-TV SIGNAL DESCRAMBLING MAY 1990 - STEREO - COMPUTERS - SE BUILD THIS UNIVERSAL DESCRAMBLER ^—-.^wr. BUILD A MORSE/RTTY DETECTOR Display Morse code and radioteletype signals on your computer INSIDE THE DIGITAL OSCILLOSCOPE Will the DSO make analog scopes obsolete? WHY ARE THERE SO MANY TRANSISTORS? How to choose the right component for your next design CIRCUIT COOKBOOK Practical security-system circuits •"■u- UNIVEHSAL VIDEO DECODEH 1 SVNC REGEN6HATCW ''W EVEL PWR LOCK Waveform processing using a PC 71896"48783' S2.50 U.S. S2.9S CAN GERNSBACK iXKcaat* CftR-RT SORT £* CRD3 75D45SHRR51S5M093 05 99 sep m RE FLUKE AND PHILIPS - THE GLOBAL ALLIANCE IN TEST & MEASUREMENT FLUK High Resolution Digital Mater: 1000 count digital readout 20,000 coin! mode [Flute 87) lor 4Vi digit resolution Backlit display: Makes it easy to read the DM wi in da/%, cramped quarters. Automatically shuts off aflerSB seconds to save the battery. 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I had the option of getting a fixed supply but decided that a variable one would be more flexible. That has turned out to be true for my work but the only draw- back I've come across is that I don't have any handy way of pre-setting par- ticular voltages. Do you have any easy addition I can build that will iet me know when my supply is outputting five, twelve, or fifteen volts? — R. James, Brooklyn, New York It seems to us that all you have to do is use a voltmeter but that might be a pain in the neck — especially if you want to have the ability to switch back and forth between vari- ous output voltages. Fortunately, there's a simple way you can add some indicators to your supply using only a handful of parts and some LED's as indicators. The circuit shown in Fig. 1 is just about the easiest voltage-detection circuit we can come up with. You'll notice that there's a fairly loose tolerance for the Zener diode. That is inten- tional since it's often hard to find Zeners with really specific break- POWER €>UPPL*i AMD/ FIG. 1 down voltages. You can use the trimmer to tweak the voltage ap- plied to the Zener and have it con- duct at a particular voltage. When the Zener diode is triggered, the transistor will turn on, and the LED will then light. The values in the schematic will work for a five-volt indicator but you don't have to be a rocket scientist to make the changes needed to have it work for just about any voitage you want. The only thing that has to be done is to change the Zener. Since you're using a trimmer to adjust the circuit's trip point, keep the Zener rating a bit below the voltage you want to detect. That means a 10- or 11-vo)t Zener for a 12-volt circuit, a 13- or14-volt Zener for 15 volts, and so on. You'll need a meter to set the trip points but once that's done, the cir- cuit will reliably indicate the output voltage. Remember that you'll need a separate circuit for each voltage you want an indicator for. The parts are cheap and the circuit is minimal so expense and space shouldn't be a problem. The circuit is drawing its power from the supply, but the impedance is high enough to keep it from load- ing down the supply. If you find that the draw is too much (although I can't imagine that), increase the val- ue of the trimmer. The rule here is that the larger the value of the trim- mer, the lower the draw but the harder you'll find it is to calibrate. Try to keep the trimmer potentiom- eter under 15K. VIDEO UPGRADE I'm about to spend some money to upgrade the video display on my IBM- compatible computer, I currently have a monochrome graphics card and an amber monitor but I want to move on to color. The problem I have is decid- ing between EGA and VGA, how much memory to get for the video card, and what's the difference be- tween register compatible and BIOS compatible?—). Robert, Chalfont, PA One of the most paradoxical things about computers is that while they might be designed to make your life easier, trying to understand them can be anything but easy. They've given a whole new meaning to the idea of standards. But let's take your questions one at a time. All of the IBM color systems are designed to be downwardly com- patible with each other — or at least that's what it says on page 12 of the manual. When the VGA standard was introduced with IBM's PS2 se- ries, there was a big price differen- tial between it and EGA, the previous system. The way things stand now, VGA cards aren't much more expensive than EGA cards (only about $75 to $100 in dif- ference- — the same goes for the price of the monitors themselves), so it really doesn't pay to get an EGA system. VGA is capable of much more colors and better resolution, and since you're going to be using it for a few years, it pays to get the better system. Remember that you buy the hardware to run the soft- ware and, as time goes by, more and more software is going to show up that's written exclusively for VGA. If you do go with an EGA system, you might want to upgrade to VGA in the future, and the chances are good that you'll have a hard time unloading the EGA card and monitor. The issue of memory is a bit sim- pler. The more memory you have on the card the better the resolution. EGA cards have the hardware to talk to a maximum of 256K but VGA cards can handle half a megabyte. In the original IBM cards, the EGA standard was 64K (expandable to 128K) and the VGA standard had a maximum of 256K. As more man- ufacturers began making cards, Discover Your Career Potential In The Fast Growing Field Of High-Tech Electronics! CIE Gives You The Training You Need to Succeed... At Your Own Pace...& In Your Own Home! 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The problem with that is that hav- ing the extra capability on the card is rather useless unless software knows how to take advantage of it. Since all the expanded display ca- pabilities of the various cards are outside the standards set down by IBM, most software houses don't support them. You might be able to get 1024 x 768 resolution from a 512K VGA card but, since that isn't a standard resolution, the chances are that your favorite paint program has no driver to support it. Most card manufacturers supply software to adapt a few major pieces of software (AutoCAD, Microsoft Windows, GEM, etc.), to the higher resolutions that their hardware can display. The rule here is to make sure your software can run on the hardware you buy. The question of BIOS and register compatibility is one of hardware and the final difference is mostly speed. Both EGA and VGA cards are micro- processor-controlled devices and, as such, they need instructions to work — and that's what the BIOS is. The BIOS takes video commands from the computer and translates them into values that are then stuff- ed into the internal registers of the display microprocessor. Being "BIOS compatible" means that the entry point for the video routines in the card's firmware is the same as those in the IBM. Being register compatible means that the microprocessor is organized in the same way as the IBM. The former is software compatible and the latter is hardware compatible. People who write graphics soft- ware are always trying to make things happen as quickly as possi- ble, and the fastest way to drive a display is to write directly to the reg- isters. Talking to the BIOS is both slow and limiting. The bottom line is that you should get yourself a VGA system and it makes a lot of sense to get a VGA card that specifically features both BIOS and register compatibility. The only other thing to keep in mind is that most of the enhanced display features of a 512K VGA can be used only on a multisync continued on page 32 CIRCLE 86 ON FREE INFORMATION CARD AT $299.95, NO OTHER DESIGN WORKSTATION GIVES YOU SO MUCH FOR SO LITTLE. proto BOARD BRAND Function Generator ..sine/square/triangle ...plus TTL Large Breadboarding area holds 24 ICS ...2,500 tie points Triple Power Supply ... +5V fixed, plus two variable 5-15V 8 TTL Logic Probe Indicators Audio Speaker Two Digita Pulsers Two BNC Connectors for oscilloscopes and counters Here's PB-503, the total design workstation. It has everything! Instrumentation, including a func- tion generator with continuously variable sine/square/triangle wave forms — plus TTL pulses. Bread- boards with 8 logic probe circuits. And a Triple Power Supply with fixed 5VDC, plus two variable outputs ( + 5 to 15VDC and - 5 to 15VDC). Throw-in 8 TTL compatible LED indicators, switches, pulsers, OVER $600 WORTH OF WORLD CLASS TEST EQUIPMENT FOR UNDER $300! potentiometers, audio experimenta- tion speaker. . .plus a lifetime guar- antee on all breadboarding sockets! You have everything you need right there in front of you! PB-503 — one super test station for under S300! Order yours today!! A016 Call foil-free for details 1-800-572-1028 GLOBAL SPECIALTIES CIRCLE 191 ON FREE INFORMATION CARD Mnterplex Industries Global Specialties, ' ™" sm " S 70 Fulton Terrace. New Haven, CT 06512. company 3j Telephone: (203) 624-3103. 2 Interplex Electronics. 1990. _l All Global Specialties breadboarding products made in USA. Jg ProtoBoard is a registered trademark of Global Specialties. ° 13 Letters W^ 1 zsrrEAs AA0/O-£LECT# O^/C S soo-a 6i- count r soul£. yard FAXMtNGOALE, N Y //7SS AVOIDING AM INTERFERENCE The "Ask R-E" column in the March issue of Radio-Electronics ex- plained to a reader how to rid a ster- eo of AM-radio interference. As Chief Engineer of a 50-kW direc- tional AM station (our studios are located in about a 20mV/m RF field) I can think of a few easier solutions to try first. I almost never have to resort to soldering caps across an input. Ground the amp with a decent piece of wire to a good ground. If that doesn't eliminate the inter- ference, ground the rest of the com- ponents to the same ground. Or you might try an AC-line RF filter. Often the RF gets in through the power supply. The filters can be ob- tained disguised as computer surge protectors — but make sure they have the filter in them as well as the surge protector. Also, try to keep the speaker and component inter- connection leads as short as possi- ble. Here are some tips for telephone interference. If you hear the station on all the phones on your line, call the phone company; it's often a wet or faulty connection out on a pole that causes the audio to be de- tected. If the interference is on only one phone, you can try a O.OI-^F, 200-volt capacitor connected across the red-green pair. If that doesn't work, AT&T phone centers sell an effective filter for just that sort of problem. As a last resort, call the engineer at the station for more advice. We are not obligated to work on your g equipment, but it is in our best in- z terest as good neighbors to help en you get rid of the problem, o STUART ENGELKE ^j Whitehouse Station, NJ o Q < AND MORE.... The solution proposed in "Ask R-E" for "Overpowering AM Inter- ference" works fine on interference from VHF and UHF stations, such as FM and TV, but you can never get enough capacitance across the in- put stages to bypass an AM broad- cast radio station without ruining the audio response of the stereo amplifier. In many cases the medi- um- and high-frequency inter- ference rides into the set via the speaker leads — the longer the lead, the worse the interference. The cure is to choke it off or by- pass it. The bypass-capacitor meth- od is cheaper and easier. A 0.1-^.F bypass capacitor