR WRITE FOR OUR 60 PAGE CATALOG WITH OVER 4000 PARTS! OUTSIDE THE U.S.A. PLEASE SEND $2.00 POSTAGE FOR A CATALOG MAIL ORDERS TO: ALL ELECTRONICS P.O. BOX 567 VAN NUYS, CA 91408 INFO: (818)904-0524 FAX: (818)781-2653 MINIMUM ORDER $10.00 QUANTITIES LIMITED CAUF. ADD SALES TAX USA: $3.50 SHIPPING FOREIGN ORDERS INCLUDE SUFFICIENT SHIPPING. NO COD. > c a c co CO CO o CIRCLE 107 ON FREE INFORMATION CARD 95 SCIENTIFIC & ELECTRONIC PRODUCTS 6RA1- ANTIGflMTY GENERATOR LC7— WWWTBUflNING CUTTING LASER . . g^RUW- HI POWER PULSED DRILLING LASER giaBTCS- 1 MILLION WLTTESLA COIL. = khcf1- hi velocity coil gun £ellsi- laser light show 3 methoos t/y eh1 - electronic hypnot ism techniou es z emu - lower powered coil gun launcke r 3 j l3 - jmxjb ladoip, 3 models sd5- seeinthedark q. levi - lewtation device Siono S2OO0 S2OO0 $2000 S15J0O CfiDO S80C moo S100O $1000 S10.00 FMV1K- 3 MILE FM VOICE TRANSMITTER $34.50 PFS1II - HAND CONTROLLED PLASMA FIRE SABER . . $4950 NIG7K- HI FLUX NEGATIVE IDH GENERATOR $3450 PG5K- PLASMA LIGHTNING GLOBE $4350 LHC2K - VISIBLE SIMULATED 3 COLOR LASER $4450 HOOTK - HOMING/TRACKING BEEPERTRANSMITTER. .$4450 LQU6K - 25 MW RAND-HELD VISIBLE LASER GUN $24950 BTC3K- 250.000 VOLT TABLE TOP TESLA COIL .. $24950 I0G2K - ION RAY GIN , project eneijy wilhout "■» ■ J129S5 TKE1K - TELIKINETIC ENHANCER/ELECTRIC MAN SI950 VWPM7K - 3 MILE AUTO TELEPHONE TRANSMITTER . $4950 o UJ LIST10- _1 IPG70- CQITMHI- STAT30- UJ PSP40 - GO DNE10 - e/3 LGU2Q - < BLS10 - ASSEMBLED IN OUR LABS INFINITY XMTfl Listen in via phone fcnes . . . S19950 INVISIBLE PAIN FIELD BLAST WAVE GENERATORST4.50 1 00.000 VOLT I NTIMIDATOR UP TO 20 ' . . $9950 AUTOMATIC TELEPHONE RECORDING DEVICE $2450 PHASOR SONIC BLAST WOVE PISTOL SB950 ALL N EW 26 ' VIVID COLORED NEON STICK .. $7450 5 TO 1MW VISIBLE RED HeNe LASER GUN $19950 100,00 WATT BLASTER DEFENSE WAND . . $8950 EAST ORDERING PROCEDUHE - TOLL FREE 1 -8G0-221-17O5 or 24 HRS ON 1-603*734730 or FAX IT TO 1-603572-5406 VISA, WC, CHECK . MO IN US FUNDS. INCLUDE 10% SHI PPING. DRDE RS S1t»004UP0NLYADOS10.00.CATALOGJ1O0OflFREEWrm0RDER. INFORMATION UNLIMITED RO. BOX 716, DEFT. HZ, AMHERST. NH 03031 THE ELECTRONIC GOLDMINE BATTOTT OPERATED BLACK LIGHT KIT * OMds Impale Faxrcxai Ida, FuxBzfl Minerals, tc * Uses Utqi umwM u Snaw Sbs Litfi tj» . 4 iji 2 z o rr G LU o Q < or: 96 Corns w» PC Bud, fists, Tutt an ttstauitrs ' ~ CpeUK torn Any 6V Way Sura (rot 111) * Sin 1* Bar* J"«1i SS35& £12££ MINI GEIGER COUNTER KIT * MKtSAU tflJSS MFafcSiXl * Uses Sws«m Wu. Wins* Tube -*■ tostfs Ipcm W Ballsy (not Inch} * Comes with PC Board, Pats, Tut* and t^aixi«.