LAWN MOWER \ JULY 1990 || ^ ECHNOLOGY - VIDEO - STEREO - COMPUTERS - SERVICE UILD R-E's IGITAL ASHBOARD dd hi-tech monitoring to ny car l£OM jfidS© CA31SIE LED"" UILD A SUPER IRECTIONAL MICROPHONE iur novel design gives you ong-distance ears \DD A DISPLAY TO YOUR PROJECT How to use multi-line LCD displays 30CK, RELIGION, & RHETORIC \ look at U.S. -based shortwave stations CIRCUIT COOKBOOK l Marm generator circuits ind fault indicators for four security system 3UILD A SOLID STATE _l^ >ISK DRIVE Jse static RAM to speed up rour computer and save wear ind tear on your mechanical drives #•••36*89*' CAM61t RCA H 836 v&&£&&&3v L-HK ft 1 SUK ! **_WsU QU^DbhKKOlbDilLii/O li( « GERNSBACK .95 CAN m -_■--.' A ---A Better resolution and accuracy can change the whole picture* Clear up the uncertainty in your test measurements with these three versatile Fluke multimeters. When you need performance that leaves no room for doubt, focus on the Fluke 25, 27and 37 Analog/Digital Multimeters. With their patented A/0 converters, they deliver DC volts accuracy within 0.1%. An easy-to-view display also provides a full 4 digits of resolution for readings up to 3200 counts. Fully sealed, drop proof cases protect the handheld Fluke 25 and 27 from abuse on the job site. The unique design of the Fluke 37 is well suited for benchtop and portable use, and includes a convenient storage compartment for test leads and small accessories. The circuitry in each model is shielded to eliminate interference — even near motors, radar, or other transmitters. And thirty-six components are dedicated to high-energy overload protection, for you and the meter. All three instruments offer simplicity of operation. Select functions with one rotary dial. Don't worry about range selection — it's automatic. Plus, the auto-polarity digital readout and analog bar graph give you two ways to look at the signal. The 27 and 37 also add extra features like MIN/ MAX Recording and Relative mode. Next time you make a measurement, think about what you're missing. Then call us toll-free 1-800-44-FLUKE, ext. 33 and ask about the Fluke 25, 27 and 37 meters. You'll get the picture. FROM THE WORLD LEADER IN DIGITAL MULTIMETERS Johl FlukB H lg. Co. . Inc. , R 0. Boi CSHm:baidwMtt ICCVtmtXMVacanddc Touch Holfl-lunarm Relative I d i M crer.ee i mad e and V.I N .' WAX rccordim] mode 1 2 7 i i';i-;r,-; handle, storage comparlmeot t3T). Three-year warranty \2i. 21'' Twe year warranty 137) FLUKE1 ® July 1990 EJ ill ectronics Vol. 61 No. 7 Earn 31 RE 's DIGITAL DASHBOARD Give your dashboard a facelift with six attractive, and accurate new gauges. Ross Ortman 41 SUPER DIRECTIONAL MICROPHONE Ourbuild-it-yourself model outperforms many store-bought models! Dale B, Blackwell 45 THE LAWN RANGER: PART 2 A look at the robotic iawn mower's motor control board. Raymond Rafaels PAGE 31 50 ADD A DISPLAY TO YOUR PROJECT Installing the alpha-numeric display in your project. Steven Avritch 56 SECURITY SYSTEM COOKBOOK An assortment of security circuits to build for your home and car. Ray Marston imiiKi'iTii ComputerDicbst 53 ROCK, RELIGION, AND RHETORIC Tune in to privately owned, U.S. -based shortwave stations Gerry L. Dexter BUILD A SOLID-STATE DISK DRIVE EDITOR'S WORK- .„'! Bench:'.: "3! ^23*1^ — . . ~ :r.=7=c*=*- ^ mm &*£= WB 1W.KW— — ■■ 1 1 — "%**■ ggmi i^gr ==■£"■=5 »k££3S ^TST^r^* £S£'::~','~~ jVviv^v.'.jf: ■ EEEEES PAGE 75 "m^^"' 6 VIDEO NEWS What's new in this fast- changing field. David Lachenbruch 18 EQUIPMENT REPORTS Tektronix analog/digital- storage oscilloscope. 62 HARDWARE HACKER Power-control fundamentals. Don Lancaster 75 BUILD A SOLID STATE DISK DRIVE Retain important PC data with our inexpensive battery-backed RAM disk. Mark Hatten 69 AUDIO UPDATE Taking care of your tapes. Larry Klein 72 DRAWING BOARD Scrambling and Macrovision. Robert Grossblatt 75 EDITOR'S WORKBENCH Reader mail. Jeff Holtzman 94 Advertising and Sales Offices 94 Advertising Index 8 Ask RE 95 Free Information Card 1 4 Letters 82 Market Center 25 New Lit 21 New Products 4 What's News o ON THE COVER y z o LU o □ < If your car's "instrument cluster" (commonly known as a dashboard), consists primarily of idiot lights that don't provide all the information you want, take a look at our digital dashboard. We show you how to put together six digital gauges: voltage, oil pressure, water temperature, fuel level, vacuum, and an auxiliary dis- play whosefunction you can choose. Not only do these gauges give accu- rate, detailed level readings, they also look good. To give your dashboard an updated, high-tech look worthy of the name "instrument cluster," turn to page 31. THE AUGUST ISSUE GOES ON SALE JULY 3. BUILD A VIDEO GRABBER Capture a frame of video and manipulate it on your computer. BUILD A 100-MHz FREQUENCY COUNTER An easy-to-build, accurate instrument based on the Intersil 7216. AC POWER MEASUREMENT A refresher course. MICROWAVES A look at the many uses of microwaves in the past, present, and future. BUILD A TELEPHONE LINE CONTROLLER A programmable card that lets your computer control incoming and outgoing calls. 