BUILD A VOCAL EFFECTS MIXER FOR HOME RECORDINGS #77 ECHNOLOGY - VIDEO - STEREO - COMPUTERS - SERVICE ut PC power in your home ideos with this GA-TO-NTSC CONVERTER iuild R-E's IIRECT DIGITAL YNTHESIZER nd generate sinewaves igitally n in-depth look at IAGNETIC FIELDS ■ ' v;»»\j-» »;v i Troubleshoot microprocessor- based systems with our t J rum. r. hi Jb ■!'■ Win * OM,p-J(»JCKi:, W c* H U M BlU w w m w MICRO MONITOR □ "71896 48783'" 1 1 $2.95 U.S. S3.75 CAN A look at how BINAURAL RECORDING re-creates realistic sound Build Call-Alert and ADD SELECTIVE CALLING to your ham or CB rig "I'l'vu'i'va' -■^H.-f ^"LiDD^i CSJ% tf *Q7 GERNSBACK MTHJ "3." FLUKE AND PHILIPS THE GLOBAL ALLIANCE IN TEST & MEASUREMENT 7 SERIES II 8 New Meters. 8 Old-Fashioned Values. Introducing Fluke's 70 Series II, next- generation multimeters that meet the increasing demands of your job and your budget. Consider. At the top of the line, the new Fluke 79 and 29 deliver more high-performance features - capacitance, frequency, a fast 63- segment bar graph.Lo-Ohms range, Smooth- ing™, faster ranges - than DM Ms costing much more. At the entry level, the new model 70, Fluke's lowest-priced DMM ever, delivers unparalleled Fluke quality at a price comparable to "dispos- able" meters. And in between are all the models that have made the 70 Series the most popular DMM family in the world - updated, refined and delivering even more value than ever. "BASICS" REDEFINED No matter which 70 Series II you choose, you get simple, one-handed operation. High resolution. And built-in, go anywhere reliability. Automatic Touch Hold* - standard on every model - locks the reading on the display and signals you with a beep, automatically updating for each new measurement without a reset. Leaving you free to concentrate on your work, not on your meter. YOUR BES T CHOICE Best of all, every 70 Series II is a Fluke, backed by a worldwide service network and an industry- leading 3 year warranty. So the next time you're in the market for a new meter, ask for the one that guarantees old- fashioned value. Fluke 70 Series II. For more information call 1-800-6789-LIT Or call 1-800-44-FLUKE, ext 33 for the name of your nearest Fiuke distributor. CIRCLE 121 ON FREE INFORMATION CARD Fluke 79 Series II & 29 Series II S1B5- *-&y^^^^ RD-2110 Radar Detector 95 Reg. 109.95 Yours for only U KdUd '49 ! Feature Packed! Contemporary Look' with your order of any item on this page SCOPE 3 1 /s Digit lcr Meter ideal for field applications! •Light weight 'Portable 'Hand Held •Overload Protection «Test Leads Model LCR-680 A SALE HW Optional Carrying Case CA-92 $9.95 St LCD Meter •0.5% Accuracy • DC/AC Voltage. DC Current •Diode & Battery Test 'Overload Protection DC 50OV, AC 350V, Ohms 250V DC/AC Model DVM-630 SALE $32!! Optional Deluxe Carrying Case CC-30 $4.50 $50.00 Sweep Function Generator Sale! Reg S319.95 Model FG-801 •Selectable Wave & TTL Pulse •7 Freq. Ranges (0.2 Hz to 2MHz) •Sweep Ratio 100-1 scope Analog Lab Sale! now W Reg. S225.0O Model sc-6000 •5 Freq. Ranges •Variable Positive Power •Potentiometer Proto-Board Station Special! $ 298° MOdel SC-9000A • 3 Wire AC Line Input • Function Generator •Triple Power Supply •8 Logic LED's Feature Packed! hitachi oscilloscope NOWW ^ Reg. S615.00 Model v-212 Dual Trace •DC to 20 MHz, 1mVMv •6" Rectangular Screen PROBES INCLUDED! hitachi Dual Trace oscilloscope NOW $ 598 00 Model V-355 •19 Calibrated Sweeps •6" CRT «Auto Focus PROBES INCLUDED! Fordham 260 Motor Parkway, Hauppauge, New York 11788 ASK FOR YOUR FREE CATALOG TOLL irdham 1991 Offiers expire Dec 51. 1991 800-695-4848 Money orders, checks accepted CO.Q's require 25% deposit Service & Shipping Charge Schedule Continental U.S.A. FOR ORDERS ADD FOR ORDERS ADD SQ-25 $4.50 $26-50 $6.00 $51-100 $7.50 $101-200 $9.00 $201-300 ....$10.00 $301-400. ,,$12.00 S401-500....S14.00 WHAT S NEWS A review of the latest happenings in electronics. Commercial solar-electric power plants The next generation of solar elec- tric plants are being heavily promoted in the Sunbelt states by solar engi- neers at Sandia National Laborato- ries (Albuquerque, NM). Unlike earlier plants, which suffered from power-output and efficiency limita- tions due to the use of steam, the new solar plants will use molten salt to transfer heat and store energy in the system. The engineers have been trying to sell utilities, regulatory agen- cies, and environmental groups on the benefits — in terms of cost, en- vironmental safety, and efficiency — of building a molten-salt central re- ceiver power plant that would be ca- pable of producing 100 megawatts or more of electricity. Central receiver power plants, such as Solar One in the Mojave Des- ert near Barstow, CA, consist of a field of sun-tracking mirrors that con- centrate sunlight onto a receiver that absorbs the energy and transfers it to a heat-transport fluid. The fluid is heated to more than 540°C C1000°F), and the resultant energy is either used to drive a turbine to produce electric power or is stored for later use. Molten salt presents an attrac- tive alternative to steam because of its lower cost, high heat-transfer ca- pabilities, and increased safety. The development of molten-salt systems began in the late 1970s, and national laboratories, private industries, and universities have been working to- gether since then to develop and test the system components. Recent Sandia experiments — many per- formed at the scale of an operating plant — have proved the feasibility of such a commercial solar power plant and demonstrated the reliability of major components. Solar One used a receiver in which water was boiled by concentrated sunlight to produce steam, which passed directly to a turbine to pro- duce electric power. It is difficult, however, to store energy in the form of high-pressure steam, so the plant lacked an efficient energy-storage system. That caused operational problems — particularly during cloudy weather — which had the effect of lowering electricity production. The use of molten salt eliminates most of those problems. Because the hot salt is stored at atmospheric pressure, the energy-storage system design is simplified. In addition, the molten -salt central-receiver systems do not produce hazardous waste or emit gases linked with acid rain or global warming and could reduce our dependence on foreign oil. One of the most attractive benefits of the technology is the plant's load- shifting capability, or the ability to de- liver electricity to consumers when demand is highest. Its highly efficient energy-storage system also allows a molten-salt plant to operate cost effectively more than 60% of the year without using fossil fuel as a backup. A 200-megawatt second-genera- tion solar-power plant could produce electricity at a cost competitive with power from a fossil fuel facility. For instance, the cost of electricity from a molten-salt solar-power plant is just one to two cents per kilowatt hour higher than from a similar-sized coal plant, and the price is likely to go down as the technology is improved. The key to getting the costs down lies in reducing the cost of the field of mirrors — which could be achieved with mass production. Other benefits are that the new solar plants would be TESTS AT SANDIA'S NATIONAL SOLAR Thermal Test Facility have proved the viability of a commercial, utility-scale, so- lar thermal-power plant using molten salt for efficient heat transfer and energy stor- age. Such a facility, using a field of sun- tracking mirrors as pictured here, could produce electricity at a cost competitive with coal-fired plants. able to deliver electricity on demand, even at night; produce electricity much cheaper than any other utility- size solar power plant; store energy inexpensively; and reduce our depen- dence on foreign oil. Radio signals via fax? Fax-Max Services, a Montauk, NY- based communications company, has petitioned the FCC to create a new service in which radio signals could be broadcast to facsimile ma- chines, tf the advertiser-supporter service was approved by the FCC, it could allow fax machines to function like radios that provide a printout of their broadcasts. News updates, weather maps, sports scores, stock- market reports, and public-service announcements could be transmit- ted on a regular basis, at much less cost than transmitting data over tele- phone lines. The petition asks the FCC to make legal a new class of broadcasting ser- vices to be known as the Public Fac- simile Broadcast Service CPFBS). PFBS would use at least three radio channels at about the 930-MHz band. Fax- Max plans to begin experi- mental services in the New York area by October 1 , and has initiated patent proceedings for a radio receiver that accepts signals transmitted to fax machines. About the size of a ciga- rette pack, the receiver is intended to be attached to a fax and plugged into the phone line. According to current plans, advertisers and other compa- nies transmitting data would pay a per-page fee to Fax-Max. Recipients would buy the receiver, but would re- ceive broadcasts at no charge. They could select both their broadcasts and the channels, as well as the sub- ject categories. Information would be transmitted at regular intervals; for examples, news updates could be sent every 30 minutes. Fax-Max envi- sions the transmission of a broad range of services, from general hourly newspapers to specialized services like civil-service alerts or wanted poster to law-enforcement agencies. R-e IAXIMIZED SENSITIVI We've Carefully balanced the amount of gain used in our input amplifiers - too much or too little results in poor performance. OPTOELECTRONICS' HANDI-COUNTERS™ with maximized sensitivity give you the maximum range for antenna pick-up. K Made in the USA MODEL 3000 Multi-function Counter 10Hz-3GHz, 10 Digit LCD with frequency, period, ratio, interval & signal level bargraph.,,.$375. Maximum Security Device. Increase your frequency finding™ by 10 times the distance or more. Tunable Preselector APS-104 $995. Counter Sold separately MODEL 6030 With all the features of the 3000 plus enhanced input signal conditioning and enhanced TCXO time base $579. iiii s 199 The Original Pocket-Sized LED Handi-Counter™ All of OPTOELECTRONICS' LED Handi-Counters™ will: • Count frequencies above 2.4GHz. Have display saving Power Switch (avoids premature LED burn-out, leading cause of counter failure.) Accept no substitutes - Look for the OPTOELECTRONICS name on the label! Model 2300 - 1MHz-2.4GHz| Available with NiCads and AC Charger Adapter. Complete Package only... .$128. I Only OPTOELECTRONICS offers you MAXIMIZED SENSITIVITY. 1-800-327-5912 Model 221 0A Factory Direct Order Line FL(305)771-2050 • FAX(305)771-2052 5821 NE 14th Ave. • Ft. Lauderdale, FL33334 • 5% Ship/Handling (Max. $10) 10Hz-2.4(jHz t-iJll range us & Canada 15% oulside continental U.S.A. counter.Pnce includes Vjsa and Master Card acce pted. Nicads & AC charger/adapter. CIRCLE 193 ON FREE INFORMATION CARD VIDEO NEWS What's new in the fast-changing video industry. DAVID LACHENBRUCH O o DC \- o o • Wooing Nintendo. Sony and Philips, which jointly developed the Compact Disc, appear to be going in different directions in CD-ROM multi- media systems for the consumer market. Both of them have deals with Nintendo involving different — and in- compatible — CD-ROM game sys- tems. Sony will introduce a CD- ROM-based home-entertainment system called Play Station, which will also have a port for Nintendo's new 16-bit video-game cartridges. How- ever, the CD-ROM's for Play Station will all be original Sony titles, not adaptations of Nintendo games, and Nintendo has announced that it won't support Play Station with any CD games. Instead, Nintendo is casting its lot with Philips" CD-I approach, and an- nounced at the Consumer Elec- tronics Show in Chicago that it will develop CD-ROM games for that for- mat. Both Sony and Philips consider Nintendo to be a major asset be- cause of the widespread popularity of its games. At our deadline, Sony and Nintendo were involved in discus- sions which could result in a closer alliance. It's known that Philips' an- nouncement of Nintendo CD-ROM games took Sony by surprise in view of the fact that Sony apparently thought it had an exclusive CD-ROM deal with the game company. Additional video-game— CD al- liances: JVC and Sega have formed a partnership for sophisticated video motion CD-ROM games, incompati- ble with both CD-I and Play Station. • JVC goes widescreen. JVC may be the first brand to bring wide- screen TV sets with a 16:9 ratio pic- ture tube to the United States. The company is introducing a set with a 34-inch wide-ratio tube in Japan this fall and says it will bring the same set to the U.S. shortly thereafter. Thus it could well beat Thomson, which is selling a widescreen set in Europe, to the U.S. market. JVC's set is de- signed for standard NTSC pictures, but can accommodate letterboxed videos full-screen, convert normal ratio (4:3) pictures to 16:9 by elim- inating part of the top and bottom, or show standard pictures on the screen with space left over at one side for three small pictures (a "ptcture-out- side-of-picture" version of pjcture-in- picture). • 8mm Snapshots. Electronic dig- ital video still cameras flopped on the consumer market — probably be- cause they were too expensive. Now the Japanese manufacturers have a better idea: Why not let video cam- corders make digital snapshots as well? The first such camcorder to em- brace this idea was shown in pro- totype form recently by Hitachi. A high-band 8mm (Hi8) model, it can record a high-resolution digital still picture at the same time it's making a moving analog video. The still pic- tures are recorded in pulse code modulation on the audio track at the rate of one every 12 seconds. The PCM digital audio track can't be used while stills are being recorded, but the hi-fi AFM analog stereo track can. • Philips' LCD Projector. Philips will soon introduce a unique LCD projector in the U.S. under its Magnavox label. Using three 2.8-inch LCD panels, it can project a 660,000- pixel picture on a screen up to about 100 inches in diagonal measurement. It uses a 2000-hour metal-halide lamp developed by Philips' lighting division. An on-screen countdown can be ac- cessed by the remote control unit to tell how many hours of life the lamp has left. Unlike Sharp's somewhat similar LCD projector (Sharp sup- plies the LCD's to Philips), the Mag- navox unit has a TV tuner. It has a "convenience speaker" in the proj- ector and two outboard speakers as well, for placement at either side of the screen. The picture can be re- versed or turned upside down so the same projector may be used in rear projection as well as front projection systems. The price will be in the $5QQ0-$7000 range, according to Philips. Although the first model is rather large (but still fairly portable). Philips says it's aiming at a future ver- sion about the size of a VCR. • Hail to the King. Japan is agog over a new TV picture tube, used in high-end Matsushita TV sets, that goes under the name of "Gao." Loosely translated, that means "king of pictures." Having conquered Ja- pan, the King is coming to the United States. The Gao tube (which, of course, will be called something else here) is notable for its almost (but not quite) flat faceplace and its high-con- trast picture. The contrast is obtained by the use of a very dark faceplate with a light transmission of only 33% to 36% (depending on tube size). The tube can be driven at very high volt- age and has a new gun and shadow- mask system to provide the required brightness even at the extremely high-contrast level. In addition to the high contrast and flat front surface, Matsushita says a multifocus cath- ode results in an improved focus. In Japan, Gao comes in three sizes, none of them cheap) — 25-inch sets start at about $1265, two 27- inch versions cost up to $1825 and two 31-inchers go as high as $3500. In the U.S., it's expected that 27- and 31 -inch versions will show up in Pan- asonic's Prism line next year. • VHS-C compatibility. Speaking of JVC, that company has a goal of across-the-board com- patibility of its full line of VHS decks with VHS-C cassettes by 1993, The company currently has two decks — at $500 and $1600 suggested list prices— which can play the small VHS-C cassettes without an adaptor. JVC currently is developing a sec- ond-generation system to accommo- date compact- and standard-size VHS cassettes in the same loading mechanism but at a much lower cost than the current compatible loading- drawer system. Its goal is a loading system that costs no more than the current full-size-only tape slot. R-E Afford Ability C I9DI ltfHi-k-i|.-p. i «-kLud{ , o.TM!^ll>]aai?E In a dc power supply. Now, put a dependable, 30-watt dc power supply on your bench for just $300* You'll get the low noise your work demands (200 (iV mis). Constant-voltage or constant- current operation. And built-in reliability ensured by conservative design margins and rigorous environmental testing. Outstanding value in a dc power supply. It's just one in a full line of basic instruments developed by HP to give you uncompro- mising performance at an affordable price. , To order, call HP DIRECT, 1-800-538-8787, Ext.TW13. We'll ship your order the day its received. Instruments come with a sixty-day, money-back guarantee. All you need is a ^mh company purchase ■■■■ order or credit card. HP 30-watt power supplies E3610A S Range 1 f" ] o Range Z toad or line regulation Ripple and noise 110 Hz-10 MHz) 8V.3A 15V, ZA E3611A 20V, 1.50A 35V, 0.85A 0.01% + 2 mV ZOO uV rms/2 mV p-p ' L'.S. Ila[ price There is a better way. Wiat HEWLETT mLfim PACKARD o o 3 CD m 3} CIRCLE 180 ON FREE INFORMATION CARD ASK RE Write to Ask R-E, Radio-Electronics, 500-B Bi-County Blvd., Farmingdale, NY 11735 O z o m o o a < SLOWER RECORDING I would like to modify my cas- sette tape recorder so it can play and record at ts /ie inches per sec- ond instead of the standard speed of 1 % inches per second. Doing this will let me get 180 min- utes of recording time from a standard C-90 cassette. I've seen ads in various magazines for ma- chines that have been modified like this but I'd like to do it to my own machine. Do you know of any articles or information I can get that will show me how it's done?— M. Couch, Warren, Ml I read a lot of magazines every month but I can't remember ever hav- ing seen an article on this subject. I wouldn't be surprised if some of our readers have better memories Cor dif- ferent reading lists), but I'm willing to bet that, even if you find an article on the subject, it won't be much use to you. The only way to be able to modify the speed (and, ideally, make it switch-selectable with the standard speed) is to know how your machine works. The most valuable information you can get is the service manual for your cassette recorder — it will give you a head start in modifying the cir- cuit. Otherwise, you'll first have to figure out how your recorder works before you can attempt any changes. In actual fact though, what you want to do is not terribly difficult, since the method of controlling the speed of the tape on most cassette recorders is fairly simple. The details of the designs will vary from machine to machine but there are really only two basic ways to do the job. Inexpensive recorders usually have a variable-speed (voltage-depen- dent) motor, and the speed is main- tained by regulating the voltage sent to the motor. The regulation can be as simple as a pair of resistors (not com- mon since there would be a lot of wasted power), or a Zener-based reg- ulator circuit. If you have a recorder like that, you can change the speed by replacing the Zener with one that provides a lower voltage. There are two important things to watch out for if you decide to do this. The first is that you have to be sure you've identified the right Zener di- ode on the circuit board and you've verified the voltage by actually mea- suring the voltage at the motor. The second is that you have to verify that the motor will work reliably at the re- duced voltage. Some motors, par- ticularly those in cheap recorders, don't develop a lot of torque and. if you slow them down by reducing the voltage, they'll stop running at a con- stant speed, or may pack it in com- pletely — and there's a good chance it will eat some of your tape before it decides to die. More expensive cassette record- ers usually have circuitry that monitors the speed of the motor and constantly adjusts the voltage as the power starts to drop. These ma- chines have a tachometer on the shaft of the motor that sends a signal to a frequency- to- voltage converter where it's compared to a reference voltage. The error voltage generated is used to ensure that the motor is always being fed with the proper volt- age for the right speed. If your cassette recorder has a tach-driven motor, you'll usually find there's a potentiometer you can tweak to adjust the speed. Mark the current setting with a pen before you start fooling around with it since you may want to put it back to the original position some time in the future. You'll also need some way to monitor the speed of the machine while you're adjusting it. The standard way of doing that is to use an alignment tape and a frequency counter but, if you've got the mind to mess around with this stuff in the first place, you can more than likely come up with some other creative ways to do it. While it's possible to modify the speed of just about any cassette re- corder in existence, the only ones that are usually used are the more expensive machines with tach-driven motors. Those machines are the ones that you've seen advertised. There's no reason why you can't modify your own cassette recorder, but trying to do it without the service manual is kind of like doing an appen- dectomy on a Neptunian. The pro- cedure is fairly simple but you have to know where the appendix is before you start cutting. INTEL 8052 I built a single-board computer based on Intel's 8052AH-BASIC chip which has an onboard 8K ROM containing the Basic Inter- preter. I've successfully copied the language to an EPROM but I haven't been able to get the EPROM to work with the standard 8052-AH. This less-expensive version of the 8052AH-BASIC chip is identical in every respect except that it doesn't have BASIC in the internal EPROM. Do you know of any way to make the 8052AH read the EPROM from the moment it's turned on as if it were its own ROM? I don't have a 8052 AH simulator so any solu- tion will have to be in BASIC— D. Nikolaidis, Melbourne, FL I've done quite a bit of designing around Intel's 803X, 804X. and 805X family of microcontrollers but haven't had a lot of experience with the BASIC versions of the chip. The first thing you should do is get your hands on any information on the 8052 that you can, since the more information you have in front of you, the less risk there is for brain damage at the bench. You didn't send any schematics with your letter, but let me tell you right off that the 8052AH and the 8052AH-BASIC are not, as you said, identical in every respect. There are differences between them, and it may be that these differences are causing your problems in the first place. The pinouts of both chips are shown in Fig. 1 and you can see that, while the chips are similar in function, the differences in their internal organ- ization has resulted in different as- signments to the pin functions. I'd strongly suggest that you call Intel's literature department Why take chances in today's job market? Graduate as a fully trained electronics professional To get ahead and stay ahead in today's economy, you need the electronics training CIE has been providing its 150,Q00-plus successful graduates with for nearly 60 years. Meet the Electronics Specialists. When you pick an electronics school, you're getting ready to invest time and money And your whole future depends on the education you receive in return. That's why it makes so much sense to go with number one... with the specialists... with CIE! There's no suclt thing as a bargain education. If you talk to some of our graduates, and we recom- mend you do, chances are you'd find a lot o1 them shopped around for their training. Mot for the lowest priced, but for the best training available. They pretty much knew what was available when they picked CIE as number one. Because we're specialists we have to stay ahead. At CIE we have a position of leadership to maintain. Here are just a few of the ways we hang onto it... Programmed Learning. That's exactly what happens with CIE's Auto -Prog rammed Lessons*. Each lesson uses famous "programmed learning" methods to teach you import- ant electronics principles. You explore them, master them completely, before you start to apply them. You thoroughly understand each step before you go on to the next. You learn at your own pace. And, beyond theory, some courses come fully equipped with electronics equipment to actually let you perform hundreds of hands-on experiments. Experienced specialists work closely with you. Even though you study at home, CIE's faculty and staff stand ready to assist via CIE's toll free number. And, each time you return a completed exam you can be sure it will be reviewed, graded and returned with the appropriate instruc- tional help, you get it fast and in writing from the faculty technical specialist best qualified to answer your question in terms you can understand. Pick the pace that's right lor you. CIE understands people need to learn at their own pace. There's no pressure to keep up... no slow learners hold you back. If you're a beginner, you start with the basics. If you already know some electro- nics, you move ahead to your own level. "Same Day" grading cycle. When we receive your lesson, we grade it and mail it back the same day. You find out quickly how well you're doing! State-of-the-art laboratory equipment. Some courses feature the CIE Microprocessor Training Laboratory. An integral part of computers, microprocessor technology is used in many phases of business. including service and manufacturing industries. The MTL gives you the opportunity to program it and interface it with LED displays, memory devices and switches. You'll gain all the experience needed to work with state-of-the-art equipment of today and tomorrow. New Courses! CIE now offers two new career courses: Automotive Electronics and Computer Operation and Programming. CIE offers you an Associate Degree. One of the best credentials you can have in electronics — or any other career field — is a college degree. That's why CIE offers an Associate in Applied Science in Electronics Engineering Technology. And all CIE career courses earn credit toward your degrees. Which CIE training (its you? Beginner? Intermediate? Advanced? CIE home study courses are designed for ambitious people at all entry levels. People who have: No previous electronics knowledge, but do have an interest in it; Some basic knowledge or experience in electronics; In-depth working experience or prior training in electronics. At CIE you start where you fit and feel comfortable where you start, then go on from there to your Diploma, Associate Degree and career! Today is the day. Send now. Fill in and return the postage-paid card attached. If some ambitious person has already removed it, cut out and mail the coupon below. You'll get a FREE CIE school catalog, plus complete informa- tion on independent home study. Mail in the coupon below or. if you prefer, call toll-free 1-800-321-2155 (in Ohio, 1 -800-523-91 09). AE27 I O YES! I want to get started. Send me my CIE school catalog including details I about the Associate Degree program. (For your convenience, CIE will have a I I representative contact you — there is no obligation.) Print Niime Address Apt, City State Age . Area Code/Phone No. ( ) Check hox for G.I. Bulletin on Educational Benefits □ Veteran □ Active Duty \MZ CLEVELAND INSTITUTE OF ELECTRONICS, INC. 177& Egst J 7th Street ' Cleveland. OTl« 44 n4 * (SIS) 761-5400 h ,»"" .^ \ A school of thousands . f^TT | A class of one. I 1 -"/ Since 1 934. 11 Which symbol represents a variable inductor? CD O z o Be p o 111 6 D < DC 12 What is the principal disadvantage of neon lights? What are out-ol-phase signals? Heath Video Courses speed your learning curve! Learn basic electronics at home at your own pace with four, 60-minute video tapes. Know the variable inductor symbol. Recognize a PN junction. Understand oscillator fundamentals. Clearly SEE what most basic electronic books can only describe. DC BfCTRQHCS. Covers electron move- ment to troubleshooting and repairing a simple electronic circuit. EV-3101-A. AC BfCTROMCS. Follow-up to DC Electron- ics. Covers the principles of AC, voltage and electrical measurement. Includes motors, generators and test instrument meter movements. EV-31D2-A. SBUICONDUCTORS. Complete the DC/AC videos and you're ready to learn how semi- conductor devices are made, plus the principles of discrete devices, integrated circuits & optoelectronic devices. EV-3103-A. ELECTRONIC CIRCUITS. Complete the basic course with amplifier configurations, biasing, coupling, audio amplifiers, closed-loop vs. open-loop operation and more. EV-3104-A. An activity-filled workbook and explanation of how to solve each problem comes with each tape so you learn three ways— video . workboo k and hands-on ! Order today! Call Tod free, 24-hours a day. 1-800-253-0570. We accept VISA, MasterCard, American Express and Heath Revolt. Charge card. Use Order Code 601-060 Heath' Benton Harbor, Ml Call for a FREE catalog 1-800-44HEATH. ©1991 Heath Company ED-238-R2 Prlcfl dOM not Include shipping and handling or applicable sales tax. CIRCLE 86 ON FREE INFORMATION CARD A JL J_ -2J JL JL a JL\ i£ JL JL Jl M. it zo (TZ) fl.O ZlfrZCQ® Phi PI.Z pa 3 MV PI.5- Phi, PJ.7 pEser CPXP)P3.o rrxD}P3.> rww>P3-Z fTQ)P3-f Cri) PS.* (Jrp>PJ.6 (P0)P3.7 XTAL 2, XTAL ! ^ZZT BOS 2 A H t/ct, PO.OCAD0) POJ(ADI) P0.2CPDZ) P03y32. 