^ S6tdPC8tSflt r«tj- C6430 SS9.95 20W + 20W STEREO AMP KIT * Bmg Ci saran let Piijw, Poame Wot He * fstia 2 Seme tok me Arts ».u level Cxais * Ogeaesen Standid W On Busy * Comes win PC Bant Pars and JBtruiam-you swV spe*io C6442 S19.S5 * SatfPCaaard S"t;2y o-TTnTTg ^ O 0-TrTTiTn^-, INFRARED DETECTOfl KIT Deters ALL Type Dt rirj-M (TYACR RmoB, LE[>;| Produce Sam and BncH RsO L£D Sa « PC Soant r I 3" I <■ # WFBAflED LEO Jumbg cfejr est SnU* 4 iMd DWSiDnTV B bl HMd till J»ICwrflowrwri2i/Kifl25«« Jw *nto Lbw«rt lion Com* tihjjdw N1703 HOO EACH IdLVtlTflft ADVERTISING INDEX IiHiiiMUM ORDER: SiOLXJ plus S3 DO stuping am tunttig We ncces4 WC. Visa and Monty Order, SEND ORDERS TO: 1i« 61eCn3nis GoUitinj P O Bw 54DS SuKIKtate. AZ 852S1 PHONE ORDERS: '6021 451-1 I 45J CIRCLE 177 ON FREE INFORMATION CARD RADIO-ELECTRONICS does not assume any responsibility for errors that may appear in the index below. Free Information Number 108 AMC Sales 82 75 Ace Products 26 107 AH Electronics , 95 — Amazing Concepts 96 77 B&K Precision CV4 67 Banner Technical Books 82 98,195 Beckman Industrial 5, 7 109 C&S Sales CV3 70 CEI 88 — CIE . 8 — Command Productions 72 176 Communications Specialists 64 58 Cook's Institute 83 186 D&D Electronics 13 — Damark International 14 127 Deco Industries. 26 177 Electronic Goldmine 96 — Electronics Book Club 36 121 Fluke Manufacturing CV2 188 Global Specialties 17 — Grantham College 15 86,199 Heathkit 25, 83 191 ICS Computer, Training 13 178 International Components Corp .91 113,170 JDR Microdevices 94 114 Jameco 92,93 104 Jan Crystals 83 179 Jinco Computers 88 — King Wholesale 86 202 MD Electronics 86 93 Mark V. Electronics 89 61 Microprocessors Unltd. 79 — NRISchools 29,55 187 Optoelectronics 21 184 PMC Electronics 26, 87 — Pacific Cable 85,89 56 Parts Express 90 201 Photronics, Inc 26 192,200 Print Products 22, 24 78 Radio Shack 30 196 SCO Electronics ..71 185 Sencore 23 193 Smith Design. 19 83 Synergetics 68 — Star Circuits 22 190 TECI 64 123,180 Test Probes 3 225-228 Test Probes 3 181 Unicorn 87 197 U.S. Cable 71 182 Viejo Publications 72,88 183 WPT Publications 64 ADVERTISING SALES OFFICE Gemsback Publications, Inc. 500-B Bi County Blvd. Farmingdale. NY 11735 1(516) 293-3000 President: Larry Stockier Vice President: Cathy Steepler For Advertising ONLY 516 293 3000 Fax 1-516- 293-3115 Larry Sleekier publisher Arline Fish man advertising director Denise Haven advertising assistant Christina Estrada advertising associate Kelly McQu-T.de credit manager Subscriber Customer Service 1-800-288-0652 Order Entry for Mew Subscribers 1-80O-999-7139 7:00 AM - 6:00 PM M-F MST SALES OFFICES EAST/SOUTHEAST Stanley Levitan, Eastern Sales Manager Rad io-Electro n ics 259-23 57th Avenue Little Neck, NY 11362 1-718-428-6037, 1-516-293-3000 Fax 1-718-225-8594 MIDWEST/Texns/Arkansas/Okla. Ralph Bergen, Midwest Sales Manager Radio-Electronics 540 Frontage Road — Suite 339 Northfield, IL 60093 1-708-446-1444 Fax 1-708-446-8451 PACIFIC COAST/ Mountain States Marvin Green, Pacific Sales Manager Radio- Electro nics 5430 Van Nuys Blvd. Suite 31 6 Van Nuys, CA 91401 1-818-986-20O1 Fax 1-818-9B6-20O9 ELENCO & HITACHI PRODUCTS AT DISCOUNT PRICES ^jrt RSOs (Real-Time & Storage Oscilloscopes) From HITACHI *$^ The RSO - its the new solution ***"^f> View, Acquire, Test, Transfer and Document Your Waveform Data * % 4-Channel, 1 OOMS/s Model introductory Price 1 0OMS/s (25MS»s on 4 channels simultaneously!, 100MHz, 4kw x leh., 2k* x 2eh., I kw x *ch. VC-61 45 $ 4,695.00 Compact, Full Feature Models Compact Series Scopes "~1 40MS/5. 