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 workmanship 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'ELECTRGNICS may relate to or be covered by U.S. patents, RADIO- ELECTRON ECS disclaims any liability for the infringement of such patents by the making, using, or selling of any such equipment or circuitry, and suggests that anyone interested in such projects consult a patent attorney. RADIO-ELECTRONICS, (ISSN 0033 7862) June 1990. Published monthly by Gernsback Publications, Inc., 500-B Bi County Boulevard. Farmingdate. MY 1 1735 Second-Class Postage paid at FarmingdaJe, NY and additional mailing offices. Second-Class mail registration No. 9242 authorized at Toronto. Canada. One-year subscription rate U.S.A. and possessions $17.97. Canada $23. &7. all other countries $26. 97. All subscription orders payable in U.S.A. funds only, via international postal money order or check drawn on a U.S.A. bank. Single copies $2. 50, 6 1990 by Gernsback Publications. Inc, All rights reserved Printed in U.S.A. POSTMASTER; Please send address changes to RADIO-ELECTRON ECS, Subscription Dept . Sox 55115, Boulder CO 8032 V -51 15. A stamped self-addressed envelope must accompany all submitted manuscripts and/or artwork or photographs if their return is desired ihould 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 Ge msback (1 364- 1 967) founder M. Harvey Gernsback editor-in-chief, emeritus Larry Sleekier, EHF, CET. editor-in-chief and publisher EDITORIAL DEPARTMENT Brian C Fenton, editor Marc Spiwak, associate editor Daniel Goodman, technical editor Teri Sc.tduto. assistant editor Jeffrey K. Holtrmnn computer editor Robert GrossbEatt, circuits editor Larry Klein, audio editor David Lachenbruch contributing editor Don Lancaster contributing editor Richard D, Fitcti contributing editor Kiithy Campbell, editorial assistant ART DEPARTMENT Andre Duzant, 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 Marcella Amoroso production assistant CIRCULATION DEPARTMENT Jacqueline P. Cheeseboro circulation director Wendy Alanko circulation analyst Theresa Lombardo circulation assistant Michele TorriHo, reprint bookstore Typography by Mates Graphics Cover photo by Diversified Photo Services Radio-Electronics is indexed in Applied Science £ Technology Index and Readers Guide to Perf&dic&l Liter- ature. Microfilm & Microfiche editions are available. Contact circulation depart ment for details. Advertising Sales Offices listed on page 94. fladio- Electronics Executive end Administrative Offices; 1-516-293-3000. Subscriber Customer Service: 1 800-288-0652. Order Entry for New Subscribers: 1 -800 999-7139, PLUG IN. TURN ON. GET DATA. FAST. FREE SOFTWARE. NO PROGRAMMING. 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. V 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 J\fc w ^S^ 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! m ICall toll-free for details GLOBAL 1-800-572-1028 SPECIALTIES Global Specialties. An Interplex Electronics Company 70 Fulton Terrace. New Haven. CT 06512 Telephone: (203) 624-3103. c Interplex Electronics 1989. All Global Specialties breadboarding products made in USA L CO CO o CIRCLE 189 ON FREE INFORMATION CARD A0012 WHAT'S N EWS w o z s LU _l LU 6 I EC New earth-to-orbit launcher will use electromagnetism A new technology that might be used to launch small satellites from earth to orbit, currently being de- veloped by Sandia National Labora- tories (Albuquerque, NM), uses electromagnetic induction and in- volves no sliding electrical contact between the projectile and the bar- rel. Providing an alternative method to rockets for the launching of satel- lites up to 1,000 pounds, it could have potential military and commer- cial applications. In the new launcher, the proj- ectile passes through a series of cyl- indrical coils that form a contactless barrel. Just before firing, a pneu- matic device sets the projectile spin- ning, for aerodynamic stability. The firing is under electronic control: One after another, coils are ener- gized by a heavy capacitor dis- charge, accelerating the armature forward down the length of the flyway. Between each coil, a high- speed optical-fiber sensor mea- sures the precise position and ve- locity of the projectile and instructs the computer to fire the next coil at the right instant to provide max- imum effect. The launch mass for a full-scale earth-to-orbit projectile would include an iron or other mag- netizable armature, a removable aeroshell, small rocket motor, and the pay load. An existing mock up re- sembles a small rocket or a very large artillery shell, with the tapered aeroshell streamlined to reduce at- mospheric friction. A sophisticated code called "WARP 10" has been used to sup- port the experiments. The code has successfully predicted the results of all of the experiments made so far. Its predictions for scaled-up ver- sions of the electromagnetic launch system are making scientists ex- tremely optimistic that the larger systems will also be successful. A FUTURE FULL-SCALE EARTH-TO-ORBIT electromagnetic launch system might look like this. The flyway, consisting of hundreds of stages, is built up the side of a hill to present a 30-degree launch angle. 