21 32 Ed. A LL A Ji JL IL Jt JL Ml IL IL JL •ss. CALE D/SABLE 1P1.3 CPRO&PAM PL)L5£)f>lM rPKO&XAM ENABLE)P1.5 CDMA ACKNOWLEDGE-} PI (um PRINTER OUT) PI. 7 P£SEr COAJSOLE SEPTAL JN COfllSOLE SEW- OUT AD0 AW ADZ AD 3 A04 I, AE>5 AD 6 AD7 #5V ALE C/AIT0) DMA REQUEST /AIT1 ra Tl tVP PO xrALz X.TALI GPOUND SOSZAH 3 A 5TC PJiSN A 25 A13 A1Z All A Jo A? AS SL IL *L 2L 3L £0 SI SL FIG. 1— THE 8052 AH AND THE 8052AH-BASIC. Differences in their internal organization has resulted in different assignments to the pin functions. (1 -800-538-4725) and get a copy of their Microcontroller Handbook, it u;\it\ VMI CLEANING/MAINTENANCE/REPAIR EARN UP TO $1000 A WEEK.WORKING PART TIME FROM YOUR OWN HOME! THE MONEY MAKING OPPORTUNITY OFTHE1990'S IF you are able to work with common small hand tools, and are familiar with basic electronics (i.e. able to use voltmeter, understand DC electronics). . . . IFyou possess average mechanical ability, and have a VCR on which to practice and learn. . . .then we can teach TOW 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! Vieju'i 400 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 all the info you'll need regarding the BUSINESS-SIDE of running a successful service op- eration! fREE , HFaRMATI0N CALL TOLL-FREE 1-800-537-0589 Or write to: Viejo Publications Inc. 5329 Fountain Ave. Los Angeles, CA 90029 Dept. RE has all the information you need and several interesting article reprints as well. In general, the two main dif- ferences between the chips are that the 8052AH-BASIC requires external memory to operate, and it doesn't have as many I/O ports as the 8052AH. The remaining I/O port lines on the 8052AH-BAS1C also have to do double duty to support some fea- tures of the Basic Interpreter. It may very well be that the reason you're having trouble is that you're not properly handling the differences in the pin assignments. If you're really lucky, however, the only reason you're stuck is because you're not properly using pin 31. Even though it's not so evident by looking at Intel's official listing for this pin on both chips, they're identical. If you tie pin 31 high on either chip, the IC will look for code in its internal EPROM. By making pin 31 low, both chips will expect the program code to be found in an external device such as an EPROM. This means that a low on pin 31 will cause the 8052AH-BASIC to behave very much like a regular 8052AH microcontroller chip since it won't be able to address its own inter- nal EPROM. continued on page 87 CIRCLE 189 ON FREE INFORMATION CARD A total computer simulated electronics laboratory including Free built-in Instruments and Components to build and test circuits New, PROTOLAB " 3.0, a state of the art electronics tab for your PC, upgraded with the most requested enhancements. With Releasi you slill build, experiment and test actual circuits < boosing from an unlimited number ot passive components, just as the original Release. Then analyze vour circuit with the built-in multimeter, oscilloscope or signal generator, but in a more advanced way. PROTOLAB'" 3.0 includes color F.GA/VCA graphics, quick function key menu selection, and on-line help , plus user preferences which customize your program! Most importantly, Release 3.0 supports advanced components available with PROTOWARE^ circuit modules. I'KOTOWARE" circuit modules expand your lab into the world of diodes, transistors, and special function linear circuits. Each PROTOWARE" disk, sold separately, covers a particular topic, SUt h as transistor amplifiers. Circuits are presented in a "cook-book" formal making it easy to learn and understand. Change component values, and analyze the circuit in the same way as always. Or "play" the Electronic Organ while you study it's operation. Plus, view the circuit in schematic or pictorial presentation. Imagine a PROTOBOARD*' layout to follow right on your computer screen! In the future, your fun will continue as new PROTOWARE" modules are introduced taking you into more advanced topics. Where else cou Id you find thousands of clol la rs worth of pa rts and instruments for the one low price of$1 29.95? Order now for a limited time, PROTOLAB Release 3.0* $1 29.95 • Require IBM/PI D2K HAM, EGWCA Vftfa). A mouse BONUS OFFER 3 PROTOWARE "MODULES $19.95 ~d^n fo Kope ' n (Diodes, Transistors & Electronic Organ) Voltmeter Ohmmeter PROTOWARE Circuit Module Ammeter Signal Generator m an Mnterpiex /Industries company Global Specialties 70 Fulton Terrace, New Haven, CT 06512 '151991 Inlerplex Electronics A030 GLOBAL SPECIALTIES t-200-S72-t02f CIRCLE 194 ON FREE INFORMATION CARD LETTERS CHROMINANCE CLARIFICATION Regarding the project "Color Bar Generator" (Radio-Electronics, July 1991), there were a couple of statements relating to chrominance that were incorrect. It was stated that "A 3. 58-MHz subcarrier is senf by ffte transmitter and used in the receiver to restore the original color informa- tion." It also stated that "the color- burst signal is used as a reference to synchronize the phase and amplitude of the color subcarrier," and that "the colorburst also determines the tint and saturation of the color that is dis- played." (The italics were added to pinpoint errors.) At the transmitter, the R-Y and B - Y signals are each applied to sep- arate modulators. Each of these also receives a 3. 58-MHz carrier. The car- riers are 90° out of phase with each other. The two resulting amplitude- modulated carriers are applied to a balanced modulator that suppresses the 3,58-MHz subcarrier, leaving only the sidebands containing the chroma information for transmission. At the receiver, a 3.58-MHz sub- carrier is generated and reinserted to enable the extraction of the original R-Y and B-Y signals on their re- spective carriers. The colorburst, which has the phase and frequency (not amplitude) of the original 3.58- MHz carrier, is used as a reference to lock the new one. The colorburst, however, does not contain the infor- mation relating to hue or saturation. This information is contained in the color sidebands. To understand how the hue and saturation is determined, try to view the R - Y and B-Y and their respec- tive carriers as two phasors that differ by 90°. The phase angle of the resul- tant determines the hue (or color) while the amplitude of the resultant determines the saturation. If proper lock between the colorburst and the 3.58-MHz subcarrier generated in the receiver isn't maintained, im- proper tint will result. I have presented this additional in- formation because I believe it fills a gap in an otherwise reasonably thor- ough discussion of the NTSC meth- od of luma/chroma transmission. S.J. BABBERT Worthington, OH PSUEDO TUBE AMPLIFIER I read Larry Klein's Audio Update column about making a transistoram- plifier sound like a tube amplifier by adding resistance to the speaker line (Radio-Electronics, April 1991), and I tried his method. I own an old tube Dynaco and a transistorized, later model Technics set. I know how the Technics should sound because the 70-watt Dynaco is practically the best any amplifier could sound. I tried it and it works! It really sounds much better. Larry Klein is a very creative thinker to come up with such a simple and effective approach. It saved me a couple hundred dollars. KARLG, MAEDER Hemet CA SATISFIED SUBSCRIBER Bravo! for the "PC-Based Test Equipment" articles by James Barba- rello (Radio-Electronics, May, June, and July 1991). Those pieces make me glad that I renewed my sub- scription to Radio-Electronics, which I had considered canceling. Well done, guys. You've allowed me to renew my work on a long-term proj- ect by letting me get inside my PC. AMBROSE C CAMPBELL MAGNETIC-FIELD EXPOSURE After reading the concerns and opinions expressed in the Letters section of the July 1991 issue of Ra- dio-Electronics, I thought the po- sition of the American Conference of Governmental Industrial Hygienists (ACGIH) concerning exposures to magnetic fields should be expressed. First, a definition is in order. The standard of measure used by the ACGIH is the Threshold Limit Value (TLV), which represents "conditions under which it is believed that nearly all workers may be repeatedly ex- posed day after day without adverse health effects." Second, a distinction is made between "Static Magnetic Fields" and "Sub-Radiofrequency Magnetic Fields." the ACGIH (1990-91) recommended exposure limits are as follows: Static Magnetic Fields: Routine occupational exposures should not exceed 60 millifeslas (mT) — equiv- alent to 600 Gauss — over the whole body or 600 mT (6000 Gauss) to the extremities on a daily, time-weighted average basis. A flux density of 2 Teslas is recommended as a ceiling value. Safety hazards from the me- chanical forces exerted by the mag- netic field upon ferromagnetic tools and medical implants may exist. Workers having implanted cardiac pacemakers should not be exposed above 1.0 mT (10 Gauss). Perceptible or adverse effects may also be pro- duced at higher fiux densities result- ing from forces upon other implanted ferromagnetic medical devices, e.g., suture staples, aneurism clips, pros- theses, etc. Sub-Radiofrequency Magnetic Fields (30 kHz and below): These TLV's refer to the amplitude of the magnetic flux density CB) of sub-radi- ofrequency magnetic fields in the fre- quency range of 30 kHz and below, to which it is believed that nearly all workers may be exposed repeatedly without adverse health effects. The magnetic field strengths in these TLV's are root- mean -square (RMS) values. Those values should be used as guides in the control of exposure to sub-radiofrequency magnetic fields and should not be regarded as a fine line between safe and dangerous levels. Routine occupational ex- posure should not exceed B TLV = 60 mT/f. where f\$ the frequency in Hz. At frequencies below 1 Hz, the TLV is 60 mT (600 Gauss), The permissible magnetic flux density of 60 mT/f (Hz) at 60 Hz corresponds to a maximum permissible flux density of 1 .0 mT At 30 kHz, the TLV is 2uT, which corre- sponds to a magnetic field strength of 1 .6 A/m. For workers wearing cardiac pacemakers, the TLV may not protect 14 Learn to Use Your Computer's Full Potential.' TikkAAi New Career Course from * CIE! V* If you've been hesitating about upgrading your computer skills because you couldn't find the time or locate the right program to teach you everything you need to know to be successful in today's world of computers, you'll be happy to hear that CIE's new career course can provide you with the computer technology curriculum you seek in an independent study program you can afford to invest your time in. CIE's COMPUTER OPERATION and PROGRAMMING course was designed and devel- oped by CIE to provide a complete overall under- standing of the unlimited potential today's computers offer, once you learn and discover their full capabili- ties, in today's high tech environment. CIE's new computer course quickly provides you with the electronics fundamentals essential to fully understand and master the computer's technological potentials for your personal and professional advancement. Upon mastering the fundamentals you will move into high level language programming such as BASIC and C- Language and then use that programming in order to relate the interfacing of electronic hardware circuitry to programming software. As a gradu- ate of the Computer Operation and Programming course, you will be able to successfully understand, analyze, install, trouble shoot, program and maintain the various types of electronic equipment used in business, manufac- turing, and service industries. Since 1934, CtE has been the world leader in home study electronics by providing our 150,000- plus graduates with the curriculum and hands-on training they've needed to become successful in today's highly competitive and computer oriented society. As a CIE student you'll receive a first rate education from a faculty and staff with only one desire. Your future success! We encourage you to look, but you won't find a more comprehensive computer course anywhere! And it's a course designed to fit around your lifestyle and commit- ments today, so you can be assured of professional successes and financial gains tomorrow. Please, do yourself a favor and send the attached card or fill out and mail the coupon below for more information about CIE's Computer Operation and Programming course. Do It Today! Computer not Included with course □ YES! I want to get started. Send me my CIE school catalog including details about the Associate Degree program {for your convenience, CIE will have a representative contact you - there is no obligation). Print Name Address City Apt. State. . Zip Area Code/Phone Nc Age_ Check box for G.I. Bulletin on Educational Benefits D Veteran [CLEVELAND INSTITUTE OF ELECTRONICS, INC. 1776 East 17th Street • Cleveland, Ohio44114 • (216) 781-9400 i^necK mix lur ^ □ Active Duty ^""'tu. A school of thousands . A class of one. Since 1934. AE26 o q a CD m ID <9 to 15 o < Shortwave Listening Guidebook by Harry Helms The world is talking on shortwave radio, and here's the book that tells you how to listen inl In direct, nontechnical language, Harry explains how to get the most from your shortwave radio. Its 320 heavily illustrated pages are filled with practical advice on: ■ antennas ■ when and where to tune • selecting the right radio for you • accessories • reception techniques Learn how to hear the BBC, Radio Moscow, ham radio operators, ships at sea, even Air Force One! Includes hundreds of frequencies for stations around the world and the times you can hear them. HigKText Only $16.95 plus $3.00 shipping (CA residents lj i-uiiianioM, inc. please include 7m Mimmar R 0Q( i Sales tax). SuLIb 15L. 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Starting immediately, you will be eligible for our Bonus Book Plan, with savings of up to 80% off publishers' prices. * Club News Bulletins. 15 times per year you will receive the Book Club News, describ- ing all the current selections — mains, alternates, extras— plus 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 automatically. If you prefer another 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 mem- ber, you agree to purchase at least 3 books within the next 12 months and may resign at any time thereafter. • Ironclad No-Risk Guarantee. If not satisfied with your books, return them within 10 days without obligationl • Exceptional Quality. All books are quality publishers' editions especially selected by our Editorial Board. IPubl.shors' Pcices Shown) Please accept my membership in the Eleclronics Book Club and send Lhe 5 volumes listed below, billing me $4.95. If not saiislied, I may return (he books within ten days without obli- ge! ion and have my membership cancelled I agree to purchase al least 3 books at regular Club prices during the next 1 2 months and may resign any lime thereafter. A shippingVhan- dling charge and sales tax will be added Id all orders. Signature Valid to* new members only. Foreign applicants will receive special orde'ing insErucliohs Canada RW3t remit in U.S. currency This order suojec! id acceptance by liie Electronics Book Club. RPIE1091 2S6SP SU 95 3627 S29.9S Counts as 2 Troubleshooting ft Repairing VCRs SECOND EDUlON Gordon Mccone 3777 S32.95 Counts as 2 3175 S27.95 Counts as 2 £1991 ELECTRONICS BOOK CLUB Blue Ridge Summil, PA 17294-0910 o o m 33 17 Learn to troubleshoot and service today's computer systems as you build a 386sx/20 MHz mini tower computer! Train the NRI way — and learn to service today's computers as you build your own 386sx computer system, now with 1 meg RAM, 40 meg IDE hard drive, and exciting new diagnostic hardware and software! Jobs for computer service technicians will almost double in the next 10 years according to Department of Labor statistics, making computer service one of the top growth fields in the nation. Now you can cash in on this exciting opportunity — either as a full-time industry technician or in a money-making computer service business of your own — once you've mastered electronics and computers the NRI way. NRFs practical combination of "reason- why" theory and hands-on building skills starts you with the funda- mentals of electronics, then guides you through more sophisticated circuitry all the way up to the latest ad- vances in computer technology. Train with and keep a powerful 386sx/20 MHz computer system plus popular Microsoft* Works software! Only NRI gives you hands-on training with the finest example of state-of-the-art technology: the powerful new West Coast 386sx/20 MHz mini tower computer. As you assemble this 1 meg RAM, 32-bit CPU computer from the keyboard up, you actually see for yourself how each section of your computer works. You assemble and test your computer's "intelligent" keyboard, install the power supply and 1.2 meg, high- density floppy disk drive, then interface the high-resolu- tion monitor. Your hands-on training continues as you install a powerful new 40 meg IDE hard disk drive — now included in your course to dramatically increase the data storage capacity of your computer while giving you lightning- quick data access. Plus you now go on to work with today's most popular integrated software package, Microsoft Works, learning to use its word processing, spreadsheet, data- base, and communications utilities for your own personal and professional applications. But that's not all. Only NRI gives you hands-on training with the remarkable RA.C.E.R. plug- in diagnostic card and QuickTech diagnostic software from Ultra-X— professional, state-of- the-art diagnostic tools that make computer trou b leshooting fast and accu- rate. Your NRI computer training includes all this: • NRI's unique Discovery Lab 1 " for circuit design and testing * Hand-held digital multimeter with "talk-you-through" instructions on audio cassette • Digital logic probe that lets you visually examine computer circuits • The new West Coast 3868x120 MHz computer system, featuring a high-speed 80386sx CPU, 1 meg RAM, 101 -key "intelligent" keyboard, 1.2 meg high-density floppy drive, and high-resolution monitor • 40 meg IDE hard drive • MS-DOS, GW-BASIC, and Microsoft Works software • R~A.CE.R. plug-in diagnostic card and QuickTech menu- driven diagnostic software * Reference manuals with guidelines and schematics printer ports, serial communications ports, video display memory, floppy drives, and hard disk drives. Only NRI gives you such confidence-building, real-world experience. Only NRI gives you both the knowledge and the professional tools to succeed as today's in-demand computer service technician. No experience needed ... NRI builds it in NRI training gives you practical, hands-on experience that makes you uniquely prepared to take advan- tage of today's opportunities in computer service. You learn at your own convenience in your own home. No classroom pressures, no night school, no need to quit your present job until you're ready to make your move, NRI starts you with the basics, building on that foundation step by step until you have the knowledge and skills you need for success. And all throughout your training you've got the full support of your personal NRI instructor and the entire NRI technical staff, always ready to answer your questions and help you achieve your training goals. FREE catalog tells more. Send today! Send today for NRI's big, free catalog that describes every aspect of NRI's innovative computer training, as well as hands-on training in other growing high-tech career fields. If the coupon is missing, write to: NRI School of Electronics, McGraw-Hill Continuing Education Center, 4401 Connecticut Avenue, NW, Washington, DC 20008. NOW! Training now includes Ultra-X diagnostic hardware and software for quick, accurate troubleshooting! Now you train with and keep the latest in diagnostic hardware and software: the extraordinary R . A . C . E . R . plug-in di agnostic card and QuickTech diagnostic software, both from Ultra-X. Using these state-of-the- art tools, you learn to quickly identify and service virtually any computer problem on XT, AT 80286/80386, and compatible machines. You discover how to use the R.A.C.E.R. diagnostic card to identify individual defective RAM chips, locate interfacing problems, and pinpoint defective support chips. Plus you learn to use your QuickTech diagnostic software to test the system RAM and such peripheral adapters as parallel IBM is o registered trademark of International Business Machines Corp. RACE. ft. and QuickTech are registered trademarks of Ultra-X, Inc. SEND TODAY FOR FREE CATALOG McGraw-Hill Continuing Education Center 4401 Connecticut Avenue, NW SchOOlS Washington, DC 20008 m if Check one FREE catalog only □ MICROCOMPUTER SERVICING □ TV/Video/Audio Servicing □ Telecommunications D Industrial Electronics □ Security Electronics D Electronic Music Technology D Basic Electronics U Automotive Servicing For career courses approved under GI Bill LJ check for details. D Computer Programming j PC Software Engineering Using C U Desktop Pubhsmng U Word Processing Home Business D Paralegal □ Building Construction G Bookkeeping & Accounting (please print) Age Address City/State/Zip Accredited Member, National Home Study Council 3-101 EQUIPMENT REPORTS Units + Conversion Factors Unit-Conversion Software en o z o i LU _l LU 6 Q < EC Know your coulombs from your amp-hours, CIRCLE TO ON FREE INFORMATION CARD Without common units, we would never be able to get anything done. Although the engineering and scientific com- munities use metric units as a matter of course, the U.S. still is insistent on keeping English units for everyday use. Even people who are not in- volved in technology or engineering can relate to the problems that in- compatible units can cause. Some of us, for example, think of parcels of land in terms of their dimensions and in square feet. Others are more com- fortable thinking and working with acres, an area of about 43,560 square feet. Boaters think in terms of fathoms and knots, instead of miles and miles per hour. It's said by some that the tower of Babel was doomed not by differences in language, but by differences of units. In electronics and engineering, problems with units still exist. In the U.S., for example, we talk of capaci- tance in units of microfarads and picofarads. Our European counter- parts, however, are equally comfort- able using nanofarads. Although few things are simpler than shifting a deci- mal point three places in one direc- tion or the other, it can still cause frustration and confusion. A greater problem can result when engineers in different disciplines try to communicate. One may be used to thinking of magnetic flux density in units of webers/m 2 or tesla, and the other in units of kilogauss. Convert- ing between units is never an unsur- mountable problem, but it can cause headaches and, occasionally, an er- ror. We recently found an $89,95 soft- ware package for IBM PC's and com- patible computers that takes all the work out of moving from one unit to another: Units + Conversion Factors from David E Taylor, Jr. (P.O. Box 562, Commerce, TX 75429). To run Units, your system requires a mini- mum of 51 2K memory, one floppy- disk and one hard-disk drive, and ei- ther CGA or EGA graphics com- patibility. A mouse, though not units required, is supported. The working screen of Units con- tains six major sections or windows: "Options," "Units of," "Original Number and Units." "New Number and Units," a "Dimensions window, ,.and a command-menu bar. To convert a given quantity and unit, you click on the "Units of" win- dow and enter, or scroll to, the type of unit you want to use from "accelera- tion" to "wave number." If you want- ed to convert from cubic meters, for example, you would scroll to "Vol- ume." You would then go to the "Original Number" window and enter the quan- tity, and then scroll to call up the given original unit Cm 3 ). Moving down to the "New Units" window, you can then enter the units you're converting to, or scroll through the available list until you get to the one you want. We, for example, were curious how many teaspoons were in a cubic meter. The answer, which we arrived at easily enough, is slightly more than 202,884. If you need to find out more about a compound unit, you can "dissect" it and examine the nature of its compo- nent parts. You can then "transplant (Continued on page 102) conuERSion factors (C) Copurlglit 1991 D.F.Taylor.Jr 1,02 Constntl Accel. due to Gr*vlty Cgl Units of I Uoltire elp onstnt lossry Issect dd cnove ind iscel nit EincnBlont J l: *J /I , P H: •0 /I f: ■0 /I EC: ♦0 /l II! AS: •0 /l «0 /I LI: ♦0 /l ■ PA: *o 'I \\ SA: *o n , 1,989 613 7H 37 THE MAIN SCREEN OF UNITS. Note the "Dimension" window in the lower right corner. Since we're working with units of volume, it shows the basic SI unit of length being rased to the third power. 22 Now, You Can Eavesdrop On The World. Introducing the new Drake R8 Communications Receiver. It's world class, world band radio, made4n the U.S.A. From Perth to the Persian Gulf, Moscow to Mozambique, local or global, you hear events as they happen with amazing clarity. Since 1943, Drake m Hi has been setting the standards in electronic communications . . . and then raising them. Today, there's no better shortwave receiver than the Drake R8. Out-Of-This- World Performance. The new Drake R8 has more standard features than other shortwave radios. You get wide frequency range (100 KHz to 30,000 KHz), coverage of all world and local bands, and excellent dynamic range. But you also get important features you won't find on receivers costing hundreds of dollars more. A multi-voltage power supply. Pre-amp and attenuator. Five filter bandwidfhs and synchronous detector. Dual mode noise blanker and passband offset. Non- volatile 100 channel memory. All designed to give you the best reception with the least distortion. Down-To-Earth Design. The ergonomic design of the R8 gives you real ease of operation. You have convenient keypad entry, with large, legible controls. The face is bold. Uncluttered. And the liquid crystal display (LCD) is backlighted for easy reading. Try The R8. . . At Our Risk. If you're not impressed by Drake's quality, performance and ease of operation, return the R8 Receiver within 15 days and we'll refund your money in full, less our original shipping charge. For more information, or to order, call TOLL-FREE, 1-800-9-DRAKE-l. Telephone orders may be placed on a major credit card. $979.00 (Shipping and handling $10 in continental U.S. Ohio residents add 6Vz°7o tax.) Call TOLL-FREE, 1-800-9-DRAKE-l today. You can't lose. In touch with the world. R.L. Drake Company • P.O. Box 3006 * Miamisburg, Ohio 45342 U.S.A CIRCLE 197 ON FREE INFORMATION CARD NEW PRODUCTS Use the Free Information Card for more details on these products. PC BOARD DIAGNOSTIC SYSTEM. Automated printed-circuit board tests were not within the bud- gets of low-volume users, either because the board volumes were too low or too varied, or because the company lacked the tech- nical capability to maintain an automated test system. Other deterrents included concerns about obsoles- cence, operational com- plexity, and the difficulties in obtaining the schematic documentation usually re- quired for programming. A cost-effective, in-circuit and out-of-circuit PC-board diagnostic system from B&K-Precision solves those problems and fills the gap between expen- sive ATE systems and ser- vice instruments. De- signed for use in bench-top production testing, depot repair and testing. SRO's, and independent or third- party service organiza- tions, the Pro-Line Model PL 5000 will troubleshoot complex boards in-circuit or out of circuit. The user can define all test routines and voltage thresholds for compatibility with a wide variety of semi- conductor technologies and component types. In- circuit configurations are "learned" and tested from a resident library that con- tains more than 2000 de- vice types, including LSI devices, in addition to TTL, CMOS, and ECL devices, the Pro-Line PL 5000 sys- tem tests analog devices. Test graphics and an histor- ical-fault database guide the user to the failure. The on-line networkable system is capable of gener- CIRCLE 16 ON FREE INFORMATION CARD ating productivity and pro- cess management reports, including reports based on fault symptom, component types, or board serial number. A resident soft- ware tool for developing custom IC libraries is also included. Programming is simplified with menu-driven software to guide the pro- cess of inputting PC-board characteristics, compo- nent designations, types, and x-y coordinates for the component locations. The PL 5000 then automatically learns the circuit configura- tion by prompting a "walk" from IC to IC using the test clip, until the entire board is learned. The system's standard capability is 48 channels in- cluding six guard points, but it can test up to 64 channels with expansion options. "Clip-on" testing provides easy Interfacing to the device under test. To eliminate contact errors, probe-contact-sensing cir- cuitry assures proper con- nection to the device under test and automatically initi- ates the test sequence. The Pro-Line PL 5000 uses an 80286-based, IBM-compatible computer with 1 MB of standard memory Cexpandable to 4 MB) and two expansion slots. The package in- cludes one 40-MB hard drive and a 1.2-MB 5Vi- inch floppy drive, a 13-inch EGA monitor, and an AT- style keyboard. Complete software is supplied, in- cluding debug tools, a se- curity utility, and diagnostic routines that verify opera- tion of the test unit. The Pro-Line PL 5000 PC-board diagnostic sys- tem costs $14,950. — B&K-Precision, Divi- sion of Maxtec Interna- tional Corporation. 