connected across each of the speaker terminals on the back of the set usually eliminates all of the interference. What is par- ticularly nice about that cure is that you don't have to enter the stereo cabinet to complete the job. The other solution involves chok- ing the signal before it enters the set, using RF chokes. One very-low- resistance RF choke would be used in each lead. The best way to choke it off is by winding the speaker leads around a ferrite rod or torroid core as close to the set as possible. HAROLD ISENRINC, W9BTI Colgate, WI BRAIN POWER I subscribe to Radio-Electronics and I've always enjoyed Don Lan- caster's Hardware Hacker column — particularly his item on the "Santa Clause Machine," which he picked up at least a week before any of the other publications that I read did. I was extremely displeased by misinformation in the January 1990 column. One does not need to un- derstand the workings or structure of the brain to realize that the stated capacity of "four billion memory bits or so" must be an infinitesimal frac- tion of its actual capacity. For an ex- ample, let's use the CD platter analogy, but this time let's imagine the CD's are storing digitized music: How many songs do you think the average person could identify at age 40? How many CD platters would it take to hold those discrete memo- ries alone? Now, how much memo- ry would it take to store the memories of events and people that might be associated with the hear- ing of those songs? And how much to store the sights, smells, tempera- ture, and tactile sensations accumu- lated over the span of 60 years? I am equally disturbed by Mr. Lan- caster's "threshold effect." Comput- er languages, operating systems, expert systems, etc., are just al- gorithms. Those algorithms could be carried out by a computer or by people using filing cabinets and in- dex cards. Increasing a computer's memory space does not automat- ically imply the ability to create more sophisticated algorithms. At the most, it might inspire some per- son to think of a more sophisticated algorithm to take advantage of the new, more powerful machine. I am familiar with the theory of computers reaching a certain mem- ory size and "waking up" (see Robert A. Heinlein's The Moon is a Harsh Mistress), and perhaps a cer- tain number of synapses could be the only requirement for intel- ligence. But even if that were true, Mr. Lancaster's estimate is stag- geringly inadequate. just look at existing systems. My desktop workstation at my job is linked to a network that has about 3.5 gigabytes of disk memory. That is by no means a large network; in fact, there are only 14 workstations on it. But that is already seven times the capacity of his original 4 gigabit "human brain" capacity. That net- work is hooked into the division 14 LAN, where it can access another 5 gigabytes or so. If we consider this very typical computer installation as one of (shall we underestimate) 500 local computer networks hooked to the internet... . So far I have seen no signs of that network waking up. Nor has it inspired anyone to create a new category of algorithm that will change the face of the world (unless you'd place a destructive virus in that category). Hardware Hacker and other such information sources are the forces that help shape the technical minds of this and other countries. When such poorly thought out concepts are presented as facts, I worry that someone might believe them and set us all back a few paces. I would hate to go back to the times when some people were afraid of the pho- nograph because it could "talk." JON ROLPH San Diego, CA EASIER IC REMOVAL Regarding "Chip Removal" (Ask R-E, Radio-Electronics, March 1990), I was sad to see the answer given. The first method mentioned, using a solder pot and extractor, requires equipment not likely to be available to the average home technician. And, as you suggested, the chances of failure are very high. A method that has been around for many years — the only one ap- proved by government organiza- tions — will work, and with practice it is virtually foolproof. Dip "solder- wick" desoldering braid (the fine braid jacket from coax will do nicely) nto liquid flux. Hold the end on the oint to be cleaned and press a hot ron on the braid above the solder oint. The joint will almost instantly be as clean as it was before the DIP was first installed. Each joint can be treated that way, and the chip will be easy to remove. I would recommend practicing on a defunct board to get a feel for the best iron heat and the wick and iron placement. A somewhat hotter iron than usual is best so that the heat is on the board a minimum time, to avoid damaged compo- nents and loosened foil. After each solder joint wicking, the loaded end of the braid is cut off, dipped in liquid flux again, and moved to the next joint, JOE D. PERDUE Neiiysford, VA The Only 5-Digit Sweep AM/FM Function Generator At A 3-Digit Price. FG3A Sweep/Function Generator ■ 7 Frequency Ranges from 0.2Hz to 2MHz ■ Sine, Square, Triangle, Ramp, TTL and CMOS Outputs Linear or Logarithmic Sweep Internal/External AM or FM Modulation For more information and the location of yaur nearest authorized Beckman Industrial dealer call 1-800-854-2708 (In California 1-800-227-9781). Instrumentation Products Division, 3883 Ruffin Road, San Diego, CA 92123-1898 © 1989 Beckman industrial Corporation. SpMificalions aie subject lo change without notice. CIRCLE 177 ON FREE INFORMATION CARD JN 164-01 -0590 CHEMICAL SOLUTIONS FREE CHEMTRONICS CATALOG! Comprehensive new source for over 200 products used in electronic man- ufacturing and field service. Precision cleaning agents, flux removers, bulk solvents, circuit refrigerants, precision dusters, non-residual wipers, foam swabs, premoistened padsswabs, antistatic compounds, conformal coat- ings, lubricants, adhesives. desolder- ing braids, rosin core solder and solder masking agents. Complete with tech- nical specifications and application guide. Chemtronics Inc. 681 Old Willels Pain Hauppauge. N Y 117SS S16-5a2-3:i22 CIRCLE 54 ON FREE INFORMATION CARD EARN YOUR B.S.E.E. DEGREE THROUGH HOME STUDY Our New and Highly Effective Advanced -Place- ment Program tor experienced Electronic Tech- nicians grants credit for previous Schooling and Professional Experience, and can greatly re- duce the ftne 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 I Write for free Descriptive Lit- erature. 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However, the method suggested in Mike Rogalski's "Test Methods" (Radio-Electronics, March 1990) will not make things easier. When the impedance of a signal source is complex — -that is, consists of resistance and either inductive or capacitive reactance — there is no fixed relationship between the ap- plied resistive load, the resulting drop in output voltage, and the equivalent resistance of the source impedance. The reason is that the phase angle of the impedance vec- tor is unknown. A bridge, such as the Wheatstone type, drives the un- known impedance with a signal of its own and therefore obtains phase-angle information — the phase angle between the voltage across the unknown impedance and the current the bridge provides to produce that voltage. Mike's method will work for sig- nal sources that are generally purely resistive, such as the line or speaker outputs of audio equipment. How- ever, the drop in output when R1 equals the signal source impedance is not 3 but 6 dB — half the open circuit voltage. One must be careful when measuring the output imped- ance of audio power amplifiers that employ large amounts of voltage feedback since their dynamic im- pedance is very low (on the order of fractions of an ohm). Do not attempt this measurement without experi- ence. That could be the subject of a complete article in itself. ARMAND LUCCHESl jersey City, NJ ETCHING TANK TIPS Regarding the article, "Make Your Own Etching Tank" (Radio-Elec- tronics, December 1989), I'd like to add a couple of pointers. I built the board using Vm-inch Plexiglas that I cut with a radial arm saw using a plywood blade. It made a smooth cut, and I didn't have to file or sand any edges. Slow is the way to go when cutting the Plex- iglas! As no cement was suggested in the article, I asked at my local hardware store and was advised that methyl-ethyl-ketone would work as continued on page 35 YOUR ONE-STOP STORE FOR BIG ELECTRONIC VALUES Build with the Best— Over 1000 Components in stock! Amateur Radio License Guides 495 .0 19 g 5 Home Study Courses For FCC License Tests Novice Voice Class License Prep Course. With cassettes. #62-2402 19.95 Technician Class Manual. #62-2403 4.9S General Class FCC License Course. #62-2404 19.95 Parts "Hotline" Service! Thousands of Items Available Your Radio Shack store manager can special -order a huge variety of parts and accessories direct from our electronics warehouse- Realistic* Long-life tubes, linear and digital ICs, microprocessors, support chips, phono cartridges and styli, crystals, special- purpose batteries, diodes, selected modules for TVs and audio equipment, autosound wiring harnesses, accessories, even SAMS Photofacts®. 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Monaural. #274-855 3.49 (5) Three -Conductor (Stereo) W Phone Plug. #274-856 3.99 (6) Vs" Plug. #274-857 2.79 (7) 3 -Conductor. Va" Phone Plug. Stereo. #274-858 3.49 (8) 3-Conductor Vi" Inline Phone Jack. #274-859 3.99 ic Tool set 6|5 = Install and remove 6-pin to 40-pin DIPs without damage. Works with LSI, MSI, and DIP devices. Both tools are groundable. #276-1581 Dress it Up (1) Classy Two-Piece Enclosure, Accepts PC board and 9V baltery. 5% x £>&, x 1 Vie': #270-257 . . 4.99 (2) Project Labels. Four 7 7 tex3" sheets of rub-on tetters and symbols. #270-201 Set 2.99 Motor and Chime (1) 1.5-3V DC Motor. For robotics, projeete-IVaxishe" dia. #273-223 (2) Doorbell Chime. !CJ mini -speaker combo. 6-18VDC, 5" leads. #273-071 Halogen Lamps 395 Each (1) HPR50. For 4-cell flashlights and 6-voll lanterns. #272-1189 (2) HPR52. For 2-cell flashlights and 3 -volt lanterns. #272-1190 Wire Connectors & Accessories (1) (» < 3 > Btt®(ttE (4> (5) (6) (7) H9. Pos. lyoe Amps Ca!. flu. Each ! 2 G ■2 Male Male Male 20 15 12 274-151 274-152 274-153 .99 1.69 1.99 2 2 6 12 Female Female Fern alt 20 15 12 274-154 274-155 274-156 .99 1,69 ' 33 (3) 2 -Row Strip. #274-670 ... 1.99 (4) Jumper. 8-pOs. #274-650, 1.59 (5) 45° T-Lugs. #274-645 . . 4/79C (6) Dual Solder-Lug Adapters. #274-644 Pkg. of 4/79C (7) Heavy-Duty Bonded Wire. 25 ft., 2x18-gauge, #278-1250 . . 3.99 Engineering Calculator , J J-IUL.L, f ■ £J 3 L3 !