4.5 km/sec, to achieve orbit velocity. The combination of electromag- netic and rocket techniques re- duces costs and risks for the electromagnetic launch. Still in the exploratory develop- ment phase, the work has achieved a record velocity for contactless electromagnetic launchers of 1 kilo- meter per second with a 160-gram projectile. Experiments are now un- derway with a larger, six-stage launcher that fires a 4-kilogram (10- pound) projectile that is 5Vi inches in diameter. Subsequent develop- ment stages will focus first on still larger launchers. After that, the con- cept would be scaled up further by adding more stages to the launcher, increasing the length of the flyway along which the launch mass is ac- celerated. For earth-to-orbit launch, the flyway would consist of multiple stages, each powered by its own ca- pacitor bank, and elevated at a 30- degree angle. The technology seems especially promising for the economical launching of large num- bers of relatively small objects into earth orbit. R-E SANDIA EXPERIMENTER Ronald Kaye in- serts a projectile into the breech of a six- stage electromagnetic launcher, which is being developed as a possible alternative to rockets for frequent launches of small pay loads. The electromagnetic launcher would provide enough velocity — about 4.5 kilometers per second at the end of the flyway — to send the main part above the earth's atmo- sphere (the armature would drop away shortly after launch). Once the projectile was above the atmo- sphere, the aeroshell would drop away and the rocket motor would step up the velocity about another 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" 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. Greal lor a variety of projects. Popular .100" contact centers. 4%k5'Vi*? #276-192 4.99 (2) Socket lor Above. #276-1462 . . 4.69 (1) Thermistor. #271-110 1.99 2) 0.1W Trimmers. Ik. #271-280; 4.7k. #271-281: 10k. #271-282; 47k, #271-283; 100k, #271-284 Each 49e (3) Color-Code Decoder. #271-1210. 69C Car Connectors Tran and Choke id V 9 (2) V 9 (3)1 99 (1) Soiderlsss Motorola -Type Plug. Fils car radios and many scanners. #274-709 (2) Solder! eas Jack. #274-710 (3) Lighter Outlet DC Plug. #274-336 id 8 (2) 99<> M) Power Transformer. 120VAC primary. Secondary is 1BVAC. 2.0 amps, center- lapped. 2*x2Vcy. This order >ub|sct to aceapianco by tr» Elnclronics Book Clut>. RE790 Call Toil-Free 1-800-233-1128 to join Now! ELECTRONIC, CIRCUITS 1938P $23.95 Counts a$ 2 2ioor> tte.es 27MP S13.J5 All books are hardcover unless number is followed by a "P" lor paperback. (Puhlishsrs' Prices Shown) O CIRCLE 181 ON FREE INFORMATION CARD Ask RE ASK R-E Radio-Electronics 500-B Bi-County Blvd. Farmingdale, NY 11735 CO o z o cc O LLI 6 o < RING MY PHONE There is not enough line current to ring the telephone bells in our house. Either we're too far out or there are too many phones on the line. Is there any other way I can get the phones to ring? — C. Myers, Meridian MS Before we start on this, and by the way the answer is yes, let me tell you that I haven't heard of a problem like this in a long time. In these post- divestiture days, most phones have gone a long way from the original Western Electric 2500 series. CMOS has replaced most of the circuitry in the old phones and I haven't seen a real carbon granule in years. The popular lore and certain leg- ends have it that the telephone line voltage is fixed at a value written in stone. Nothing could be further from the truth. It has never been promised by the telephone compa- ny that you'll find 50-volts DC on- hook, 5-volts DC off-hook, and a 90- volt AC ringing voltage. All the phone company guaran- tees is that the phone circuit is a 20- milliamp line. As a historical note, that's interesting because 20-milli- amp current loops have been around for a long time. But this isn't helping you solve your problems. The development of CMOS- based telephone parts has resulted in a sort of revolution in telephone design. Given a 20-milliamp limit, most phone manufacturers have been able to design multi-featured telephones that draw their power directly off the phone line. )ust about the only use for batteries is to preserve memory in phones that let you store numbers. Several semiconductor manufac- turers make chips that are designed with your specific application in mind. An example of those is made by AMI (3800 Homestead Road, San- FIG. 1 ta Clara, CA 95051 (408) 246-0330). The chip you need is their S2561 — a dedicated telephone-ringer IC that can be powered directly