6470 West Cortland Street, Chi- cago, IL 60635; Phone: 312-889-1448. NTSC/PAL/FILM SYNC GEN- ERATOR. MicroKey/Gen- lock. an add-on for Video Associates' MicroKey/A system, is an NTSC/PAL film synchronization gener- ator that allows a computer to be treated as a standard broadcast video source, eliminating the need for an expensive frame syn- chronizer. The device is unique in its ability to han- dle not only PAL and NTSC signals, but also the 24- frame-per-second film speed. The film genlock mode eliminates frame shutter bars on final film products. The MicroKey/A fea- tures digital audio and high- resolution VGA graphics output to a video system. Its digital-audio capability allows ADPCM-encoded 12-bit audio to be ap- pended to an image source for message insertion and cuing. MicroKey/Genlock provide s syn chronization of MicroKey/A's 15-kHz VGA to an external refer- ence for film, PAL, or NTSC with 24-, 25-, and CIRCLE 17 ON FREE INFORMATION CARD 30-frame-per-second dis- play rates, respectively. Two BNC input connectors allow loop-through of exter- nal reference black burst or video. Chromalock fea- tures include NTSC comb filtering and PAL chroma 24 separation. The composite input signal is one volt, peak- to- peak. Video over- lay is provided by an op- tional keyer (MicroKey/ Link). On the MicroKey/ Genlock board, control of the computer's power-up timing is managed by card- edge adjustments for the horizontal phase and sys- tem subcarrier phase. The included software can set and store multiple timing assignments. Pulse assign- ments quickly change tim- ing for multiple designa- tions. The package in- cludes one board, soft- ware, a 20-pin ribbon cable, and a looping terminator. MicroKey/A, MicroKey/ Genlock (shown), and Micro Key /Link have sug- gested retail prices of $1495, $695, and $195, re- spectively—Video As- sociates , 492 6 Spicewood Springs Road. Austin, TX 78759; Phone: 512-346-5781. WIDEBAND ANTENNA. In- tended to improve the per- formance of many types of VHF/UHF communica- tions equipment, the com- pact model DA-301 wide- band transmit and receive antenna from Ace Commu- nications covers the 100- kHz to 1.3-GHz frequency range. The 51-inch-tall, Dis- cone-type antenna fea- tures eight horizontal radi- als, eight diagonal radials, and a single, vertical top whip element. Transmit and receive characteristics are flat within 2 dB over the en- tire 25-1300-MHz range. The antenna has an input power rating of 200 watts and 50-ohm impedance. The DA-301 comes with re- type and BNC connectors along with 50 feet of coax- ial cable. The DA-301 wideband antenna has a suggested retail price of $99.50.— Ace Communications, Monitor Division. 10707 East 106th Street, Indi- anapolis, IN 46256; Phone: 317-842-7115; Fax: 317-849-8794. AMATEUR-RADIO HEADSET. The noise-canceling micro- phone on the Contester amateur-radio headset favors the 100-8000- Hz human-voice range for maximum speech intel- ligibility. The microphone CIRCLE 18 ON FREE INFORMATION CARD CIRCLE 19 ON FREE INFORMATION CARD boom rotates, so that it can be worn on the right or left side of the head, and auto- matically shuts off the mic when placed upright. To take full advantage of the noise-canceling feature, the microphone should be placed almost touching the user's lips toward one cor- ner of the mouth. Accord- ing to Telex Communica- tions, the Contester has the same rugged con- struction as the headsets the company makes for commercial broadcasters, pilots, and professional football coaches. The CRAMOLIN DeOxidizer IMPROVES CONDUCTIVITY DEOXIDIZES • CLEANS • PRESERVES • LUBRICATES For M Meiuts, Including Gold! CRAMOLIN* DeOxrdizet improves condoctiwiy by dis- solving oxides thot form on metal tonnedor ond ton- tact suites, eliminating unwanted resistance llwt impedes electrical performonce. CRAMOLIN® is on active ingredient that does not rely on solvents for performance. Doe to the excel- lent migration properties, CRAMOLIN® coots trie entire mewl surface ond protects it from fulare oxidotion. CRAMOLIN® continues to be the most effective ond economical product for improving ortd maintoinirvg electricol component reliability. m MHUf ACTUM, lOWBUMa AND SERVICE Of: • Switches & (eloys • Coble Connectors £ Adopters • Edge Connectors • lerminol Strips * Plugs I Sockets • Gold Plated Connectors • Potentiometers * Botteiy Contacts USED BY THOSE WHO DEMAND THi BEST: • Bell £ Howell • (opilol Records * Dolby Laboratories. • Hewlett Pncbrd • John Fluke Mfg. • Mdnlosh into • MCI (Sony) • ttotorolo • NASA • Nokamfchi • RCA • Switdicraft • and Mony More. R 0. Box J I LABORATORIES. INC. Esconldo, tt VZ033-3679 (619)743-7143 FSM619) 743-2460 CIRCLE 50 ON FREE INFORMATION CAHD An ETCHED circuit hoard from a Printed PAGE in just 3 Hours The ER-4 PHOTO ETCH KIT gives you the tools, materials and chemicals to make your own printed circuit boards. The patented Pos-Neg 1 " process copies artwork from magazines like this one without damaging the page. Use the circuit patterns, tapes and drafting film to make your own 1X artwork. Or try the Direct Etch™ system (also included), to make single circuit boards without artwork. The ER-4 is stocked by many electronic distributors, or order direct. Add $3.50 for handling and shipping. ER-4 PHOTO ETCH KIT(NV and CA residents add sales tax) S38.00 DATAK'S COMPLETE CATALOG lists hundreds of printed circuit products and art patterns. Also contains dry transfer letter sheets and electronic title sets tor professional looking control panels. WRITE FOR IT NOW! DATAK Corporation • 55 Freeport Blvd. • Sparks, MV 89431 CIRCLE 177 ON FREE INFORMATION CARD O O CD m ± as 25 headset's dynamic re- ceivers have a 50-15.000- Hz frequency response and impedance compatible with amateur transceivers. The five-foot headset cord is unterminated to accept any connector suitable for the user's transceiver. Washable cotton covers come with the headset and slip over the foam-filled ear cushions for long-term comfort. The Contester headset has a suggested list price of $102— Telex Com- munications, Inc., 9600 Aldrich Avenue South, Minneapolis, MN 55420: Phone: 612-884-4051; Fax: 612-884-0043. HAM RADIO SWR/P0WER METER. Designed to help amateur-radio operators optimize antenna settings for handheld transceivers as well as mobile or fixed ham radios, Radio Shack's CIRCLE 20 ON FREE INFORMATION CARD Micron ta SWR/Power Meter (catalog number 19-320) is intended for use on two popular amateur-ra- dio bands: 2-meter (144 MHz) and 70cm (440 MHz). The SWR/power meter features low inser- tion loss, which enables it to remain connected at all times. Its wide accuracy range lets the user mea- sure power up to 60 watts. The rugged, compact de- vice is encased in a sealed die-cast aluminum en- closure and measures ap- proximately 2'/2x2%x% inches. The Micronta SWR/ Power Meter retails for $39.95 at Radio Shack stores nationwide. — Ra- dio Shack, 700 One Tan- dy Center. Fort Worth, TX 76102; Phone: 817-390-3300. SCREEN-MOUNTED SCOPE CAMERA. To allow users of oscilloscopes and other measuring instruments to take high-resolution pho- tos of screen images in areas where printers and plotters are impractical — even in clean-room environ- ments — Tektronix's C-9 camera offers Autofilm ca- CIRCLE 21 ON FREE INFORMATION CARD pabilifies. With Polaroid's Autofilm. the C-9 camera can automatically advance, eject, and develop film into a clean, dry print. The cam- era also offers an optional chamber to hold and pro- tect the photos as they are ejected and developed. The remote shutter actu- ator is also useful in clean- room and medical environ- ments, where film handling might cause con- tamination. The C-9 can be used with screen-based in- struments including small video monitors, logic ana- lyzers, and medical-imag- ing equipments. With an optional pistol grip, the C-9 can be used with instru- ments lacking camera at- tachments. Also available optionally is a variable-in- tensity flash unit. The C-9 camera costs $490. — Tektronix, Inc., P.O. Box 19638, Portland, OR 97219-0638; Phone: 800-426-2200. R-E m c z i & LU _1 UJ < 26 ■ FCC NO-CODE ™ AMATEUR RADIO LICENSE The FCC recently passed Docket 90- 55 which for the first time allows a new codeless entry ham radio license of technician grade. Privileges 30 MHz and above — All modes! (See R.E. ar- ticle in April 1991 issue). Get all the no-code license details, study & testing information plus a one- year subscription to one of ham radio's longest running specialty mode publi- cations that will teach you all about the new modes you will be able to operate! FSTV SSTV FAX RTTY PA CKET AMTOR OSCAR FM REPEATERS MICROWA VE AND LOTS MORE! SEND $25 CHECK OR MONEY ORDER OUR 24TH YEAR SINCE 1967! Lrz. The SPEC-COM Journal P.O. Box 1002, Dubuque, IA 52004 (319)557-8791 MC/VISA (5% atidxJ) EARN YOUR B.S.E.E DEGREE THROUGH HOME STUDY Our New and Highly Effective Advanced- Place- ment Program for experienced Electronic Tech- nicians grants credit for previous Schooling and Professional Experience, and can greatly re- duce the lime required to complete Program and reach graduation. No residence schooling re- quired for qualified Electronic Technicians. Through this Special Program you can pull all of Ihe loose ends of your electronics background together and earn your B.S.E.E. Degree. Up- grade your status and pay to the Engineering Level. Advance Rapidly! Many finish in 12 months or less. Students and graduates in all 50 States and throughout the World. Established Over 40 Years! Write for free Descriptive Lit- erature. COOK'S INSTITUTE OF ELECTRONICS ENGINEERING ^SJ-W-E 4251 CYPRESS DRIVE ^-'-*- E JACKSON. MISSISSIPPI 39212 CIRCLE S8 ON FREE INFORMATION CARD Save on cable rental fees! 3 CABLE TV 1 Idescramblers iWE'LLBEAT* i ANY PRICE 1 i we'll beat: 4 JERR0LD-T0C0M-ZENITH f HAMLIN-OAK-PIONEER & SCIENTIFIC ATLANTA 5$ 24 HOUR SHIPMENTS! M I 5 MASTER CARD /AMEX/ VISA /C.O.D M SB | ifc • MONEY BACK GUARANTEE! x£ ' QUANTITY DISCOUNTS! i I Have make and model number of equipment used in you area ready. I q^'Ll jOLL-FpEE I 11-800-284-8432! f CABLE WAREHOUSE S W 10117 West Oakland Park Blvd., m 6? Suite 51 5, Sunrise, FL 33351 Jf TJ WO FLORIDA SALES 5JJ %&&&&$*&£*&$*&>$* CIRCLE 187 ON FREE INFORMATION CARD NEW LIT Use The Free information Card for fast response. 1991 ELECTRONIC MARKET DATA BOOK; from Electronic Industries Association, Pub- lications, EIA Marketing Services Department, 2001 Pennsylvania Avenue, N.W., Washington, DC 20006-1813; Phone: 202-457-4955; $100. If you're involved in any area of the electronics in- dustry, this edition of the ElA's annual encyclopedia of the U.S. electronic in- dustries is a valuable busi- ness tool. Electronics man- ufacturers, market re- search firms, financial in- stitutions, schools, and libraries keep the book on hand for up-to-the-minute information on consumer electronics, communica- tions equipment, computer and industrial electronics, electronic components, government electronics, in- ternational trade, employ- ment, and research and development. It covers new and upcoming develop- ments in consumer elec- tronics, such as DAT, CEBus, and HDTV; out- lines the government's fiscal year 1992 budget (and budgets for NASA and the Departments of Energy and Transporta tion), the Strategic De- fense Initiative, and a ten- year forecast for military electronics; reports on the average annual employ- ment and earnings and the job market outlook; and provides a full-industry summary. The book in- cludes illustrative charts, graphs, and tables, along with a glossary of terms. One chapter is devoted to electronic-related products and services, such as auto- motive electronics and home-office products, and extensive coverage of key technological develop- ments are included. PLL DESIGN CHART; from RF Prototype Systems, 9393 Activity Road, Suite C, San Diego, CA 92126; Phone: 800-874-8037 or 619-689-9715 (in CA); Fax: 619-689-9733; free. CIRCLE 22 ON FREE INFORMATION CARD CIRCLE 23 ON FREE INFORMATION CARD Of particular interest to synthesizer and PLL de- signers, this reusable PLL design chart can also be used as a general Bode- plotting tool. The chart fea- tures key decade slope lines to aid in plotting the open-loop response of a second- or third-order PLL, phase noise floor data for commonly used phase de- tectors, and a procedure for predicting phase noise at the synthesizer output. The chart, designed for use with only water-based eras- able pens, can be easily wiped clean for repeated use. Step-by-step instruc- tions are included. 1991-1992 EQUIPMENT, TOOLS & SUPPLIES CATA- LOG; from Print Products In- ternational Inc., 8931 Brook- ville Road, Silver Spring, MB 2 910; Phone: 800-638-2020 (301-587-7824 in MD); Fax: 800-545-0058 (301-585-5402 in MD); $2.00, This 62-page catalog is filled with electronic main- tenance and service prod- ucts from major manufac- turers. Highlighted in the „ CIRCLE 24 ON FREE INFORMATION CARD 1991-1992 version are Pace desoldering/solder- ing and surface-mount re- work and repair systems; test equipment from Lead- er, Hitachi, B&K, Kenwood, Simpson, Beckman, Tri- plett, Global, and Viz; Print's own line of tool kits and cases; and tools from Cooper, Crescent, Weller, and Xcelite, Also included are computer accessories and supplies, including RAM testers, EPROM pro- grammers, troubleshoot- ing supplies, and diag- nostic disks. TOTAL HARMONIC DISTOR- TION; CARTOONS FROM STEREO REVIEW; by Charles Rodrigues. Published by Perfectbound Press, 1120 Avenue of the Americas, Suite 4118, New York, NY 10036; $7.95. Do you take your audio/ video gear very seriously? If so. this collection of car- toons is sure to make you Total .. jARMONIC OlSTORTTON IflrClSUlxEfctrt^iWw CIRCLE 25 ON FREE INFORMATION CARD laugh — at the consumer- electronics industry, at the high-end manufacturers and distributors, at the family and friends who must live with your obses- sion, and at yourself. EQUIPMENT CATALOG; from Optoelectronics Inc., 5821 NE 14th Avenue, Fort Lauderdale, FL 33334; Phone: 800-327-5912 or 305-771-2050; tree. Aimed at two-way radio users, monitoring hob- byists, cellular phone tech- nicians, law-enforcement and security personnel. TV and radio-station engi- neers, and others involved CIRCLE 26 ON FREE INFORMATION CARD with radio broadcasting and reception from sub-au- dio to 3 GHz, this 16-page catalog describes Op- toelectronics newest hand- held and bench-top instru- ments. Included are de- scriptions, technical data, tips on how to use frequen- y cy-finding handi-counters, § universal counter-timers J3 for lab and field, and PC- ± based counters. Ft-E 2 27 The two most comprehensive electronics Take any 3 books for only $ 9 as your introduction to the new ELECTRONICS ENGINEERS' BOOK CLUB 95 3258 $27.95 This book offers up-to-date instructions for troubleshooting and repairing all major brands of equipment, with hundreds of diagrams, specs, and schematics. Covers TVs. VCRs, CD play- ers, and much mom. 310 pp. THE PJCTC LOPEDtfOr « ELECTRONIC J 'CIRCUITS VOLUME ONE f\ 193S $60.00 For quick -reference and on-the- job use, this sourcebook puts over 1,300 state-of-the-art designs at your fingertips . From A (ahum circuits) to Z (zero crossing detector circuits) this compendium excels in content, scope, and design. 768 pp. Counts as 2 020975-8 599.50 The essential reference for all electrical engineers. Complete- ly revised and updated, this classic handbook covers the generation, transmission* dis- tribution, control, conservation, and application of electrical power. 2,416 pp., 1.388 illus.* 430 tables. Counts as 3 10010P $19,95 More do-it-yourself circuits from the master— Steve Ciarcia. Step-by-step guidance on pro- jects ranging from a gray-scale video digitizer to parallel inter- facing. 256 pp. ."BLESH00T1N IIHIROMC "BQtlFHESl WmfiltSEft'H 9290 $36.00 This guide provides a practical approach to pinpointing symp- toms and causes, and effective- ly troubleshooting malfunctions. Providcs many nevcr-before- published techniques and ease histories, 315 pp. Counts as 2 EXP ttiMEN TSIN ARTFK1AL 9255 $97*50 "Outstanding 1 extensive refer- ence to current technology of electronics. Covers everything from principles to applications.* 1 —Computer Book Review 2*528 pp.* 1.800 illus. Counts as 3 SHiWIS SYSTEMS 3557 $29.95 A detailed study of signal analysis as it applies to the operation and signal-generating capabilities of today's devices. Explains the composition and use of test instruments, transmission media, satellite systems, broadcast and reception facilities, and more. 272 pp. 3037 $24.95 This is a practical introduction to artificial neural networks- complete with 1 1 circuits readers can build, using the schematics and software provided in the book. Also covers theory, hard- ware, mathematics, and the future of neural computing. 160 pp. PRINTED CIRCUITS DE5IQM Jijmum.u,>;.ii.i,..fc HP 10016 $39.95 Design tighter, more complex circuits, on time and on budget with this book, one of the First to provide a thorough coverage of all aspects of PCB design, including CAD. 320 pp. Counts as 2 3837 $27.95 Focuses on the specific digital circuits used in electronic power applications. Presents state-of- the-art approaches to analysis* troubleshooting, and implemen- tation of new solid-state devices, 272 pp. 9373 $46.00 This completely updated edition helps electronics professionals discover the wide variety of applications possible using op-amps. Covers signal genera- tion, instrumentation, and filter and control circuits. 516 pp. Counts as 2 003957-7 $49*95 Written for technical personnel, engineers, managers* and operators, this is a practical guide to design, implementation, and maintenance of cable TV systems, includes an overall introduction to standard NT.SC and HDTV systems. 400 pp. Counts as 2 Sesi'ga & Bu/Id ELECTRONIC POWER SUPPLIES J540 $26.95 This guide brings you up-to-date on today's most advanced power supply circuits, components, and measurement procedures. Co- vers switching rates up to 3-MHz and higher as well as the 20-kHz standard. 176 pp. 2672 $49.50 A one-stop sourcebook for the data needed on how linear ICs are fabricated, how they work, what types are available, and techniques for designing IC cir- cuits. 624 pp. 071231-X $54.95 A wealth of information on both analog and digital devices. Covers many types of sensors, semiconductor devices and basic circuit, signal amplification and processing, data switching, con- trol and readout, and much more. 377 pp. Counts as 2 28 engineering clubs have joined forces. . . 053570-1 $64.95 Everything you need to design or work with communications receivers such as: shortwave. broadcast, radar, military. marine, and more. 608 pp., 402 Olus. Counts as 2 COMPimR TECHNICIANS HAMJHOOh iP*«lv— MUlB > - 3279 $36.95 Perform routine maintenance, and diagnose and repair any kind of computerized device. This popular reference covers large dynamic RAMs, 32-Bil pro- cessors, 802 S6, 80386, and Z3O0I-Z8OO2 processors. 570 pp. Counts as 2 9401 P $19.95 A step-by-step guide to op-amp circuit operation for technicians, engineers, and scientists. Explore fundamental c i rcu its using bipolar, JFET-inpul, CMOS* and Norton-type op-amps. 250 pp. 15041P $19.95 Explore memory capacity, architecture, page-based virtual memory, input/output, and pipelining. Learn about the 80386 registers, real mode artd protected mode operation, special fields, and more. 45B pp. 2962P S17.95 This complete EPROM instruc- tion manual provides a detailed explanation of underlying theory, plus 15 different projects, including programmers, erasers, and EPROM -based circuits. 240 pp. 001013-7 $69.95 A comprehensive review of all dements of applied fiberoptic in- formation transfer, h covers operational principles at the system and component levels, comparative data on components. and more. 608 pp. Counts as 2 Y/m& CABLE FOR ELECTRONICS A User's Honctrao* 3787 $29,95 The most current information available on the properties of conductors and insulation. system design and assembly techniques, and guidelines on its-. ing the latest equipment. ]5<- pp. 3365 $14.9"; Use this broad study to prepare you for your FCC General Radiotelephone Operator Li- cense or CET exam, then keep it on your desk as a handy work- ing reference. 7W pp. Cotinu as 2 10017 $44.95 The most up-fo-date guide on CMOS ami PifMOS. Gain practical engineering solutions to designing and building reliable, COSt-tftfee Ligila! tvsfems, "Pi pp. Counts us 2 01'«0 I $27.95 Gives technicians, engineers. scientists, and students the precise data they need to solve day-to-day problems. Provides inslant access to specifics on components, circuits, power supplies, op-amps, and more. ftf># pp. Counts as 2 How the Club Works: The Electronics Engineers and Designers Book Club and the Electronics and Control Engineers* Book Club have joined forces to bring you nil the best titles from the most prominent electronics publishers. YOUR BENEFITS: You get 3 books for $9.95 plus shipping and hand- ling when you join. You keep on saving with discounts of up lo 50% off as a member. YOUR PROFESSIONAL BOOKSTORE BY MAIL: Every 3-4 weeks, you will receive the Electronics Engineers Book Club News describ- ing the Main Selection and Alternates, as well as bonus offers and special sales, with scores of titles to choose from. CLUB CONVENIENCE & EASY RISK-FREE TERMS: If you want the Main Selection, do nothing and it will be sent to you automatical- ly. If you prefer another selection, or no selection 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. If not satisfied with your books, return them within 10 days without obligation! BONUS BOOKS: Starting immediately, you will be eligible for our Bonus Book Plan, with savings of up to 80% off publishers' prices. EXCEPTIONAL QUALITY: All books are top-quality editions from ALL the publishers in the field especially selected by our Editorial Board to ensure the information provided is reliable and specific enough to meet your needs. AH books are hardcover unless number is to I lowed by a "P" for paperback. [Publishers' Prices Shown) ©1981 EEBC. Blue Ridge Summit, PA 17294-0860 . . .to bring you the largest selection of titles available anywhere —at savings of up to 50% off publishers' prices! Electronics E ngineers' MM^^^M^^^^^^HB^^ BOOK CLUB HW Blue Ridge Summit, PA 17294-ORfin [JYES! Please accept my membership in the FLBCTRONICS ENGINEERS' BOOK CLUB and send my 3 volumes listed below billing me $9.95. If not satisfied, 1 may return the honks within 10 days and have my membership cancelled. I agree to purchase 3 or more books at regular Club Prices during the next 2 years, and may resign any time thereafter. A shipping/handling charge and sales lax will be added to all orders. Name , Address City State Zip Phnne Vultd tor new members only. Foreign applicant* will receive special ordering instructions. Canada mini remit in U.S. currency, rhiv order Subject to oCcepuulM hiy liic Electronics Engine m Stmt Club. DHFIOSI O CD m _L CD CO 31 SM C < DC (1) NEW! "Shirt Pocket" Multimeter. Take it along! Features LCD display, autoranging with manual override, continuity sounder. Mea- sures to 400 volts AC/ DC and resistance. With fold- up vinyl case, manual and replaceable batteries. #22-169 27.95 (2) NEW! Building Power Supplies. Easy-to-understand, 96-page book explains linear and switching supplies. Includes complete plans for building five useful supplies with Radio Shack parts. #276-5025 4.95 (3) Mini Audio Amplifier, Great for computer voice/music synthesis, signal tracing and more. Has a built-in speaker, Vs" headphone jack, Va" input jack and volume control. Put one on your bench today! #277-1008 11.95 (4) Digital Logic Probe. LEDs and tone outputs reveal logic states instantly. It's the fast way to check operation and pinpoint problems in all types of digital circuits. #22-303 16.95 Parts Special-Order Hotline. Your local Radio Shack store stocks over 1000 popu- lar electronic components. Plus, we can special-order over 10,000 items from our warehouse— linear and digital ICs. tran- sistors and diodes, vacuum tubes, crys- tals, phono cartridges and styli, even SAMS' 5 service manuals. Your order is sent directly to your Radio Shack store and we notify you when it arrives. Delivery time for most items is one week and there are no postage charges or minimum order requirements. (1) Shielded RS-232 Jumper Box. Top- quality inline D-sub 25 adapter. Wire the included jumper wires and board to suit your need. #276-1403 9.95 (2) Computer RS-232 Tester. Dual- color LEDs monitor seven data/control lines to help you spot problems quickly. D- sub 25. Connects inline. #276-1401 14.95 (3) Grounded-TIp Soldering Iron. 15W. #64-2051 7.49 (4) Vacuum-Type Desoldering Tool. #64-2120 6.95 (5) Locking Forceps. 6" long. Stainless. #64-1866 4.95 (6) Rosin Soldering Paste Flux. 1 oz. #64-021 1.79 (7) Lead- Free Solder. 96% tin, 4% sil- ver. 0,25 oz. #64-025 1.99 (8) 10-Amp Microwave Overt Fuses. #270-1256 Pkg. of 2/1.29 (9) 2-Amp Fast-Acting Fuses. #270-1275 Pkg. of 3/79C (10) 5-Amp "Blade" Vehicle Fuses. #270-1205 Pkg. of 2/89C Computer/Printer/Business Machine AC Power Cords. 6 feet long. (11) Extension. Just plug in to lengthen existing cord #278-1259 4.99 (12) With Space-Saving 90° CEE Con- nector. #278-1260 5,99 (13) With Straight CEE Connector. #278-1257 3.99 Since 1921 Radio Shack has been the place to obtain up-to-date electronic parts as well as quality tools, test equipment and accessories at low prices. Our 7000 locations are ready to serve you — NOBODY COMPARES (3) * ' B —^ i ^ i (4) (1) Voltage Regulator ICs. Feature built-in overload protection and ther- mal shutdown. Great for custom pro- jects. Maximum input: 35VDC. 7805. 5V. #276-1770 1.19 7812. 12V. #276-1771 1.19 (2) Lo w - Vo Itag e M otor. J u st th e t hi n g for science projects, robotics and solar power demos. Operates from 1'fe to 3VDC. About Viz" long. #273-223 99C (3) High-Speed 12VDC Motor. Up to 15,200 RPM, no load. About 2" long. #273-255 2.99 (4) "Ding-Dong" Chime. This IC and mini-speaker combo is ideal for a customer-entry alert or doorbell. Pro- duces 80 dB sound pressure at 12VDC. Operates from 6 to 18VDC. #273-071 8.99 (5) Surface-Mount Resistors. 200- piece assortment of 15 popular values. Rated Va watt, 5%. #271-313 Set 4.99 (6) Metal Project Cabinet. An attrac- tive, easy-to-drill housing at a low price. 3xSVix5 7 /s" #270-253 6.79 (7) Power Supply Project Case. Vented 2V 2 x 4 5 /b x 3.V*" molded case, #270-287 3,99 (8) to 15 DC Voltmeter. Quality jew- eled movement. #270-1754 7.95 (9) Box/Board Combo. Molded en- closure plus predrilled 2 x Vis" board, labels and more. #270-291 4.99 (10) Eight-Position Audio Phono Jack Board. #274-370 1.69 (11) 1:1 Audio Transformer. Z: 600- 900Q. #273-1374 3,59 (12) Three-Pin XLR Mike Plug. Metal body. #274-010 2.99 (13) Three-Pin XLR Inline Socket. #274-011 2.99 (14) Three-Pin XLR Panel Socket. #274-013 3.69 32 Pricss apply a! uaMiciQa ting Radio Shack stores and dealers. Radio Shack is a division q( Tandy CorpQTaibon CIRCLE 78 ON FREE INFORMATION CARD .Radio /hack AMERICA'S TECHNOLOGY STORE PC-TO-TV CONVERTER Put PC power into home videos with this VGA to NTSC television adapter. ANTHONY STEVENS <3»- WITH OUR VGA TO NTSC VIDEO CON- verter, you can have video pro- duction right at your fingertips. A part of multimedia is con- necting your computer to the outside video world. In the past, $100,000 computer-controlled video consoles were required to produce many video effects you see today. Now with animation software, a video tape recorder, and this video converter board we present here, it's possible to turn your PC into a home video production studio! You don't even need the latest equipment. If you have a VCR and a PC that's compatible with a video graphics array (VGA) video card, you're on your way. Creat- ing your own TV video produc- tions, insert-editing titles on home videos, or playing comput- er games over a projection TV are just some of the many exciting possibilities that await you If you build our video converter. Displaying a computer video picture on a VCR requires a VGA- to-NTSC signal converter. The converter board mounts in the computer and is connected in line with the computer's VGA monitor cable. A memory-resi- dent software program monitors the VGA board, and with a key stroke on the computer, it can be turned on or off. When conversion is off, the computer monitor displays nor- mal VGA video. When conversion is on, the board converts the VGA monitor display and outputs NTSC broadcast-quality signals for recording. The conversion is in real time and is fast enough to display full-action computer games. Computer video In the early days of personal computers, video monitoring suffered because the circuit de- signs had to use low-density, high-cost memory components. Various innovative display for- mats were developed in order to store video text and video graph- ics with less memory. That need for efficiency started the comput- er graphics monitor design down a path of noncompatlbillty with standard broadcast video. Lately, the VGA standard has become widely accepted. With VGA, a picture is displayed on a video monitor in a serial fashion. Figure 1-a shows how the picture is painted one line at a time. The picture starts at the top of the screen and traces, line by line. until reaching the bottom of the picture. That is repeated fast o z o cc (- o W _l HI 6 3 < cr homhm&i nuns FIG. 1— DOT SCANNING OF THE PICTURE TUBE creates the image that you see. VGA uses a noninterlaced technique which scans once to make a complete picture (a), NTSC uses an interlaced method to scan twice to make a complete picture (+hbib + hb). The amplitude of the deflected signal versus time is shown in c. enough so the eye sees a continu- ous picture without flicker. Con- trol, or sync signals are also sent to the monitor to align the pic- ture properly on the screen. An NTSC signal scans twice in an interlaced mode to make a com- plete picture (Fig. 1-b). The difference in the control and sync signals between VGA and NTSC makes it impossible to display a VGA picture on stan- dard television without a format converter. Conversion from VGA to NTSC is not an easy task. Let's see how those systems work. VGA versus NTSC standards VGA boards have become very popular in recent years. The VGA TABLE t— SYNC POLARITY AND VGA MODE RELATIONSHIP Fixed-Frequency Monitor Display Mode Horizontal Sync Frequency Polarity Vertical Sync Frequency Polarity 350 lines 31.5 kHz + 70,1 Hz - 200 lines 31.5 kHz - 70.1 Hz + 400 lines 31.5 kHz - 70.1 Hz + 480 lines 31.5 kHz - 59.9 Hz 132 columns 31.5 kHz - 70.0 Hz + Multi-Frequency Monitor 350 lines 31 .5 kHz + 62.3 Hz - 200 lines 31.5 kHz - 62.3 Hz + 400 lines 28.0 kHz - 62.3 Hz + 480 lines 31.5 kHz - 59.9 Hz - 132 columns 27.6 kHz - 61.5 Hz + 600" 35.2 kHz 56.2 Hz - 768t 35.5 kHz + 86.9 Hz + **8Q0x 600 Graphics 1 1024 x 768 interlaced graphics Video Signals Black level = 0V Full intensity level + 0.7V standard has several modes of operation for compatibility with existing software. Those dif- ferent modes define the control signals that generate the hori- zontal, vertical, and pixel clock- ing rates. The horizontal rate is the time it takes to paint one line from left to right across the face of the video monitor. The pixel clock sets the dots of resolution for each horizontal line. The ver- tical timing sets how many hori- zontal lines that make up the whole picture from the top to the bottom of the display. PC video standards and