100MHz, 4kw x led.. 2kwx 2ch. 20MS/S. SOMHi, 2kw it 2ch. Low Cost/High Value Models 20MS/S, 50MHz, 2kw * 2cD. 20MS/S, 20MHz, 2kw x 2ch. VC-6045 $3,049.00 VC-6025 J 2,295.00 VC-6024 VC-6023 J 2,049.00 S 1,749.00 RSOs from Hitachi feature such functions as roll mode, averaging, save memory, smoothing, interpolation, pretr^gering, cursor measurements, plotter interface, and RS-232C interface. With the comfort ol analog and the power ol digital. V-212 $435 v-422 40MHz Dual Trace 20MHz Elenco Os cilloscope $375 MO- 1251 • Dual Trace • Component Tester • 6' CRT • X-Y Operation • TV Sync ' 2 p-1 Probes Hitachi Portable Scopes DC to 50MHz, 2-Channel, DC offset z function. Alternate magnifier (unction Dual Channel v " 52s CRT Readout, Cursor Maas. $1,025 V-523 Delayed Sweep $995 $795 V-522 Basic Model S8S5 Delayed Sweep Lightweight (13lbs) 2m V Sens 3 Yr Warranty Modal V-1065 Shown This series provides many new functions such as CRT Readout, Cursor measurements (V-1 085/1 065/665), Frequency Ctr (V-1085), Sweeptime Autoranging and Trigger Lock using a 6-inch CRT. You don't feel the compactness in terms ot performance and operation. V-660 60MHz Dual Trace $1,195 V-665 60M Hz Dual Trace w/Cursor $1^45 V-1 060 1 00MHz Dual Trace $1 ,425 V-1065 100MHz Dual Trace w/Cursor $1,695 V-1085 100MHz Quad Trace w/Cursor $2,045 V-1100A 100MHz Quad Trace w/Cursor $2,295 V-1150 150MHz Quad Trace w/Cursor $2,775 FREE DMM with purchase of ANY SCOPE SCOPE PROBES P-1 65MHz, Ix.lOx $19.95 P-210OMHZ. lx, lOx $23.95 Elenco 35MHz Dual Trace * . oe Good to 50MHz $*l95 MO- 1252 • High luminance 6' CRT • 1mV Sensitivity • 6KV Acceleration Voltage • 10ns Rise Time ■ X-Y Operation • ZAxis - Delayed Triggering Sweep .Includes 2 P-1 Probes All scopes include probes, schematics, operators manual, and 3 year (2 yrs for Elenco scopes) world wide warranty on parts & labor. Many accessories available for all Hitachi scopes. Call or write for complete specifications on these and many other tine oscilloscopes. WE NOW CARRY COMPLETE LINE OF FLUKE MULTIMETERS Models 21 F 63 85 87 8050A 8060A 8062A + More CALL FOR SPECIAL PRICING 23F 25F 27F 73 75 77F True RMS 4 1 /2 Digit Multimeter M-7000 $135 .05% DC Accuracy ,1% Resistance with Freq. Counter and deluxe case Function Generator F^^^rS fitox i '■*•» .s. #9600 $28.95 Provides sine, triangle, square wave from 1Hz to 1MHz AM or FM capability 10 Function Multimeter CM-365 $65 AC + DC Voltage & Amps , , s Resistance to 2M0MQ f : Diode. Logic, 1 Trans test i^nanB Capacitance 1o 20QuF Digital Capacitance Meter CM- 1550 $58.95 9 Ranges 1pf-20 0Mu1d .5% basic accy Zero control will) case Triple Power Supply XP-620 . Assembled $65 Kit $45 2to tSVatIA, -2 lo -15V at tA (or A lo 30V el 1A) and 5V at 3A Contains all the desired leatures for doing experiments. Features