off the phone line. You can use a battery if you're afraid of loading the line. The chip doesn't need much sup- port to make it work, and everything you could want to know about it is described in the data sheet. The cir- cuit in Fig. 1 shows you what has to be done to put the IC to work. You can use it to drive a small speaker, since the chip puts out up to 50 milliwatts when you power it off 10 volts. As an alternative, you can feed the output to an amplifier and get even more gain. TOUCH TONE DECODER I've been trying to design a circuit that would decode Touch Tone fre- quencies and display them on LED's. So far, the best I've been able to do is less than what I want. Can you point me in the right direction? — W. Brown, Golden CO Once upon a time, doing some- thing like that was a real pain in the neck, since you had to do analog decoding of the frequencies in the high and low groups used for DTMF (Dual Tone Multi frequency) tones. Fortunately, this is America, and capitalism usually fills any consum- er needs that show up in the mar- ketplace — and that is even true in the world of semiconductors. Several manufacturers make DTMF decoders, including such well-known names as National, AMI,andMostek. I'm not listing any of the chip numbers because each of those companies have several of them and which one you use de- pends entirely on what you want to do. Call or write them and get your- self a handful of data sheets. What all of the decoders have in common, though, is that they de- code only the incoming frequency and put out a binary equivalent. If you want to build something that can display a dialed number, you're NRI gives you two unbeatable opportunities for top pay, security, even a business of vour own. Everybody wants to get ahead, but most people want assurance they're making the right job choice. According to the U.S. Department of Labor, jobs for electricians and air conditioning, heating and refrigera- tion technicians offer high earnings and good job prospects. Now NRI can show you how to go after the high earnings, the steady pay increases, even how to be your own boss in a business of your own. You'll get all the skills to get there. No night school, no need to quit your job until you're ready to make your move. NRI trains you right at home in your spare time. No Experience Needed. NRI starts you with the basics, then builds your knowledge and skill a step at a time, all the while adding practical know-how through hands-on training. You even get tools you need on the job or in a business of your own. Over a million and a half stu- dents have trained the NRI way since 1914, Be an Electrician. Each year, the demand for skilled construction, maintenance, commercial and utility electricians continues to grow. The U.S. Department of Labor estimates that close to 1 00,000 new jobs wil I open up in the next ten years - a conservative estimate compared to industry and union predictions. And few jobs can match the money-making potential of the qualified electrician. You can earn a salary in excess of $25,000 or be your own boss with your own electrical contracting business. Only NRI gives you this kind of practi- cal, job-oriented, hands-on training. You master practical skills like this with the equipment, test instruments, and training materials included in your course . . .you duplicate on-the-job wiring with your NRI Residential Wiring Practical Lab*. . . you learn professional troubleshooting using your Volt-Ohmmeter and ClampOn Ammeter to test the circuits you build up on your NRI Circuit Demonstrator . . . and by installing and testing an electronic- programmable thermostat and a micro- processor-controlled remote power control, you come to understand today's electronics as it applies to the latest devices electricians install and repair. Training in the latest need-to-know electronics required of today's electrician. NRI created this new course so you can move from the simplest fundamentals of electricity, through professional wiring and trouble-shooting techniques, all the way up to mastering the practical field skills you need to become today's electronic-smart electrician. Be an electrician. It could be the best and last job choice you'll ever have to make. Be an Air Conditioning, Refrigeration, Heating Technician. When it comes to targeting the good paying jobs, regular pay increases, and mm^Wm schools McGraw-Hill Continuing Education Center 4401 Connecticut Avenue. NW. Washington. DC 20008 ■ ' 4k We'll give you tomorrow. ■ 'Til m CHECK ONE FREE CATALOG ONLY O Electrician □ Atr Conditioning Heating & Refrigeration □ Small Engine Repair J Appliance Servicing D Locksmilhing D Building Construction Name- Slreau the steady demand for your skills in this field, the U.S. Department of Labor scores a solid hit... high earnings and good job prospects attract many individuals... because people in business depend on their air conditioning, heating, and refrig- eration