operat- ing frequencies can differ greatly, depending on the type of monitor used. For instance, a 640 x X400 mono/color VGA monitor has a video bandwidth (dot rate) of 25.175 MHz with a horizontal scan rate of 31.5 kHz, while a 640XX350 EGA monitor has a 16.257-MHz bandwidth with a 21.85-kHz horizontal scan rate. Other mono and color monitors, such as CGA, MDA, HGC, and MCGA also have different video bandwidths and horizontal and vertical scan rates. The VGA sig- naling to the computer monitor consists of multiple signal lines. Figure 2 shows that three inde- pendent signal lines carry the ac- tual analog video in a red, green, and blue (RGB) format, one color per line. One other line carries the horizontal sync pulses, and another line carries the vertical sync pulses. Some of the various VGA modes are indicated by the polarity of the two sync signals. Table 1 shows the relationship between sync polarity and the VGA mode. As we will see, VGA technology differs greatly from the NTSC broadcast standard. NTSC is the standard used by television broadcasters in the United States. Video cassette re- corders (VCR's) and cameras/ camcorders also use that same standard. The NTSC signal is a composite of all the signals nec- essary to generate a broadcast quality picture. The three analog color signals are combined to- gether with the horizontal and vertical sync signals and color subcarrier to make up the total NTSC signal. The NTSC sync signals and color subcarrier are fixed in their frequencies; the horizontal scan- ning frequency is 15,734.26 Hz, 34 VGA MONITOR CABLE PIN OUTS | PIN FUNCTION SIGNAL 1 2 3 5 red vrr.it (i JWv^_A*w_ _/u^ \ GREEN VIPFC BLUE VIDEO 6 7 3 > GROUNDS 10 13 14 HORIZONTAL SYNC VERTICAL SYNC _n_n_n_n_ n n _TL_ ■i i i FIG. 2— THESE ARE THE PINOUTS OF A VGA MONITOR CABLE, with their corresponding signals. Note that pin 15 is not used. VERTICAL BUFFER AND INTERRUPT CONTROLLER \ POWER 11 7S. PC BUS D FIG. 3— BLOCK DIAGRAM OF THE BROADCAST VIDEO CONVERTER. The unit consists of two main sections; an NTSC color encoder/modulator and an NTSC synchronizer synthesizer. the vertical scanning frequency is 59.94 Hz, and the color subcar- rier frequency is 3.579545 MHz. By contrast, the different VGA modes have different horizontal and vertical timing rates, de- pending on the video mode chosen. Another difference between VGA and NTSC is the field scan- ning. NTSC uses interlacing, which scans the picture tube twice per picture (Fig. l-b). There is one scan for the even lines and another scan to fill in between the evens with the odd numbered lines, making one complete pic- ture. Most modes in VGA, on the other hand, use noninterlaced scanning, where the complete picture is painted in only one pass over the face of the picture tube. The challenge of converting from VGA to NTSC standards in- volves stripping off the VGA hori- zontal and vertical control sig- nals, changing the video timing, and recombining properly gener- ated NTSC horizontal and ver- tical sync. The three color signals are then mixed and added 1o the color subcarrier, finishing the job. About the circuit The video converter's power and software interrupt control signals are supplied directly from the PC bus. The video signals from the VGA board are con- nected to the converter using the VGA monitor cable. The comput- er monitor is then plugged into the converter board by another VGA monitor cable. An RCA jack on the converter board is used to supply the NTSC video signal output. Figure 3 shows a block di- agram of the video converter, and the schematic is shown in Fig. 4. The circuit consists of two main parts: an NTSC color encoder/ modulator, 1C1, and the NTSC sync generator, IC2. Horizontal and vertical VGA sync signals from the VGA connector (pins 4 and 5 of PI) are buffered by R32. R33, IC3-a, -b, and -dbefore driv- ing 1C2. The vertical sync is also conditioned by RIO, Rll, C12, and IC3-C. Those conditioned signals are narrow pulses, which drive Q2. The collector of Q2 and R17 are wired ored to the PC bus interrupt request input (1R92), which tells the computer when conversion begins. Two input clocks are required by IC2: The 14.31818-MHz crys- tal, XTAL1, and components R19-R21, C21-C23, and Dl make up a phase-locked os- cillator clock that's generates the color subcarrier and runs the in- ternal workings of IC2. Compo- nents L4. C25-C28. R24-R26. and D2 make up the second clock oscillator, which is used to com- bine all the necessary sync sig- nals together. The output of IC2 is the com- posite NTSC synchronizing sig- nal (pin 21) and the color subcarrier (pin 27). The subcar- rier signal is buffered bv R31 and IC3-e. Components R12, C16, and C33 reduce the subcarrier amplitude to match ICl's input. The NTSC composite sync and color subcarrier signals are then applied to the NTSC color en- coder/modulator. Motorola's MC1377 is used for the NTSC modulator, IC1. The VGA RGB signals are applied c o 3 cr 35 CO z O BE i- o _i LU 6 5 FIG, 4— THE SCHEMATIC OF THE VIDEO CONVERTER. IC2 is used for computer control, rr as an NTSC signal synthesizer, and for NTSC composite sync and subcarrier output. IC1 is an NTSC modulator; a 200 jis-detay circuit is used to align the luminance part of the 36 picture with the chrominance part. ■'IDE! 1 ' . FIG. 5— PARTS PLACEMENT DIAGRAM. The square pads on the PC board indicate the positive teads for polarized capacitors, the cathode of diodes, and pin 1 of the IC's. through the VGA connector pins 1-3. Components C3-C5 block any DC on the video. A chromi- nance bandpass filter consisting of R7, Cll. C19, C30, and L3 re- duces mixing harmonics. That filter introduces a 200- (is delay to the color image. A 200-lis delay circuit consisting of R8, R13, CI 7, C18, LI, and L2 was added in the luminance path to match the delay of the chrominance cir- cuit, which makes the black and white part of the picture line up 15-PIN CONNECTS VIDEO CONVERTER BOARD 9-PIN CONNECTOR RCA JACK VIDEO m COMPOSITE VIDEO TV MONITOR COMPUTER MONITOR VGA CABLE WIRING r. pin 9 PIN 1 3 2 4 3 5 4 INO CONNECTION* 5 (NO CONNR HON) HB 7 6 / 9 INO CONNECTION) 10 1 11 1 12 (NO CONNECTION) 13 8 14 9 15 (NO CONNECTION) FIG. 6— HERE IS THE HOOKUP DIAGRAM for the video converter. PARTS LIST All resistors are ' -i-watt. 5%, un- less otherwise indicated. R1-R5 — not used R6, R22-^7,000 ohms R7— 1500 ohms R8, R11, R13, R15, RR23, R31-R33— 1000 ohms R9— 75 ohms R10, R16, R17, R21, R26, R28, R29, R34— 10,000 ohms R12— ■ 170 ohms R14— 220 ohms R18, R27— 75,000 ohms R19, R24— 1 megohm R20, R25— 100,000 ohms R30— 22,000 ohms Capacitors C1.C2. CIO— not used C3, C4, C5— 22 u.F, 16 volts, electrolytic C6, C12, C22, C23, C27, C28— 1000 pF, 100 volts, disc C7, C8, C11, C15, C24, C29, C30, C32— 0.01 p.F, 100 voits, disc C9, C13, C14, C20, C31— 0.1 pF. Mylar C16— 18 pF, 100 vote, disc C17, C33— 100 pF, 100 volts, disc C18, C25, C26— 39 pF, 100 volts, disc C19— 82 pF, 100 volts, disc C21— 33 pF, 100 vote, disc Semiconductors IC1— MC1377 RGB/NTSC encoder, Motorola IC2— HD440072 sync generator, Hitachi IC3— 74HC04 CMOS hex-inverter buffer Q1, Q3, Q4— 2N3904 NPN transistor Q2— 2N3906 PNP transistor D1-D3— 1N4001 diode Other components XTAL1— 14.31818 MHz resonator (HC-49U) L1 — 39 u.H epoxy choke, 5% l_2, L4 — 100 n.H epoxy choke, 5% L3— 22 ^H epoxy choke, 5% Connectors P1— 15-pin female DB15F connector P2 — 9-pin male DM9M connector CE1 — card edge connector In PC J1 — RCA phono jack JP1 — 2-pin header Note: The following items are available from Video Control, 3314 "H" St., Vancouver, WA 98663, (206) 693-3834: • A complete kit including PC board, D-connectors, mounting hardware, all parts and convert- er software package — $164. • An etched, drilled, and plated through PC board with tC2 and conversion software — $125. Please specify 5V> or 3V4 inch flop- py disk for software, add $5.50 for shipping and handling; bank cards and checks are accepted. Allow 4 to 6 weeks for delivery. o o £ CO CO 37 1 • •••• ••••• t • ••• 9 AV* INCHES - THIS IS THE FOIL PATTERN of the component side of the PC board. g z Q o UJ O Q < IX 38 with the color part. The pass- band of the delay circuit is 4 MHz to ensure the sharpest possible picture. The composite NTSC video sig- nal from 1C1 pin 9 is buffered by R14, R15, and Ql. A 75-ohm out- put impedance required to drive a video cable is provided by R9. Components R22, R23, R34, Q3, and D3 make up IC2's power reg- ulator. Now let's build the video converter. Construction The entire video converter cir- cuit is located on one double- sided PC board. The foil patterns of the component side and solder side are provided if you wish to make the board yourself. The PC board is a card-edge type, de- signed to fit into a short slot di- rectly into a PC motherboard. A parts-placement diagram is shown in Fig 5. Assembly of the unit is straightforward, just make sure the orientation of the tran- sistors, diodes, electrolytic ca- pacitors, and IC's is correct. The positive ( + ) leads for polarized capacitors, the cathode of di- odes, and pin 1 of the IC's are identified by a square pad on the board. After soldering, visually inspect it to make sure there are no solder bridges between closely spaced traces. lb test the board, hook it up as shown in Fig. 6. A test program is available on the Radio-Elec- tronics BBS (516-293-2283, 1200/2400, 8N1) as VGA. ZIP and will give you a go/no-go indica- tion of proper operation. The complete software is available from the source mentioned in the parts list. This VGA to TV broadcast con- verter is an excellent, easy to use multimedia tool. To record the computer's video on your VCR, plug a cable from the VCR's video input into the converter board's NTSC output. With two VCR's and a switch box you can insert- edit text or graphics from your computer using the pause con- trols. (A time-base corrector is re- quired if you want to overlay the computer images onto your vid- eos.) Now you can create your own video productions, record computer graphic images on VCR's, or play video games on projection TV. R-E HERE IS THE FOIL PATTERN of the sotder side of the PC board. Build this vocal effects mixer and get studio-quality sound "reverberations' 9 in your recordings. TERRY WEEDER IF YOU ENJOY EXPERIMENTING WITH home recordings, you'll be inter- ested in our vocal effects mixer. With a few evenings' work and a cost of $50, you'll be able to shape your voice with tone controls and create a "multiple-echo" effect while mixing in audio from a tape, CD, or other stereo source. The effects mixer can also be used with the lead vocal filter i Radio-Electronics. September 1990), to mix your own voice with vocal-less music. Lets see how your stereo's channels are mixed together and delayed to produce the reverberation effects. How it works The effects mixer takes the line-level output from your ster- eo's record jacks and applies it to two mixers — one for each chan- nel (left and right). Figure 1 shows a block diagram of how the circuit works. The signal from a microphone is amplified by a pre- amp and is then sent to an equal- ization stage where bass and treble levels can be adjusted inde- pendently. That signal is fed to an 8-ms delay circuit whose output is remixed with the original to simulate an echo. The delayed signal is attenuated and fed back to the input of the delay circuit, to generate the effects of multiple echoes. Finally, the vocal signal and it's echoes are fed to two mixers, where they combine with the mu- sic program being received from the stereo system. The output of those mixers are then fed to the stereo amplifier, via its play input jacks. Circuitry The schematic mixer is shown stereo input signal is coupled via CI and C2 to the two mixers, IC1- of the effects in Fig. 2. The c and ICl-d. The signal from the microphone is coupled via C13 to IC4-c, which amplifies it 30 times to a line level of approximately 200 mV. The impedance seen by the mike is set by R24, while C14 and R25 filter out frequencies above the voice spectrum. The output of IC4-C passes through tone controls R28 and R30 (with the associated capaci- tors) and is applied to the non- inverting input of IC4-b. The gain of IC4 is set by R33 and R34 at 12, which makes up for the loss occurring in the tone-control stage. The signal then goes through ICl-b to 1C2 (an RD5106 256- sample bucket brigade by EG&G Reticon), which delays the signal about 8 milliseconds. An os- cillator made up of 1C3 and its associated components gener- ates a clock pulse for IC2, which determines the delay time and o o CD m to 39 can be calculated by 51 2if c = total delay, where 4 represents the clock fre- quency. A low-pass filter is formed by ICl-a, which smooths out the sample steps caused by the delay chip. The output oflCl- a is then fed through feedback potentiometer R9 back to the in- put of the delav stage, via mixer ICl-b. The output of ICl-a is also fed MIXER f$ LME IN' IfFTCH „ RIGHT CH t FEEDBACK ■VA MIXER 8ms DELAV LOW pass ML1ER MIXER 6^^ LINE EFFECTS LEVEL MIC PREAMP EQUALIZATION BASS :H fc MIXER TREBLE VOLUME \ \* VOLTAGE AMP FIG. 1— BLOCK DIAGRAM. The mike signal is adjusted with bass and treble controls. Echo is produced by delaying the signal 8 milliseconds then remixing with the original signal. Feeding the output ot the delay circuit to it's input causes multiple decaying echoes. The mike signal with echoes are mixed with the stereo signal. to mixer IC4-a through effects- level potentiometer R15. IC4-a combines that signal with the original signal coming from IC4- b. The volume level is adjusted using R41 together with IC4-d. From there the signal is sent to ICl-c and ICl-d where it mixes with the signal coming from the stereo. Construction The author's finished pro- totype is shown in Fig. 3. The main circuit is mounted on a sin- gle-sided PC board, while the power supply (Fig. 4) is wired on a perforated construction board. An etched and drilled PC board is available from the source men- tioned in the parts list, or you can build your own using the foil pat- tern provided. Mount the compo- nents according to the parts placement diagram shown in Fig. 5. Note that R24 sets the in- put impedance at the mike in- put. The value of that resistor should be 300 ohms when using a low- impedance microphone, or 10K with a high-impedance mike. A '/4-inch phone jack can be mounted on the front panel for use with a high-impedance mi- crophone, or an XLR 3-pin jack can be used for a low-impedance mike. C/3 z o □c I- o < a: PARTS LIST All resistors are ! '-.-watt. C4— 1 |i.F, tantalum C3, C4— 10 jxF, 16 volts, electrolytic R1,R2,R5— 150,000 ohms C7 — 0.15 p.F, tantalum C5, C6 — 0.1 m-F, ceramic disc R3, R13, R16-R18, R21-R23. R40— C8 — 200 pF, ceramic disc D1, D2— 12-volt Zener diode 47,000 ohms C9 — 0.002 jjlF, ceramic disc R1, R2— 220 ohms R4— 100,000 ohms CI 0—270 pF, ceramic disc R3— 1000 ohms R6 — 1 megohm C11, C12-^*.7 |xF, tantalum S1— SPST switch, 1 amp R7, R27— 33,000 ohms C13— 10 [iF, electrolytic LED1 — light emitting diode, any color R8— 10 ohms C14 — 39 pF, ceramic disc Miscellaneous: PC board, stand- R9, R15, R28, R30, R41— 100,000 C15— 0.005 u.F, mylar offs, hardware, wire, shielded ca- ohms, potentiometer C1 6— 0.033 p,F, mylar ble, power-supply cord, strain R10, R12— 10,000 ohms C17— 0.01 ixF, mylar relief, four RCA jacks, XLR jack or R1 1—43,000 ohms C18— 0.068 ixF, mylar 'A-inch phone jack, five knobs, and R14, R19, R20, R37— 15,000 ohms Semiconductors enclosure. R24— 300 ohms or 10,000 ohms (see IC1, 1C4 — LM324 quad op-amp NOTE: The following are available text) IC2— RD5106 256-sample bucket- from Weeder Technologies, R25, R29— 20,000 ohms brigade analog delay line, EG&G 14773 Lindsey Rd.. ML Orab, R26— 1000 ohms Reticon Ohio 45154: An etched, drilled, R31 — 3000 ohms IC3 — 4011 quad two-input nand gate and plated through PC board, R32— 2200 ohms Power-supply parts $10.00; all board-mounted com- R33— 5100 ohms F1 — 0.5 amp fuse and fuseholder ponents, $19.00; power-supply R34— 56,000 ohms T1 — 24 VAC center-tapped trans- components (not including the R35, R36, R38, R39— 39,000 ohms former, 100 mA perforated construction board, R42— 130,000 ohms BR1 — 1.5-amp bridge rectifier, 100 fuse, fuseholder, and switch), Capacitors PIV $12.50. Include $2.00 for ship- C1, C2— 2.2 p.F, tantalum C1 T C2— 1000 ixF, 25 volts, ping and handling. Ohio rest- C3, C5, C6. C19— 0.1 ti-F, mylar electrolytic dents add 5.5% sales tax. 40 •SEE TEXT FIG. 2— SCHEMATIC OF THE EFFECTS MIXER. The output from the stereo's record jacks are fed to mixers ICI-c and -d. The mike signal is amplified by preamp IC4-c. IC4-b corrects for signal attenuation in the tone-control stage. IC2 delays the signal 8 milliseconds and ICI-a smooths out the sample steps. The delayed signal combines with the original in the IC4-a mixer, then passes through volume control amp IC4-d to mixers IC1-c and -d where it combines with stereo music. The output is then fed back to stereo via the play jacks. -6 INCHES- SOLD THIS IS THE SOLDER SIDE of the PC board. o 5 m 3D 41 LIME OUT L,R LINE IN L.R USE 3/4-INCH STANDOFFS MIKE INPUT FIG. 3— THE AUTHORS FINISHED PROTOTYPE, Both boards are mounted on y4-inch standoffs. The left and right channel line inout jacks are mounted on the rear enclosure. The author used heat-shrink tubing to insulate the primary switch terminals. t — ** — r +J_ C3 , D1 1N4742 12V . D2 1N4742 C4 , IOm-F* t + 12V 10nF # cs 0.1 C5 0.1 — < OGND ©LED1 R3 1K -0-12V FIG. 4— POWER SUPPLY SCHEMATIC for the effects mixer circuit. Note that this is a dual supply. Lout Mn R) K Rcur IP TTTTTTT -12- C!3 C14 + -R2fI -R25- -R?4- ~R26- -R40- IC-1 g z o rr 5 UJ _1 LU g < rr -R42- U. -R39- -RJ5- -ni7- -r2t: +R3T-9 3 C , 5 C4Tr-rcr 1» -R3S- ci-> -rcn TfiorjJJya If 7 id: I mi I -nfi- J -Co Ik R41 R31 I -C1B- cT7 "«29- ce IC3 l R3Q l C1R €15 R?fl R9 - I R15 J =il FIG. 5 — PARTS PLACEMENT DIAGRAM. Remember to connect the two jumpers. Use shielded cables for all inputs and outputs, and make sure the capacitors are installed with correct polarities. Use shielded wire to connect pins 1 and 3 should be connected the jack to the mike input on the to the shield and pin 2 to thecen- board. When usingan XLR jack, ter conductor. Shielded wire should also be used to connect the line in/out terminals on the board to RCA jacks mounted on the back panel. The power supply shown in Fig. 4 is the same as the one used in the vocal filter project. In Tact, one power supply can be shared by both units if they're mounted in the same enclosure. Mount the power-supply com- ponents on a perforated con- struction board. Mount that board in the enclosure opposite the mike input of the main PC board. The high -gain mike input stage should be kept some dis- tance from the power-supply transformer to reduce noise and hum pickup. Hookup and operation The effects mixer can be con- nected into the tape-monitor loop of your stereo system. Use shielded cable with phono con- nectors on each end to connect inputs to the record jacks on your stereo, and outputs to the play jacks. You can now mix your voice in with the program materi- al selected by your stereo (for ex- ample phono, CD player, FM broadcast, and so on). There are a number of ways of using the vocal filter and the effects mixer together to replace the lead vocals with your own. By placing the vocal filter in the ster- eo/tape deck record path, you can produce recordings of your favor- ite songs, minus the lead vocals. Then by placing the effects mixer in the tape deck/stereo playback path, you can dub in your own voice live, or record the music and your voice together with a second tape deck. You can also remove the lead vocals and add your own simulta- neously simply by hooking the input of the vocal filter to the ster- eo's record jacks, the output to the input of the effects mixer and the output of the effects mixer to the stereo's play jacks. (Keep in mind that your stereo's record jack is an output, and play is an input. For your tape deck, record is an input, and play is an output.) Once you have the effects mix- er connected, plug in a micro- phone and set the mike volume slightly less than 12 o'clock and the effects controls at their mini- continued on page 88 42 STEVEN D. SWIFT DIGITAL SINEWAVE SYNTHESIZER Build this direct digital synthesizer, and generate low-distortion sine waves digitally. HOW OFTEN HAVE YOU WISHED YOU had one of those fancy frequency generators that let you set your frequency accurately without having to fiddle with the uncali- brated tuning knob? Without a high-quality frequency counter and without nearly infinite pa- tience, it is impossible to keep your audio oscillator on frequen- cy without constant tweaking. If you eliminate the expensive ex- tras, while retaining resolution and stability, you'll end up with the synthesizer project presented in this article. While this synthesizer doesn't have the features of some very ex- pensive products, it does provide 1-Hz resolution at over 500 kHz with crystal-controlled precision, all for less than $70. Once you add a suitable enclosure and power supply, you'll have a digital frequency synthesizer small enough to fit on even the mes- siest workbench. And it's perfect for providing that odd-ball fre- quency that your new project needs. Direct digital synthesis As the name implies, direct digital synthesis (DDS) is a meth- od of frequency generation that uses digital methods rather than the traditional analog oscillator, phase-locked loop, or bank of crystals. The availability of fast digital circuits and D/A convert- ers make this technology avail- able to the average electronics enthusiast. A review of trigonometry is im- portant to the understanding of DDS before delving into the de- tails of the electronics. Figure 1 shows a circle with a radius whose length is arbitrarily set to one. The radial line labelled R is allowed to rotate about the circle through an angle P. which will be referred to as the phase. Drawing a horizontal line from the tip of R until it intersects with the ver- tical axis defines the length S shown in the figure. As the radi- us, R, is allowed to make a com- plete rotation around the circle, the length of S takes on all values between + 1 and - 1, while P var- ies from to 360 degrees. The length S is precisely the sine function of P, sin(P), shown in Fig. 2-a. If, rather than allowing R to ro- tate smoothly around the circle, o we make 8 equal steps around Q the circle, then the values of S § form the stepwise approximation 3 shown in Fig. 2-b. As the number £ of steps are increased, the ap- 2 43 cc o z o DC F o UJ Q Q < (-1.0) (0.-1) FIG. 1— THIS CIRCLE HAS A RADIUS whose length is arbitrarily set to one. As R rotates around the circle, S takes on all values between +1 and -1. 1.0V 0.5V 0.0V -0.EV -1.0V 1.0U 1 1 1 ov o i 1 » 1 t a t it 2 i J50 i m / / \ i ■ o.ov / \ \ \ f 1 \W ■ \ S £ / I) 5 i 1 lo 1 2 A 2 ,0 3( 3 U FIG. 2— THE LENGTH S, AS R ROTATES, Is the sine function of P (a). If we make 8 equal steps around the circle, then we get the stepwise approximation shown in h. If we make 64 steps, the approximation be- comes closer to the actual sine function proximation becomes closer to the actual sine function, with Fig. 2-c showing the approxima- tion for 64 steps. In practice, analog filtering is used to smooth out the steps, as we'll see in a minute. From this simplified discus- sion, a method for generating a varying frequency can be de- rived. Assume that each step oc- curs at a precisely determined instant, then by varying the step size the number of steps around the circle can be varied. The fewer the steps, the faster the complete circle is covered, hence the higher the frequency of the sine-wave approximation. Note that fewer steps means a coarser approximation to the actual sine function, with the output even- tually reducing to a square wave, which points out one of the limits of this technique. All we need now is a circuit that will syn- chronize the variable-phase steps to a precision clock. Figure 3-a shows a block di- agram of the system. The block labelled Phase Accumulator re- petitively adds the value set by the Step Size Programmer to the sum performing the function of stepping the radius (R) about the circle in equal phase increments. The phase accumulator behaves like a simple counter, except that rather than incrementing its out- put by one on each clock pulse, the output advances by the value set by the step size programmer on each clock pulse. The block labelled SIN(P) converts the value stored in the phase accumulator to a sine amplitude approxima- tion. The step size programmer is simply a bank of DIP switches, the phase accumulator is a series of cascaded 4-bit adders, and the SIN(P) block is a sine look-up ta- ble contained in an EPROM. The digital data present at the output of the SIN(P) block must be converted to an analog voltage in order to be useful. A method for doing this is shown in Fig. 3- b, which consists of a D/A con- verter, filter, and output ampli- fier. The filter helps to smooth out the jagged steps in the sine ap- proximation, while the output amplifier buffers the output of the D/A converter. In the actual FIG. 3 — BLOCK DIAGRAM of the phase accumulator and phase-to-sine converter (a), and the block diagram of the digital-to-analog converter and output stage (b). 1 »> B .-> 74LS283 A v ■ „ V?74LS374 > k ?-*■';.-£-: OUTPUT FIG. 4 — PARTIAL SCHEMATIC of the phase accumulator (a) and the converter and output stage (to). 44 FIG. 5— HERE'S THE COMPLETE SCHEMATIC for the phase-accumulator circuitry. o o d CD m I 45 to o z i o LU o D < It FIG. 6— THE SCHEMATIC for the analog section. implementation, the buffering and the filtering functions are combined. The frequency resolution of a DDS system is set by the master clock frequency, /" c , and the number of bits. N, in the phase accumulator. For the binary ac- cumulator that we have here, the resolution is then /" C /2 N . If the step size programmer is set to a binary value, M, then the output frequency is M x f c /2 N . The de- sign presented here keeps M less than N/4 to minimize distortion at the output. Circuitry There are several manufac- turers of complete integrated cir- cuits that can perform the digital 46 portion of the block diagram, but these parts are expensive and not readily available. Figure 4-a shows a partial schematic of the phase accumulator using compo- nents that are inexpensive and easy to get. The complete phase ac- cumulator consists of six 74LS283 4-bit adders, with their outputs latched by three 74LS374 octal D flip-flops. The outputs of the 74LS374's are fed back to the B inputs of the 74LS283, which forces the sum stored in the latches to be added to the value set by the switches on the A inputs. Since the 74LS374 stores data only at the positive edge of its clock input, the fact that the data presented to its inputs will be changing short- ly after the clock causes no er- rors. The delay through the latch and adder guarantee glitch-free operation. At each clock pulse a new sum is present at the output of the latch. The output of each adder then stabilizes with the new sum allowing the cycle to re- peat continuously. This sum rep- resents the value P in the theoretical discussion, while the value set by the DIP switch repre- sents the size of each phase step. The sine-wave lookup table is contained within a single 2716 EPROM providing phase-to-am- plitude conversion. Although 24 bits are available in the phase ac- cumulator as implemented here, only 21 bits are used to maintain compatibility with readily avail- able crystals. For those who wish to program their own EPROM, both a hex dump of the contents of the EPROM and an S-Record formatted hex dump for use with PROM programmers can be downloaded from the R-E BBS (516-293-2283. 1200. 2400. 