_; i— U 3QQIQOQ ■DODD DBQBD 39 95 Uses Standard Electronic Symbols EC-4035 makes design math a snap! Has 110 (unc- tions, memory. With case and batteries. #65-983 30-Range Multimeter 79 95 Tests Capacitors and Transistors A great value! Measures to 1000VDC and 750VAC. With 0.5" digital display. Battery ex- tra. #22-194 Over 1000 items in stock! Binding Posts, Books, Breadboards, Buzzers, Capacitors, Chokes, Clips, Coax, Connectors, Fuses, Hardware, ICs, Jacks, Knobs, Lamps, Muititesters, PC Boards, Plugs, Rectifiers, Resistors, Switches, Tools, Transformers, Transistors, Wire, Zeners, More! Prices apply at participating Radio Shack stores and dealers Panel-Mount Counter 1495 Electromechanical —Counts to 99,999 One count per 12VDC pulse, pushbutton reset. Mounts in Vh&xV hole. Depth: V^t%". With leads and data. #277-222 mRadiQ/haek AMERICA'S TECHNOLOGY 5 A DIVISIOH OF TANDY CORPORATION CIRCLE 78 ON FREE INFORMATION CARD 17 Learn to troubleshoot and service today's computer systems as you build a fully AT-compatible micro, complete with 1 meg RAM, and powerful 20 meg hard drive Train the NRI Way— and Earn Good Money Servicing Any Brand of Computer 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 10 growth fields in the nation Now you can cash in on this exciting opportunity— either as a full-time industry technician or in a computer service business of your own— once you've mastered elec- tronics and computers the NRI way. NRI's practical combi- nation of "reason-why" theory and hands-on building skills starts you with the fundamentals of electronics, then guides you through more sophisticated circuitry all the way up to the latest advances in computer technology Train With a Powerful AT-Compatible— Now with 20 Meg Hard Drive and 1 Meg RAM! lb give you hands-on training with the absolute in state-of- the-art computer technology, NRI includes the powerful West Coast 1010 ES computer as the centerpiece of your training. As you assemble this fully IBM AT-compatible micro from the keyboard on up, you actually see for yourself how every section of your computer works. You assemble and test your computer's "intelligent" keyboard, install the power supply and 5Vi" disk drive, then interface the high-resolu- tion monitor. But that's not all. Your hands-on training continues as you instaU a powerful 20 megabyte hard disk drive— today's most- wanted computer peripheral— now included in your course to dramatically increase the data storage capacity of your com- puter while giving you light- ning-quick data access. Plus you work with exclusive word processing, database, and spreadsheet software, yours to use for your own professional and personal applications. As you build your com- puter, performing key demon- strations and experiments at each stage of assembly, you get the confidence-building, real- Your NRI computer training includes all this: • NRI's unique Discovery Lab - for circuit design and diagnosis • NRI's hand- held digital multimeter featuring "talk-you- th rough" instructions on audio cassette • A digital logic probe that lets you visually examine computer circuits • The new AT-compatible West Coast 1010 ES computer with high-speed 60286 CPU, 101-key "intelligent" keyboard, 1.2 meg high-density floppy disk drive, 1 meg RAM (expandable to 4 meg), 64K ROM • 20 megabyte hard disk drive • MS-DOS, GW-BASIC, word proces- sing, spreadsheet, and database software ■ Reference manuals with programming guidelines and schematics prepared to take advantage of today s oppor- tunities 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. And all throughout your training, you've got the full support of your personal NRI instructor and the NRI technical staff, always ready to answer your questions and help you whenever you needit. FREE 100-Page Catalog Tells More world experience you need to wori with, troubleshoot, and service today's most widely used computer systems. New! Explore the Latest Advances in Voice Synthesis Now NRI also includes innovative hands-on training in voice synthesis, one of today's most exciting and wide- ly applied new developments in com- puter technology. You now train with and keep a full-featured 8-bit HI A converter that attaches in-line with your computer's parallel printer port. Working with the exclusive text-to-speech software also included with your course, you explore the fascinating technology behind both digitized and synthesized com- puter speech. NRI 's new hands-on training in voice synthesis is just one more way you get the confidence-building experience you need to feel at home with the latest advances in computer technology. Send today for NRI 's big, 100-page 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. School of Electronics No Experience Needed, NRI Builds It In This is the kind of practical, hands-on experience that makes you uniquely McGraw-Hill Continuing Education Center 4401 Connecticut Avenue, NW Washington, DC 20008 IBM «j*J AT in registered trademarks of luttra atiwm l Business Machines Corporation McGraw-Hill Continuing Education Center 4401 Connecticut Avenue. NW, Washington, DC 2000S Sf CHECK ONE FREE CATALOG ONLV p Telecommunications D Compu ler Electronics D Industrial Electronics U TV/ Video/ Audio Servicing rj Electronic Circuit Design D Robotics Q Basic Electronic! D Elect tonic M usic Technology □ Booklteepinf it Accounting D Security Electronics □ Building Construction □ Digital Electronics Servicing n Automotive Servicing □ Air Conditioning, Heating, & Refrigeration □ Small Engine Repair D Electrician D Locksmithing D Travel Careers □ Writing □ Paralegal □ Computer Programming Name (Please print) Age City/State/Zip We'll give you tomorrow. Accredited Member National Home Study Council 3-505 | Equipment Reports r Integrity Electronics IER-109 60-Hz Magnetic Field Meter Keep tabs on your exposure to potentially dangerous 60- Hz magnetic fields. CIRCLE 19 ON FREE INFORMATION CARD LONG TAKEN FOR GRANTED, THE 60-Hz power lines criss-crossing our neighborhoods and running through the walls of our homes are emerging as a potential health threat. The issue is being discussed more and more frequently in the popular press, and it shows no signs of going away. The subject has been studied by many respected organizations, in- cluding the World Health Organiza- tion, the American Institute of Biological Sciences, and the New York State Department of Health. There seems no doubt that ex- posures to ELF (Extremely /.low Frequency) magnetic fields can cause biological effects. Just what effects are unknown at this time, and many studies are underway to determne safe exposure levels. However, the report issued by the g New York State Department of z Health recommended that a major g research be undertaken by utilities, £3 appliance makers, and the like to ^ find ways to reduce exposures to Jij ELF magnetic fields in homes. S We're not holding our breath 2 waiting for the scientific community 22 to come to firm conclusions regard- ing the relative safety of exposure to the 60-Hz magnetic fields generally assumed to be harmless — the stud- ies will take years, and conflicts are sure to arise. Because we're so en- trenched in our power-generation and -distribution system, it's unclear whether we'll be willing — or able— to change even if the threat is sub- stantiated . However, it seems prudent to us to at least be aware of the potential danger, and to be aware of the strength of fields we encounter every day. We recently found a good way to do just that: the model IER-109 60-Hz Magnetic Field Meter from Integrity Electronics and Re- search (558 Breckenridge Street, Buffalo, NY 14222; 716-886-6985). The IER-109 measures magnetic field intensity, or magnetic flux den- sity, in three ranges: 2, 20, and 2000 milligauss. A narrow bandpass filter gives the unit a sharp frequency re- sponse centered around 60 Hz— its 3-dB bandwidth is specified as 11 Hz. That sharp response is important because harmonics can cause havoc with proper measurements. The meter measures roughly 3x4x7 inches and weighs about a pound. It features a 3-1/2-digit LCD readout and runs on a single 9-volt alkaline battery. An alarm feature allows you to pre-set an intensity level above which you want an alarm to sound. If you wish, the alarm can be turned off, and the alarm condition will be indicated by a front-panel LED. For those more interested in total exposure than simply the intensity at a given instant, the IER-109 fea- tures a 200-millivolt output to a re- corder for dosimetry measure- ments. Using the meter Since some reports have indicat- ed that continuous exposure to fields greater than 3 milligauss from power lines have been linked to in- creased incidence of childhood leu- kemia, we set the alarm for that level and examined various situations where we might receive chronic ex- posure. In front of the computer on which this report was prepared, the field was measured at 1.5 milligaus at the normal operating position. Un- der an electric blanket, the field was measured at 66 milligaus! It's not surprising that such blankets are often referenced in reports con- cerned with magnetic-field safety. The field inside the wall closest to our power-line drop was better than 4 milligauss, but fell rapidly only a few inches from the wall. Since our test site was not located near a distri- bution transformer, that was ex- pected. The IER-109 sells for $595. Because many potential customers may be curious about their field exposure, and not need the meter on a day-to- day basis, Integrity also offers a rental service for a fee of $50 per week. It seems a small price to pay for peace of mind. R-E jameco Electronics Metex M-3900 Digital Multimeter and Dwell/ Tach Meter A multimeter at home on your test bench — or in your garage. CIRCLE 20 ON FREE INFORMATION CARD WE ALWAYS CRINGE A LITTLE BIT WHEN we have to take our digital multi- meter out to our car to check on the condition of its battery, or to diag- nose a wiring problem. There's really no logical reason for that, ex- cept that it just doesn't seem right to get grease on our expensive, high- accuracy instrument — even though the meter's seals will protect it. That meter just doesn't fit in with the wrenches and our other automotive tools. We have, however, found a new digital meter that cries out to be used in automotive applications: the Metex 3900, available in the U.S. from Jameco Electronics (1355 Shoreway Road, Bellmont, CA 94002). The Metex 3900 adds ta- chometer and dwell-angle func- tions to the usual resistance, current and voltage ranges. Basic specifications The M-3900 is housed in a rugged, yellow plastic case that measures about 6X3Y2XVA inches. Its front panel features a 3H»-digit LCD read- out, a 30-position rotary function se- lector, four input jacks, and a power switch. A 9-volt battery provides power to operate the meter. The meter offers five ranges, from 200 millivolts to 1000 volts, for mea- suring DC volts. The specified ac- curacy is ±0.3%, +1 digit. Two AC voltage ranges, 200 and 750 volts, provide a worst-case measurement accuracy of 1.2%, +3 digits. Both DC and AC current can be mea- sured in two ranges of 2 and 20 amps, with a worst-case accuracy of ±3%, +7 digits. Six resistance ranges, from 200 ohms to 20 megohms, provide a measurement accuracy within ±1%, +2 digits. An audible continuity test, along with a diode-test function (which displays the forward voltage drop of a diode) is also offered. Those basic features are just what you'd expect from a basic digital multimeter. But the M-3900 isn't just a bench-top meter. Dwell-angle measurements and tachometer readings are also available. Ta- chometer readings, in two ranges of 2000 and 10,000 RPM, can be made on 4-, 5-, 6-, and 8-cylinder engines with a rated accuracy of ±2%, + 1digit. Dwell-angle measure- ments can also be made on 4-, 5-, 6,- and 8-cylinder engines with the same accuracy. Automotive measurements Although electronic ignition has taken over most new automobiles, many cars still use points to control spark generation. The dwell angle is a measurement of the time that the points remain closed during the ig- nition cycle. One result of setting the engine dwell incorrectly is that sufficient energy cannot be built up in the coil to provide good spark. Poor acceleration, or missing at higher engine speeds, is the usual complaint. Excessive dwell shortens the life of the points. Although the increasing use of electronics under the hood makes it difficult for Saturday mechanics to perform many maintenance func- tions, a tachometer is still useful to determine whether the engine is operating efficiently, the choke is working according to specifications, the idle speed is correctly set, and the like. To make the automotive measure- ments easier, the M-3900 comes equipped with an extra set of test leads with clips, and a manual that details automotive measurements. The total cost of the Metex M-3900 is $69.95. R-E Go ahead, examine them closely. Pomona has the best tips around. From an SMD Grabber* to a BNC Coax connector, you can choose both ends just the way you want them to meet your exact applications. The Best Quality You Can Buy. From tile wire or cable itself to the tip you want— like gold plated con- tacts, beryb'um copper springs, swaged banana plugs, and molded on stress relief And, here's the best tip yet: Pomona's cable assemblies will give you many years of accurate contact See your nearest Autho- rized Pomona Distributor, or contact POMONA ELECTRONICS 1500 E. Ninth St., P.O. Box 2767 Pomona, CA 91769 (714)623-3463 FAX (714) 629-3317 *>. ■■*«. ohms/sq. The wrist- band includes a 6-foot coiled cord, and a 10-foot ground- ing cord with an alligator clip. The Statfree CP636 ESD field-service kit has a list price of $40.00.