systems, the need for skilled tech- nicians to do maintenance work has to be met regardless of swings in the economy. Add millions of window units in older homes requiring maintenance and repair; heat pumps so popular they're now as common as furnaces; commercial refrigeration alone calling for skilled tech- nicians to install and service walk-in cool- ers, freezers, ice makers, and food cases. Wherever you look, there's tremendous opportunities for the trained air conditioning, refrigeration, and heating technician. NRI training so complete, professional tools even included. NRI trains you for this lucrative field, gets you ready to land a good paying job, pick up extra income in your spare time, even start a business of your own. You're ready to jump right in because NRI includes the tools you need: system analyzer, leak detector, tubbing and joint tools, a top- quality vacuum pump for purging systems, plus demonstration panel units for hands- on systems training. Graduates of our Master Course also get optional free residential training at the world-famous York Institute in York, PA. Go after high earnings, pay increases, a business of your own. Send for NRl's free catalog. Find out what hands-on projects you do, the profes- sional tools you train with, and the future that can be yours. Act today. LJ Automotive Servicing D Bookkeeping & Accounting □ Photography □ Computer Electronics D TWAudirWIdeo Servicing □ Telecommunications □ Robotics D Data Communications □ Industrial Electronics H Computer Programming □ Electronic Design Technology G Cellular Telephone Zj Digital Electronics Servicing ' Basic electronics . — .Age City/Slale/Zip- L. Accredited Member National Home Study Council £070 id % 11 Pomona's Boxes Are Everything But Wired. When you're looking for just the right box for your connections, we've probably got it. Good chance it's even in stock. Ther- moplastic, Phenolic, Extruded Aluminum or Die-Cast Al umi nu m. Plain or with con nectors ; BNC, UHF, Type N, Binding Posts, Banana Plugs, or any combination of the same. Dependable Choices. All you need to worry about is your circuit. There are dozens r j$ of standard choices Ab ~ 4 Friendly Videos reo7 PO Box 5684 Garden Grove, CA 92645 (714) 893- 4055 Please rush me the following VHS format titles: H Xfone Assy" @ £39.95 rn "Shake" @ $29.95 ~ "PC Upgrade" @S24. 95 H 'LaserJet" ©S49.95 J Complete Set inc I ud i rig F REE software @ $ 1 00 (Add £1 S&H per video, and sales tax If CA address) Name Street Address . City, Stale, Zip _ Telephone icons that represented functions, devices, and subroutines, and drawing lines between them. Labels and function parameters were typed. In the space of ten minutes, we had run data acquisition and spectrum analysis on a sound sam- ple, crunched a selection of the analysis in Excel, and displayed a color bar chart. And the com- patibility was excellent. The seminar was conducted on Macintosh II 's with large, high-resolution color monitors. The demo disk ran equal- ly well without any tinkering on a low-end MacPlus. Apple is thick-headed in its pric- ing and marketing practices. The Mac is not cheap, but it does avoid the hidden costs associated with open architecture — buying boards, hardware compatibility, etc. I feel safe buying a second-hand Mac be- cause the probability that anyone has opened the case and touched the hardware is very small. As far as tinkering goes, if l want to modify hardware, I'll use an inex- pensive "classic computer." If I want to sit right down and get to work, I'll use the Mac. I'd like to build some stuff to at- tach to my SCSI port, but hobbyists and hackers are seriously ne- glected. It would be a great service to a sizable (and growing) popula- tion of users if Radio-Electronics would address that issue occasion- ally. Connectivity is a hot issue. Ex- pand our horizons! MICHAEL ]. SCHENK Baltimore, MD Do You Know the ABC's of Home Theater? If you're looking to recreate the movie theater experience at home, home theater is just what you're looking for The integration of large screen televisions, videodisc players. VCRs and surround sound processors is one of the most exciting trends in today's consumer electronics world. The following quiz will tell you how much you know about home theater. Score 10 points for each question you answer correctly. r 1 . True or False: Only large screen televisions can be used in home theater systems 2. Which of the following are types of televisions used in home theater systems? [a) Rear projection (bO Direct view (c) Front projection (d) Combination television/monitors (e) Virtually any type of television can be used in a home theater system 3. True or false: Television programs have never been broadcast in Dolby surround sound. 