8N1) in a file named DIGSYN.HEX. A programmed EPROM is available from the source shown in the parts list. The data in the EPROM repre- sents the values generated by the mathematical function 127.5(sin(2JTP/2048-Ji/2}) trun- cated to 8-bits, with P taking on values from to 2047, that is, the addresses of the EPROM. The for- mula offsets the sine function so that its value ranges from to 255 as P ranges from to 2047 and avoids negative values which would complicate the next stage. That matches the function to the 2716 EPROM with its 11 -bit ad- dress space and with its 8-bit output range. A C-program used to generate the values in the table is shown in Listing 1. Since the EPROM has only 1 1 address lines, only 11 lines fioin the ac- cumulator are used in this ap- plication. The 8 bits at the output of the EPROM are a digital repre- sentation of the amplitude of the sine wave and must be converted to an analog voltage before being filtered and buffered. Since simplicity and low-cost were design goals, the output of the EPROM is latched by another 74LS374, which allows the full clock period for the EPROM out- put to setde, permitting the use of inexpensive slow EPROM's. The latch also guarantees a glit- ch-free input to the D/A converter section. Figure 4-b shows the D/A con- verter circuitry. The D/A con- version is accomplished using a DAC08 8-bit D/A converter (an MC1408 can be substituted with some loss in performance). The output of the converter is a cur- rent proportional to the digital value present on its 8-bit parallel input. The current is set by R8 to a maximum of 1.06 mA. The dig- ital word presented to the D/A varies from to 255, forcing the current output to vary from to (255/258) x 1.06 mA. The current is then fed to op-amp IC4-b which converts it to a voltage that varies from to approximately 1.0 volt. The complete schematic for the phase accumulator cir- cuit is shown in Fig. 5, and the schematic for the analog section is shown in Fig. 6. First-order filtering is accom- plished by C9 in this conversion stage. Op-amp IC4-a provides ad- ditional filtering to further smooth out the steps in the sine approximation. The output of this two-pole filter is AC-coupled to the output connection. Figure 7 shows the relative response of the filtering provided in the out- put stage. The comer frequency of the filter is set by the formula fo = V(2jiVR7xC10xR6xC11) which, for the values shown, is equal to 482 kHz. A high-speed LISTING 1 /* This program calculates the value of the sine function offset so that the 4th and 1st quadrants cause a code from to 255. Code is generated to fill a 204 8 byte prom (2716 or equivalent) for a full circle of 2*pi radians. Other size memory may be used by changing the value of bytes in the declaration table. */ # include ♦include main I double p=0; double S=0,' int s /* phase input to sin fen */ /* output value of true sin fen */ f* amplitude truncated to 8 bits */ double sin(); /■• true sin fen */ double pi<=3.141592654; int addr-0; /* address of EPROM */ int bytes-2043; /* size of EPROM in bytes */ printf (" 1 2 3 4 5 6 7 8") printf (" 9 a b c d e f \n") ,- while (addr < bytes ) { if ( addr % 16 = ) printf ("\n%4x ", addr); p = 2,Q*pi*( (double) addr )/( (double) bytes) ; S - 127.5*(1.0+sin(p - pi/2.0) >,' /* gives at s - ( (int) S ) ; /* convert to an integer */ if ( S - { (double) s ) >- 0.5 ) s++; printf (" %2x",3); addr++; /* increment address */ 90 deg */ rounds if necessary *; } O O m 3 1 47 b \ -20 -30 -,15 \ \ \ \ w o z o cr P o o 5 < 10kHz 30kHz 100kHz 300kHz 1.0MHz 3.0MHz FREQUENCY FIG. 7— THE RELATIVE RESPONSE Of the filtering in the output stage. The corner frequency is equal to 462 kHz. A high- speed op-amp is required to effectively filter the waveform. op-amp is required in this stage to filter the waveform effectively. The 4558 op-amp we used is a good compromise between per- formance and cost. The clock for all functions is provided by a crystal oscillator running at 4.194304 MHz, which happens to be exactly the 22nd power of two. The clock is divided by two to provide the phase-ac- cumulator clock and EPROM latch clock. Additional inverters are used as delay elements to en- sure that the latches are clocked at precisely the right instant to prevent glitches. With the clock and timing as such, EPROM s with access times as slow as 475 ns can be used. With 21 bits of the phase ac- cumulator used and a- clock fre- quency of 4.194304/2 MHz (f c ), the output resolution is precisely 1 Hz. Since 19 bits are presented as the input to the phase ac- cumulator by the DIP switch, the maximum output frequency is: 2 ia xf c /22i = f c /4 = 524.288 kHz While a DDS system can ap- proach f c /2, f c /4 was chosen as a maximum to limit the total dis- tortion in the output waveform. The top frequency is actually 1 Hz less than that because the max- imum setting is 2 19 - 1 for a 19- bit binary input. The filter rolloff shown in Fig. 7 attenuates clock- related distortion by over 30 to 1. Construction A double-sided PC board is available from the source shown in the parts list, and we've also provided the foil patterns in case you want to make your own board. If you're using the PC board, follow the parts-place- U'Jq q U!0 o o o o o o o o e o o o e o no o » ° « asi ^—WW B OOB COMPONENT SIDE SI aoooaooooov OPOOObOOOB O ^O*«-0-0) a small current segment I dl of another conductor experiences a force due to the segment E 1 dl,. I, dl, experiences an equal and opposite force. lelogram with sides I, dl t and r t . That is similar to scalar multi- plication where A times B gives the area of the rectangle with sides A and B. The direction of dF m is that of the extended right hand thumb with the fingers wrapped through the smallest angle from I dl to Ij dl, xr,. In Fig. 1-6, the current seg- ment I dl experiences a force to- wards I, dl,. I, dlj experiences an equal and opposite force towards I dl. For other current segments, the force on an I dl is not equal and opposite to that on an I, dl,. That may appear to be a violation of Newton's third law. however the actual constant currents ex- ist only in closed loops or circuits as dictated by charge con- servation. The I dl and I, dl, are only a part of each loop. The total force is found by summing up all the infinitesimal contributions around each closed loop. We must sum twice by integration, first to find the forces of all the I, dl, s on an I dl. and then to sum the forces on each I dl The force on the entire loop com- posed of I dl is always equal and opposite to that on the entire loop composed of I, dl,. Ampere went on to suggest that in a permanent magnet, the force F m is produced by some sort of closed current loops that exist in the material. The magnetic field B Figure 2 shows that the space around a constant current seg- ment Ij dlj can be explored using a very small constant current loop obtainedbyaddingallits I dl contributions and symbolized by j 1 dl. Since each I dl will experi- ence a force due to the presence of I, dl, even though nothing material connects them, one has the impression that the condition of space itself is af- fected by the presence of the I, dip We can say that a constant current gives space the propen- sity to exert a force on another constant current, if it were present, according to Ampere's force law. To find that propensity, we re- move I dl from the force law to obtain the definition of the magnetic field (also called mag- netic flux density) in units of webers/meter 2 , which equals the tesla dB = -^2. 4p dl-, x r t This is called the Biot-Savart law. The force on each I dl is dF m , which equals I dl X B. Op- posite sides of the loop will ex- perience forces in the opposite direction since the dl's are in opposite directions. The loop will, Iherefore, experience a tor- que. Since \ x dl, exists only as a part of a closed loop, the total B at any point in space is Any current loop is called a magnetic dipole because it re- sults in a B field. The magnetic-field test in- strument must be a very small magnetic dipole, just as a very small positive charge + q is the electric-field test instrument. The distinction is that/ 1 dl is a sum of all the vectors for which magnitudes and directions must be taken into account, whereas + q has only a magni- tude. If a current I is considered as just an individual electric charge q, moving with constant velocity through a point, the magnetic force it would experi- ence in the B field at that point is F m =qvxB. If an electric field is also present, q would experience an additional electric force F c , and the total force would be F = F c + F m = qE + qvxB = q[E + (vxB)]. This equation is known as the Lorentz force law. r MAGNETIC DIPOLE = /Bds (webers). Imagine moving over the sur- face, adding up the dB-ds contributions from each I dl. At each ds, r points from I dl to- wards ds. Since dB is perpen- dicular to r, the only place dB-ds is non-zero is where ds is not di- rected along r. That is where ds moves away from or toward 1 dl. Since the surface is closed, for each place we move away from I dl by a certain amount and direc- tion, there must be another place that we move back in towards I dl by the same amount and in op- posite direction. Whatever B-ds contribution is found over some of the surface is canceled by a - B-ds contribution over another part of the surface, therefore we can say that As in electric flux, any B pro- duced by currents outside the surface will not contribute to the total. If the original Gaussian sur- face is shrunk so the volume en- closed approaches zero, the ratio of the change in flux to the change in volume would reach a limiting value even if the flux were not zero. That is the diver- gence of B, and since = for any Gaussian surface V-B=0(T/m3). That is the unnamed Maxwell equation. It simply says that the total spreading out, or diver- gence, of the B field through an infinitesimal closed surface about any point is zero. Whatever B field appears to leave from a particular point must return to that same point. Magnetic mo- nopoles, therefore, cannot exist. That relationship allows magnet- ic dipoles, which produce equal amounts of outward and inward magnetic flux from a point. If a number of our B-field instru- ments were scattered about the FIG. 3— CHARACTERISTICS OF A B FIELD. In (a), a Gaussian surface composed ol an Infinite number of Infinitesimal ds areas surrounding part of a current loop. The total apparent flow of B, the magnetic flux J B ds, through the surface is zero. Flux from currents outside the surface does not contribute since whatever flux "flows" in through the surface also flows back out. In (b). an ampere an loop composed of an infinite number of infinitesimal dL lengths encircles a current segment. The magnetic circulation around the loop^B-dL is proportional to the current encircled. For currents not encircled, /BdL point, they would not spread out. The apparent rotation of the B field around an infinitesimal area containing a point can be found by imagining an amperean loop about some current loop as shown in Fig. 3-b. Divide the am- perean loop into an infinite number of infinitesimal lengths dL. The B field at each dL is again just the sum of each of the infi- nitesimal dB contributions from each I dl, where B = /dB. The magnetic circulation around the loop is proportional to the cur- rent encircled. If you take B-dL you get the magnitude of B times the magni- tude of the effective length paral- lel to B. which is the apparent flow along dL. The direction of dL is taken as the direction of the curled fingers of the right hand with the extended thumb point- ing in the direction of I dl. The total apparent rotation, also called the magnetic circulation, around the amperean loop is found by adding those parts by integration over the entire closed loop fBdL. Imagine moving along the loop, in the direction of dL, adding up the dB-dL's. r points from I dl to dL. When we move at right angles to dB, that is along r or I dl, where dB-dL is zero. At all other places there will be a non-negative contribu- tion since we are always travel- ing in one direction around the loop. The contributions are pro- portional to the current I through the loop since B = /dB is proportional to that current. The proportionality constant is U-n, so fB-dL = u, I(T-m). If the amperean loop is shrunk so the area enclosed approaches zero, the ratio of the change in circulation to the change in area reaches a limiting value. That is the curl of B, which must be pro- portional to the current per unit area J through the loop, therefore VxB = m.oJ (T/m 3 ). That relationship is called Am- pere's law for constant currents. It simply says that the total ap- parent rotation, or curl of B, around any point is proportional to the constant current density at that point. The right hand rule gives the direction of apparent rotation. If a number of the B- field instruments were scattered about a point, they would rotate. Next time, we'll discuss some magnetic phenomena and how in- ductance is related to the magnetic field. The concept of a magnetic circuit will be developed based on an analogy to the electric circuit. Well see that in matter, the mag- netic field can be considered as the linear superposition of two fields, similar to what was shown with the electric field. r-E o o CD m 59 BUILD R-E's CALL-ALERT w g Z o or. u LU o < cr 60 RODNEY A. KREUTER and DAVID PLANT MOST PEOPLE DONT SEE MANY PAR- allels between the amateur radio service and the citizen's band, but there are similarities. CB channel 9 has helped thousands of stranded motorists, and Hams have provided communication when all else has failed during a disaster such as an earthquake. However, because of all the ac- tivity that may be on your favorite CB channel or two-meter re- peater, it is often tempting to turn off the rig or advance the squelch to the point where only the next-door neighbor can get through. In the case of CB, this greatly reduces your range, and with amateur radio it works only with simplex operation. The end result of all this is that you may miss a call from a friend or an emergency call from someone in trouble. The solution to this problem is a selective call system whereby your receiver or trans- ceiver is always on, but does not pass audio until the correct Touch-Tone sequence is detected. Then you {and your entire team, if the system is used for club or emergency use) hear the call. The Call-Alert Call-Alert consists of two com- ponents, an encoder and a de- coder. The encoder is a pocket- sized battery-powered device that produces the Touch Tones; it is held next to the transmitting mi- crophone to provide acoustic coupling. The decoder, or monitor, is coupled to the re- ceiver by plugging it into the ex- ternal speaker jack. It can be powered from either an AC or DC source, for home or mobile use. Note that no modifications to your existing station are required to use either the encoder or the decoder. The Call-Alert simply Eliminate the constant chatter on your favorite channel or repeater with the Call Alert acts as a switch between the re- ceiver output and the listener. The system contains an indicator light to let you know that a call has been received, a switch to by- pass the device when originating a transmission, a reset switch, and a built-in speaker and vol- ume control. As shown in the decoder block diagram in Fig. 1 , the input from the receiver takes two paths. The lower path goes straight to an au- dio amplifier (IC7) through vol- ume-control R25. The amplifier is held inoperative by flip-flop IC6-b until the upper logic path is satisfied. The audio stage can INPUT FROM TRANSCEIVER FIG. 1— DECODER BLOCK DIAGRAM. The lower input path goes straight to an audio amplifier (IC7), which is held inoperative until the upper logic path is satisfied. ^ u also be turned on manually via switch S2. In the upper path, ICl-d is an input buffer for the tone decoder, IC2. Buffering is necessary be- cause the tone decoder can be damaged by high input-signal levels; the buffer limits levels to under 5 volts. The buffer is bi- ased by ICl-b, which also biases ICl-a, the level-indicator ampli- fier. Driven by its buffer, the tone decoder provides two outputs. The first output indicates which DTMF tone is received. The data is sent to the two comparators that compare the decoder's out- put with the user-selected switch settings. More about the switch- es later. The decoder also puts out a data valid signal (dv) that goes high when any valid tone is re- ceived, which keys timing logic later in the circuit. The first tone comparator, IC3, triggers IC5 when the tone and switch inputs coincide and the timer runs for 4 seconds. The timer resets everything after that time period to prevent "hacking" a system entry, and it also pro- vides the signaling to set and re- set flip-flop lC6-a. The flip flop enables the second comparator to listen for the second tone. When IC4 validates the second tone, it triggers a latch, IC6-b, which enables the audio stage and turns on the call-alert light. Reset switch S5 unlocks IC6-b, thus preparing the monitor for the next call. Circuitry The schematic for the decoder section is shown in Fig. 2. The whole system runs on 5 volts (with the exception of the audio stage), so the output of ICl-d will swing up to just under V cc , thereby protecting the tone de- coder's input (IC2). At high audio input levels, however, ICl-d's out- put will clip, preventing the de- coder from functioning. Other- wise, at normal receiver output, levels, the decoder works fine. There are level-set and data-val- id indicators (LED1 and LED2, respectively) on the board that we'll discuss in detail later on. Pin 5 of ICl-b is set to Vi V cc so the outputs of all three op-amps idle at 2.5 volts. The level amp (ICl-a) is set up to drive LED1 at proper audio input. The 74HC85s (IC3 and IC4) are 4-bit magnitude comparators that compare two 4-bit "words," and indicate whether one word is larger, smaller, or equal to the other. Inputs ao-A3 are tied to the 4-position DIP switches S3 and S4, and the decoder outputs are tied to comparator inputs bo-bs. When both words match (the words can be binary, BCD, or hexadecimal, which is the case with the decoder as there are 16 DTMF tones) the comparator output at pin 6 will go logic high. Because the comparator's en- able line (pin 3) has to be high to operate, 1C3 will respond first, as its enable is brought high by the dv (data valid) output at pin 12 of the decoder. When that happens, flip-flop IC6-a is toggled by a 4- second input from the 555 timer (IC5) and the second tone dv signal. That allows IC4 to listen for the second valid tone. The timer resets the flip-flop and the device waits for the next input. If the second valid tone arrives within 4 seconds, IC6-b latches on, which turns on audio ampli- fier IC7 and lights LED4. Reset switch S5 will clear IC6-b. The audio amplifier, IC7, is a Motorola MC34119. That part was chosen because it can be powered from up to 18 volts and, at rest, it draws virtually no cur- rent which makes it totally silent. Keep in mind, though, that nei- ther speaker lead can be grounded, so if you plan to add an external speaker jack, isolate it if you are using a metal case. The decoder will work from 6 to 12 volts AC, or 9 to 15 volts DC. Although the bridge rectifier will work with either input polarity, it is a good idea to ground the nega- tive with a DC input in case you share a power supply with other equipment — in a mobile environ- ment, for example. For home or office use, a 9-volt DC adapter works perfecdy. The encoder The encoder schematic is shown in Fig. 3. The circuit con- sists of a tone encoder, a switch to go from the first tone to the second, and an amplifier to drive £} the speaker. The heart of the unit g is the TCM5089 tone encoder, !g manufactured by Texas Instru- -- ments, that will generate all 16 2 61 -VA-" RS-R11 10K S5 -RESET + 5V SOURCE LED3 *• POWER C1 1 - C15 .1 FIG. 2— SCHEMATIC FOR THE DECODER. Everything but the audio stage runs at 5 volts so the output of ICI-ct will swing up to just under V cc . Tbuch Tones by returning a row pin and a column pin to V ss or, in our case, ground. {Although most Touch-Tone keypads have only 3 columns and 4 rows, there is a fourth column available for use, or four additional tones called A-D, for a total of 16 tones.) The encoder uses two 8-posi- tion DIP switches, one for each tone. As there are four columns and four rows, and one of each is 03 o z o i UJ O Q < DC WRTS LIST— DECODER All resistors are Vt-watt, 5% R1, R5, R16-R19, R29, R31— 27,000 C7— 100 u-R 16-volt electrolytic LED1 , LED2— miniature red light-emitting ohms C1 0—1000 (iF, 16-volt electrolytic diode R2, R14— 100,000 ohms C16— 10 (j,F 16-volt electrolytic LED3 — green panel-mount light-emitting R3. R8-R12, R20-R24, R26, R30— C17— 4.7 nR 16-volt electrolytic diode 10,000 ohms C18— 1 u-F, 16-volt electrolytic LED4 — red panei-mount light-emitting R4— 100 ohms Semiconductors diode R6 — 1 megohm IC1— LM324 quad op-amp Other components R7, R32, R33— 330 ohms IC2 — SSI204 Touch Tone decoder XTALt— 3.58-MHz crystal R13 — 2200 ohms IC3, IC4— 74HC85 4-bit magnitude S1— SPST switch (mounted on R25) R15. R28— 10 ohms comparator S2— SPST toggle switch R25 — 10,000 ohms, audio taper potenti- IC5— NE555 timer S3, S4 — 4-position DIP switch ometer with SPST switch (S1) IC6— dual D-type (lip-flop S5 — momentary pushbutton switch R27— 330,000 ohms IC7 — MC34119 power amp with enable J1 , J 2— audio and power input jacks (use Capacitors ICS— 7805 5-volt regulator whatever best suits your needs) C1. C2, C4-C6, C8, C9, C11-C15— 0.1 D1, D2— 1N914 switching diode Miscellaneous: PC board, project case, iiF, ceramic disk Q1-Q3— 2N3904 NPN transistor speaker, control knob, labeling, hardware, C3 — 47 jiF, 16-volt electrolytic BR1— 50-volt bridge rectifier wire, solder, etc. 62 FIG. 3— ENCODER SCHEMATIC. The heart of the unit is the TCM5089 tone encoder that will generate all 16 Touch Tones. required to determine a par- ticular DTMF tone, two on posi- tions are required per DIP. This is also the derivation of the expres- sion "2 of 8" coding. The two DIP switches, S2 and S3, are con- trolled sequentially by IC1, a 555 timer running in its astable mode to generate a square wave. When first turned on by pushbut- ton switch SI, the output at pin 3 goes high and is inverted by Ql which triggers S2 to key in the first tone. After a half second, ICl's pin 3 goes low to enable S3, generating the second tone. The AM resistors are Vt-watt, 5% R1— 1000 ohms R2, R5— 10,000 ohms R3, R7— 33,000 ohms R4— 2200 ohms R6 — 1000 ohms, miniature PC -mount potentiometer R8 — 330,000 Ohms R9— 10 ohms Capacitors CI, C2, C7— 0.1 jjlF, ceramic disk C3, C4, C8— 47 (xF, 16-volt electrolytic C5-^t.7 ^.F. 16-volt electrolytic C6— 1 jaF. 16-volt electrolytic Semiconductors IC1—NE555 timer RC network of C3-R3 at the base of Ql creates a delay between the two tones; otherwise a combina- tion of two of the same tones would be read as a single tone. The diodes in series with the switches isolate the row and col- umn programming for each tone. The 300 milliwatt output from IC2 is attenuated and fed to IC3. Decoder construction With the exception of the con- trols and indicators, all parts for the decoder mount on the PC board. A pre-made PC board is PARTS LIST— ENCODER IC2— TCM5089N Touch Tone encoder IC3— MC34119 audio amplifier D1-D16— 1N914 switching diode Q1— 2N3904 NPN transistor Other components XTAL1— 3.58 MHz crystal S1 — momentary pushbutton switch S2, S3— 8 position DIP switch Miscellaneous: 1-inch speaker, PC board, project case, 9-volt battery clip, foam rubber, wire, solder, etc. Note: The following items are available from Project-Mate, Ste. 207, 2727 W. Manor PL, Seattle, WA 98199 (206) 283-4700: available as part of a kit (see the parts list), and a foil pattern for the board is provided here if you want to make your own. Perfo- rated construction board and point-to-point wiring can also be used. If you're using a PC board, follow the parts layout shown in Fig. 4. The authors used jacks for Jl and J2 (for power and audio in- puts, respectively) that mounted directly on the PC board. How- ever, the jacks are not provided with the kit because each builder will have his own idea regarding • A decoder kit containing a PC board and all PC-mounted components (ex- cept J1 and J2>— $48.50 + $2.50 S&H • An encoder kit containing a PC board, battery clip, and all PC- mounted components— S22. 50 + $2.50 S&H (Orders may be combined for the same $2.50 S&H fee) • A 1-inch speaker— $4.50 post paid There is a 10% discount on a second kit, and a 15% discount on 5 or more by radio clubs. o o i TO 10 ID 63 ._._„,3- J - #■ ^*Wr^ R16 R2 — -R1— B ALERT J2 INPUT LED1 IW —R1R— R , 3 R19 C5 -f] J1 JJpow POWER BR1 H* -R32— _ R31 _ ~T~j * t ™ R25 VOLUME C16 R29- — R6— HOhXTALI J I | iR7 J "f,2 6 01 D2 -J- LI S5 RESET IC3 IC4 IJ^LEDZ R j n °1 1 AUTO MM - - r &• S/\_fD3 POWER , , — R8— . , R21 — sa i - R9 ~ S4 i - R22 ~ cTs ] —RIO— | ) — R23— l/lB -R33- — BU- ST POWER S2 R28 C13 _,_ -R24- •R27- SPKR CO O Z O DC (- O ai 6 D < RG. 4— DECODER PARTS-PLACEMENT DIAGRAM. With the exception of the controls and indicators, all parts for the decoder mount on the PC board. jack selection. By hardwiring the input connections, the jacks can be eliminated entirely. The finished decoder board, shown in Fig. 5, measures 4x4 inches, with a loaded height of 1 inch. It can easily be installed in- side any suitable enclosure. The prototype has the speaker mounted on the top side of the case; for mounting the unit un- der an automobile dashboard, you may want to mount the speaker on the bottom of the case for better sound quality. Keep in mind that all front-panel controls return to ground, so a single wire can connect all of them to the board. Encoder construction The encoder is assembled on its own PC board, which is also available from the source men- tioned in the parts list or can be made from the foil pattern we've provided. Figure 6 shows the parts-placement diagram for the encoder. Before you can build the en- coder board, the two diode arrays (D1-D8 and D9-D16) must be as- FIG. 5— THE FINISHED DECODER board can easily be Installed inside any suitable enclosure. All front-panel controls return to ground, so a single wire can connect all of them to the board. B1 r'l-'K XTAL1 IC2: S3 I39-D1B ttm.m^ [SEE TEXT) FIG. 6— ENCODER PARTS-PLACEMENT diagram. See Fig. 7 before stuffing this board. FIG. 7— THE TWO DIODE ARRAYS consist of eight 1N914 diodes spaced 0.1-inch apart with the cathodes all soldered to a common bus. A spare piece of perforated construction board can be used as a 0.1- inch spacing guide. FOIL PATTERN FOR THE ENCODER. sembled. Each array consists of eight 1N914 diodes spaced 0.1 inch apart with the cathodes all soldered to a common bus. Fig- ure 7 shows how you should as- semble the arrays, and a spare piece of perforated construction board can be used as a 0.1-inch spacing guide. Position DIP switches S2 and S3 with the number-1 position on the outer edge of the board. (The prototype has the switches backward, although it doesn't af- 64 FIG. 8— THE POCKET-SIZED ENCODER CASE used for the prototype has a built-in compartment for a 9-volt battery, although you should secure a piece of foam rubber in the bottom of the battery compartment to hold the battery in place. feet the operation.) The authors drilled a hole in the PC board un- derneath potentiometer R6 and a matching hole in the back of the case so that the level adjustment could be set with the case closed: this, however, is not necessary. The pocket-sized case used for the prototype has a built-in com- partment for a 9-volt battery, al- though you can use any case you like. The PC board is held inside the case with double-sided foam tape. Pushbutton switch SI, the battery-clip leads, and a 1-inch Mylar speaker are wired to the cir- cuit board, and the switch and speaker are mounted on the front and top panels of the case, re- spectively. A 5 /e-inch hole is drilled on the top of the enclosure for the speaker, which was se- cured to the case with some in- stant glue. We suggest that a bead of glue be placed completely around the speaker for a good acoustic seal. When you position the holes for the speaker and SI, make sure they do not interfere with the circuit board. When the case is assembled, the final step is to secure a piece of foam rub- ber in the bottom of the battery compartment to hold the battery in place. Figure 8 shows the com- pleted encoder. Preliminary setup The first step is to pick an arbi- trary two-bit code (two tones) and set both units to the same code. Legal codes are from 0-0 to D-D (0-0, 0-1, 0-2, etc.), including the "#,""*," and A— D tones. The pro- totype units were set to code 3-6, so we'll use that combination to demonstrate setting the DIP switches. The decoder is hexadecimal, so two 4-position DIP switches are used to set the code — one DIP switch per tone. Because the 10K pull-up resistors in the decoder are connected to ground when a DIP switch is closed, an "on" switch position provides a low and an "off switch position pro- vides a high. Figure 9 shows the DIP-switch settings for S3 and S4 depending on which digit, or code, you have selected. For the 3-6 code, DIP-switch S3 must have switches 1 and 2 in the "on" position and 3 and 4 "off, " and S4 must have switches 1 and 4 "on" and 2 and 3 "off." The encoder requires the set- ting of two 8- position DIP switch- es, S2 and S3 (one DIP switch per tone), to generate the two-tone code. Figure 10 shows the DIP- switch settings for S2 and S3. From Fig. 10 we can see that, to generate the first tone (3 in this example), that DIP-switch S2 should have switches 3 and 7 closed. For the second tone (6 in this example), S3 should have switches 3 and 6 closed. At this point, when pressing SI (with a good battery installed), the en- coder should produce a two tone warble, and potentiometer R6 sets the volume. ON X X X X 12 3 4 2 ON X X X I X 12 3 4 3 ° N X X X X 12 3 4 ON 4 X X X X 12 3 4 5 0N X X X X 12 3 4 6 ° N X X X x 12 3 4 ON 7 X X X X 12 3 4 8 ° N X X X X 12 3 4 ON 9 X X X X 12 3 4 t ON X X X X 12 3 4 0N X X X X 12 3 4 ON # X X X!X 12 3 4 , ON A X X X X 12 3 4 B m X X X X 12 3 4 C 0N X X X X 12 3 4 D 0N X X X X 12 3 4 o I CD FIG. 9— THE DECODER has two 4-posi- S tion DIP switches used to set the code. ^ Here they're set for the 3-6 code. 2 65 0} g z o g a < ON X X X X X X X X 12 3 4 5 6 7 8 2 ON X X X X X X X X 12 3 4 5 6 7 8 ON 3 X X X X X X X X 12 3 4 5 6 7 8 . ON 4 X X X X X X X X 1 2 3 4 S 6 7 B 5 0N X X X X X X X X 12 3 4 5 6 7 8 ON 6 x X X X X X X X 1 2 3 4 5 6 7 8 ON 7 X X X X X X X X 12 3 4 5 6 7 8 8 ° N X X X X X X X X 12 3 4 5 6 7 8 q ° N X X x|x X X X X 12 3 4 5 6 7 8 ON X X X X X X X X 12 3 4 5 6 7 8 0N X X X X X X X X 12 3 4 5 6 7 8 ON # X X X X X X X X 12 3 4 5 6 7 8 A ON X [x X X X X X x 1 2 3 4 5 6 7 8 B ™ X X X X X X X x 1 2 3 4 5 6 7 8 C 0N X X X X X X X X 12 3 4 5 6 7 8 D m X X X X X xlxlx 12 3 4 5 6 7 8 FIG, 10— THE ENCODER has two 8-posi- tion DIP switches, S2 and S3, that must be set to generate the two-tone code. FOIL PATTERN FOR THE DECODER. System test The first test of the decoder is to apply power and see if LED2 (data valid) flashes briefly. This indicates that the decoder. IC2, is functioning. Now, with a receiver supplying audio, adjust its vol- ume using LED1 to set the level. With an FM receiver, and the squelch off on a quiet channel, the LED should show about Vz brightness. On a busy channel it should flicker following voice peaks. CB is somewhat different because the background noise is quieter, and here we adjust to an active channel. A weak glow fol- lowing voice peaks is the correct setting. At this point the LED2 should remain off until a valid code ID received. For two-meter testing, a scan- ner, set to the experimental portion of the band, can be used as the receiver and a hand-held used as the transmitter. Using the built-in Touch-Tone pad, pressing any Touch-Tone digit should cause LED2 to light, and code 3-6 will trigger the decoder on and you will hear your trans- mitter. The alert lamp, LED4, will stay lit after transmitting, and the reset button will turn it off. The next step is to set the en- coder level by using it to key the decoder. Note that if the encoder is held directly against the mike, the audio may become distorted. Try holding the encoder a quarter of an inch from the mike ele- ment. Get it to the point where the receiving station hears clean Touch Ibnes at approximately the same level as voice. You will find that it takes very little audio from the encoder when it's placed close to the microphone. For CB you can use a rig with a 50-ohm dummy load for the transmitter and another trans- ceiver (a walkie-talkie) as the re- ceive source. Set the encoder output level to work best with the transmitter, then set receiver au- dio. For an on-the-air test, set the levels and drive around with the encoder making various calls throughout the day. The system should work well and it will be a pleasure to have the rig quiet be- tween calls. Another test pro- cedure is to attach the encoder speaker to the decoder input with clip leads and fire up the system. The proper encoder out- put should be close to that for on- the-air use. You can probably think of other applications. For example, the output of the alert lamp (LED4) can be used to control other de- vices in your shack. R-E 66 DEVELOPMENT AND DEBUGGING tools have improved tremen- dously since the introduction of the microprocessor. Logic ana- lyzers and development systems, widely used by hardware and software developers alike, make child's play of otherwise tough debugging chores. There are sev- eral problems with these tools, however: They're processor-de- pendent, hard to use, and costiy to purchase. It doesn't have to be like that. however. We've designed a univer- sal, easy-to-use, low-cost, yet pro- fessional-quality logic analyzer with separate LED displays for sixteen address lines and sixteen data lines, single- and auto-step- ping operation, the ability to work with both 8- and 16-bit sys- tems, and more. A complete kit of parts with attractive silk- screened panel is available for well under $200 — a fraction of the cost of comparable commer- cial units. Partial kits as well as a PC board all by itself are also available. MICRO-MON features MICRO-MON attaches to any microprocessor design chores with our under-$200 logic-analyzer kit standard ROM or EPROM on the target system via an IC clip. MICRO-MON works with both 8- bit and 16-bit parts with capaci- ties ranging from 2K x 8 to 64K x 16, in 24-, 28-. 