— Charleswater Products, Inc., 93 Border Street, West New- ton, MA 02164, STAND-ALONE RADIO MODEM. Megadata's SA9600 stand-alone radio modem al- lows mini- and mainframe CIRCLE 18 ON FREE INFORMATION CARD computers to communicate at data rates up to 9600 bits per second via a narrow- band UHF radio line. Con- necting to a synchronous se- rial port of the host comput- er, the radio modem con- verts the serial data stream to radio packets transparently. Because the host computer perceives the SA9600 as a conventional synchronous telephone modem, no soft- ware modification is re- quired to establish a wireless link. The radio modem allows data communication where conventional wiring is im- practical, expensive, or im- possible. Potential applica- tions include land mobile, ship-to-ship, building-to- CONNECTION PROTECTION ^/fe '^ CT^ G t>' 0LE S £DG £co m£c7Dffs tHAMOUN PLUGS &S qGKETS c o^ eCT TEB MINAL STR^S GOLD PLATFn COHNECnSg fyrn £*}y CRAMOLIN C °**ck Even the finest equipment in the world cannot guarantee noise-free operation. One "dirty" connection anywhere in the electrical path can cause unwanted noise or signal loss. "MORE THAN A CONTACT CLEANER" CRAMOLIN -" is a fast-acting, anti-oxidlzing lubricant that cleans and preserves all metal surfaces, Including gold. Whe n applied to metal contacts and con nectors. C R AM O LI N *' removes resistive oxides as it forms a protective molecular layer that adheres to the metal surfaces and maintains maximum electrical conductivity. CRAMOLIN* - USED BY THOSE WHO DEMAND THE BEST: Bell 4 Ho*rt Hawlatt PKkuKl MC«Sony) NaJuuntctii Boeing John Flute Mfg. Motorola RCA Cjpiiol n«oid» Mdnloih Labs NASH. Swilenetift rATfliM : M;f,l^hU^ 1 1 75-0 I ndufcU lal Am. , {P. O. Box J] - Escond iCo. CA TOG2&-O05 1 U . S.A (B1 9) 743-7143 CABLE - TV SIGNAL REMOVERS ■FOR ELIMINATION OF SEVERE INTERFERENCE •FOR "CENSORING" OF ADULT BROADCASTS ■ ATTENUATION • 45 dB TYPICAL ■ BANDWIDTH - 4 MHz AT S dB POINTS ■ INSERTION LOSS - 2 dB MODEL TUNING FOR CHANNELS 'a^.an; PRICE 51. ip^ Ni". 23 H 50-66 MHz 2.3 lor 6 meter ham) 50.300 MHz S30 NO SHIPPING 46FM 4.5.6 |or any FM'I 50-300 MHz S30 1417 1 20-114 MH: 14[A) 15(B) 16(C) 17(DI V.. ■:■■..!.'■■:. S3S or 1822 144-171MHI 16(E) 19(F) S0fG)!l(H) 22(1) 50-400 HH! 630 CHARGES 713 174-£16MH[ 7.6.9.10.11 12.13 50-400 MHi 530 3 for $75 - 1 for $200 - mix or match CALL TOLL FREE FOR C.O.D. OR SEND CHECK TO ORDER FAST DELIVERY 30 DAY MONEY BACK GUARANTEE (3 FILTER LIMIT) Star Circuits P. 0. Box 94917 Las Vegas, NV 89193-4917 1-800-433-6319 CIRCLE 50 ON FREE INFORMATION CARD CD to o 27 Join the Electronics and Control Engineers' Book Club TROUBLESHOOTING ELECTRONIC EOUIPMENT WITHOUT SERVICE data. Second Edition. By R.G. Middletcn. 320 pp., ittus. This indispen- sable new edition features all the informa- tion that made the first edition so suc- cessful, plus the latest developments in digital testing, phase checks. IC trouleshooting, and repair of VCRs, ste- reos, TVs, tape recorders, and much, much more. 585992-3 Pub. Pr.. $30 JO Club Pr., 522.50 PRINTED CIRCUITS HANDBOOK, Third Edition, By C.F. Coombs, Jr. 960 pp., 556 iltus. Here in one handy volume is all the information you need to design, manufacture, test, and repair printed wir- ing boards and assemblies. This new edition features ten all-new chapters, Including three on SMT. 125/097 Pub. Pr., $54.95 Club Pr., $45.50 SOUND SYSTEM ENGINEERING, Second Edition. By D. Davis and C. Davis. 665 pp., iltus. The definitive source for all professionals responsible for audio system design, covering every- thing from concert hatls to virtually every oscillator in use today. Packed with proven strategies for solving design and engineering problems and cutting your clients' costs 584657-8 Pub! Pr., $39,95 C!ub Pr., $31.50 McCRAW-HILL ENCYCLOPEDIA OF ELECTRONICS AND COMPUTERS. Second Edition. S. Parker. Editor-in- Chief. 1,047pp., 1,250illus. Featuring 160 new and revised articles, this new edition treats the entire spectrum of applications, devices, systems, and theory in areas ranging from the flow of electricity to hardware, software, robotics, and IC fabrication. 454- 59 X Pub. Pr., $79.50 Club Pr.. 554.95 COMMUNICATIONS RECEIVERS: Principles and Design. By uirich L. Rohde and TT.N. Bucher, 608 pp., 402 iltus. Everything you need to know if you design or work with communications receivers, from theory to practical design approaches. Coverage includes all types of receivers: shortwave, broadcast, radar, military, marine, aeronautical, and more. 535/701 Pub. Pr., $64.95 Club Pr., $44.50 • your one source for engineering books from over 100 different publishers • the latest and best information in your field • discounts of up to 40% off publishers' list prices New Members! Take any one of these great professional books for only as a premium with your first selection! Spectacular values up to $199.50 ENGINEERING FUNDAMENTALS FDR THE PROFESSIONAL ENGINEERS' EXAM, Third Ed. By L, M. Polenti. 432 pp. 170 Htm. Features worked -out solutions and full explana- tions for all sample problems so you can learn how to solve them. It's a dependable way to prepare for the exam or a perfect on-the-tob reference. 503/931 Pub, Pr, $39.50 Club Pr.. $27.95 CO O z O rr t- o UJ — I LU 1 o D < rr 26 PORTABLE ELECTRONICS DATA BOOK 360 pp., 5x9. illus.. SOftCDVer 585390-6 A-to-Z coverage of all the essential facts, figures, and formulas you need, in a format that's easy to use and easy to carry. John Douglas- Young has filled this handy on-the-job companion with equations, algorithms, calculus tormulas, and BASIC programs in areas ranging from alternating current and amp! if ers to transducers and waveguides . . . and they're all yours ABSOLUTELY FREE! A $19.95 Value - Yours ABSOLUTELY FREE when you join! AUTOMATIC CONTROL SYSTEMS, Fifth Ed. By B. C. Kuo. 736 pp., iltus. Provides an overview of automatic control systems, including in-depth coverage of classical control techniques, optimal con- trol theory, and analog and digital control system design. This up-dated edition discusses the latest ideas on the use of computers to design control systems and as components of such systems. 583706-4 Pub. Pr., $57.49 Club Pr, $43.59 CIARCIA'S CIRCUIT CELLAR, Vol- ume VII. By S. Ciarcia. 256 pp., 100 iltus., soltcover. More do-it-yourself cir- cuits from the master— Steve Ciarcia. Step-by-step guidance on projects rang- ing from a gray-scale video digitizer and the Circuit Cellar AT Computer to parallel interlacing and the Neighborhood Strate- gic Defense Initiative. 1DQ/699 Pub. Pr., $19.95 Club Pr., $15.95 THE COMPACT DISC: A Handbook of Theory and Use. By K. C. Pohlmann. 288 pp.. iltus. soltcover. The most readable and comprehensive guide to CD technology offers clear descriptions of disc design and manufacturing . . . player circuitry . . and comparisons of different types of players — all without complicated theoretical or mathematical discussions. 585096-6 Pub. Pr., $29.95 Club Pr. $22.50 MOBILE CELLULAR TELECOM- MUNICATIONS SYSTEMS. By W.C.Y. Lee. 442 pp. , 215 ittus. A to Z coverage of state-of-the-art cellular systems, from de- sign to implementation and troubleshoot- ing. Clearly explains spectrum efficiency, propagation models and prediction, inter- ference treatment, and more. 370/303 Pub. Pr., $62.95 Club Pr., $44.50 TRANSFORMER AND INDUCTOR DESIGN HANDBOOK, Second Edi- tion. By Col. W.T. McLyman. 440 pp., ittus. All the information you need to design today's lighter, smaller transform- ers and inductors, without relying on out- moded approximation methods, in ready- reference tabular format, this new edition covers the latest equations in transformer and gapped design applications. 584646-2 Pub. Pr„ $55.00 Club Pr., 538.50 MICROCOMPUTER TROUBLE- SHOOTING AND REPAIR. By J. G. Stephenson and B. Cahill. 354 pp. iltus.. softcover. This nuts-and-bolts guide pro- vides expert tips, troubleshooting toots and shortcuts, and practical help on decid- ing if you really do have to bring it in to the shop. It also explains techniques tor antic- ipating and defending against most com- mon computer problems. 5B5106-7 Pub. Pr., $24.95 Club Pr.. $18.95 microelectronics. Second Ed. By J. Millman and A. Grabel. 1,001 pp., 646 itlus. Takes you from the basics of semiconductor properties to an under- standing of the operation of solid-state devices, and then to more advanced topics. Its up-to-date coverage, real-lite examples, and practical data make this an ideal reference for the working engineer. 423/30X Pub. Pr., $56.95 Club Pr., $41.50 ENGINEERING MATHEMATICS HANDBOOK, Third Ed. fly J. J. Tuma. 512 pp.. iltus. This best-selling handbook gives you the essential mathematical tools-formulas, definitions, theorems, ta- bles, and models for computer program- ming — that you need for your day-to-day engineering calculations. 654/433 Pub. Pr., $52.50 Club Pr., $34.50 BASIC TELEVISION AND VIDEOSYS- TEMS. Fifth Ed. By B. Grot). 59? pp., illtis. Provides the clearest picture of how television and video systems work, and what to do when they don't. Covers television receivers, VCFTs, video cam- eras, and cable systems - all in readable. practical detail. 249/334 Pub. Pr, $39.95 Club Pr,. S24.96 BUILD YOUR OWN UNIVERSAL COMPUTER INTERFACE. By B. Chubb. 309 pp., illtis., soltcover. Guiding you from theory to step-by-step assembly instructions, this lively manual shows you how to construct a computer interface and haok it up to virtually any IBM or IBM com- patible personal computer, including the XT, XT-286. AT, and System/2 Model 30. 5850B0-X Pub. fir., S19.95 Club Ft., S15.95 HANDBOOK OF ELECTRICAL NOISE MEASUREMENT AND TECHNOL- OGY, Second Ed.ByC.A. Vergers. 440 pp. 213 itlus. Provides answers to all your questions about noise origins, causes, effects. Also shows you how to predict and measure noise, and Sow to design low-noise circuits. 