4- Which of the following arc necessary to experience surround sound? (a) A universal remote control (b) A surround sound processor (cj Two extra speakers (d) None of the above 5i Videodisc players that play all sizes of videodiscs and compact discs are called (a) All-in-one players (b) Multi-players (e) Continuation players (d) Combination players D* What is a television set without a tuner that accepts input from such sources as a VCR, videodisc player, home computer, and a video game? (a) Monitor (b) Large screen television (c) Viewer (d) All the above I • Videodisc players offer consumers two different formats: one with few special effects, and another that allows such added features as frame search, free -e- frame, and multi-speed pEay. Those formats are: (a) CLV and CAV (b)DBAandDBD (c) CNV and CYA [d) SLO and FAS 8. How many projection televisions were sold in 1989? (a) 50.000 (h) UO.OOO (c) 265.000 (d) 1,000.000 Si. Itllc or false Surround sound decoders must be incorporated in a home theater system for the system to work properly. 1 U. How many speakers arc required for surround sound? (a) 2 (b)5 (d)l TURN IT OH IN THE fcft Electronic Industries Association Consumer Electronics Group >0l pa:iModto3Ui si punos punojiins ssautn ipj iou si ruaumojiAus isjestp auioi) aip jo i^ajp |]nj atp trEnounB '^pjj-5 "3-9 y-/ "V"9 'Q'£ '3 '9"F r punos punouns .^qjoQ ui issapEoiq sib sauoui Xm*^ as|ej-£ °g-j sdn -iss j3]E*jLp aujou; ui XpAiujjja posn sq ueo dn pug£,upu; f£ tuoij raijs uaajsc, 3S[ej-| :SidMSuv 16 No other training— in school, on the job, anywhere— shows you how to troubleshoot and service computers like NRI DIGITAL MULTIMETER Professional test Instrument for quick and easy measurements. LESSONS clearcut, Illustrated texts build your understanding of computers step) by step. HARD DISK 20 megabyte hard disk drive you Install Internally for greater data storage capacity and data access speed. /VEW.'at-compatible computer High-speed 30286 CPU 112 MHz clock, wait statesi. i meg BAM. 1.2 meg, 5'/*- high- density floppy disk drive. MONITOR it m SOFTWARE including MS-DOS, cw BASIC, word processing, database and spreadsheet programs. Only NRI walks you through the step-by-step assembly of a powerful AT-compatible computer system you keep— giving you the hands-on ex- perience you need to work with, troubleshoot, and service all of today's most widely used computer systems. You get all it takes to start a money-making career, even a business of your own in computer service. No doubt about it: The best way to learn to service computers is to actually build a state-of-the-art computer from the keyboard on up. As you put the machine together, performing key tests and demonstrations at each stage of assembly, you see for yourself how each part of it works, what can go wrong, and how you can fix it. Only NRI— the leader in career-building, at-home electronics training for mom- than 75 years — gives you such practical, real-world computer servicing experience. Indeed, no other training — in school, on the job, anywhere— shows you how to troubleshoot and service computers like NRI. You get in-demand computer servicing skills as you train with your own AT-compatible system— now with 20 meg hard drive With NRl's exclusive hands-on training, you actually build and keep the powerful new AT-compatible West Coast 1010 ES computer, complete with 1 meg RAM and 20 meg hard disk drive. You start by assembling and testing the 10 1 -key "intelligent" keyboard, move on to test the circuitry on die main logic board, install the power supply and 1,2 meg 5 'A " (loppy disk drive, then interface your high-iwoluiion monitor. Bui that's not ail. Only NRI gives you a top-rated micro with complete training built into the assembly process Your NRI hands-on training continues as you install the powerful 20 megabyte hard disk drive— today's most wanted computer peripheral— included in your course to dramatically increase your computer's storage capacity while giving you lightning- quiek data access. Having fully assembled your West Coast 1010 ES, you take it through a complete series of diagnostic tests, mastering professional computer servicing techniques as you take command of the full power of your computer's high-speed 80286 microprocessor. In no time at all, you have the confidence and the know-how to work with, troubleshoot, and service every computer on the market today. Indeed you have what it takes to step into a full-time, money -making career as an industry technician, even start a computer service business of your own. No experience needed, NRI builds it in You need no previous experience in computers or electronics to succeed with NRI. You start with the basics, following easy-to-read instructions and diagrams, quickly HIgn-resolutlon, non-glare, 12* m monochrome monitor with tilt and swivel base. TECHNICAL MANUALS with professional programs and complete specs on your computer. DIGITAL LOGIC PROBE simplifies analyz- ing digital circuit operation. DISCOVERY LAB complete breadboard mg system to let you design and modify circuits, diagnose and repair faults. moving from