32-, and 40- pin packages. Two conveniently located connectors accept the in- terface cables. Connector pinout was designed to use standard ribbon cables and standard IC clips. Each address and data line has its own dedicated LED, so it's easy to Identify shorted lines. In addition, MICRO-MON will blink the corresponding LED of any floating or open address or data line. By attaching a single lead to the target's wait or ready line, you can single step or continu- ously step through micro- processor instructions with the press of a switch. For the step- ping function to work, the target system must be static — that means that the wait or ready line must be able to stall the micro- processor without adversely af- fecting system operation. Continuous stepping works like auto-repeat on a keyboard: MICRO MONITOR JIM COOKE Wl' 1 • • * ®* D °« ss # • • • • • i +%& ■ . • • » • • li. o* ° a » A f^ a • • iS, & " °» » * * * * - u O I o m 33 67 g z o BE o UJ _i UJ 6 < a: MICRO-MON steps the target sys- tem twice per second as long as the Step switch remains de- pressed. This powerful feature al- lows you to observe all bus activity, thereby enabling you to easily debug both hardware and firmware. Another feature allows you to stop the target system on a spe- cific address pattern, data pat- tern, or combination thereof. MICRO-MON has a three-posi- tion switch for each address and data bit, so each bit can be pro- grammed to match on a high. low, or don't care. An external connector carries the Match signal, which can be used to trig- ger a scope or other device. MICRO-MON has its own power supply, so it does not consume power from the target system. Also, to reduce cost, or if the match capability is not required, the unit can be depopulated for 8- bit-only operation. Theory of operation MICRO-MON consists of three major circuits that we'll discuss separately: Display, Single-step, and Match. Display Circuit. The display circuit, shown in Fig. 1, consists of inverting buffers IC1-IC4. Ad- dress and data lines from the tar- get system feed the buffers via the IC clip. The buffers feed ad- dress and data buses used by the rest of the system. In addition, the output of each buffer drives the cathodes of the display LED's via 470-ohm current-limiting re- sistors (those resistors are con- tained in resistor networks RN1-RN4). A unique feature of the display circuit is the Floating Line In- dicator, which identifies open and floating lines by blinking the associated LED. Blinking is ac- complished by connecting the in- put side of each buffer to a 2-Hz oscillator via a 47K resistor (con- tained in resistor networks RN5-RN8). The inputs of HCT buffers IC1-IC4 are high-imped- ance types, so open or floating inputs will easily allow the 47K resistors to couple the 2-Hz sig- nal into the circuit. On the other hand, if an input is not floating or open, but is high or low, the logic level will override the 2-Hz signal, clamp the buffer either high or low, and display the corre- PARTS LIST All resistors are ' i-watt, 5%, un- less otherwise noted R1— 150.000 ohms R2— 100,000 ohms R3— 200,000-ohm PC-mount potentiometer R4 — 1000 ohms R5, R10—1 0,000 ohms R6— 10 ohms R7— 2.2 megohms R8, R9 — 47,000 ohms RN1-RN4— 470 ohms x 9 resistor network, pin 1 common RN5-RN1 2-^7,000 ohms x 9 re- sistor network, pin 1 common Capacitors C1— 2.2 p-R 25 volts, tantalum C2— 0,1 |iF, 25 volts, tantalum C3 — 1 jiF, 25 volts, tantalum C4 — 33 pF, ceramic disc, with socket (see text) C6-C15— 0.1 u-F, ceramic Semiconductors IC1-IC4— 74HCT240, octal three- stale inverting buffer IC5— 74HCT221, dual monoslable multivibrator IC6— 74HCT14, hex Schmitt trigger IC7— 74HCTO0, quad nand gate IC8— 74HCT32, quad or gate IC9-IC12— 74HCT688, eight-bit magnitude comparator IC13— 7805 + 5-volt regulator Q1— 2N2222 NPN transistor D1—1N914 diode LED1-LED32--red LED (T1-3/4 package) Other components Jl-a— 16 x 2 0.1" header J1-b— 20 x 2 0.1" header J2 — 3.5mm coaxial jack J3-J4 — RCA PC-mount phono jack JU1, JU2, JU4— 3-pin 0.1" header JU3, JUS— 2-pin 0.1" header S1-SPDT toggle, center off, one side momentary (Alcoswitch MTA-106H-PC Or equiv.) SW2-SW33— SPDT slide, middle NC SW34— SPST slide Miscellaneous: 6-volt, 300-mA DC adaptor, front panel, enclosure (Hammond P/N A9086265), ca- bles for 28-, 32- and 40-pin ROM's, cable for wait line, assembly hard- ware. Note: The following items are available from Jim Cooke, P.O. BOX 834, Petham, NH 03076 (603) 882-4460: Complete kit, $189; PC board only, $29; PC board kit and all components, $99; enclosure with silkscreened front panel, $49; cable assembly with 28-pin chip clip, $49. New Hampshire resi- dents add appropriate sales tax; all orders add 5% for shipping. MC and Visa accepted. sponding state in the appropriate LED. Single-step Circuit. This cir- cuit consists of the logic shown in Fig. 2. Switch SI selects one of four stepping functions (Run, Stop, Step, Autostep). all of which are executed by control- ling the Wait or Ready line of the target microprocessor. Switch SI is special: It is an SPDT type with a center "off" position, and a spring return on only one side (Step). Here are the four stepping functions: Run— With SI in the "run" position, the wait line is unaffected by MICRO-MON. so the target microprocessor runs at full speed. Stop— With SI in the center "off position, the wait line is asserted, so the target mi- croprocessor halts. In this state, MICRO-MON displays current address and data lines. Step — By moving SI into the "step" posi- tion and releasing it, one-shot IC5-a fires once, thus allowing the microprocessor to execute a single operation. The time con- stant of the one-shot is adjusta- ble and must be set for the particular microprocessor and clock rate. The combination of IC6-a. R2, and C2 form a filter that prevents switch bounce from falsely triggering IC5-a. Autostep — If SI remains de- pressed, the delay generated by R7 and C3 expires, which in turn allows the 2-Hz oscillator signal (generated by IC6-d, Rl, and CI) to feed into the one-shot via IC7-C and IC6-e. Thus the one-shot will be retriggered twice per second as long as step-switch S 1 remains depressed. Match circuit. As shown in Fig. 3, four cascaded octal com- parators (IC9— IC12) generate the match signal, which is enabled or disabled by S34, match enable. Each address and data line has a corresponding three-position switch (S2-^S33) that is used to specify a match on 0, 1, or X (don't care). Let's see how the comparators work. Each address or data line is always connected to one leg of a comparator; a switch determines the connection to the other leg of the comparator. For the "don't care" position (down), the two comparator inputs are shorted together, forcing a match. For a match on 1. the switch grounds <- & <> <- z ^ 4- LE01 LED3 Lt05 ^ J® 4 LED10 IEQ11 LED13 LED16 ^ -r. J? r® LEDap ^ ^ LED25 10 ircjfi ^ ^ >£> ® ® l ED?! ^ ^ LEO30 6 ^ e i -VSVhi -Whi RN1 ; ■ 31 -VA->' -WH ~Wy- P.N? 470« (*9> -Wv- *t •VWH' HN3 47011 (K9| ■*AHi W > m -V^-o RN4 470(1 (*9) -Wr^ -W, « -w*- O o FIG. 1— THE DISPLAY CIRCUIT consists of several octal Inverting buffers that drive discrete LED's to display 16 address lines and 16 data lines. en m 3> to 69 IT J 8 a> -I 3 B si <° r s s I s- t/i a. 2 to S in ■ g- E. ■ I 6 r> =■ in eg to < *- c J3 ,$_ svNcy 10 < A=B? 12 IC6-1 Vs 74HCT14 V< ICB-C 74HCT3Z 13 ice-b '/< 74KCT32 FROM FIG.1 I — °S18 BDO BD1 > I B02 > - "— °S19 DDO RN11 47K (x9) -o*-o- ~°S20 DD1 o*-o- DK M$ 10 QD8 DD9 DDA DOB DDC ODD DDF nni i! $ # 13 15 17 RN12 47K (x9) iSjMMfjfjM! DDO D01 D02 DD3 DD4 DD5 DPS DD7 IC11 74HCT6B3 PO PI P2 P3 P4 P5 P6 P7 P=Q> QO 01 02 03 04 05 06 Q7 13 16 IC12 74HCT6B8 X^ PO p=a P1 P2 QO P3 01 P4 02 P5 P6 03 04 P7 05 Q6 G at ,19 DO 09 DA DB 12 DC DD DC 1B OF DO Dl D2 D3 12 D4_ 14 D5 16 Dj^ 18 07 1 3 Vcc 74HCTB88 PO P=Q P1 P2 00 P3 0.1 P4 Q2 P5 03 P6 04 P7 as 06 G 07 A8 Aa A10 All A12 ~N A 13 A14 A15 AO A1 N A2 "> A3 \ A4 ~A^ t v ■ 5XHDG KELVIN 200 Advanced S3995 FREQUENCY COUNTER TOS0MHZ IDEAI FOR TROUBLE SHOOTING AOOC VOLTAGE RANGES ACjOC CURRENT RANGES 5 FHEOUENCY HANGES S CAPACITANCE RANGES LOGIC TEST CONTINURY TES1BWUHEH CHODE CHECK THANSISTOR hFE TEST LED TEST VERIFY GOOD HAD DISPLAY • 3 Ml DIGIT LCD ACCURACY - 0.5% IMPEDANCE - lohtajthm KELVIN PRO 400 95 FLUKE 70 Series II ■Jiinj^jJhi'.'n^M.'i.'j BEST BUY NEW Series II FLUKE 70 series 11. s 63 FLUKE 73 series 11. • 89 FLUKE 75 series 11. M27 FLUKE 77 series 11. M49 FLUKE 79 series 11. J s 169 FLUKE 83 [ s 199 FLUKE 85 s 229 FLUKE 87 s 269 $ 69. r Models 100. 150. 200 . 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Qty •2,951 KEL VIN ELECTRONICS CIRCLE RESPONSE CARD or WRITE lor our CATALOG full of WHOLESALE PRICED fTEMS. OVER 10,000 ITEMS IN STOCK ELECTRONIC COM POME NTS 1 TECHNOLOGY ACTIVITIES VISA & MASTERCARD ACCEPTED S20 MINIMUM ORDER MINIMUM FREIGHT $5 H KELVI Electronics 7 Fairchild Avenue, Plainview, NY 11803 CIRCLE 1B6 ON FREE INFORMATION CARD Call: 1 (800) 645-9212 1 (516)349-7620 FAX:1 (516)349-7830 o o 00 m 73 a z o EC 1- o LU I LL' 6 Q i Hacker, Although these induction coils can stiil be spectacular and lots of fun, they are really nothing but an oversize auto ignition coil or a TV flyback transformer. For smaller demos, it makes far more sense to hang a voltage multi- plier on a color- TV flyback than it does to build a Tesla coil from scratch. Outside of the science museums, induction coils just aren't that big a deal any more. Not to mention the incredible radio and television inter- ference that a sloppily done Tesla coil generates. Or all of the very real X-ray dangers. Is there any point in hacking ultra- high voltages? Most electrical (or "E") fields have a magnetic Cor "H") field associated with them. In theory, you could build up your motors and generators using only the electric field, using only the magnetic field, or using any combination of the two. But look around you, and you'll find just about every common motor or gener- ator is a magnetic one that uses the H field nearly exclusively. The only ob- PartO Parti Part 2 Parts Part 13 Part 15 Part 18 Part 21 Part 22 Part 23 Part 25 Part 68 Part 73 Part 74 Part 78 Part 80 Part 87 Part 90 Part 94 Part 95 Part 97 Part 99 Part 100 Structure and organization of the FC Rules, fees, certification, type approval. Frequency spectrum allocations. Experimental radio services. Commercial radio operations. Radio frequency devices (includes computers, peripherals) Industrial and medical equipment. Public service fixed communications. Public service mobile communications Shortwave broadcasting. Satellite communications. Telephone terminal equipment. AM and FM broadcasting. Auxiliary AM and FM broadcasting links CATV cable television. Maritime and shipping communications. Aviation communications. Private mobile services. Microwave relay. Personal and CB citizens bands. Amateur radio. Disaster and emergencies. DBS Direct broadcast satellites. FIG. 1— FEDERAL COMMUNICATIONS COMMISSION regulations are presented in title 47 of the Code of Federal Regulations, Here are how the more useful and popular parts are arranged. NEW FROM 1 DON LANCASTER HARDWARE HACKER STUFF Hardware Hacker Reprints II or III 24.50 Midnight Engineering Reprints 1S.50 Incredible Secret Money Machine 15.50 CMOS Cookbook 24.50 TTL Cookbook 19.50 Active Fiher Cookbook 19.50 Micro Cookbook vol I or II 19.50 Lancaster Classics Library 119.50 Enhancing your Apple I or II 17.50 AppleWriter Cookbook 19.50 Enhance I or II Companion Disk 19.50 AppleWriter CB or Assy CB Disk 24.50 Bakerizing film (25 sheets} 14.50 POSTSCRIPT STUFF Ask The Guru Reprints I, II Or III 24.50 LaserWriter Secrets (lle/Mac'PC) 29.50 PostScript Show & Tell 39.50 Intro to PostScript VHS Video 39.50 PostScript Beginner Stuff 39.50 PostScript Cookbook (Adobe) 16.50 PostScript Ref. Manual It (Adobe) 28.50 PostScript Program Design (Adobe) 22.50 Type I Font Format (Adobe) 15.50 LaserWriter Reference (Apple) 19.50 Real World Postscript (Roth) 22.50 PostScript Visual Approach (Smith! 22.50 Thinking In PostScript (Reid) 22.50 The Whole Works (all PostScript) 299.50 FREE VOICE HELPLINE VISAJMcJ SYNERGETICS Box 809-RE Thatcher, AZ 85552 (602) 428-4073 j vious exceptions that prove the rule are such nanopower niche items as piezo fans. Most previous hackers who have explored the E field have now found electric field machinery to be ex- tremely large in size, besides having unacceptably low power densities and even lower efficiencies. To this day, creating the insulation materials, the surface treatments, and the vac- uum needed to support ultra strong E fields remains a very difficult problem to solve. On the other hand, for free energy, all you need is an insulated stationary vertical antenna several miles high to tap the Earth's 100-volts-per-meter calm-day E field. Then you hack up some sort of efficient DC-DC down- converter at the bottom. Uh Huh. Sure. 5 volts from a AA cell Fortunately, a lot more genuine pro- gress has been made by going the other way, stepping up the voltage of one or two AA cells into the + 5 volts needed by most of today's digital log- ic projects. Maxim has a new MAX-655 chip and a handy 655-EV evaluation kit that goes for $25. The kit includes the printed circuit board and all the parts you'll need to step a pair of AA cells up to a regulated 4- 5-volts DC at currents of 1 70 mA or less. I — mm . »i — p \ T ~ ~r ■ FIG. 2— A SWITCHING MODE step-up con- verter. Briefly but repetitively closing the switch causes the current in the inductor to ramp up to a high value. On release, the high current is transferred to the load re- sistor, appearing as a voltage that is al- ways higher than the input. The switching duty cycle sets the amount of voltage step-up you will get. Figure 2 shows you a type of switching-mode power supply called a step-up converter. If you do not close the switch, the output voltage will equal the battery voltage, minus the voltage drop across the diode. If you briefly close the switch, the cur- rent in the inductor will start increas- ing at a linear rate. When you open the switch, the higher current in the inductor will be forced into the load and stored by the output capacitance. By carefully changing your on-off duty cycle, you can provide any output voltage that is higher than the input battery voltage. There is one problem with this clas- sic circuit when it comes to low input voltages. A MOSFET switch likes to have ten or more volts on its gate to give you an acceptably low turn-on resistance. To beat this, the MAX655 74 Plug a friend into f Ectroriics this Christmas ... and Save $19AS! This Christmas give an electrifying gift... plug a Mend into Radio-Electronics and brighten his whole new year! Whether electronics is his livelihood or his hobby, your gift will sharpen his focus and illuminate the whole spectrum of electronics throughout the coming year. Radio-Electronics will keep him informed and up-to-date with new ideas and innovations in all areas of electronic technology ... computers, video, radio, stereo, solid state technology, satellite TV, industrial and medical electronics, communications, robotics, and much, much more. He'll get great plans and printed circuit patterns for great electronic projects. In just the last year, Radio-Electronics has presented voice scramblers, video switchers, frequency standards, wireless audio links, radiation monitors, function generators, and much more. 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But you must rush the attached Gift Certificate to us to allow time to process your order and send a handsome gift announcement card, signed with your name, in time for Christmas. So do it now ... take just a moment to fili in the names of a friend or two and mail the Gift Certificate to us in its attached, postage-paid reply envelope. That's all it takes to plug your friends into a whole year of exciting projects and new ideas in Radio-Electronics! n 4.7 mHy o-^MJL TWO ALKALINE AA CELLS -or- 3V LITHIUM BATTERY 47 jiHy 1N5818 c3£, +5 VDC OUTPUT FIG. 3— THIS MAXIM POWER-SUPPLY KIT gives you a tightly regulated + 5 volts DC at 170 milliamps or less from a pair of ordinary alkaline AA cells. The secret is a second internal switching regulator that gets used to raise the efficiency of the main one. Do not sub- stitute the recommended inductors or the Schottky diode. has two step-up converters in it. The first one generates a low current and high voltage that gives the switch in the main converter a low enough turn- on resistance. Take a look at the circuit in Fig. 3. This is what a model hobbyist would call a shake-the-box kit. Just drop the parts in place, being careful to watch the polarity, solder it up, and away you go. Assembly time should be around nine minutes. I suggest adding your own 14-pin IC socket, rather than ac- tually soldering the regulator in place. This is an ideal first hardware hacking project. One warning: The two inductors and the Schottky diode are critical. If you do not choose exactly the parts supplied by Maxim or their exact rec- o z o DC H O U! 6 D < 76 NO COMPLICATED ELECTRONICS, NO EXPENSIVE INSTRUMENTS: Home study course shows you how to make good money in VCR repair. An amazing fact: you can do more than four out of five VCR repairs with ordinary tools and basic fix- it proce- dures. Our home study pro- gram shows you how. 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Maxim also offers a MAX654 that runs on a single AA cell and can start at an incredibly low 1.15 volts. By the way, AA flashlight cells pro- vide considerably more energy at lower costs in less volume than by using a 9-volt battery. Except when you need ultra-low currents for a very long time. Which gives the 9-volt ap- proach a slight edge. More on this in r-the free Maxim Design News. As the first of our two contests this month, just tell me what you'd do with an AA-cell-to- + 5-VDC converter. Smoothing fuzzy data Every once in a while, I like to take time out and play with pure math, I do this by just shoving some numbers into a computer or laser printer and seeing where it can lead. In the past, this has gotten me into such useful wonderments as the pseudorandom sequences, equally tempered music, Fourier synthesis, fractal ferns, stock market analysis, quadrature art, non- linear transforms, Bezier secrets, phase plane plots, wavelets, and, of course, the avuncular sleezotds. I overwhelmingly prefer to use the PostScript language for this. Besides the absolutely unbeatable graphics, PostScript is a totally general-pur- pose computer language that can do most anything that Basic or C can. And often do so in a simpler and far more obvious manner — besides being lots of Fun and very easy to understand. One fairly common hardware-hack- ing problem is taking a bunch of slop- py data points and drawing a smooth curve through them. You might want to do this for a lab report, to produce an engineering data curve, or to try and convert some noisy bitmap, scanned, or hand-coded input into smooth outline typography. Some samples of smoothed data points are shown in Fig, 4. while the hairy-looking equations appear in Fig. 5. You can get the documented PostScript code all ready to run as my file #294 FUZZYFIT.PS on GEnie PSRT. Typical downloading costs 48 HOUR SHIPPING ELENCO & HITACHI PRODUCTS AT DISCOUNT PRICES 48 HOUR SHIPPING Hitachi RSO Series (Portable Real-time Digital Storage Oscilloscopes) VC-0O23 -20MHz, 20MG/a_ *!MI15 (8001 292-7711 I 70S i 541-0710 15 Day Money Back Guarantee 2 Year Warranty wom sublet to change WRITE FOR FREE CATALOG CIRCLE 109 ON FREE INFORMATION CARO O 9 rn 13 77 LINEAR (first order) QUADRATIC (second order) CUBIC (third order) CO o z o rr h- o LU o Q < rr FIG. 4 — SMOOTH CURVES CAN be quickly and drawn through fuzzy or noisy engineering data by using the PostScript language and the least squares fitting method. Here are three popular types of curves which can give good fits to many hardware hacking problems. (A) The LINEAR or FIRST ORDER least squares fit uses an equation of... y = a^ + ao Here are the two linear equations in two unknowns that you need to solve to get the best tit for your data... (sumx'ja, + (#pts)a = (sumy) (sumx 2 )a 1 + (sumx 1 )a = (sumx 1 y) (B) The QUADRATIC or SECOND ORDER fit uses an equation of... y = a 2 x 2 + a.|X + a Here are the three linear equations in three unknowns that you need to solve to get the best fit for your data... (sumx 2 )a 2 + (sumx^a, + (#pts)a = (sumy) (sumx 3 )a 2 + (sumx 2 )a 1 + (sumx 1 )a = (sumx 1 y) (sumx 3 )a 2 + (sumx^a, + (sumx 2 )a = (sumx 2 y) (C) The CUBIC or THIRD ORDER least squares fit uses an equation of.,, y = a 3 x 3 + a2X 2 tajx + ag Here are the four linear equations in four unknowns that you need to solve to get the best fit for your data... (sumx 3 )a 3 + (sumx 2 )a 2 + (sumx 1 )a l + (tfptsjag = (sumy) (sumx 4 )a 3 + (sumx 3 )a 2 + (sumx 2 )a 1 + (sumx 1 ^ = (sumx'y) (sumx s )a 3 + (sumx 3 )a 2 + {sumx^a, + (sumx 2 )a = (sumx 2 y) (sumx 6 )a 3 + (sumx 5 )a 2 + (sumx 4 )a, + (sumx 3 )a = (surnx 3 y) (D) For QUARTIC or HIGHER ORDER least square polynomial fits, just extend the math in the obvious direction for n linear equations in n unknowns. Solve for the coefficients. Little is usually gained by going beyond a third order polynomial. Especially in two dimensions. (E) For least square fits to OTHER EQUATIONS, write out the least squares error equation. Then take partial derivatives with respect to each coefficient and set them to zero. This again leads to n linear equations in n unknowns. FIG. 5— HERE IS THE "MAGIC" MATH behind least squares curve fitting. My FUZZYFIT.PS PostScript program on GEnie PSRT does it all for you quickly and painlessly. Just shove in the raw fuzzy data and out pops a smooth curve. should be around twenty cents. The best curve for any noisy data usually uses what is called a least squares fit. All that means is that you try to spread the errors out as evenly as you can. Your main reason for squaring is to make all the errors positive, even if the data point lies HIGH-ENERGY RESOURCES American Science & Surplus 601 Linden Place Evanston. 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While you can go beyond a cubic, you'll usually gain sur- prisingly little extra in doing so. One way to derive a least squares algorithm is to write out an equation for the total error for a given number of terms. Then you try to minimize the error by finding out how to separately minimize the error created by each individual term. To find a minimum in an equation or on a curve, you find the slope of your curve and set it to zero. Math freaks will immediately recognize this mini- mization process as taking the partial derivatives with respect to each co- efficient and setting them to zero. Which results in a humongous mess known as n linear equations in n un- knowns. You then solve the mess as best you can and out pops your co- efficients needed to plot your best fitting curve. I personally use an old method in- volving determinants. The needed tools appear in FUZZYFITPS, while the tools and a detailed background tutorial is separately available as GEnie PSRT file #289 LIN- EAREQ.PS. Incredibly, only one sin- gle pass is needed to find the best possible curve, no matter how many terms in your polynomial or the number of points involved! Figure 5 shows you the equations to use for a linear slope, a quadratic, and a cubic fit. These are the ones you would be most likely to use. I'm sure I've just horrified all the genuine math freaks in our audience with my really weird notation here. But all Csumx 3 ) means is to take your first x data value and cube it. Then take the second data value and cube it and add it to the first one, and so on for all the data. By (sumx 3 ), I simply mean the sum of the cubes of each individu- al noisy x data value. #pfs is simply equal to your total number of noisy x,y data point pairs that you are trying to put your smooth curve through. The (sumxy) expres- sion means to multiply the first x val- ue by the first y value. Then you multiply the second x value by your second y value and sum them. And so on. Fortunately, PostScript does all of your grunge work for you — quickly, invisibly, and automatically. It takes around half a second to do the whole job. Say you have five noisy data points and want to put the smoothest and most accurate possible cubic curve through them. All you do is... [2 4 4 11 6 14 12 16 16 121 findcubicfit That's all there is to it! In this specif- ic instance, your first data point is at x = 2 and y = 4. Your second data point is at x = 4 and y = 1 1 , and so on. The findcubicfit operator then will automatically generate your needed magic a , a,, a 2 , and a 3 best-fit coeffi- cients for you. 80 Among the other handy PostScript routines in my new FUZZYFIT.PS are plotxyvalues. which automatically draws the actual data points on the graph, and ploteqn, which sketches the smoothest possible curve through your points. there's no sane limit to the number of data points allowed. Much of your typical engineering data gives a good fit to a cubic polynomial. Especially stuff that is only slightly nonlinear. Note that, roughly speaking, your a coefficient is strongest at the low val- ued end of all the data. Your a, coeffi- cient sets the initial slope of your data. Your a 2 coefficient works best in the middle, while your a 3 coeffi- cient has by far the strongest influ- ence at the high value end. You can easily go beyond a simple cubic fit. If you know the underlying physical laws to your lab data, you can try and make your least squares fit the expected math. Other fuzzyfit curves of engineering interest include exponentials, sine waves, statistical distributions, hyperbolas, circles, and ellipses. Your same "set the partial slopes of the error equation to zero" idea works well with these. For graphics and typography, you can step up to a fancier method of curve fitting that permits loops and cusps. This goes by the name of cubic splines, or Bezier Curves. PSRT has lots more on this exciting topic. I'd sure like to have some good hardware hacking examples involving curve fitting for fuzzy data. For the second contest for this month, just send me an example of fuzzy data smoothing or else some data that needs to be smoothed. Preferably using PostScript. There'll be a dozen or so of our brand new second edition Incredible Secret Money Machine books, with an all-expense-paid (FOB Thatcher, AZ) tinaja quest for two go- ing to the best of all. As usual, be sure to send your written entries directly to me here at Synergetics and not to Radio-Electronics editorial. New tech lit From PMI. a new Audio Handbook, volume one, that covers the older SSM analog electronic musician products. Included are nineteen ex- cellent application notes on syn- thesizer ideas. From Cypress Semi- conductor, a new MOS Databook on their memory and programmable log- ic products. And from Signetics/Phi- llips, a new Master Product Catalog on all of their analog and digital inte- grated circuits. Included are such od- dball goodies as cellular radio chip sets. Motorola has a new free booklet on Pressuie Sensuis available, along with a literature packet on several of their transducers. But by far your best sources for very low cost pres- sure transducers still remain SenSym, IC Sensors, and Novasensor. Zilog has the new Shortform 91 catalog on microcontrollers, micro- peripherals, and telecomm stuff. A new Technical Guide and Cross Ref- erence on replacement semiconduc- tors is available from NTE. The cost is $3.25. Printed Circuit Design is a new trade journal that is heavy on PC layout tools and software. And an in- teresting Gas Density Calculator slide rule is available from the folks at Fisher- Klos terman. Let's see. I've just reprinted my Incredible Secret Money Machine, along with a new intra and update section. And for more on PostScript, I stock the best books and software by the best authors in my bargain-priced The Whole Works package. 