shod circuit protection, all supplies. * 9 Digital LCR Meter LC-1801 $125 Measures: Coils 1uH-2»H Caps 1pl-200uf Res .01-ZOM Wide Sand Signal Generators SG-9000 $129 RF Frog 1MK-4 50MHz AM Modulation ol 1 KHz Variable RF output SG-9500 w Digital Display and 1 50MHz built-in Counter $249 t AC Current Meter ST-1010 $69.95 1000 Amps \ Daia & Peak hotd S Fund ions Deluxe Case *&* Decade filox r#9610 or #9620 $18.95 s-3610 Resistor Bloi 47 ohm to 1M & 130* pol 1 9620 Capacitor Blox 47ptto 10MFD Quad Power Supply XP-580 $59.95 Fully regulated and shod circuit protected XP-575 without meters $39,95 LEARN TO BUILD AND PROGRAM COMPUTERS WITH THIS KIT! INCLUDES: All Parti. Aisombly and Lotion Manual Model MM-8000 $129.00 Digital Triple Power Supply XP-765 S249 0-20Vat1A 0-20Vat1A SV at 5A Fuly regulated. Short circuit protected wilti 2 I mil control, 3 separate supplies XP-660 with Analog Meters $175 GF-8016 Function Generator with Freq. Counter $249 Sine, Square. Triangle Pulse, Ramp, .2 lo 2MHi Freq Counter .1 - 10MHz 4^3111 GF-G015 without Freq. Meter $179 Starting from Scratch you bulk) a complex system. Our Micro Master irajnof teach ss you to write into RAMs , ROMs and run a 0085 micraprooes* sor, which uses similar machine language as tBM PC- You will write The imaal insTnictJans to tell the 8065 processor to get started and stone these instructions in permanent memory in a 2816 E PROM. Teaches you all about input and output ports,, computer tmers. Build your own keyboard and learn how lo scan keyboard and display. No previous computer knowledge required- Simple easy to understand instruction Leaches you lo write in machine language. ROBOTICS KIT FOB ABOVE (MM-GQ10) $71.95 WE WILL NOT BE UNDERSOLD! £ & S SALES INC 15 Day Mone V Back Guarantee UPS Shipping: 4B Slates 5% ;-=«=«=. 12 45 Rosewood, Dterfield, 1L 60015 2 Year Warranty p«- .*** to »»*, ($10 Max) IL Res., 7% Tax C^fggJ (80 0) 292-771 1 (708) 541-0710 WRITE FOR FREE CATALOG CIRCLE 109 ON FREE INFORMATION CARD LIVE ACTION W ^ STOP ACTION, INSTANT REPLAY Catch all the action with the new B&K-PRECISION 2522 Digital/Analog oscilloscope. The new B&K-PRECISION Mode! 2522 is a full-feature analog scope for live action and a DSO for stop action. ■ Full analog and digital operation. ■ 20MHz analog operation. ■ 10 MS/second sampling rate on 1 or 2 channels. ■ Equivalent time sampling to 20MHz. ■ 2k memory per channel. Pre-trigger capture. A touch of a button switches the 2522 from analog to digital operation. It's an easy-to-operate scope with the performance you need, at a price you'll like. Don't let the action pass you by. The 2522 will put you on the fast track for performance and results. For immediate delivery or complete specifications, contact your local B&K-PRECISION distributor. ^ CIRCLE 77 ON FREE INFORMATION CARD MAXTEC INTERNATIONAL CORP. Domestic and International Sales 6470 W, Cortland St., Chicago, 1L 60635 312-889-1448 • FAX: 312-794-9740 Canadian Sales, Atlas Bectronics, Ontario