the fundamentals to sophisticated computer servicing techniques. Step by easy step, you get the kind of practical hands-on experience that makes you unique- ly prepared to Like advantage of every opportunity in today's top- growth field of computer service. What's more— you learn at your own pace in your own home. No classroom pressures, no night school, no need to quit your pre- sent job until you're ready to make your move. And all throughout your training, you have the full support of your personal NRI instructor and the NRI technical staff always ready to answer your questions and give you help whenever you need it. Your FREE NRI catalog tells more Send today for your free full-color catalog describing every aspen of NRI's innovative computer training, as well as hands-on training in robotics, videos audio servicing, electronic music technology, security electronics, telecommunications, and other growing high-tech career fields. If the coupon is missing, write to NRI School of Electronics, McGraw-Hill Continuing Education Center, 4401 Connecticut Avenue, Washington, DC 20OO8. AT if a registered trademark of Interraoorul Business Machines Corporation School of Electronics m McGraw-HiLI Continuim; Kducatiun Center 4401 Connecticut Avenue. Washington, DC 2(XH1B L?] Check one FREE catalog only _J Computers and Microprocessors n Robotics It TV/YideoMudio Servicing I I Computer I'rogamtviing For diver courses approved under til bill 3 check for details n Security Electronics \_J Electronic Music Technology |~] Basic Electronics ] Telecommunications 'jplL'UM.'prinD *& Cm y /State/ftp I Accredited Member. National Home Study Council 421 9-07 Q ID 10 O 17 Equipment Reports V) o z UJ _i LLI 6 D < Tektronix 2214 Digital/Analog Oscilloscope A unique combination of features makes this scope ideal for physical-system measurements. CIRCLE 28 ON FREE INFORMATION CARD WHAT DO YOU GET WHEN YOU CROSS A 20-MHz, 4-channel oscilloscope with four digitizers and an RS-232 interface? You get the 2214 Digital/ Analog oscilloscope from Tektronix (P.O. Box 500, Beaverton, OR 97077). At first glance, the 2214 doesn't appear any different from a standard analog scope. The front-panel con- trols are laid out in an intuitively easy-to-use format. Above each BNC input connector is its corre- sponding input-coupling switch, at- tenuation selector or volts/div switch, position control, and x10 selector. To the right of the four ver- tical-amplifier controls are the time- base controls. The trigger controls are grouped together at the top right of the front panel, next to an- other group of controls for storage functions. The front-panel layout is kept un- cluttered in part by using a single push-button where you might ex- pect more. For example, to select one of six possible trigger sources, a single push-button is used. Each time the button is pressed, a call-out above the button is back-lighted to indicate the choice. Connectors that are used less fre- quently are relegated to the side panel. They include external-trigger and Z-axis inputs, and a trigger-level output. The Z-axis input doubles as an external-clock input when the scope is in its digital-storage mode. The hardcopy serial interface con- nector and its related parameter-se^: lection switches are also located on the side panel. Special features The basic specifications of the 2214 may not seem too impressive at first: an analog bandwidth of 20 MHz, a bandwidth in digital-storage mode of 8 MHz. Such specifica- tions, however, tell only part of the story. The 2214 offers a number of features that make it stand out as an excellent tool in electromechanical and process-control applications, for which it was designed. One of the interesting features worth noting is that the scope can operate at a wide variety of speeds. Its roll mode can be used to slowly display up to 500 seconds of on- screen data. Such a display can often make the data easier to com- prehend. Alternately, the digitizer can be clocked from an external source at any rate from DC to 8 MHz. The 2214's horizontal timebase is variable even in the storage mode. Waveforms — even frozen captured signals, which consist of 16K data samples — can be expanded by up to a factor of 50 to let you zoom in for close examination. All 16K sample points are visible on the screen in the expanded mode. Alt four chan- nels, and all 64K samples, can be displayed simultaneously. You can freeze and store the sig- nals from any or all channels and - o. "~ ■-. *m , V. >, s. I-. *. Fig. 1 16 ELENCO & HITACHI PRODUCTS AT DISCOUNT PRICES 0& RSOs (Real-Time & Storage Oscilloscopes) From HITACHI The RSO - its the new solution View, Acquire, Test, Transfer and Document Your Waveform Data % *? 