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You even use your modem to "talk" to your instructor, meet other NRI students, and download programs through NRI's exclusive program- mers network, PRONET. ▼ Send today for your FREE catalog Now you can have the professional and financial rewards of a career in computer programming. See how NRI at- home training gives you the experience, the know-how, the computer, and the software you need to gel started in this top-paying field. Send today for your FREE catalog. If the coupon is missing, write to us at the NRI School of Computer Programming, McGraw-Hill Continuing Education Center, 4401 Connecticut Avenue, NW, Washing- ton, DC 20008. '"I Schools McGraw-Hill Continuing Education Center 4401 Connecticut Avenue, NW, Washington, DC 20008 W\ Check one free catalog only gffil fiffli D Computer Programming D PC Systems Analysis D PC Software Engineering Using C Name □ Microcomputer Servicing □ Desktop Publishing and Design D Word Processing Home Business (please print) is® Address j City L_ J ' Accredited Member. National Home Study Council . State . .Zip. 5415 101 J o o 3 on m 3J 93 COMPUTER CONNECTIONS History in the making JEFF HOLTZMAN IBM and Apple recently signed an accord that may be the most elab- I orate smoke screen ever perpe- trated on the PC industry. On the other hand, it may mark the beginning of the end of Microsoft's domination in operating system software for PC's. Details are still to be worked out. but highlights of the agreement in- clude the following; • The two companies will set up an independent company, funded by both parents, that will develop a new object-oriented, platform-indepen- dent system-software foundation that will run on Intel C80X86), Motorola (680X0), and IBM's own proprietary RS/6000 CPU s, and that will be backward compatible with AIX (IBM's version of UNIX), OS/2, and the Macintosh operating system. Of course, compatibility with OS/2 im- plies compatibility with DOS and Windows as well. There is also talk that IBM will develop a version of AIX that will offer both Macintosh and OSF/Motif interfaces. • IBM will license RS/6000 CPU manufacturing rights to Motorola; providing a second source will help legitimize the chip as a platform other vendors (Apple, for instance) might want to support. • The two companies will develop networking products that will allow easy integration of Macs into IBM- based corporate networks. • The two companies will try to de- velop platform-independent stan- dards for multimedia data. Given the recent sparring between IBM and Microsoft, it seems clear that the operating system issue is most important. But what does it g mean? z To answer that question, it's nec- § essary to first examine several sub- f3 sidiary questions. What does Apple !fj have that IBM wants? Assuming IBM jj could get its hands on it, what could it a do with it, and would that be sufficient £ to have any market impact, given the assured fact that Microsoft is not go- ing to roll over and play dead? Look and feel What Apple has is that Macintosh look and feel. And rightly or wrongly, the courts so far seem content to allow Apple to maintain intellectual ownership of the Mac interface. IBM on the other hand has de- veloped an operating system kernel for OS/2 2.0 that by all accounts is a robust and stable environment for building advanced applications soft- ware. Problem is that it's missing a shell — a user interface — not to men- tion significant applications— not to mention credibility. A Macintosh-like look and feel would solve the First of those problems. Near-perfect com- patibility with present-day applica- tions would solve the second. The third, though least technical, may be most difficult to overcome. IBM has several other OS cards up its sleeve. There's AIX, which powers the RS/6000 line. There's also OSF/1 , the Esperanto of UNIX-like dialects, which is being developed by the Open Software Foundation, and to which IBM has made major contri- butions. Could one of those serve as the underlying foundation for a new world order in operating systems? Perhaps. But keep in mind that IBM also belongs to several other key consortia, in addition to OSF. First is Patriot Partners, which IBM and Met- aphor systems co-founded about a year ago to develop ... an operating system-independent, object-ori- ented software layer that would allow the same application to run on multi- ple platforms, regardless of underly- ing file and graphics systems. Then there's the Object Manage- ment Group (OMG), whose focus is the development of a set of API's for managing objects in a distributed computing (network) environment. Confused? Excellent! (And we haven't even mentioned mainframe operating systems!) A little help from your friends Suppose there is a method to the madness. Suppose you're a huge company, with products ranging from PC's to mainframes, segregated into four distinct and totally incompatible product lines (PS/2. RS/6000, AS/400, mainframe), which for sev- eral years you've been trying to inte- grate through an ambitious undertak- ing called Systems Application Architecture (SAA). Suppose that even though you have trouble adapting to rapidly changing market conditions, you have a great deal of influence and a clear vision of how you think your industry's technology should and will evolve over the next ten to twenty years. How can you make your vision reality, knowing you can't do it all by yourself? One way is to make some friends and try to get by with a little help from them — and in the mean- time, reduce your dependence on proprietary (expensive) underlying technologies. For example, join an operating sys- tem consortium (OSF), make enough contributions to make the other members feel secure enough to make contributions of their own, take the results back to your labs, en- hance the technology for your cus- tomers, begin weaving it into the half dozen or so operating systems you presently support, and gradually phase them out. Eventually what you get is a single, unified OS that runs on multiple platforms and that supports a high degree of applications portability across all of them. The world is changing to a dis- tributed (networked) computing model. OK, fine. Develop some stuff internally (Distributed Application En- vironment or DAE) in the meantime, and join another consortium (OMG) just in case they come up with any- thing interesting. Oh, yeah — graphics environments are inevitably slow, so buy some third- party technology (Micrografx) to 94 R-E Computer Admart A CONCISE INTRODUCTION TO THE MACINTOSH SYSTEM AND FINDER B P29 8 — Th is introduction forthosenewto the Mac, this book also serves as a quick refresher for those experienced owners thai have not used the machine in some time. To order your copy send $6.25 plus S2.5Q for shipping in the U.S. to Electronic Technology Today Inc., P.O. Box 240. Massapequa Park, NY 11762-0240. Rates: Ads are 2JS"x'2W. One insertion $995 each. Six insertions $950 each. Twelve insertions $925 each. Closing date same as regular rate card. Send order with remittance lo Computer Admart. Radio-Electronics Magazine. 500-B Si-County Blvd., Farmingdale. MY 11735. Direct telephone inquiries to Arline Fishman, area code-1-516-293-3000. FAX 1-516-293-3115, Only 100% Computer ads are accepted for this Admart. HOW TO EXPAND, MODERNIZE AND REPAIR PCs AND COMPATIBLES BP271 — Includes PC overview, memory up- grades, adding a hard disc, adding floppy drives, display adapters and monitors, install- ing a co-processor, preventive maintenance, repairs, do it yourself PCs and more. To order your copy send $7.75 plus $2.50 for shipping in the U.S. to Electronic Technology Today Inc., P.O. Box 240, Massapequa Park, NY 11762-0240. PCB and SCHEMATIC C.A.D, EASY-PC ($195) EASY-PC : *>'^&— 4 Kuril ui P(.77C7*AT.'7JIAO*4 ■ 111, 1 1 , r . - . nii.ll., \i.i * DriltB. Single >14rf. Peubk • iiird .1111! Mullibwr ti.ui ij, * Prfnldn Surftur .Mdiiiit support. * Slamljird .iiiLpul in, Jmlr. ttix Matrix t tmmt Ufejfft Prinlrr. Ven Ploilcr, P.h[H[>.ptn|[rrjir,d N.L'. IJriN. ■ A.w»rd winning F-tSY'.IH." i» new in uhi 1ft o\tr 400U I.- i II .:, . , . ... ■■■ VrmMriti Wofld^or. * -I I'l i:i.l ', i ■.-.: I. . LEAKNANDLSE \oi < i,p. Protected, OptlDni - lOOgpinC' tymbbl library S7S'l* Gpfpf Import tacllHy 1195.00 For fuH Into', twist. r*>, all or uit Inquiry m ^— ■.>«.. Number One Syitenu Ltd. 1 HEF: HEUS, HAfiOINC WAY, ST.IVES, HUNTINGDON, "* CAMAS., ENGLAND, PE17 4WR. Tetpohcftp; Fu: USA; 011 -44-440-6 < 774 USAro 1 1-44-4BD-4P4Q42 AMEX.VISA, IrrtrX:- * 44-490-&177I Inlnl:, * 44-410-494043 MtttfliCtrd UK ■- 0410 01774 UK :• 0490 494042 Welcome CIRCLE 188 ON FREE INFORMATION CARD speed things up. While you're at it, get the premier networking company (Novell) to port its wares to your pro- prietary systems (e.g.. AS/400) and resell it under your own label. One important thing — don't forget the developers who will be building the great new things your users will use. Pamper those developers, get thern slick tools, an integrated de- velopment environment. Team up with a class act (Borland), and sell your tools for 10% of what the com- petition charges. All of the above have happened. Now last but certainly not least, don't forget your users this time. They want something sexy, something fun, something productive. License some of the flowery stuff from the artsy guys out on the west coast (Apple, NeXT), Build in a set of basic applica- tions that will wet users' whistles. Make it compatible with their old soft- ware. Make it easy to install and up- grade. Sell it inexpensively. Make it reliable, reliable, reliable and you'll have it all. (There are more pieces to the puzzle, but you get the idea.) The problem is that, when you start thinking about it, the pieces don't ex- actly fit. One seems too big, another too small, another dangles out in space . . . True, but so what? Don't worry about it. If you get enough chunks out on the table, you know that eventually you'll find a way of fitting enough of them together that overall you'll have a coherent system. Sure, you'll throw away a few bucks on R&D, but you're a big company; in the long term it'll be worth it. In the mean time, keep pushing on all fronts, knowing that some pieces are already starting to fit, and believing that others will come on-line soon. Next thing you know you've got something that sticks together when you throw it against the wall. But what do you call it? Be careful of the stigma attached to similar efforts in the past. So what? IBM makes yet another strategic alliance. Ho hum. To produce an oper- ating system? Yuk, yuk. yuk. Takes three, four, maybe five years to do that type of job right, and the compa- ny's track record in that field isn't good. Yeah, but they're not starting from scratch; many of the pieces are in place already. Look at the basic facts. IBM • Doesn't want to depend on Micro- soft. • Wants to integrate its vast product line. • Has a big stake in object-oriented technology. • Has done lots of development on core OS technology. • Needs help with look and feel in the PC market, including product op- eration, packaging, and marketing. The latest alliance may give Big Blue the shove it needs to crest the operating system hill currently domi- nated by Microsoft in the PC arena, and by various vendors in others. I think we're going to see a new king of the OS hill — and a lot sooner than most people expect. OS/2 and you A coherent picture of OS/2 2.0 has started to emerge: • Multiboot allows booting DOS, OS/2, or other operating system without running FDISK. • A high-performance 32-bit version of the traditional DOS file system. • A Mac-like desktop for launching programs and managing files. • Bundled applications including a useful graphics/charting package from Micrografx. • Reduced prices ($1Q0-$150), • Fhendly installation. • The ability to run multiple DOS sessions simultaneously with as much space as provided by DOS 5.0, • The ability to run Windows 3.0, DOS, 16-bit OS/2, and 32-bit OS/2 applications simultaneously. Rumor has it that Windows compatibility is still shaky and may not be fully de- veloped in time for the year-end re- lease. I hope IBM can work out the technical details; I'm getting awfully tired of UAE's (Unrecoverable Ap- plication Errors) under Win3. News bits Not only do we have to worry about which operating system we're going to run, but also about which CPU it will run on. Intel recently released 5 sketchy details on the architecture, 5 95 She's waiting at her home... for you to open the door to yours. Hundreds of foreign exchange students will be unable to study in America unless you become an OPEN DOOR host family. Without you they can't enrich their own and Our understanding of other cultures. Our local high schools won't benefit from their fresh, glohal perspective Give your family a unique opportunity to learn per- sonally about and make life-long friend- ships with visiting students from around I the world. Only you can open the door. Help us make the connection. For a free Host Family brochure, tall: 1-WJ0-366-OPEN (6736), or write: CO O LU D < 96 OPEN DOOR STUDENT EXCHANGE 25D I'ultou Strcet 111). ] ins 7 ] &>■' Hcmpshai. NY JJS51 (i CSIET I'll ,IM -.IT Nauru 1 : J nw a Inst family h flu'tourc Addrrsv iVi« *f: y.m- Mmnt-I ' I 386 UNIT FLOATING-POINT UNIT BUS UNIT SUPERSCALAR PIPELINED RISC CPU INSTRUCTION CACHE CACHE MANAGER DATA CACHE FIG. 1— INTEL'S UPCOMING P5 (AKA 80586) uses three million transistors to power three separate execution units, separate data and instruction caches, and a sophisticated multiprocessing bus interface unit. shown in Fig. 1, of the 586 Caka "P5"), a simulation of which is al- ready said to be running in Intel's de- sign labs. Samples are due in about a year, with systems scheduled for de- livery in late 1992. The P5 consists of more than three million transistors powering three ex- ecution units, including a 386 com- patibility unit, a floating-point unit, and the new star of the show, a 100 MIPS RISC-based execution unit that will handle basic x86 instructions at a rate of two per clock cycle. (The 386 unit will execute more complex 386 instructions at a slower rate.) Meanwhile, in response to com- petitive threats by AMD and others, Intel has been barraging the market with more variations on the 486 than you can count on one hand. There are 25-, 33- T and the recently introduced 50-MHz 486DX, along with a 66-MHz version promised for sometime in 1992. In addition, there is the 20-MHz 486SX, with a 25-MHz version also promised for '92. Nearly all PC's come with a socket for a math coprocessor. That socket has all the address, data, and control lines necessary to take complete control of the computer. Who says that socket is only good for a math coprocessor? Suppose you installed some other type of device — for ex- ample, a next generation CPU? Intel has publicly stated plans for such de- vices, first implemented in the 487SX math coprocessor, which is really a full-blown 486DX with support logic to disable the "main" 486SX and take control of the system. In addition, after months of rumors, Intel finally announced plans to re- lease double-speed CPU's that exter- nally appear to run at standard speeds, but that internally run at twice the bus rate. Imagine dropping a 50-MHz 486 into that "old" 33- MHz 386. Claris is a subsidiary of Apple. A couple of years ago. Apple relin- quished control of Claris, but about a year ago. regained control. Recently, the Claris has been going through organizational upheaval, and has ad- vertised in national trade journals for programmers experienced in OS/2 and Windows development. There are some speculators out there who think that, like Novell, Apple wants to get out of the hardware business al- together On the semiconductor side of the house, IBM and Siemens have an- nounced plans to pool resources in manufacturing the next generation of DRAM's — 16 megabits. Think about it: Nine of those would provide almost as much memory as hard disks of only five years ago. The companies are also expected to jointly develop the follow-up, 64-megabit chips, due around 1995, re MARKET CENTER FOR SALE OSCILLOSCOPE 50 MHz. dual channel, solid slate calibrated, manual $250 1 (600) 835-8335. TOCOM and Zenith "test" chips, Fully activates unit. $50.00. Cable descramblers from $40.00. Orders 1 (800) 452-7090. Information (213) 8S7-O081. 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Copy to be in our hands on the 5th of the third month preceding the date of the issue, (i.e., Aug. issue copy must be received by May 5th). 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. COMPUTERS AT/XT compatible systems and components at discount orices. Catalog $2.00, re- fund with first order. MPS ENTERPRISES, Box 1048, Lemon Grove. CA 91946. WANTED; old, Western Electric, Mcintosh, Altec, Marantz, Jensen, JBL, EMT, Elect rovoice, RCA, Telefunken, Weslrex, Fairchild, Fisher, Dynaco; tubes, speakers, amplifiers, (713) 728-4343. MA- URY COHB, 12325 Ashcroft, Houston, TX 77035. CB RADIO OWNERS! We specialize in a wide variety of technical information, parts and services for CS 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. 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Cata- log $5.00 moneyorder (credited first orrder). service manuals, schematics, SURPLUS ELECTRONICS, PO Box 10009, Colorado Springs, CO 80932. O O n> m 3J CD CD 97 Quality Microwave TV Antennas WIRELESS CABLE ■ IFTS • MMDS - Amateur TV Ultra High Gain 50db I » > • Tumble 1.9 ID 2.7 Gtu. 36-Channel Syston Complete S1 49.95 « 1 2 'Channel System Complete S 11 4 95 • Can Or Mile |SASE) l« "FREE" dialog PHILLIPS-TECH ELECTRONICS P.O. Etoi 8533 . Seottsilsle, IZ 85252 r (602) 947-7700 {13.00 Crtdlt HI nimnt onleri) WARRANTY MaitarCard • Vila ■ COD'S * Quinsllir Prising ENGINEERING software, PC/MSDOS. Circuit design and drawing, PCB layout, Logic sim- ulation, FFT analysis, Mathematics, Circuit analysis. Call or write tor free catalog. 1 (800) 728-3805, BSOFT SOFTWARE, INC., 444 Colton Rtt, Columbus, OH 43207. RESTRICTED technical information: Electronic sur- veillance, schematics, locksmithing, covert sci- ences, hacking, etc. Huge selection. Free brochures. MENTOR-Z, Drawer 1549. 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F & P ENTERPRISES, Box 51272, Palo Alto, CA 94303-L TOCOM-Jerroid Impulse-Scientific Atlanta 8580 & 8590 converters with two yr. warranties, also test modules for Star Comm 6 S 7s, ail Tocoms, and Scientific Atlanta. Full details. (219) 935-4128. DESCRAMBLERS cable TV converters, lowest prices, guaranteed, best quality, special Sacramen- to units, CNC CONCEPTS, INC., Box 34503, Min- neapolis. MN S5434, 1 (800) 535-1843. j ELECTECH / CABLE T.V. DESCR AMBLERS • All quality brand) names • • All fully guaranteed • All the time • Knowledgeable Sales Service Department FOR FREE CATALOG 800-253-0099 PLANS AND KITS DAZER personal protectors! Lasers! AM/FM/ln- frared transmitters! Detectors! More! Kits/as- sembled. Catalog $2.00. QUANTUM RESEARCH, 16645-113 Avenue, Edmonton, Alberta T5M 2X2. SURVEILLANCE — Audio/video/infra- red/laser equipment Industrial or private. 500 item catalog $7.00. SECURITY SYSTEMS, 3017G Hudson PL. New Orleans. LA 70131. DESCRAMBLING, new secret manual. Build your own descramblers for cable and subscription TV. Instructions, schematics for SSAVI. gated sync, sinewave, (HBO, Cinemax, Showtime, UHF, adult) $12.95, $2,00 postage. CABLETRONICS, Box 305O2R. Bethesda, MD 20824. REMOTE CONTROLKEYCHAIN ..: REMOVE LEAD VOCALS „ From Records 1 CD's Quid This kil tar undsr 160 wtii£*i remove* load vocals horn eland ord fttaraa record*. CDV »p« or FM broadcasts. Eauly oennacte re ony home component tteroo. Perform irvs widi tha background!. You can bo Bie load tinqer of your lavorit* band. Detailed Plana. J* .95 Weeder Technologies 14773 Lindsay Rd. ML Offlb, Ohio 45154 . TELEPHONE caller identifiers. Displays incoming caller's telephone number, kit $49.95 postpaid, SURVEILLANCE catalog $5.00, EDE, FOB 337, Buffalo, NY 14226. DESCRAMBLER kits. Complete cable kit $44.95. Complete satellite kit $49.95. Add $5.00 shipping. Free brochure. No New York sales. SUMMIT RE, Box 489, Bronx, NY 10465. CL-" VISITECTINC, (415)531-8425;: Complete w'rriinMr h ri otw Wot-:-. a rtd -+5.v'dc RF receiver;;: Fulfy asBerfrbfeti including pJarai;:; . to. build your. t> wn auto alarm . OUflniiJy dtscoLtnto. qvaHobfe y D Add 5 3 9hippJng: ; ; Sox 141 W r FremonV'Ca, &4S3B: Fax (415) 531^442- $24 HYPNOTIZE or Relax electronically! Alpha/medita- lion goggles. Complete kit $53.00. Free information. MARK WORLEV; Box 261113, San Diego. CA 92196. SURVEILLANCE transmitter kits tune from 65 to 305 MHz. Mains powered duplex, telephone, room, combination telephone/room. Catalog with Popular Communications, Popular Electronics and Ra- dio-Electronics book reviews of "Electronic Eavesdropping Equipment Design," $2.00. SHEFFIELD ELECTRONICS, 7223 Stony Island Ave,, Chicago, IL 60649-2806, FREE cable and satellite descrambler plans. Send self addressed stamped envelope, MJM INDUS- TRY, Box 531, Bronx, NY 10461-0208. HO BB Y/b roadcast i ng/H AM/CE3/surve i llance I rans- mitters, amplifiers, cable TV, science, bugs, other great projects! Catalog $1.00. PAN AXIS. Box 130- F10, Paradise, CA 95967. CABLE DESCRAMBLERS OAK M35B COMBO S39.95 Jerrold, Zenith, Hamlin, Sci. Atlanta, Pioneer & MORE! OUR PRICES ARE BELOW WHOLESALE! CABLE+ PLUS 14417 Chase St. M81-A Panorama City, CA 91402 1-800-822-9955 * Other Info. 1-818-785-4500 NO CALIF. SALES - DEALERS. WANTED BUILD from simple materials, over 100 miles per gallon carburetor. Detailed plans, five versions. Good science project. $20.00 Visa welcome. (902) 467-3577 VALLEY MICROWAVE, Station C. Etear River, N.S.. Canada BOS 1B0. INVESTIGATORS, experimenters — Quality new plans. Micro and restricted devices. Free catalog. Self addressed stamped envelope required. KEL- LEY SECURITY, INC. Suite 90, 2531 Sawtelle Blvd., Los Angeles, CA 90064. PCB and schematic CAD. $195.00 IBM EGA CGA Multilayer, rubberband, autovia, NC drill, laser, dot matrix, plotter, library, Gerber, AUTOSCENE, 10565 Bluebird St., Minneapolis, MN 55433. (612) 757-8584 free demo disk. VIDEOCIPHER ll/scanner/cable/satellite modifica- tions books. Catalog $3.00. TELECODE, PO Box 6426-RE, Yuma, AZ 85366-6426. ANTIQUE RADIO CLASSIFIED Free Sample! Antique Radio's Largest Circulation Monthly. [offQ, Articles, Ads S Classifieds. 6-Month Trial: $15. 1-Yr: $27 ($40-1 st Class). A.R.C., P.O. Box 802-L9, Carlisle, MA 01741 DIGITAL recorder. Digitally record any audio source with special effects. Microprocessor con- trolled device. Detailed plans, $9.75: T. ZURAW. Box 341, Dearborn Hts, Ml 48127. REMOVE VCR copy protection. PCB PAL instruc- tions $16.50 w/P&H. LOGICAL CHOICE, Box 1256. Lomita, CA 90717. POWER: 900 watt amplifier for less than $t00.00! SASE for information. Plans $10.00 E.D.S., N90 W20756 Scenic Drive, Menomonee Falls, Wl 53051. SCANNER antenna plans mulfi frequency indoor outdoor easy designs $5.00. SCANTENNA, 729-B North Golden State Blvd., Turlock, CA 95380. 98 CIRCLE 202 ON FREE INFORMATION CARD PROTECT your home (or pennies. Alarm kit. As- sembles in one night. Thousands already installed. Also receive booklet "How to Install art Alarm Sys- tem in Your Home." $24.95: NOBLE ELEC- TRONICS, 17 Farmington Avenue, Suite 169, Plainville, CT 06062-1726. ROBOTICS- powerful, compact, inexpensive, mi- crocomputer, perfect for robotic/microprocessor control applications. Plans/application notes $5.50, ACS, 6220Shallowford Rd. #152, Chattanooga, TN 37421. BEST BY MAIL Rataa: Write National, Bqi 5, Sarasota, FL 34230 FINANCIAL 1% INTEREST LOANS; No Limit! No Refusal Guarantaal Write: JEF, Bon 234?-(RE), Ada, OK 7482 0. LOANS AVAILABLE! Business Easy quality. (619)693-0498. Personal. No front tees. HEALTH & BEAUTY LOSE WEIGHT WHILE Sleeping! Revolutionary! No Dieting/Exercise! Free Hawaiian Vacation For Trying,. 1-800-937-3096X121. SATELLITE TV FREE catalog — Lowest prices worldwide. Save 40 — 60%. Systems, upgrades, parts, all major brands factory fresh and warranted. SKYVISION, 2009 Collegeway, Fergus Falls, MN 56537. 1 (800) 334-6455. VIDEOCYPHER II descrambling manual. Sche- matics, video and audio. Explains DES, Eprom, Clonemaster, 3 Musketeer. Pay-per-view (HBO. Cin- emax, Showtime, adult, etc.) $1 6,95, $2.00 postage. Schematics for Videocypher Plus, $20.00. Sche- matics for Videocypher 032, $15.00. Collection of software to copy and alter Eprom codes, $25.00. CABLETRONICS, Box 30502R, Bethesda, 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. Cable Descramblers New Aula Tri-Bi guaranteed no flashing SI 65.00 SB 3 $99.00 ZENITH SUPER TRTMODE 1109.00 SAAVI J199.00 HAMLIN $99.00 TOCOM. „. $319.00 SCIENTIFIC- EAGLE..— „. 1119.00 ATLANTA $119.00 COPY GUARD SS9.95 OAK M35B.... $».00 STARGATE 2003... $88.00 ZENITH $175.00 M.D- Electronics will match or beat any advertised wholesale or retail price. Venn best buys and warranties fur cable converters and descramblers start with a FREE catalog from MD EXCELLERATOR CABLE CONVERTERS WHEN QUALITY COUNTS For Information Call 402-554-0417 To order or request a free catalog 1-800-624-1150 New Dynatrack™ fine tuning provides unmatched picture quality 550 Mhz inner provides S3 channel capacity Steep timer for automatic shut off within 15-90 minutes 2/3 swi tch» bit HRC I IR C / Sla ndard S w i tc h able 2 Year warranty, Last channel recall. Favorite channel select. Scan Double vented high efficiency transformer Tor cool performance Stargate-2001 $99.00 Stargate-550XL $119.00 With Volume Control Don't settle for anything less. rf **. BE75 SO 72nd St Tfp* loir W ^T^ * J^-vIm. lYcwTou^cAitiTViwiramTnioMM^^ w^- -fc.0 Oman*, NEoBTM ji^reraTOccMiiYunTHALL5TATiANDn»i^Li^^ S C.O.D. ^Qte®^ CIRCLE 53 ON FREE INFORMATION CARD * * * * PRESENTING * * * * CABLE TV y ***** STARRING ***** JERROLD, HAMUN, OAK AMD OTHER FAMOUS MANUFACTURERS ■ FINEST WARRANTY PROGRAM AVAILABLE • LCWEST RETAIL J WHOLESALE PRICES IN US. • ORDERS SHIPPED FROM STOCK WITHIN 24 HRS - ALL MAJOR CREDIT CARDS ACCEPTEO FOR FREE CATALOG ONLY 1 -8O0- 3 4 5-89 2 7 . FOB ALL INFORM ATtON 1-81 8-7OT-99 3 7j PACIFIC CABLE CO.. INC. 7325V; Reseda Blvd.. Dent. 2107 Reseda. CA 91335 SATELLITE TV — Do tt yourself — Systems. Up- grades. Parts. Major brands discounted 40% — 60%. We'll beat everyone's price. L.J.H. Inc., call LARRY (609) 596-0656. FREE catalog — Compare our prices for new sys- tems and upgrades. Latest receivers and dishes — all top brands. ALPHA SATELLITE DIST., PO Box 197A. Hawthorne, NJ 07507-0197. 1 (300) 535-AL- PHA. SATELLITE TV descrambler. Build your own. Easy to follow instructions, parts list. Circuit board, wiring diagram. $9.95 ABG ENTERPRISES, 27081A. Halifax. NS B3H-4M8. SATELLITE TV and cable descrambling secrets. Surveillance transmitter plans. Send stamp for free catalog. COMMUNICATIONS ENGINEERING, 76 Boulevard, Hudson Falls, NY 12839. BUSINESS OPPORTUNITIES MAKE $50/hr working evenings or weekends in your own electronics business. Send for tree facts. MJME INDUSTRY, Box 531, Bronx. NY 10461-0208. YOUR own radio station! Licensed/unlicensed AM, FM, TV, cable. Information $1.00. BROADCAST- ING, Box 130-F10, Paradise. CA 95967. LET the government finance your small business. Grantsrloans to $500,000. Free recorded message: (707)449-8600. (KS1). ELECTRONIC ASSEMBLY BUSINESS Start home spare lime. Investment knowledge or experience unnecessary. BIG DEMAND assem- bling electronic devices Sales handled by profes- sionals. Unusual business opportunity. FREE: Complete illustrated literature SAFrTAREO0Bux248 Walnut Creek. Cairl. 94S97 MAKE $75,000 to $250,000 yearly or more fixing IBM color monitors (and most brands). No invest- ment. Start doing it from your home. (A telephone required.) Information, USA. Canada $1.00 cash. US funds, other countries $8.00 RANDALL DIS- PLAY, Box 2168-R, Van Nuys, CA 91404 USA. Fax (816) 990-7803, EASY work! Excellent pay! Assemble products at home. Call for information (S04) 641-8003 Ext. 5192. MAKE SSS! Become an American electronics deal- er! Profit opportunities since 1965. Call SCOTT PRUETT, 1 (800) 872-1373. HOME assembly work available! Guaranteed easy money! Free details! HOMEWORK-R, Box 520, Danville. NH 03819. MONEYMAKERS! Easy! One man CRT rebuilding machinery. $6,900.00 rebuilt. $15,900.00 new. CRT, 1909 Louise, Crystafake. IL 60014. (815) 459-0666. Fax (815) 477-7013. EDUCATION & INSTRUCTION F.C.C. Commercial General Radiotelephone li- cense. Electronics home study. Fast, inexpensive! 'Free'' details. COMMAND, D-176. Box 2824, San Francisco, CA 94126. LEARN color television in 2hrs VMS-tape work- book NTSC S37.00 + $3.50 guaranteed. WILLIAMSON LABS, 6613 Lynndale Dr., Raleigh, NC 27612. (919)848-8955. Be a TV/VCR Repair Specialist Now you tan train at hrjrne in spare hme for a money-making career as a TV.'VCR Repair Specialist. No previous experi- ence necessary No need to quit your job or school Everything is explained in easy-lo-undersland language with plenty of draw- ings, diagrams and photos. We show you how to troubleshool and repair video-cassette recorders and TV sets, how to handle house calls and shop repairs for almost any make ol television or VCR. Tools are included with your course so you can get "hands-on ' practice as you follow your lessons step by step. Send tor tree facts about the exciting oprjorlunthes in TV'VCR Repair and find out how you can slart making mnnev in this c.ik r.aresr_ MAIL_COlJPqN TDDAY_ J *"fcax* Haj 3 aa.1 Iw Ikn tWCM and sj. acrtwi tajraQ fSPFf Uwi C t^najry and hmcuI UV ureor Aiiurrblud jxt mady «3 u«. ria n*w RiiT'ina tflen c no* avaJabeai at ■ fiaogn d tm &i;roi c«i {Rpfjyrcn tiV 6*1 •¥, not ncUdid ) .*„_. __ a _ HINIMUH OFIDEH: SI 00 plus $350 shfipng and hsndtng We accept MC, Visa and Money Ovrfere SEND ORDERS TO: Die Electronic Gotorrvm P O. Box 540S Sojftsdafc. AZ 65K1 PHONE ORDERS (602| 431-7454 FAX ORDERS (60!) 451-M95 IMPROVE YOUR DESIGNS Save power, board space, and fabrication lime. The PAL Com pilar program lets you combine the (unctions of several ICs into a single PAL, GAL, or PEEL device. Use either truth-tabte or logic equations as input. Stan- dard JEDEC file is output. Quick logic term minimization is included. $69.95 + shipping/handlingAax Call to order, or for free informal ion. (916)674-1626 TIMELY SOFTWARE, INC. 1747 Live Oak Blvd. KJ-210, Yuba Ctly, CA 95991 CONVENTIONS PRACTICE troubleshooting on your IBM PC. 32 circuits including diodes, transistors, FETs and op amps. Hundreds of troubles. Visa. MC $49,95. 3.5" or 5.25. ■ Demo S5.00. MALVINO INC., 229 Polaris Ave., Ml. View, CA 94043. WANTED INVENTIONS^ new products/ideas wanted: call TLCI for free information 1 (800) 468-7200 24 hours/ day - USA/Canada. INVENTORS: We submit ideas to industry. Find out what we can do for you. 1 (800) 288-IDEA. INVENTORS! Your first step is important. For free advice, call ADVANCED PATENT SERVICES, Washington, DC. 1 (800) 458-0352. TRAVEL! High income! Radio officers wanted for shipboard employment. Must have FCC second telegraph license. Rae Echols, AMERICAN RADIO ASSOCIATION, 5700 Hammonds Ferry, Unthicum. MD 21090. FREE CATALOG! 