583947-4 Pub. Pr., $39.95 Club Pr., $29.95 SWITCHGEAR AND CONTROL handbook. Second Ed. Edited by R. W. Smeaton. 1,056 pp., 789 fc. The only handbook that treats all aspects of switchgear control, including design, ap- plications, safety, and maintenance. Up- dated to reflect the changes brought about by trie use of computers, solid-state devices, and programmable controls. 5B4/494 Pub. Pr., $83.00 Club Pr.. $56.95 ANTENNA APPLICATIONS REFER- ENCE GUIDE. Edited by R. C. Johnson and H. Jasik. 496 pp., 368 iltus. and tables. Covers the major applications of antenna technology in all areas of commu- nications and their design methods. Em- phasizes important new applications such as earth station, satellite, seeker, aircraft, and microwave-relay antennas. 322 848 Pub. Pr.. $59.95 Club Pr.. $42.50 RADIO HANDBOOK, Twenty-Third Ed. Edited by W. I. Orr. 667 pp.. r,073 illus. and tables. The latest edition of the most complete, current resource on radio technology and its applications. Expert contributors show you now to select, de- sign, build, test and operate all kinds of equipment. 584538-1 Pub. Pr., $29.95 Club Pr., $23.95 AUDIO ENGINEERING HANDBOOK. Edited by K. B Benson. 7056 pp.. 722 il- tus. The ideal on-the-job reference for pro- fessionals who design, operate, and ser- vice audio equipment. It's a one-volume source of fundamental audio acoustics en- gineering information and practical how-to source book covering generation, trans- mission, storage, and reproduction of the audio signal. 047/774 Pub. Pr., $83.50 Club Pr., $59.95 Here's how the Club works to serve YOU: ■ IMPORTANT INFORMATION . .. WE MAKE IT EASY TO GET! In our rapidly changing world, those who perform best are those who are best informed. Designed exclusively for the practicing engineer, the Electronics and Control Engineers' Book Club provides you with information that is relevant, reliable, and specific enough to meet your needs. Each Club bulletin comes ynur way 14-lfi times a year and offers you more than 30 books lo choose from — the best and newest books from all publishers! ■ DEPENDABLE SERVICE. ..WE'RE HERETO HELP! Whether you want information about a book or have a question about your membership, our qualified slafTis here lo help. Jusl call ustoll-free or write to our Customer Service. We also make sure you get only the books you want. All you do is simply tell us your choice on the Reply Card and relurn it lo us by the specified date. If you want the Main Selection, do nothing — it will be sent to you automatically. (A small shipping and handling charge is added to each shipment.! ■ CLUB CONVENIENCE ...WE DO THE WORK! Beyond the benefit of timely information, Club membership offers many other benefits. For example, you get a wide choice of books that cannot be matched by any bookstore — anywhere. And all your books are conveniently delivered ri^ht to your door. You also gel the luxury of 10 full days to decide whether you want the Main Selection. If you should ever receive a Main Selection you don't want because the Club bulletin came lale, jusl return it for credit at our expense. ■ SUBSTANTIAL SAVINGS... AN D A BONUS PROGRAM TOO! In keeping with our goal to provide you with the best information at the greatest possible savings , you will enjoy subs tan lial>discounts — up to 40% ! — on every book you buy. Plus, you 're automatically eligible for our Bonus Book Plan which allows you savings up to 70% on a wide selection of books. ■ EASY MEMBERSHIP TERMS... IT'S WORTHWHILE TO BELONG! Your only obligation is to purchase one more book — at a handsome discount — during the next 12 months, after which you enfoy the benefits of membership with no Further obligation. Either you or the Club may cancel membership anytime thereafter. Be sure to consider these important titles as well! BUCHSBAUM-S COMPLETE HANDBOOK OF PRACTICAL ELECTRONIC REFERENCE DATA. Third Ed. By W.H. Buchsbaum 5331SDX Pub. Pr , $34.95 Club Pr., «6.50 ON-LINE ELECTRICAL TROUBLE- SHOOTING. Be L. Lundquist. 3S1 106 Pub. Pr.. $34-59 Clue Pi., 126. M ESSENTIAL CIRCUITS REFERENCE GUIDE. By J. Markus & C. Weston 404 ' «3 Pub Pi, . S59.95 Club Pi, $47.50 INTRODUCING PC-DOS AND MS-DOS, Second Ed. By! Srseldon 515,051 Pub. Pr.. $21.95 Club Pi., (19.95 HANDBOOK OF ELECTRONICS CALCULA- TIONS FOR ENGINEERS AND TECHNI- CIANS. Second Ed. Edited by M. Kaufman & A. H. Seidman. 335/281 Fu:: Pr., $49.95 Club ?r.. $37.50 INTRODUCTION TO DIGITAL SIGNAL PRO- CESSING. By J, G. ProakiSMiD. G. Manolakis. 594954-2 Pub. Pr , S50.90 Club Pr.. $37.50 CIRCUIT DESIGN FOR ELECTRONIC INSTRUMENTATION: Analog and Digital iieilcss from Sensor lo Display, Second Ed. By D. Wobsctall TO31X Pub. Pi., 552 35 Club Pi.. $36.95 BOB MIDDLETONS HANDBOOK OF ELEC- TRONIC TIME-SAVERS AND SHORTCUTS. By R G Midd ci en 593965-5 Pub Pi., $29.95 Club Pi.. $22.50 DIGITAL AND MICROPROCESSOR TECH- NOLOGY, Second Ed. fly P J O'Connor. 565184-9 Put. Pr., $42.00 Club Pr., 133.50 OP-AMP HANDBOOK, Second Ed. By FW HuQhss 583651-3 Pub. Pr. . $39 . 00 Club Pi., $27.5(1 FOR FASTER SERVICE IN ENROLLING CALL TOLL-FREE 1-800-2-MCGRAW .____ MAIL THIS COL POX TODAY - — McGraw-Hill Book Clubs Electronics and Control Engineers' Book Cluh P.O. Box 582, Hightstown, NJ Q8S20-93S9 Plfiiise irnroEl sue as , r i member and send me the two books indicated, plus I lie PORTABLE ELECTRONICS DATA HOOK. I am lo receive one hook for jusl $1 89, Ihe oilier ai [he discounted memberfc price, plus local tas, shipping and handling chaiges. I .i ■ lo purchase a minimum of one additional honk during my lirslyeaiof membership as on I lined under the Cluh plan de- scribed in this ad. I understand that a shipping and handling charge is added lo all shipments. 1 Vbur FREE Data Book S&S'&M-H Write Code ft S2.S9 sclecti o. of Ihe on here Write Cod First seh e No, for the ii liii! here Signature . Name Address/Apt. #_ Citv State . £'P - This order subject to acceptance by McGraw-Hill. All prices subject to change without notice. Offer good only to new members. Foreign member acceptance subject lo special conditions. ECGA-034 ., I to O 31 g z o £ Hi _l LU o Q < EC VALUE PRICING ON KENWOOD OSCILLOSCOPES FROM jpscph •DIGITAL READOUT •DELAYED SWEEP • VIDEO CLAMP •CURSOR FUNCTIONS •HIGH SENSITIVITY •AUTOMATIC TRIGGERING •HIGH RESOLUTION 12KVCRT • 2-YEAR WARRANTY Model (SMS Cull Joseph Eleclranies for value quotes on oil KENWOOD models. KENWOOD 'The Company You've Been Listening To For Years." 40 MHz VERTICAL MODE SENSITIVITY HORIZONTAL MODE SWEEP TIME TRIGGER SOURCE TRIGGER MODE COUPLING PROBES DUAL-CHANNEL OSCILLOSCOPE CHI, CH2 r DUAL (ALT, CHOP), ADD ImV/DIV la 5 tf/DIV IN 1? RANGES A, ALT, B, K-T A0.ZnSTO0.5S/DIVl3SROranses) B0.2 M ST0J0mS±3K(17 ranges) VERT MODE, CHI, CH5, EXT, LINE AUTO, NORM, FIUINGLE-RE5ET HFrej, DC, TV FRAME, TV LINE 2 PC-33 PROSES Included Model CS-51 30 Reg. $1095 *899 100 MHz VERTICAL MODE SENSITIVITY HORIZONTAL MODE SWEEP TIME TRIGGER SOURCE TRIGGER MODE COUPLING PROBES 2-CHANNil 4-TRACE OSCILLOSCOPE CHI, CH2, ALT, CHOP, ADD lmV/DIVlo5V/DIVIH12RANG£5 MLT,B,X-Y t0.5L ( S TO 0.5 S*13S(Z2 ranges) B 0.5nS TO 50mS/div +3% (1 9 ranges) VERT MODE, CHI, CHZ, EXT, UNE AUTO, NORM, FIX, SINGLE-RESET AC, HFrej, DC, TV FRAME, TV LINE 2 PC-31 PROBES Included 1399 Model CS-5170 Reg. $1695 CM or write far our 526 pg. Catalog. Only $4.95 — FREE Willi mitt. CALL TOLL-FREE • SAME-DAY SHIPPING et£L, i riur vr&^z* ffWW/V 8B30 N. Milwaukee Ay. Niles, IL 6064S 708- 297-4200 FAX: 708- 297- 6923 Add $7.50 Shipping and Handling (or endi unit acdDrri. IL Rf sinenh add 7% Sales T« CIRCLE 190 ON FREE INFORMATION CARD ASK RE continued from page 12 monitor since the horizontal fre- quency needed to do 1024 k 768 resolution is beyond the 31-kHz VGA standard. Multisync monitors aren't that much more expensive than regular VGA's, and they are a lot more versatile. TWO INTO ONE I have a stereo amplifier and I want to connect both outputs to one speak- er. My reasons for doing that are com- plicated but it will solve a need I have. The problem is that I don't know ex- actly how to go about wiring the speaker to the left and right outputs. I'm not that experienced in elec- tronics but it does not seem that all I have to do is connect the two speaker outputs together. — G. Offrey Madison, AL What you're missing in experi- ence you obviously make up for in intuition. Connecting the two out- puts together is more than not a good idea — it's definitely a bad idea. If you did that, you would be run- ning the risk of having one output /NPUT A -SW — Q XZ f FIG. 2 drive the other. You didn't tell me how powerful your amplifier is but, no matter how many watts you have pouring out of each channel, driv- ing one directly into the other is a sure recipe for an enormous elec- tronic disaster. The way around the problem is to connect things so that each of the outputs always sees a reasonable load. That's pretty easy to do, and the most straightforward solution is shown in Fig. 2. Make sure the re- sistors are chunky enough to han- dle the power output of the ampli- fier. You didn't give me any num- bers but start out with some 2-watt resistors and see how warm they get. If they seem to get much too hot, replace them with a pair of higher wattage resistors. R-E building, communication to remote sites where tele- phone service is unreliable or non-existent, and com- munications within a build- ing where computers are frequently relocated. The SA9600 offers some advan- tages over other wireless data-communication meth- ods like cellular radio, in- cluding lower cost, indepen- dence from the telephone network, and a data rate four times faster than that avail- able over a cellular link. The unit's specialized FM radio transceiver and ad- vanced data-modulation techniques provide a 9600- bits-per-second data rate while requiring less than 3- kHz of bandwidth. The nar- row bandwidth allows re- peaters normally used for voice data communications to be used for data commu- nications. With a 2-watt transmit output power, the SA960O can achieve an out- door line-of-sight range of up to 15 miles. The range can be extended to hundreds of miles using repeaters, power amplifiers, and antennas. The radio modem operates at 450-470 MHz, the UHF fre- quency band allocated for business use by the FCC. Other versions of the SA9600 operate in the 406-420-MHz federal government band, or in the 420-450-MHz amateur- radio band. The SA9600 radio modem has a list price of $3,000. — Megadata Corporation, 35 Or- ville Drive, Bohemia, NY 11716-25%. 