4-Channel, 100MS/S Model Introductory Puce l OOH &s (25 MS/s on 4 channels simultaneously), 100MHz, tkw* tch„ 2fcwx2ch., 1kwx4ch. VC-6145 $4,695.00 Compact, Full Feature Models 40MS/S, 100MHz, 4kw i ten.. 2kw :< 2ch. VC-6345 % 3,043.00 20MS/S, 50MHI. 2kw x 2ch. VC-60IS $ 2,295.00 Low Cost/High Value Models 20MS/S, 50MHz. 2kw i 2ch. VC-6024 $ 2,049.00 ZCME/s, 20MHz, 2kw x 2ch. VC-5023 $ 1 ,749,00 RSOs from Hitachi feature such functions as roll mode, averaging, save memory, smoothing. Interpolation, pretriggering, cursor maas urem ants, plotter interface, and RS-232C interface. With the comfort of analog and the power of digital. V212 Hitachi Portable Scopes $435 DC to 50MHz, 2-Channel, DC offset DC to 20MHz func t'on. Alternate magnifier function Dual Channel V" 525 CHT Readout. Cursor Maas. $1,025 V-S23 Delayed Sweep 5995 V-522 Basic Modal $395 Compact Series Scopes Delayed Sweep Lightweight (13lbs) 2m v Sens 3 Yr Warranty Model V-1085 Shown This series provides many new tunctrans such as CRT Readout, Cursor measurements (V-lOB5rT 065/665), Frequency Clr (V-1085), Sweeptime Autoranging and Trigger Lock using a 6-inch CRT. You don't feel the compactness in terms of performance and operation. 60MHz Dual Trace $1,195 60MHz Dual Trace w/Cursor $1 ,345 100MHz Dual Trace $1,425 1 00MHz Dual Trace w/Cursor $1 ,695 v-422 40MHz Dual Trace $795 0MHz Elenco Oscilloscope $375 V-660 V-665 V-1060 V-1065 V-1085 1 00MHz Quad Trace w/Cursor V-1100A 100MHz Quad Trace w/Cursor V-1 150 1 50MHz Quad Trace w/Cursor $2,045 $2,295 $2,775 Elenco 35MHz Dual Trace .... Good to 50MHz *4SO MO- 1 252 » High luminance 6" CRT • 1 mV Sensitivity • 6KV Acceleration Voltage • tons Rise Time • X-Y Ope ration: ■ 1 Aiis • Delayed Triggering Sweep KF .Includes 2 p. I 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 tor all Hitachi scopes. Call or write for complete specifications on these and many other fine oscilloscopes. MO- 1251 • Dual Trace • Component Tester • 6- CRT • X-Y Operation • TV Sync • 2 p-1 Probes FREE DMM with purchase ol ANY SCOPE SCOPE PROBES P-1 65MHz, 1x. 10* $19.95 P-2 100MHz. 1x. lOx S23.95 WE NOW CARRY COMPLETE LINE OF FLUKE MULTIMETERS Models 21F a$ 23F 85 25F 87 27F 8050A 8060A 8062A 77F + More CALL FOR SPECIAL PRICING 73 75 D B True RMS 4 1/2 Digit Multimeter M-7000 $135 .05% DC Accuracy .1% Resistance with Freq. Counter and deluxe case Function Generator Blox #9600 t^t* $28.95 Provide) sine, triangle, square wave from 1Hz to 1 MHz AM or FM capability nnmi 10 Function Multimeter CM-365 $65 AC + DC Voltage t Amps Resis!anceto2000Mn Diode, Logic, I Trans lest Capacitance to 200 uF Digital Capacitance Meter m CM- 1550 $58.95 9 Ranges .Ipl-ZO.OOOufd .5% basic accy Zero control wilh case Triple Power Supply XP-620 __^___^ Assembled $65 Kit {45 210 1SV al 1A. -2 to -15V alt A (or 4 lo 30V at 1 A) and 5V at 3A Contains all the desired leaiures lor doing experiments. Features short circuit protection, all supplies. * t Digital LCR Meter __ LC-1801 $125 ^fwfc Measures: ffsjjt Coifs 1uH-2MH ^f Caps .1pl-200uf RM.01-20M Wide Band Signal Generators SG-9000 $129 RF Freq 100K-450MHz AM Modulation ol 1 KH: Variable RF output SG-9500 w Digital Display and 1S0MH: built-in Counter $249 $69.95 j^^AC Current Meter | J ST-1010 1 1C00 Amps | Data A Peak hold S Functions Deluxe Case %JL# Decade Blox I #9610 or #9620 $18.95 19610 Resisloc Blox 47ohmlo1M4100Kpol 19620 Capacitor Blox 47plto10MFD Quad Power Supply XP-S80 $59.95 Fully regulated and short circuit protected XP-575 without meters $39.95 LEARN TO BUILD AND PROGRAM COMPUTERS WITH THIS KIT! INCLUDES: All Parti, Aiwmbly and L«**on Manual Model MM-8000 $129.00 Digital Triple Power Supply XP-765 $249 0-20V8I1A 0-20Vat1A 5Vat5A Fuly regulaled. Short circuit protected with 2 limit control, 3 separate supplies XP-660 with Analog Meters S175 GF-8016 Function Generator with Freq. Counter $249 Sine, Square, Triangle Pulse, Ramp, .2 fo2MHz Freq Counter .1 ■ 10MHz GF-3015 wlihout Freq. Meter $179 Starting from scratch, you build a complete system. Our Micro-Master trainer teaches you to write into RAMs, ROMs and run a 3085 m Jcroproces- sor, which uses similar machine Language as IBM PC. You wiH write fre initial instructions to ten iha 8CS5 processor ta gat started and atom thuse instructions in permanent memory in a 2B16 E PROM. Teaches you ail about Input and output ports, computer timers. Build your own keyboard and learn how to scan keyboard and display. No previous computer knowledge required. Simple easy lo understand instruction teaches you to write in machine language, ROBOTICS KIT FOB ABOVE (MM-eOlO) $71,95 WE WILL NOT BE UNDERSOLD! Q £ S SALES INC 15 Day Mone V Back Guarantee UPS Shipping: 48 states 5% r— -ggg^ 1245 Rosewood, Deerfield, IX 60015 2 Year Warranty Prrc« «** to don,, (S10 Max) IL Res.. 7% Tax E^«S (800) 292-7711 (708) 541-0710 WRITE FOR FREE CATALOG CIRCLE 109 ON FREE INFORMATION CARD EARN YOUR B.S.E.E. DEGREE THROUGH HOME STUDY Our New arid 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. No residence schooling re- quired tor 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 1 2 months 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