1-800-648-7938 JERROLD HAMLIN OAK ETC CABLE TV • Special Dealer Prices! a Compare our Low Retail Prices! • Guaranteed Prices & Warranties! • Orders Shipped Immediately! REPUBLIC CABLE PRODUCTS, INC. -g 4080 Paradise Rd. #15, Depl ke nwr r - "^ 3 Las Vegas, NV 89109 c"T i For all other information (702) 362-9026 CABLE TV DESCRAMBLERS •CONVERTERS* and ACCESSORIES. PANASONIC. JERROLD, OAK, PIONEER, SCIENTIFIC ATLANTA AND MORE. LOWEST PRICES. FREE CATALOG. CABLE READY COMPANY (800)234-1006 THE Greater Louisville Hamfestand Comput- er Convention. Saturday, September 28, and Sunday September 29, 1991. New and used equipment, forums and testing. For addi- tional information write Post Office Box 34444-R, Louisville, KY 40232-4444 or call (502) 964-1132. BIOMEDICAL ELECTRONICS BIOMEDICAL tetter covers medical electron lea, anatomy, equipment functions, electrical safety, troubleshooting. PNP PUBLISHING, Box 333, Brooklyn. NY 11204. (718) 837-9349 exten lion 55. THIS iS A BOLDFACE EXPANDED AD with a tint background. . If you like this format, request it. Your cost is $6.80 per word. INVENTORS INVENTORS! Can you patent and profit from your idea? Call AMERICAN IN VENTORS CORP. lor free information. Serving inventors since 1975. 1 (800) 338-5656. ALARM SECURITY LOW cost burglar alarm systems for your home, business, auto, computer, and personal. We carry all lines of security and electronics supplies. Full information package send $5.00: APS, Box 1074, Moorhead, MN 56561-1074, Inquiry (218) 236-6426. YOUR HOME THAT HAS A SIMPLE SOLUTION. Call i-800-SOS-RADON to get your Radon test information. BUY BONDS «epaH 100 CIRCLE 179 ON FREE INFORMATION CARD CABLE TV "BOXES" Co nverters-D esc ram biers Remote Controls-Accessories * Guaranteed Best Prices* + 1 Year Warranty - C.O.D.'s* k Immediate Shipping * + FREE CATALOG * Call r>r VI rile NAS/TRANS-WORLD CABLE CO. 3958 North Lake Blvd.* Suite 255 Lake Park. Florida 33403 1 -800^42-9333 1 -800-848-3997 "Plant a tree today for all the world to share" You can make life better for your children and for the future, join me and plant a tree today for all the world to share. For your free brochure, write: Trees for America, The National Arbor Day Foundation, Nebraska City, NE 68410. John Denver for The National r J Arbor Day Foundation DESCRAMBLERS CABLE TV EQUIPMENT CALL TOLL FREE 1-800-228-7404 30 DW MOW BACK GUAIpY you worn f» m holej k our WKANIB WE CAiW AIL MAJOR BRANDS BEST PRICE BEST CAtlC* WRITE I VIA WtfjrW I Jjg » «— gigg. Tew Bj, THIS IS A BOLDFACE EXPANDED AD. If you like this format the cost is $5.65 per word. 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. ANNOUNCING: AN END TO HIGH MONTHLY CABLE FEES! All Jerrold, Oak. Hamlin. Zenith. Scientific At- lanta, Magnavox and all specialized cable equip- ment available for shipment within 24 hours. For fast service MC/VISA or C.O.D. telephone or- ders accepted. 60 Day Guarantee (Quantity Dis- counts). Send self-addressed Stamped enve- lope 1-800-232-5017 -l C.O.D. ORDERS ACCEPTED CABLETRON1CS, INC. 1304 E. Algonquin Road Suite 501 Algonquin, Illinois 60102 PAY TV AND SATELLITE DES GRABBLING ALL NEW 1391 EDITION Our bKi yet. The very lafesi m descfambhmj eireulis. bypasses, lurn-ons tor cable, wireless and HlEllito. Only $14.95. CfDier pay TV editions. Vol. 1 (Basics ol All Systems) S14.9S.13B9 Edition $14 95 Build satellite systems unite $650 $1 2.95. Wireless. Cable Handbook $9.95. Any 3$&& or S&44.95. SerambllnQ Hews ManlMy has alt into on ihe new "Plain ^mlla.' descrambtars which em- ulale B-Mac, VCll, Plus, Orion. $l9.9S/yr. Newulslrjg$l Special Uits mofiih Everything including video and suhscripiion lor 5-64.35. Scrambling News, 155ZA Hertel Ave,. Bulfalo, N¥. 14716. For COD S {716| 874-2086 MARK V €L€CTRONICS, INC. Competitive Pricing * Fast Shipping Since 1985 indicates the level of difficulty in the assembling of our Products. Amplifier + Metal Cabinet + Transformer Kit Set Assmb, Set TA-3600 LG-1925 #007 $155.61 $179.36 TA-477 LG-t925 #003 $125.21 $141.36 TA-802 LG-1924 #001 $100.45 S1 13.54 TA-1000A LG-1924 #001 $113.52 $133.36 TA-1500 LG-1925 #001 $130.00 $150.00 ORDER IN CALIFORNIA 800-521 -MARK ORDER OUTSIDE CA 800-423-FIVE FREE CATALOG & INFORMATION (213) 888-8988 FAX (213) 888-6368 Fully Assembled TA-1 oooa A Beginner A A Intermediate AAA Advanced Due lo Ihis special dlf&r & low prrc&, we can only exchange or repair any or Hiese units I TA-3600 TA-477. TA-8Q2 £ TA-1000A) within 15 days ol your receipt. The above prices are lor i'itj eompleta sets. For separate unit price, please see below. Transformer '*" AMPllflERS KIT ASSEMB. MODEL TA-2BMK2 TA-50A I B TA-50C TA-120MK2 TA-300 SM-302 TA-323A TA-377A TA-4Q0 TA-477 TA-B00MX2 TA-802 TA-I00OA TA-1500 TA-2200 TA-240OA TA-2500 TA-28M TA-3000 TA-3M0 5M-222 SM-328 5M-333 SM-666 sw-asa DESCRIPTION Digital voice Memo a a ^ Mullt-PurpDse MElDdy Generator A _ Mulli-Puipose Melody (Happy Birthday. Wedding March, elc.) Generator 35W Class _ A" Main Power Mono Amp. ii 30W Mulli-Purpose Smote Channel Amp. a ,~.„ — m .„. SOW + BOW Slereo Power Amplilier (wilh Mc. -.Hi _ 30WX 2 Stereo Pte-mainAmp. a Stale of Ihe Art Fully Complementary Symmetrical FET Pre-Amp. AAA 40W Solid State Mora Amp. A S20W Mosfcl Power Mono Amp. A A 120W . 120W low Tim Pre-Main Stereo Power Amp. AA BOW * SOW Pure DC Stereo Main Power Amp. AA I0OW Dynamic Class "A" Main Power Mono Amp. A A 10OW X 2 Class 'A- DC Slereo Pre-Main Amp. AAA , DC Fel Super Class "A - DC Pre-Amp. AAA Electronic Echo & Reverberalioit Amp : $30.00 .... 12.84 A 13.65 ....31.50 ....20.00 . .67.00 ....31.50 ..59.95 ....2B.00 ...69 00 ....63.32 45 34 ....59.69 .... 73.70 ..4.7.70 HQ Pre-Amp wno band graphic eauaiizer * SI -FET IC Pre-Amp wr3 way lone control AA -.,.- Stereo Simulator (For Mono TV or Any Mono Source) AA . 300W HD Hi-Fi Power Mono Amp AAA -.,...... 7 Band MI-FI Graphic Equalizer AAA 4 Channel Professional Color Light Controller* Audio/Video Surround Sound Processor AAA* Dynamic Naise Reduction A , Universal Audio/Video KARAOKE Mixer. Pre-Amp. * .......... 18.90 27.00 Z': "■ 26.80 ..65.00 ..2E.O0 T7.J0 ta.7i 42.80 29.00 78.00 42.B0 75.00 34 93 55 00 59.7! ao.53 95.61 56 24 96.00 66.60 63.57 38.50 110.(30 3B.B0 145 00 75.00 31.00 225.00 DIGITAL METERS AND COUNTER KIT ASSEMB. SM-43 3.4 Multl-Furiclional Led D.P M tw/ABS plasltc caselAA % 34.50 543,00 SM-48 4vs Hl-Precision D.P.M.AAA 33.00 45.00 5M-48A J' ; Kl-Precision D P.M. |w/AB5 plastic case'iAA A 11 .20 52.00 SM-49 3'n Mulli -Functional LCD D.M.P, (w/Hold Functinn)AA 36.00 44.50 SM-100 15DMC Digilar Frequency GounterAA A 79.00 90.00 FC-1000A 1 GHz Frequency Counter * _.. _ 179.00 MISCELLANEOUS KIT ASSEMB. MODEL TV-23B TY-25 TY-35 TY-36 TV-36 TY-41MKU TV-42 TV-43 TV-45 Tf-47 ■".'Si::... ■ DESCRIPTION 3 Channel Color Lid III Controller * . Slereo Loudspeaker Protector A . FM wireless Microphone A A&DC Quartz Digital Clock A . Sound 'Touch Control Swilch A Infrared Remote Control Unit (w/Case) AAA Rat /Dot level Meter A A 3Yr Digital Panel Meier A 20 Steps ear / Dot Audio Level Display A A . Superior Electronic Roulette AA . V Capacitor (Siujgesled loi TA-36O0. TA-477. TA-10O0A « TA-802] . ..S . 14.85 ..1125 . . 1900 .... 12.00 22 00 24 IS . .29.00 3845 19.46 S 65.00 20 85 26.20 35.00 3.1.81 38.00 46.14 27 24 23.00 REGULATORS KIT ASSEMB 1R-355A TR-355B Tft-503 0-15V 5A Regulated DC Power Supply (no case £ xlormerl A 0-30V 3A Regulated DC Power Supply (no case £ x'tormer) A 0-50V 3A Regulated DC Power Supply (no case 6 x'lormer) A A . S15B5 S21.76 ....15.65 21.76 ...16.75 23.65 METAL CABINETS WITH ALJMINUM PANEL MODEL H rrW x D' MATCHING LQ-1273 3' 12' T TA-2800, TA-377A. TA-2200 LG-16B4 4- 16' r TA-323A. TA-377A TA-2200 LS-1924 4- 19- 11<* TA-802, TA-15O0.TAI20MK 2. TA-B0OMK2. TA-10OOA . LG-1925 5' 19' 11 'A TA-477, TA-800. MK2. TA-1500, TA-tOOOA TA-SBOO .... LG-1983 2"i' 13' 8' TA-377A.. TA-2800. tA-2200. TA-120MK 2 . PRICE .. 6 22.35 27,50 ,32.60 35 80 .... 29.25 POWER TRANSFORMERS MODEL 001 002 003 004 DOS 006 007 DESCRIPTION 26Vk2 6Ato30Vk26A 36V X 2 3A 40VK26A 24V k 2 6A 26K k 2 3A 18Vk2 5A 53U k 2 8A MATCHING PRICE 1A-800 MK2, TA-802. TA-320A. TA-1 OOOA. TA-1500 527.00 TB-503. TA-323A. TA-40O. FA-3O0. TA-377A „ 22.00 TA-477 28.00 TA-120 MK 2 22.00 TR-355B 1 1\00 TR-355A 15.50 TA-3600 _ 43.00 o o CO CD US Wt aecffts iriijof C(n« Cartt Morvy Oeti'% O*to* MCOO o>««t COD f*t- .» ss oo M.nmjin opqv r . ■ jjo oo * Wv in.[» oy ups ground m^Tjc us fmi« %3 ocn jnrj -.r.^ by us it* Bu si ness & Showroom hours I Pactt ic Time I nrtvctoUS Pttwtc&wwtoia^rirfwiiaiu'ttonamitt.vt&irqFtxatNs • Aii 1 v,wi*Krr>auniij^i*nfliaG,Ti's^^ -R«»4inw Mon. thru Fri 9:30 dm to 500 pm Of CA ktyLHO o&S LBdel IvH B 7$\ * AM nWCh»ttl100;1 random random random random random >500:1 random random >500:1 random OPERATING OPER. VOLTAGE CURR. 1750v±l10v iooov ± ioo* 1050V ±100* iooov i ioo* IDOOvilOO* 1300vil00v 1300v±10C* 1300V iioov 1250v-100v 1900* -100* 1900* -100* 1750* -100v 6.5 mA 3.5 mA 2.8 mA 3,5 mA 3.5 mA 3.5 mA 5.0 mA 5.0 mA 6.5 mA 6.5 mA 6.5 mA 6.5 mA FIRING VOLT. < SkV < 7kV < SkV £ 7kV < 7kV £ 7kV < 7kV £ 7kV < 7kV £ SkV < 8kV £ SkV MIN. SERIES RES. 81k n 68k n 82k n 68k O 68k n 81k n 68k n 58k n 68k R Blk n sin n B1k a SIZE WT. DXL (GM.) (IN MM) 37x350 200 25 X 146 70 22.5x116 60 25 X 150 70 25 x 150 20x210 30x255 30x255 30x255 37x350 37 x 350 37x350 70 70 140 140 140 200 200 200 BRH Cl_ Ilia Ilia Ilia Ilia Ilia Ilia Ilia lllb int. lllb lllb PRICE 1-9 799,99 529.99 134.99 144.99 159.99 249.99 204.99 209.99 359.99 369.99 369.99 479.99 749.99 479.99 124.99 134.99 144.99 229.99 191.99 194.99 334.99 344.99 364.99 444.99 Laser Pointer • Output: 3.5 mW • Wavelength: 670 NM • Power Supply: 2xAAA Batteries (included) ■ Beam: Approx. 3" @ 100 yards Quantity Discounts Available STOCK # PRICE LSPOINT $199.99 Power Supply 4r ■ Input: 11 5/230V ■ Output: +5v @ 3.75A +12v@1,5A -12v@.4A ■ Size: 7" L x 5W" W x 214" H STOCK # PS1003 PRICE $19.99 Collimator Pen • Output: 2.5 rnW (max.) • Current: 90-150 m A ■ Op. Volt.: 2.2-2.5V • Wavelength: 82QNM • Data Sheet inc. STOCK # SB1052 PRICE $39.99 Disc Drive & Computer Cleaning Kit Not just a drive cleaner -but a complete computer cleaning kit. Includes swabs, bead cleaning fluid, anti-static cleaner, screen wipes and cleaning diskette. STOCK # SB1099 3V2" SB1100 5V Kit Kit PRICE $6.99 $6.99 Disc Drive Head- Cleaning Kit „ Anti-Static Screen Wipes Robotic Arm Kit Avoider Robot Kit Includes cleaning fluid and head-cleaning diskette STOCK # PRICE SB1105 3V 3 " Drive Kit $1.99 SB1106 5Vt" Drive Kit $1.99 For slatic-sensitive applications. Dispenser packs, individually wrapped. STOCK # PRICE S B 1 1 04 Dispenser pack $1 .99 ot 25 wipes 5B1 1 07 Dispenser pack $4,99 of 100 wipes Robots were ones conlmetf to science f icliwi mpvies. Today wKclhcr Ihey're performing dangerous tasks or pulling together comptex prod ucis. robotics are Ft ndi ng their way into more and more industries- The Roboti c A r m Kit is an educations! kit thai teaches basic robotic arm fundamentals B3 well a? lesling your own molar skills. Command it lo perform iimple tasks ♦ An intelligent robot that knows how to avoid hitting walls. This robot erniL$ an infra-red beam which detects an obstacle in front and then automatically turns left and continues on STOCK # YOI PRICE $49.99 STOCK # MV912 PRICE $49.99 O z o BE LU 6 ORDER LINE — (800) 824-3432 INTERNATIONAL ORDERS — (818) 341-8833 FAX ORDERS — (818) 998-7975 TECHNICAL SUPPORT — (818) 341-8833 CIRCLE 201 ON FREE INFORMATION CARD « 1 5.00 MINIMUM ORDER • UPS BLUE, RED S FEDERAL EXPRESS SHIPPING AVAILABLE • OPEN MON-FRI 9:00 AM - 6:00 PM, SAT 10:00 AM - 3:00 PM PDT • CA RESIDENTS ADD 7% SALES TAX • CALL FOR QUANTITY DISCOUNTS • CALL FOR FREE CATALOG (FOR 1ST CLASS DELIVERY OR CATALOGS DELIVERED OUTSIDE THE U.S. — SEND $2.00) • WE CARRY A COMPLETE LINE OF ELECTRONIC COMPONENTS 'NO SHIPPING CHARGES ON PRE-PAID OHDERS DELIVERED IN THE CONTINENTAL U.S. T04 FAX DIRECT 1-800-582-1255 TRIPP LITE - PRECISION REGULATED DC POWER SL Complete Line of DC Power Supplies to Convert 1 20Vac to 13.8Vdc +0.5Vdc. Standard Features include: -Solid state integrated circuit provides excellent regulation •Output voltage maintained up to 95% of no load value •High quality filtering for low noise operation •Heavy duty power transformer for complete line isolation •On/off indicator light and rugged on/off switch on faceplate •3 conductor grounded cord on 10 Amp and larger models •Current limiting electronic foldback for auto overcurrent protection •2 year warranty Tripp Lite DC Power Supplies Are Designed For Reliability and Superior Performance. PR4.5 Order # PR4.5 PR7 PH10 PR1S PRZ5 PR40 PR60 Price 32.95 44.95 S4.95 89.95 126.95 179.95 249.95 ICS* (amps) 4.5 7 10 15 25 40 60 Continuous Duty (amps) 3 5 7.5 12 20 32 48 Fusing Internal Chassis Mount Chassis Mount Chassis Mount Chassis Mount Chassis Mount Chassis Mount Ripple Voltage 0.1 Volt Max. 0.15 Volt Max. 0.15 Volt Max. 0.15 Volt Max. 0.15 Volt Max. 0.15 Volt Max. 0.15 Volt Max. HxWxP (Inches) 3.125x4.75x8.25 3.75 x S.5 x 7.5 4.5 x 6.625 x 7.625 4.75 X 7.5 x 8.25 5.125 X 12,5x10.5 7.25 x 12.5x10 8.5x12.5x10 Weight 5 lbs. 7 lbs. 10 lbs. 13 lbs. 20 lbs. 26 lbs. 29 lbs. 'Intermittant Communications Duty (50% Duty Cycle) SOLDERLESS PROTOTYPING BOARDS SB830 Features ■Color coordinates for easy recognition ■Insertion wire: 20-29 AWG (0.3 - 0.8 mm) ■Over 10,000 insertion cycles ■Accepts all standard components n rmn I Bill! SB1660 SB2390 SB3220 Order # SB200 SB400 SB630 SB 830 SB1360 SB1660 SB2390 SB3220 Price 1-9 2.99 4.89 5.45 6.49 12.49 17.45 22.49 31.49 Price 10+ 2.49 4.39 4.95 5.99 11.99 16.95 21.49 30.49 Dimensions (in.) LxWiH 6.5 x 0.37 x 0.4 3.3 x 2.2 x 0.4 6.5 X 1 .4 x 0,4 6.5 x 2.2 x 0.4 8,5x3.9x1.2 8.5x5.1 x 1.2 9.1 X 6.9x1.2 9.5x8.3x1.2 Dist. Strips Dist. Points 100x2 100 200 100 400 500 700 Terminal Strips Terminal Points 300 630 630 1,260 1,260 1,890 2,520 Binding Posts ORDER DIRECT 1-800-582-4044 [ACTIVE CQMPONbNIs] MICROS DRAMS Order # Price Order # Price 6821 1.75 MK4027N2 . ... .75 6845 2.45 4116-20 ... .85 8080 A Z.75 4416-12 ...2.25 8085A 2.95 4164-10 ...1.95 8086 4.45 4164-15 ...1.55 8088 4.25 4164-20 ...1.25 8237 A5 ... 4.15 41464-12... ...2.75 8250 5.75 41256-80... ...2.15 8251 A 2.25 41256-12... ...1.85 8253-5 2.25 514256-10 ...6.95 8255A5... 2.7S 511000-80. ...7.25 8275 ...18.95 511000-10.. ...6.95 STATIC RAMS Order # Price 2101 1.65 2114L25 1.15 2147-3 3.75 8116LP3 2.75 6116-3 2.25 6264LP10 4,95 6264LP1S 3.95 6264-10 4.75 6264-15 3.75 62256LP10....6.75 62256LP15....6.25 EPROMS Order # Price ...4,75 ...3.45 ...3.95 ...3.45 ...4.25 2708 2716 2732 2732 A25 2732B45 . 2764-25 3.75 2764 A25 3.25 27126A2S 3.95 27256-25 4.75 27256-30 3.45 27C512-15 6.95 D esc. 4x1 16x1 16x4 64x1 64x1 64x1 64x4 256x1 256x1 256x4 1Mx1 1Mx1 Prog ,, 25V 25V 25V 21V 12.5V 21V 12.5V 12.5V 12.5V 12.5V 12.5V | M Order* 256x9-80 1x9-80 MEMORY ODULES-SIMMS Price 19.95 64.95 Organization Speed 262,144x9 80ns 1,048,576x9 80ns | SURFACE MOUNflcTI Order # 27C64FP25 27C256FP25 41 256-1 2FL 41464FP15 6116FP12 6264LFP10 62256LFP10 74ALS32FP 74F240FP 74LS374FP Price Description Pins 3.95 64K PROM PLCC 32 4.95 256KPROM PLCC 32 2.45 256x1 DRAM PLCC 18 3.45 64x4 DRAM PLCC 18 2.45 2Kx8 SRAM SOP 24 4.25 8Kx8 SRAM SOP 28 6.95 32Kx8SRAM SOP 28 .55 Gate SOP 14 1.15 Octal Driver SOP 20 1.05 Octal Flip Flop SOP 20 ^■jEHZSSSa Motorola RF Device Data - Volumes 1 & 2 This two volume set contains over 2200 pages o\ data on RF Power TMOS FETs, RF Power Bipolar Transistors, RF Small Signal Transistors, Tuning end Switching Diodes, and RF Amplifiers. Also included are drawings, diagrams, dimensions and pin-outs on all packages. Weight: 4.25 lbs. Order # DL110 ■ 14.95 Motorola Memory Data Over 500 pages on Dynamic RAMS, General and Fast Static RAMS, MOS EEPP.OM, MECL Memories, etc. Weight: 1.25 !bs. Order § DL1 13 8.95 Motorola MPU/MCU/Peripheral Data - Volumes 1 & 2 Over 2800 pages on Motorola's Microcontroller and Microprocessor families such as the MC6800, MC6802, MC6821, MC6345, MC146818. MC68701 . MC68705. etc. Weight: 4.0 Ibs. 0rder#DL139 16.95 VISA 2917 Bay view Drive Fremont, CA 94538 1 National General Purpose Devices Linear Databook Over 1500 pages on voltage regulators, operational amplifiers, buffers, voltage comparators and instrumentation amplifiers. Weight: 3 lbs. Order #400026 19-95 El m National Programmable Logic Devices Databook Over 400 pages including data sheets, designing with PLDs. methodology and developmental tools. Also included is an introductory tutorial section. Weight: 1.01b. Order #400082 12.95 Order Direct: 1-800-582-4044 Fax Direct: 1-800-582-1255 Customer Service: 1 -41 5-770-2345 Monday-friduy, Jam - 5pm (PSl)/10nm-8pm (EST) COD-No personal checks, US funds ($5.00 Surcharge] USPS El UPS El Federal Express ED Airborne Add 5% of tola! (or shipping UPS Ground ($3.00 min.). Actual shipping charges based on weight. Call or write today for your free copy of our 1991 catalog. California residents, add appropriate sales tax. 12 month warranty on all EnsyTech products. 30 day money ba Metex Digital Multimeters General Specs: ■ Handheld, high accuracy ■ AC/DC voltage. ACDC cur/enl, resistance. diodes, continuity, transistor hFE ■ Manual ranging w overload protection M365C 5 M465Q only: - Also measure frequency and capacitance M46S0 only; * Data hold switch - 4.5 digit M3610 3.5DgitMU1imel*r $59,95 M3650 3 5 D-git Mutiirnelef wlF nequency 4 Capaoiance ..,,.574.95 M46 50 A .5 Dpi' /^Frequency, Capatilaixe and Dala Hold Switch S99.95 Handheld Multimeter • 3.5 digit LCD with automatic polity indication ♦ AC ■ , DC voltage measuremenl up lo 500 volts * AG'DG current rneasurerneni up to 200mA - Resistance measuremeni up (o 20MU ■ Con- linuity checker mlh audible tone ■ Diode and Erjgic lester * Auto/manual range and data hold lunclions * All range prelection and lunqijon in- dications DMM905 $39.95 Features: ■ Ideal tor analog, digital and microprocessor circuits • Triple DC regulated power supplies, +5V, +15V. -15V ■ 8 logic indicators * Function generator with sine, square, triangle and TTL waveforms PB503 • Two debounced push-button switches ■ Two SPDT slide switches, all leads available and uncommlled • A total of 2520 urtcommited tie-points • Potentiometers: one 1 Kn and one 10t • Includes power supply, instrumental! o and breadboard ing $299 Weller Soldering and Desoldering Stations ■ Temperature adjustable trom 350° to 850°F ■ Zero voltage circuit protects sensitrve components from damage • Lighted ontotf switch WCC10Q Soldering Station $89.95 ■ 50 Watt Temperature Controlled Desoldering Station ■ Desoldering head is temperature controlled to 800°F • Low maintenance vacuum system DS600 Desoldering Station $549.95 1 A.R.T. EPROM Programmer UVP EPROM Eraser v v nT^ • Programs all current EPHOMs in the 2716 to 27512 range plus the X2864 EEPP.OM ■ RS232 port • Software included ■ Erases all EP ROM's ■ Erases 1 chip i 15 minutes and S chips in 21 min ■ UV intensity: 6800 UW/CM 2 EPP $199.95 DE4 $89.! EPROMs - for your programming needs Part No. Price Part No, TMS2516 TMS2532-35 TMS2532A TMS2564 TMS2716 1702A 2708 2716 2716-1 27C16 2732 2732A-20 2732A-25 2732A-45 27C32 $4.25 8.95 6.95 5.95 5.95 3.95 4.75 3.39 3.75 4.25 4.95 4.49 3.49 2.95 4.75 Price 2764-20 2764-25 2764-45 2764A-20 2764A-25 27C64-15 27C64-25 271280TP 27128-20 27128-25 27128A-15 27128A-20 27128A-25 27C128-15 27C1 28-25 $3.95 3.75 3.49 3.75 3.19 3.95 3.25 3.49 7.95 7.75 4.95 4.49 3.75 5.75 7.95 Part No. Pr 272560TP $3 27256-15 5 27256-20 4 27256-25 4 27C256-15 5 27C256-20 4 27C256-25 4 2751 20TP 4 27512-20 6 27512-25 5 27C512-15 6 27C512-20 6 27C512-25 5 27C010-15 9 68766-35 9 Partial Listing • Over 4000 Electronic and Computer Components in Stock! CIFtCLE 114 ON FREE INFORMATION CARD Competitive Prices Computer Products and Electronic Components Assemble Your own Computer Kit! Jameco 16MHz 80386SX Desktop Computer Kit ■ Building your own computer provides you with a better understanding of components and their functions • In-depth assembly instructions included - Have your new computer assembled and running in an evening, using common tools • Software included • Purchase computer kits configured by Jameco or design your own ® J AMECO ^^^ ELECTRONIC COMPONENTS COMPUTER PRODUCTS 24 Hour Order Hotline (41 5) 592-8097 $799.95 mw |B " stoW ' Jameco 16MHz 80386SX Desktop Computer Kit includes: • 8038 6SX Motherboard with 2MB RAM (expandable to 8MB) - 101-key enhanced keyboard ■ Multi I/O Card ■ Toshiba 1 ,44MB, a.S' 1 DSHD floppy disk drive ■ Baby sized desktop case • 200 Watt power supply ■ DR DOS 5,0 by Digital Research and AMI diagnostic software l \ ; 1 ; 1 1 1, U. 11 Cat! for latest pricing E Relisys14" VGA Color Monitor Call for latest pricing! * Max resolution: 720 x 490 ■ Bandwidth: 30MHz •Input: DB1 5-pin (analog) RE9513 $399.95 Jameco 16-bit Super VGA Card • Emulates VGA. EGA, CGA, MDA and Hercules modes ■ Comes with 512KB video HAM upgradable to 1MB (Four 514256-80) ■ Capable ol t024 x 763 with 256 colors (1MB video RAM required) JE1058S $229.95 Integrated Circuits* Part No. 1-9 _m± Part No. 1-9 10t 7400 $.29 $.19 7472 $1.19 $1.09 7402 .29 .19 7473 .49 .39 7404 .29 .19 7474 .39 .29 7405 .35 .25 7475 .49 .39 7406 .35 .25 7476 .45 .35 7407 .35 .25 7483 .69 .59 7408 .35 .25 7486 .45 .35 7410 .29 .19 7489 2.95 2.75 7411 .29 .19 7490 .49 .39 7414 .35 .25 7493 .45 .35 7417 .35 ,25 74116 1.29 1.19 7420 .29 .19 74121 .49 .39 7427 .35 .25 74123 .49 .39 7430 .29 .19 74125 .45 .35 7432 .35 .25 74151 .39 .29 7438 .45 .35 74160 .59 .49 7442 .49 .39 74161 .69 .59 7445 .75 .65 74192 .79 .69 7446 .99 .89 74193 .79 .69 7447 .89 ,79 74194 1.19 1,09 Miscellaneous Components Potentiometers Values available (insert ohms into space marked "XX"): 500ti, 1K, 5K, 10K. 20K, 50K. 100K, 1MEG 43PXX =« Wait.15 Turn $.99 63PXX '& Watt. 1 Turn $.89 PN2222 PN2907 1N4004..... Transistors And DiodE „ $.12 1N4735. $.25 12 2N3904 12 10 1N751 15 >s 2N4401 1N4148 2N3055... .$.15 ... .07 69 2N2222A.. 25IC106B1... 59 1N270 25 Switches JMT123 SPOT. On On (Toggle) $1.25 206-8 SPST, 16-pin (DIP) $1.09 MPC121 SPDT.Cn-QflOnfToaglel $1.19 MS102 SPST, Momentary (Push-Button)..... $.39 Connectors DB25P Male. 25- pin ...$,65 DB25S Feni.te 25-pm„.75 DB25H Hood DB25MH Metal Mood $.39 1.35 Dynamic RAMs 4164-100 'MnsMKi' $1.89 41256-100 'OCns SWKit $1.95 4164-120 :20ns, WKst 1.69 41256-120 120ns. 2S6K* 1 1.79 4164-150 isOns.MKit 1,49 | 41256-150 i50ns,!56K*t 1.69 41256-60 60ns.2S6KM 2.49 5 1 1 000 P-80 Mre. 1 MB x I 7.25 41256-80 80ns.256Ki1 2,19 1 511000P-10 100ns, 1MB si 6.75 * Call for a complete listing of IC's I LEDs XC209B T1 , (Red) $.14 XC556R T1 3 H. (Bed) ... $.12 XC556GT1 3 «, (Green) ...16 1 XCS56Y T1 a rt. (Yellow). ..16 IC Sockets Wire Wrap (Gold) Level #2 8WW $.49 14WW 69 16WW 79 24WW 1.15 28WW 1.39 40WW 1.69 Solder tail Standard & Header Plug Sockets Also Available 8LP... Low Ft oiile $.11 14LP. 12 16LP. ..13 24LP. 19 28LP . 22 40LP. 28 Hard Drives •i^ Conner (16-bit IDE) CP3044 40MB 35' LowProlle $399.95 CP3184 80MB 3.S-HH $599.95 CP3104 100MB 3.5-HH $649.95 Call tor latest pricing! ADP20 Host Adapter.. ..$29.95 Look to Jameco..,.. • Wide selection of integrated circuits and components • Quality prototype and test equipment • Computer kits and accessories Additional items that Jameco offers; Tools Cables Connectors Data Books Motherboards Memory Math Coprocessors Computer Accessories Power Protection Equipment Much, much more ! Let us show you what we have to offer; call or write for the latest Jameco catalog! $50.00 Minimum Order Data Sheets SDc each Call for a FREE 90-Page catalog! '91991 Jameco Electronics 10.^1 CA Residents Add 7.25%, 7.75% or a. 25% Sales Tax Shipping, handling and insurance are additional. (Coeis may very according to weight and shipping method) Terms: Prices subject to change without notice. Items subject to availability and prior sale. Complete list of Iprms-wajrantjas is available upon request. J AMECO ^^ ELECTRONIC COMPONENTS COMPUTER PRODUCTS FAX: (415)592-2503 (415)595-2664 1 355 Shoreway Road Belmont, CA 94002 • Customer Service •Technical Assistance * Credit Department • All Other Inquiries • (415) 592-8097 CIRCLE 114 ON FREE INFORMATION CARD 7AM-4PMP.S.T. ADVERTISING INDEX FUN WITH ELECTRONICS ColO Construction 3 1GD-COIL DESIGN & CONSTRUCTION MANUAL ..„Sa.9>, How lo maka HF. IF-, and ■oand power coifs; chores and iranslofmers. Practically every possible lype Is dis- cussed. n PCP1 1 3— THE PC MUSIC HANDBOOK .... $13.95. Learn the basics of compuler music systems. For the pro- lesskinal musician, gifted am- ateur or jusl plain curious. I I BPJ97— LOUDSPEAK- ERS FOR MUSICIANS .... S6.25. Loudspeaker design from the musician's, point of view* All you need lo know, and you should bo able to de- sign your own after reading this- DBP277— HIGH POWER AUDIO AMPLIFIER CON STFIUCTION „,.S6,25. Here's background and practical de- sign information on high power audio amplifier's capable of 300-400 watts r.m.s, You'll lind MOSFET and bipolar oul- put transistors in Inverting and non-inverting circuits. High RtKWwr Audio Amplify CwWtructlofl V(, [ BP3G2— A CONCISE USER'S GUIDE TO LOTUS 1-2-3 RELEASE 3.1 .... 56.25. If you are a PC user and want 10 upgrade la Lolus 1-2-3 re- lease 3. T. Hi is book can teach you how lo do lhal In the short- est and most elective way. U BP29B— A CONCISE IN- TRO DOCTION TO THE M AC- INTOSH SYSTEM AND FINDER .... S6.25. This intro- duction for Ihose new to the Mac. this book also serves as a qurck fetresher for experi- enced owners that have not used I he machine in some time. MAIL TO: Electronic Technology Today. Inc. P.O. Box 240 Massapequa Park, NY 11762-0240 SHIPPING CHARGES IN USA AND CANADA S0.01 to S5.00 . . S5.01 to $10.00 . S10.01 to $20.00 S20.01 lo $30.00 $1.50 $2.50 $3.50 $4.50 $30.01 to $40.00 .S5.50 $40,01 to $50.00 .JS.50 $50.01 and above . $3.00 SORRY, No orders accepted outside of USA and Canada Total price ol merchandise Shipping (see chart) ... Subtotal Sales Tax [NYS only) .... Total Enclosed Name Address City .Stale. -Zip - RADIO-ELECTRONICS does not assume any responsibility for errors that may appear in the index below. Free ION 75 107 176 109 187 50 192 182 55 58 177 127 178 179 121 194 86 180 114 186 53 1% 93 71 188 193 56 198 197 Information Number Page AMC Safes 83 Ace Products 79 All Electronics 103 Amazing Concepts 100 American Reliance Inc 79 C & S Sales 77 CIE II. 15 Cable Ready Company 100 Cable Warehouse 26 Caig Laboratories 25 Chenesko Products 79 Command Productions 16 Communications Specialists 84 Contact East 79 Cook's Institute 26 Datak Corporation 25 Deco Industries 79 EasyTech 105 Electronic Goldmine 100 Electronic Technology Today ... 108 Electronics Book Club 17 Electronics Engineers B.C 28 Fluke Manufacturing CV2 Fordham 3 Global Specialties 13 Grantham College 81 Heath kit 12 Hewlett Packard 7 High Text Publications, Inc, 16 ISCET 88 Jameco 106, 107 Kelvin 73 MD Electronics 99 MJS Design 79 Mark V, Electronics 101 NR1 Schools 1 8. 93 NTE Electronics CV3 Number One .Systems Ltd 95 Optoelectronics 5 Parts Express 102 People's College of Indep. Study .82 R.L. Drake Co 23 78 Radio Shack 32 199 SCO Electronics 89 184 Sencore , i_'V4 — SMPTEC 84 — Star Circuits , 90 195 TECI 84 — The SPEC -COM Journal 26 185 The School of VCR Repair 76 201 Unicorn ]04 200 US Cable 89 189.190 Viejo Publications 12. 83 181 WPT Publications 84 202 183 Worldwide Cable . .98 Xantti Electronics 79 ADVERTISING SALES OFFICE Gernsback Publications, Inc. 500- B Bi- County Blvd. Farming dale, NY 11735 1 (516)203 3000 President: Larry Steckler For Advertising ONLY 516-293-3000 Fax 1 516-293-3115 Larry Steckler publisher Christina Estrada assistant to the President Arlme Fishm^in advertising director Denise Haven advertising assistant Kelly McQuade credit manager Subscriber Customer Service 1-800-288-0652 Order Entry for New Subscribers 1-800-999-7139 7:00 AM - 6:00 PM M-F MST SALES OFFICES EAST/SOUTHEAST Stanley Levitan, Eastern Sales Manager Radto-Etectroni c a 1 Overlook Ave. Great Neck, NY 11021 1-516-487-9357, 1-516-293-3000 Fax 1-516-487-8402 MIDWEST/Texas/Arkansas/Okia. Ralph Bergen, Midwest Sales Manager Radio-Electronics One NorthField Plaza. Suite 300 North-field. I L 60093-1214 1-708-446-1444 Fax 1-708-559-0562 PACIFIC COAST/Mountain States Marvin Green, Pacific Sales Manager Radio-Electronics 5430 Van Nuys Blvd. Suite 316 Van Nuys.CA 91401 1-818-986-2O01 Fax 1-818-986-2009 RE Shopper Joe Shere, National Representative P.O. Box 169 Idyllwild.CA 92549 1-714-659-9743 Fax 1-714-659-2469 108 NTE specializes in "replacetivityi' the science of getting things up and running again-fast! After alt, downtime is costly, so no one can wait weeks on end for an OEM part to come in. With NTE, no one has to! One call gives you access to 3,550 top of the fine universal replacement semiconductors that are cross-referenced to more than 240,000 original devices! Included in the NTE line are: bipolar transistors, integrated circuits, rectifiers, diodes, thyristors, optoelectronic devices, varistors, resistors, capacitors, and much, much more All are backed by NTE's exclusive two-year warranty. For your copy of the NTE Technicaf Guide contact your local NTE distributor, or simply fill in the coupon below and send it to us today with a check or money order for $3.25 each. Mail to: NTE, 44 T Fairand St.. Bloomfield, NJ 07003 For the name of your nearest NTE distributor, call NTE: Toll Free: 1-800-631-1250 (incl. Canada) Tel: (201) 748-5089 • FAX: (201) 748-6224 CIRCLE 71 ON FREE INFORMATION CARD Introducing The Only Complete Solution For All Your Monitor Servicing Needs! 1K>ina m »N«tf««" »««^, cl^lr. «*■■ • ft. CM2000 Computer Monitor' Patented - A Sencore Exclusive! Completely Test And Troubleshoot All High Resolution And Multi-Scan Computer Monitors From The Input Connector To The CRT... Guaranteed! Here's What The CM2000 Offers You: • Complete High Resolution Computer Monitor Analyzing •Fully Programmable Scan Rate And Pixel Resolution • Innovative Performance Testing Patterns • Special Sync-Locked Substitution Signals • Patented "Ringer" Test To Dynamically Analyze All: * Yokes * IHVTs/Hybacks * Switching Transformers . • Integrated 2,000 DCV And P-P Meter • Exclusive "Hook-up". Adapters Available For All Popular Monitors • Portable Troubleshooting For All Your Field Service Needs Call 1-800-SENCORE ext.708 (736-2673) FR 3200 Sencote Drive, Sioux Falls, South Dakota 57107 CIRCLE 184 ON FREE INFORMATION CARD