32 Lower the numbers and raise the odds. Controlling your blood pressure can reduce your risk of heart disease. American Heart Association N ew Lit ELECTRONIC TEST ACCESSO- RIES. Five new product groups are featured in Pomona Electronics' 138- page Electronic Test Accesso- ries catalog. Those include IC test clips, low-cost cable assemblies, and a family of digital multimeter test-lead kits. An index makes it easy t -r v -v .11 fl- --a -ii Pomona CIRCLE 21 ON FREE INFORMATION CARD to find items in each of ten major product categories, and helpful selection guides are provided lor the reader. The brochure contains com- plete descriptions of Pomona's popular selection of jumpers and cables, boxes, connectors, plugs and jacks, adapters, single- point test clips, and static- control devices. The catalog is free upon request. — ITT Pomona Electronics, 1500 East Ninth Street, P.O. Box 2767, Pomona, CA 91769; Tel. 714-629-3317. REMOTE-CONTROL RE* PLACEMENTS. Designed for servicers, the 1990 edition of Thomson's publication, Remote Controls for RCA and CE Instruments (#1E5790), contains all avail- ItCJl Rtmgle Centrari tor RCA and GE Instruments CIRCLE 22 ON FREE INFORMATION CARD able direct- replacement re- mote-control hand units for RCA and CE televisions, vid- eo recorders, videodisc play- ers, camcorders, and audio components. The catalog is divided into three sections. The first two parts contain cross-reference material both in model-number and remote-type-number se- quences. The last section contains photographs of over 220 different remotes, to help the reader identify the correct model. — Thom- son Consumer- Electronics, Distributor and Special Prod- ucts, 2000 Clements Bridge Road, Deptford, N) 08096-2088, ATTN: Service Dealer Merchandising, TEST & MEASUREMENT IN- STRUMENTS. The 1990 Fluke and Philips Test & Measure- ment Catalog highlights 20 new products in a full-color introduction section. Several features designed to help customers choose the equipment that best fits their test and measurement re- Wfth Just One Probe Connection, You Can Confidently Analyze Any Waveform To 100 MHz, 10 Times Faster, 10 Times More Accurately, Absolutely Error Free, Guaranteed — Or Your Money Back! SCSI Waveform Analyzer ™ Patented $3295 o 6 -■ v== o 6 J ■ EHiTtuf4iu(l(lWTS TWOCE" There are other digital readout oscilloscopes, but none ot them completely eliminate graticule counting and calculations like the SC61 Waveform Analyzer. The innovative, time-saving AUT0-TRACKING iw digital readout automatically gives you every waveform parameter you need for fast troubleshooting. The SC61 Waveform Analyzer is a triple patented high performance scope that provides you with a digital LCD read-out of all key waveform parameters (DC volts, peak-to-peak volts, and frequency) at the push of a button, and all with one probe connection. Other time-saving features include exclusive ECL sync circuits that allow you to lock quickly onto waveforms up to 100 MHz. Plus, with 3000 volts of input protection, you never have to worry about an expensive front end repair job. Call 1-800-SENCORE to find out more about what the SC61 can do for your service business. In Canada call 1-800-SENCORE. 3200 Sencore Drive. Sioux Falls, SD 571 07 100% American Made L to CO o CIRCLE 188 ON FREE INFORMATION CARD ! STOP ! COMPUTER RADIATION Have you ever observed the situation where an electric device is adversely affected by a nearby computer? We look at the waveform in the time domain and think we understand it. time 10dB per DIV 100 (IV frequency 100 MHz The scope photos show the wave form being conducted by ribbon between shielded circuit and keyboard within a computer, in Doth time (fig. 1) and frequency (fig. 2) domain. The Spectrum Probe is placed directly on the line and has no effect on the waveform because of the low capacity input. Clock and waveform harmonics are low — but unnecessary spurious is radiated by this lead up to about 70MHz. frequency 100 MHz w o z o I LU -J LU o Q < DC Fig. 3 shows the waveform being connected to the outside world (read "radiated") by a rear panel connenctor. There is no digital informa- tion present, yet there is extremely high and completely unnecessary spurious energy at about 20MHz. Most spectral lines above 50MHz are due to residual pickup of RF, even without connecting an exterior lead, indicating that a reasonably good radiating antenna is present! 107 SPECTRUM PROBE converts any scope into a 100MHz spectrum analyzer $1 99 direct Smith Design 1324 Harris Rd. Dresner, PA 19025 (215) 643-6340 CIRCLE 196 ON FREE INFORMATION CARD New sul id- stale and digital TV sets, stereos, and vid- eoreeffrderg art lough? r to re- pair lhan old-fashioned Lube type sl-L?. and require special training for the service lech- mi.:. 'n; who works on them. Only a few stales nave laws requiring competency tests for licensing technicians who repair consumer electronics. but fifteen .years aj*a the In- ternational Society of Cer- tified Electronic Technician!; I GET i began its ow n certi Flea- Lion program tn qualify incite technicians, and those in in- dustry. To Carry the CET des- ignation, technicians niuel have four years experience □ nd pass a rigid examinalinn on genera! electronics and a Specific afca of cX perlise such as audio or radio-TV Many consumers look for a Certified Electronic Techni- M.in m the shop when they need any electronic item re- paired. Free Consumer Checklist A consumer checklist for selecting a service shop is av- Modern electronic equip- rnent such as digital TVs or stereos should be re- paired hy specially trained people. ailable free by sending a stamped, self- addressed en- velope to Checklist, ISCET. 2708 West Berry. Fort Worth. T\ 76109. The list reminds consumers to check such items as "Does the business have the parts for your par- ticular brand?", "Did you get nn estimated price?", and "Did you cheek this company with the Better Business Bureau?" CIRCLE 23 ON FREE INFORMATION CARD quirements have also been added. Those include a rack- mount selection guide, a glossary of terms, and an ab- breviations and symbols sec- tion. All products and ser- vices are also indexed both alphabetically and numer- ically. The 536-page publica- tion provides descriptions, photographs, product-selec- tion guides, and ordering in- formation for more than 650 products, accessories, and software programs. Product lines in 18 major categories are included, as well as list- ings of available technical lit- erature and worldwide sales offices, technical centers, and authorized distributors. There is no charge for the catalog, — John Fluke Mfg. Co., Inc., P.O. Box 9090, Ever- ett, WA 98206; Tel. 1-800-443-5853. ENGINEERING SOFTWARE, BSO FT Software Engineering Tools #3 contains descrip- tions and ordering informa- tion for several new products and new versions of existing software. Designed for sty- dents, hobbyists, and pro- fessional engineers, it in- cludes low-cost stand-along engineering programs for IBM-PC's and compatibles. Programs are offered for drawing schematics, simulat- irra -St- l^ JBStER* CIRCLE 24 ON FREE INFORMATION CARD ing logic-control circuits, and circuit analysis. CAD programs for designing cir- cuits and PC boards are of- fered, along with computer- aided mathematics and waveform- viewer software. The catalog is free upon re- quest.— BSOFT Software, 444 Colton Road, Columbus, OH 43207; Tel. 614-491-0832. SMALL-MECHANISM DE- SIGN. A 784-page technical data book from SfocA- Drive Products, titled Design and Application of Smalt Stan- dardized Component (Data Book 757), helps the reader learn how to design mecha- nisms that use small me- chanical-drive components. The book is comprehensive enough to be used as a text- book in machine design and related courses at the voca- tion-technical level. CIRCLE 25 ON FREE INFORMATION CARD A special 51-page section on robotic component de- sign includes a detailed specification guide compar- ing 42 performance features of 147 industrial- and teach- ing-class robots. Other ma- jor sections in the book cover design procedure, se- lection, and application data for designing with small gears, belt and chain drives, speed reducers, AC motors, miniature DC motors, gear trains, stepper motors, con- stant force springs, universal joints, and vibration mounts. A "Designer's Data Section" includes more than 50 tables such as mathematical for- mulas, conversion and units, and materia! properties. Data Book 757 costs $7.95 postpaid in paperback, or $12.95 for hardcover.— Edu- cational Products, P.O. Box 606, Mineoia, NY 11501. R-E 34 LETTERS continued from page 16 a cement. Avoid breathing the fumes. 1 bought the 100-watt heater at an electronics parts store, and later found the same unit, but marked for aquarium use, for less money at a pet supply store. The air pump I bought is designed for medium-size aquariums. Your magazine and its predeces- sors have been on my workbench for about 50 years, and I've built so many of your projects that I've lost count. I like the editorial mix the way it is now — some new stuff, some like the etching tank, and some on computers. Don't forget us old "tube-type" guys who know how tubes work, but aren't really sure about solid-state circuits. I use a TI-99/4A computer, and I'd like to see some programs written in pure BASIC so I could convert them to Tl BASIC {although I'm one of the few who use the orphan). Thanks for a great magazine, and keep it coming. DAVID C. SWARTZ Aurora, CO pf^y&* RS i r " f R4 A3 R2 Hi -RIO- I 1 QD2 r I t , T J (Ml jl rn mil o h CJjfc (WHITE I (TO COIL OF RY1) RED! |(BIACKI 12-14VDC " CORRECTION Due to a printing error, the parts- placement diagram in our "Solid State Wiper Control" story (Radio Elec- tronics, April 1990) was shown im- properly registered. We have correctly reprinted that figure here. CONSUMER ASSISTANCE Radio-Electronics readers might be interested in the Consumer Complaint Assistance/Inquiries Pro- gram of the Electronic Industries As- sociation's Consumer Electronic Group (ElA/CEG). The EIA/CEG rep- resents major manufacturers of tele- visions, VCR's, audio and video systems, telephones, personal com- puters, and home-office products. The program was set up to help indi- vidual consumers who are having difficulties resolving complaints with manufacturers. Our office acts as a catalyst, mediator, or arbitrator in disputes between the consumer and the (member or non-member) manufacturer. There is a standard procedure: First, the consumer should try to resolve the complaint at the retail level. If that fails, the manufacturer whose address is on the warranty card should be contacted. If the consumer feels that the manufac- turer has not resolved Ihe problem satisfactorily, the consumer should contact this office, by mail or by phone (collect calls are accepted only on safety-related problems). The consumer must be prepared to supply his name, address and phone number; the product's brand name, model number, and serial number; date of purchase; dealer's name and address; service history, including itemized invoices and work orders. The consumer will be asked for a brief, concise state- ment of the problem and of the res- olution being sought. All complainants will receive indi- vidual replies. Our office forwards the complaint to corporate person- nel who are in a position to handle it, and each case is followed to its conclusion. If this office is not in- volved in the dispute, we will arbi- trate. Our decision is binding on the manufacturer involved, but not on the consumer. The EIA/CEG also publishes con- sumer-education materials in the form of pamphlets. Send a letter to SASE EIA/CEG, P.O. Box 19100, Washington, DC 20036 to receive the Consumer Publications List, which provides titles and postage costs for these pamphlets. SALLY BROWNE, EXECUTIVE DIRECTOR STEPHANIE L. BROWN, STAFF DIRECTOR EIA/CEG Consumer Complaint Assistance/ Inquiries Program 2001 Eye Street, N.W. Washington, DC 20006 R-E Put Professional Knowledge and a COLLEGE DEGREE in your Technical Career through HOME STUDY -™ Add prestige and earning power to your technical career by earning your Associate or Bachelor degree through directed home study. Grantham College of Engineering awards accredited degrees in electronics and computers. An important part of being pre- pared to move up is holding the right college degree, and the abso- lutely necessary part is knowing your field. Grantham can help you both ways — to learn more and to earn your degree in the process. Grantham offers two degree pro- grams — one with major emphasis in electronics, the other with major emphasis in computers. Associate and bachelor degrees are awarded in each program, and both pro- grams are available completely by correspondence. No commuting to class. Study at your own pace, while continuing on your present job. Learn from easy-to-understand lessons, with help from your Grantham instruc- tors when you need it. Write for our free catalog (see address below), or phone us at toll-free 1-800-955-2527 (for catalog requests only) and ask for our "degree catalog." • Accredited by the Accrediting Commission of the National Home Study Council GRANTHAM College of Engineering § 10570 Humbolt Street g Los Alamitos, CA 90720 s 35 Electronics DtfDD[/DD°/S\[D FREE CATALOG OF HARD-TO-FIND TOOLS is packed with more than 2000 quality items. Your single source for precision tools used by electronic technicians, engi- neers, instrument mechanics, schools, labo- ratories and government agencies. Also contains Jensen's line of more than 40 tool kits. Send for your free copy today! JENSEN TOOLS INC., 7815 46th St., Phoenix, AZ 85044. (602) 968-6231. CIRCLE 115 ON FREE INFORMATION CARD GET YOUR RECHARGE CATALOG FREE.., EARN BIG $$ IN YOUR SPARE TIME— All supplies and Do-It- Yourself kits with complete instructions available. Sup- plies cost from $9.95 in qty and you can sell recharged toner cartridges for $40.00 to $55.00 each. Printers include HP LaserJet and Series II, Apple LaserWriter, QMS, etc. Canon PC-25 Copier also. CHENESKO PRODUCTS, 62 N Coleman Rd., Cen- tereach, NY 11720, 516-736-7977, 800-221-3516, Fax: 516-732-4650 CIRCLE 193 ON FREE INFORMATION CARD THE MODEL WTT-20 IS ONLYTHE SIZE OF A DIME, yet transmits both sides of a tele- phone conversation to any FM radio with crystal clarity. Telephone line powered - never needs a battery! Up to Va mile range. Adjusta- ble from 70-130 MHZ. Complete kit $29.95 + $1.50 S I H. Free Shipping on 2 or more! COD add $4. Call or send VISA, MC, MO. DECO INDUSTRIES, Box 607, Bedford Hills, NY 10507. (914) 232-3878. CIRCLE 1 27 ON FREE INFORMATION CARD CABLE TV CONVERTERS AND DE- SCRAMBLERS SB-3 $79.00 TRI-Bl $95.00 MLD-S79.00 M35B $69,00 DRZ-DIC $149.00. Special combos available. We ship COD. Quantity discounts. Call for pricing on other products. Dealers wanted. FREE CATA- LOG, We stand behind our products where others fail. One year warranty. ACE PROD- UCTS. P.O. Box 582, Saco, ME 04072 1 (800) 234-0726. CIRCLE 75 ON FREE INFORMATION CARD APPLIANCE REPAIR HANDBOOKS— 13 volumes by service experts; easy-to- understand diagrams, illustrations. For major appliances (air conditioners, refrigerators, washers, dryers, microwaves, etc.), elec, housewares, personal-care appliances, Basics of solid state, setting up shop, test instruments. $2.65 to $7.90 each. Free brochure. APPLIANCE SERVICE, P.O. Box 789, Lombard, IL 60148. (312) 932-9550. CIRCLE 81 ON FREE INFORMATION CARD SIMPLY SNAP THE WAT-50 MINIATURE FM TRANSMITTER on top of a 9v battery and hear every sound in an entire house up to 1 mile away! Adjustable from 70-130 MHZ. Use with any FM radio. Complete kit $29.95 + $1,50 S + H. Free shipping on 2 or more! COD add $4. Call or send VISA, MC, MO. DECO INDUSTRIES, Box 607, Bedford Hills, NY 10507. (914) 232-3678. CIRCLE 127 ON FREE INFORMATION CARD ELEVEN-PIECE RACHET TOOL KIT Includes reversible ratchet handle, extension bar, six bits, two precision screwdrivers, and a cutter. Comes in fitted case. Get one for your shop, another for your car, another for your tool kit. To order send $11.75 USA shipping only. ELECTRONIC TECHNOLOGY TODAY INC., PO Box 240, Massapequa Park, NY 11762-0240. CALL NOW AND RESERVE YOUR SPACE • 6 x rate $940.00 per each insertion. • Fast reader service cycle. • Short lead time for the placement of ads. • We typeset and layout the ad at no additional charge. Call 516-293-3000 to reserve space. Ask for Arline Ftshman. Limited number of pages available. Mail materials to: mini-ADS. RADIO-ELECTRONICS, 500- B Bi-County Blvd., Farmingdale, NY 11735. WARNING Please note that unauthorized (i) reception of cable service, {ii) sat- ellite decoding, or (iii) video de- coding or copying is illegal under Federal and State law. Federal law renders illegal both the intercep- tion and reception of any com- munication service offered over a cable or satellite system, or the de- coding or copying of videos un- less specifically authorized by law. Federal law imposes both civil and criminal penalties for viola- tions of the applicable statutes. In addition, most if not all of the states have enacted "theft of cable services" statutes imposing penalties for violation thereof. Thus, the use of the unit described in this article should be restricted to educational, scientific, and/or informational purposes and prior to the use thereof authorization should be obtained from your ca- ble service company, satellite transmission service or video pro- ducer. This is not intended to con- stitute legal advice as to the propriety of their use thereof based upon their individual cir- cumstances and jurisdictions. RUDOLF F. GRAF and WILLIAM SHEETS Wt'Vt: ALL l.M -i it N ! LKLf > VIL'H 1 SIGNALS with missing, weak, or nbis) sync pulses that can make it diflieull or impossible 10 use Lhe signal, "Those disturbances may cause rolling, tear- ing, or other instability in the dis- played video image. The example we're most familiar with is a scrambled TV signal, or a Macrovi- sion-encoded video tape. The unit will restore usable sync to virtually any video signal. You can use it to watch one scrambled show while tap- ing another, to clean up Maerovisinn when watching a video tape, or to simply restore clean sync to a noisy video signal. Another difficulty is that the video itself may be incorrectly phased (negative, for example). While that is more of an interface problem than a transmission problem, it usually re- sults in a picture that has its tones reversed or colors shifted in hue due to phasing differences between the cor- rect burst (reference) signal and the burst signal actually received. Very often, lhe distortions are de- liberately introduced into the video signal to prevent unauthorized recep- tion, or to introduce other obstacles to UNIVERSAL DESCRAMBLER Restore missing video sync signals with our universal decoder. their misuse. One example is "copy guard." a technique used to dis- courage unauthorized copying of vid- eo I a pes. and another case is scrambling, used on cable systems to prevent unauthorized viewing. In order to deal with those prob- lems, a dedicated ■'decoder" box or other such device is used, lhe device nerally useful for only one type ding or scrambling scheme. The technique of syne suppression and/or video inversion is used on both cable and satellite video transmis- sions. How that works is simple; the sync pulses are altered in either level or total amplitude, or omitted entirely from the video (see Fig. 1). Tie video may also be inverted, although that is not always done. Sometimes the sync pulses may be suppressed to random levels, at different times. That is done .-to "confuse"' unsophisticated de- coders, and make video piracy more diflicuh. With all of those schemes, a "key or pilot signal must be sent along with the scrambled signal in order to prop erly reconstruct the missing or dis- torted sync signal. Tie key or pilot signal may take several forms. An au- dio subearrier, usually 15.7. 31.5 or 5 37 94 kHz (or some other frequency that has a fixed ratio to the horizontal-sync frequency of 15.734 kHz) is added to the video signal, and is used by the decoder as a reference to reconstruct the sync signal. Sometimes a digital "addressing" signal is used to acti- vate and deactivate the decoder. For our purposes, though, the addressing signals can be ignored since they are not involved in the scrambling and descrambling process. Another method makes use of a series of horizontal pulses imme- diately following the vertical-sync pulses to phase Sock a horizontal fre- quency oscillator in the decoder. That, in turn, is used to regenerate the missing or suppressed horizontal sync. That system is known as a "pi- lotless" method, and that's because no pilot subcarrier is sent along with the audio. All of those methods have one thing in common: They all alter the sync information. But in order to de- code the signal, there must be a key of some kind present in the signal that can be used to reconstruct the sync. Sometimes, as a scrambling tech- SYNC PULSE COLOR BURST r\ { s~\y FIG. 1— THE SYNC PULSES are altered in

SIGNAL SWITCHING NETWORK PROCESSOR/ CONTROLLER TEST FIXTURE T CONTROL AND I TEST SIGNALS OPERATOR TERMINAL UNIT UNDER TEST (UUT) FIG. 5— BLOCK DIAGRAM OF A TEST SETUP where a DSO is used in conjunction with ATE. The computer controls the DSO via GPIB, as are all the other test equipment in the system. Waveform parameters can be sent to the computer via GPIB for processing. TABLE 1— DIGITAL STORAGE OSCILLOSCOPE (DSO) MANUFACTURERS Analogic Corp. 8 Centennial Dr. Peabody, MA 01961 (508) 977-3000 (800) 343-8333 B&K-Rrecision Maxtec Intl. Corp. 6470 W. Cortland St. Chicago, IL 60635 (312) 889-1448 Hameg, Inc. 88-90 Harbor Rd. Port Washington, NY 11050 (516) 883-3837 (800) 247-1241 Heath Co. Hilltop Rd. St. Joseph, Ml 49085 (616) 982-3200 Hewlett-Packard Co. 1820 Embarcadero Palo Atto, CA 94303 (415) 857-8500 Hitachi Dens hi America, Ltd. 175 Cross ways Park W. Woodbury, NY 11797 (516)921-7200 plays minimum and maximum excursions of a waveform over time, thereby showing the maximum and minimum points of jitter. • Hardcopy output: Some DSO's John Fluke Mfg. Co., Inc. 6920 Seaway Blvd. Everett, WA 98203 (206) 347-6100 (800) 443-5853 Kikusui Intl. Corp. 19601 Mariner Ave. Torrance, CA 90503 (213) 371-4662 (800) 545-8784 Leader Instruments Corp. 380 Oser Ave. Hauppauge, NY 11788 (516) 231-6900 (800) 645-5104 Nicolet Oscilloscope Div. 5225 Verona Road Madison, Wl 53711 (608) 273-5008 (800) 356-3090 Tektronix, Inc. P.O. Box 500 Beaverton, OR 97077 (503) 627-9000 (800) TEK-WIDE can be connected to a graphic printer or plotter for a hard copy of a CRT s image without needing an os- ■< cilloscope camera. eg • Averaging: This lets you display ° 47 o z o DC 5 UJ _l LJJ o Q < DC the average of a repetitive signal, smoothing out jitter and noise for a clearer display. • Pre- and post-triggering: A DSO samples and stores signal data in nu- merous ways. It can sample and store data in a constant stream, then display whatever is in memory whenever trig- gering occurs. It can sample signal data either long before or long after triggering. A technician can observe what occurs on a signal either pre- or post-trigger, as shown in Fig. 2. What's available A variety of DSO's are available; see Table 1 for a list of some of the major manufacturers. Figure 6 shows a Hewlett-Packard (HP) 54501A DSO, a low-cost version of its top model. The 54501 A has four chan- nels, a repetitive waveform band- width of 100 MHz, a single-shot bandwidth of 1 MHz, and a 10-mega- sample/s digitizing rate. It also fea- tures time-base and channel controls similar to those of analog os- cilloscopes, but controlled via an on- screen menu and universal controls. Operating an HP 54501 A is dif- ferent from and much easier than op- erating an analog oscilloscope. When a user presses a menu key, a list of available functions appears on the right side of the CRT, each one in-line with a function key just to the right. A user selects the desired function, and enters the desired value via either the keypad or the universal knob on the front panel. The following features are also controlled via on-screen menus: • Display Menu provides variable persistence for display of worst-case jitter, noise averaging, and envelope display modes, as well as the ability to "connect the dots" whenever individ- ual data points are visible on the CRT. • Delta V/Delta T controls the posi- tioning of cursors to read the dif- ferences in voltage and time between two points on a waveform. • Waveform Math lets a user mathe- matically manipulate two signals. The math includes A + B, A-B, A x B , and A versus B . • Waveform Save lets a user store waveforms for later use in four non- volatile waveform memories, and two volatile pixel memories. • Measurement Definition lets a user set measurement limits, and lets the DSO itself determine if a waveform passes the test. A user can even leave ■— ^^^^^^^^^"^ , - - '1 ^^^^^^^^^^^^^^^^^^^^^— ^^^— ____ 'eass KS ffii.„. ,Tffl □ □ LJ □ a Eli SQQQG] E S S m © t= EEEE EJ [Z [T] rr \~ eltltlz 0GDE . □ E | ■ ^___^____ FIG. 6— THE HEWLETT-PACKARD 54501 A DSO is a low-budget version of the manufac- turer's top-of-t he-line models. It has four channels, a repetitive waveform bandwidth of 100 MHz bandwidth, and a single-shot bandwidth of 1 MHz. It features a 10-megasample/s digitizing rate, and time-base and channel controls similar to those of analog os- cilloscopes, but controlled through an on-screen menu and universal controls. the DSO unattended. If the waveform exceeds a limit, the results can be stored, printed, or sent to a computer. This mode allows automatic measure- ment of 16 different pulse parameters, and lets a user define measurement thresholds, like the standard rise- time measurement from 10% to 90%. The Hewlett-Packard 54501 A has a number of other useful features. Timebase Windowing lets a user zoom in on a specific waveform area. The harixopy key prints a hardcopy out- put of the DSO CRT The save and recall keys let a user store and recall four instrument setups in nonvolatile memory. The autoscale key auto- matically scales time, voltage, and trigger level for a stable display. continued on page 69 FIG. 7— THE TEKTRONIX 2432A DSO has a 300-MHz bandwidth and a 250-megasample/s digitizing rate. The 2432A includes signal averaging that reduces noise on repetitive signals. A smoothing feature uses a digital low-pass filter to improve the SNR for single- shot waveforms. There's also an AutoStep feature that lets a user build and run test procedures automatically, or by computer via GPIB. 48 MORSE/RTTY LAST MONT? WE WENT OVER MOITOFTHE internal circuitry of the,PMX-2()(), in- cluding the front end, input- tiller. AGC. detectors, and the tuning in- dic'dlor. Now we will finish up our discussion on the rest of the eycuitry. whuJh includes the AFSK section and ( the power supply. We wjll then show 'yuu how*to build and tcsl # the unit. Finally, we'll discus's *the necessary software, and show- you how to£et the detector up and running with your computer. • The AFSK (Audio-Frequency Shift K eying) and interface section, shown in Fig, 4. contains a DB25 connector that can be ptugged into your IBM PC/compatible serial ryirt for decod- ing CW with your computer. (While any computer with a serial port can theoretically be used, the software provided on the R-E BBS will run only on IBM PC's and compatibles.) There is also an input from the com- puter that can drive a relay to provide an output for*trans milling CW. To enable a radio amaieurio use the system to communicate in RTTY hi ode. an fiSK generator (IC35-IC40) is on board, that uses a digital sine-wave generator to pro-' illti'i- tT : kMi* hlt,h-f lll'l I Ifv 31 l/l 1/1 j ii Dl ill I a at J4. A CMOS counter (IC4l|is used iH '4 'Walking- ring configuration to produce a'digitized sine-wave approx- imation.. The output is very clean, since the (irsl harmonic is many times the output frequency and very low in amplitude. After filtering, we have a signal that is virtually switching-tran- sient free. The low-level audio signal is de- signed to be sent to the microphone input of an SSB transmitter, A relay output is provided to key the mike from the computer. A separate relay output is included to key the CW key input on an amateur transmitter for CW operation. Both relay outputs are fully isolated from internal circuitry. The schematic for the power supply Let your computer decypher Morse Code and radioteletype signals even if you , . » . don i know a det from a dan a LARRY -ASH WORTH, KA7AFR "•■••• %:*^3££™8* . jm ■— * — ■ — > *%_^*^j™". MMi UrK FROM FIG.3, C K3I PIN1 FIG. 4— THE AFSK AND INTERFACE SECTION contains a DB25 connector that can be plugged into your IBM PC/compatible series port for decoding CW with your computer. _L C7J J.C9T lent J-C13T Xcisj Xci7| _Lczo" -L C24I '• .Lcs " Xci3 'U.C12 ' 1 J_ci4 'J-Cia ' _Lcis; ' 1 J_C23! ' 1 _Lra T-U T' 1 l T- 1 l T- 1 i T- 1 1 T 1 * T- 1 l T 1 .C26 ■ .1 C25C27_L .1 T FIG. 5— SCHEMATIC FOR THE POWER SUPPLY. Power consumption is about 5 watts. g z o a: H O LU _1 LU 6 < 50 is shown in Fig. 5. Power consump- tion is about 5 watts, and all of it goes through the voltage regulators (IC1-IC3). Therefore, one of the 5- volt regulators (IC1) must be heat- sinked or else it will overheat during operation . The other 7805 (IC2) is set up to output about 10 volts by attaching the ground terminal to a 4.3-volt Zener diode, D7. A 1912 (IC3) provides — 12 volts. Since current demands are low, those two regulators do not re- quire heatsinking. Construction Various parts and kits of parts are available from the source mentioned in the parts list. Foil patterns for the two PC boards (the main board and the display board) are provided in PC Service. However, because of their complexity, they are not recom- mended for beginners. Parts- place- ment diagrams for the two boards are shown in Fig. 6; the two boards are connected together by two 18-pin right-angle headers (HDR1 and HDR2— HDR2 is not shown sche- matically, as it is used in various places throughout the circuitry). You should mount the 5 -volt reg- ulator to the case (a metal case can dissipate a lot of heat) , and mount the circuit board in the case in such a way as to keep lead lengths under four inches. The other two regulators (1C2 and IC3) don't dissipate enough heat to require off-board mounting. After you've assembled the boards and checked them carefully for poor soldering, etc., you must install them in an appropriate case. The one used for the prototype measures 9.8- x 1.75- X 10.25-inches, and an identi- i 1 i I § I 4fo 4ft" § I i I (H7 w n <{■ * *B • • ♦ ■- 1 ,* 0^3 , * rr « 1 U ■ — — _Jf » yo + o + OAI & - i , • . i i ii — ii — ■ rrm + 4- + 10 tf~ CJ£ £4d t33 1 I 1 n »J-' »: : * Jr- M 1 I ' ft i. i .inr ■ LJ . \ | J 1_ j ?|s T * • *4+ 1 . i- :■■■ ;■ r- 1 ■ ■ ? I- RB7 - - '-ii 1 - - s 01 rf D Q D D h"' | J LJ #■•««■**! praa *i JS| o I a" I - rnaV -LZD-LZZMZZ1 FIG. 6— PARTS-PLACEMENT DIAGRAMS for the main board and the display board. The main board is very complex, so you probably won't want to make it yourself. 2 066 1 AVW en o z O en I- o o Q < re PARTS LIST All resistors are ! 4- watt film except C57. C58— 0.0068 fjiF, mylar IC41— 4018 presettable divide-by-N where otherwise indicated. C61, C62, C64, C65— 0.047 jjlF, my- counter R1, R3. R6, R12, R43, R45, R49. lar D1-D6— 1N4003 rectifier diode R55, R81, R82, R89— 39,000 C66-C69, C86-C89— 0.01 ^F, mylar D7— 4. 3- volt Zener diode ohms C70. C71— 0.15 nR mylar D8 — 4.7-vott Zener diode R2, R9, R52, R53— 27,000 ohms C72, C73— 0.068 uE mylar Q1, Q2— TSP42C PNP transistor R4, R7, R8, R19, R22, R24 T C74, C75--0.03 julF, mylar LED1, LED16 — green light emitting R59-R62, R85— 47,000 ohms C83, C84— 0.001 nR mylar diode R5, R13, R86, R87— 68,000 ohms Semiconductors LED5. LED12— red light emitting di- R10, R11, R14, R28— 15,000 ohms IC1 , IC2— LM7805 5-volt regulator ode R15-R18, R69, R70— 33,000 ohms IC3— LM7912 -12-vott regulator LED2-LED4. LED6-LED11, R21, R51, R76— 220,000 ohms IC4— NE570 compander LED13-LED16 R23, R90— 20,000 ohms, %-inch IC5. IC26, IC36— LM311 voltage Other components single-turn potentiometer comparator T1— FP24-500 R25, R26. R34, R74. R77— 330 IC6, IC25— LM324 low-power quad HDR1, HDR2— 18-pin right angle ohms op-amp header R27, R30, R31. R78, R79— 2200 IC7, IC8, IC27, IC28-4066 quad bi- HDR3 — 2-pin jumper header ohms lateral switch S1, S4— DPDT PC-mount switch R20— 270 ohms IC9— 74LS14 hex low-power Schot- S2— DPDT PC-mount switch with R29, R32, R33, R35-R39, R41, R50, tky Sch mitt- trigger inverter center off R56-R58, R63-R65, R71-R73, IC10. IC11, IC14, IC15— 74LS161 S3 — 12-position rotary PC-mount R75— 1000 ohms synchronous binary counter switch R40 — 470 ohms IC12, !C16— 74LS30 8-input NAND J1-J4 — RCA-type jack, chassis R42, R44, R48— 48,000 ohms gate mount R46, R47, R92— 10,000 ohms IC13, IC17— 74LS244 octal tri-state J5 — DB25 connector R54, R88— 30,000 ohms buffer RY1, RY2— 16-pin PC-mount relay R66, R91, R93, R94— 20,000 ohms IC18— 74LS10 triple 3-input NAND PL1 — grounded AC line cord R67, R68, R95, R96— 20,000 ohms, gate Miscellaneous: case, hardware, 10-turn potentiometer IC19— 2.4576-MHz crystal oscillator wire, soider. etc. R80— 4700 ohms IC20— 74LS90 decade counter R83. R84— 22,000 ohms IC21, IC24— not used R100-R105— 2000 ohms IC22— 2732 EPROM Note: The following items for the Capacitors IC23— 74154 4-to-16 line decoder PMX-200 Morse Detector are C1, C2— 1000 u.R electrolytic IC29— 7416 hex inverter buffer with available from Power Mountain C3, C29, C30, C40, C46. C63— 10 high-voltage open-collector out- Systems, P.O. Box 161, Cora, Wy- jjlF, electrolytic puts oming 82925. Double-sided silk- C4-C28, C41, C47, C77, C78, IC30— 74LS147 10-line decimal to 4- screened PC boards, $79.95; C80-C82, C85— 0.1 m-R mylar line BCD encoder discrete parts kit (no boards or C31. C34-C36, C49, C51— 0.0047 IC31, IC32— LM358N low-power case), $159.95; pre-programmed uE, mylar dual op-amp EPROM, $15.95; detector soft- C32, C33— 0.0027 ^R mylar IC33— 1488 quad MDTL line driver ware package for IBM/compati- C37, C38, C43, C44, C59— 1 |xF, tan- IC34 — 1489 quad MDTL line receiver ble, $19.95; black brushed- talum IC35— 7414 hex Schmitt-trigger in- aluminum case ready for you to C39, C45--2 (xF, tantalum verter drill, $79.95; complete kit (con- C42, C60— 30 pR ceramic IC37, IC42— 74LS00 quad 2-input tains everything), $269.95; an C48, C76, C79— 0.22 hR mylar NAND gate assembled, aligned, and tested C50, C52— 0.002 \lF, mylar IC38, IC39— LM555 timer unit, $389.95. All prices include C53, C55— 0.003 \>.F, mylar IC40— 74LS05 open collector hex in- UPS Ground, or mailing charges C54, C56— 0.0005 \lF, mytar verter in the USA. cal one is available from the source mentioned in the Parts List. A pho- tograph of the installed boards is shown in Fig. 7. Tune up The master oscillator is crystal- controlled and preset. Since we're dealing with a digital system, set up isn't very difficult. However, a few tips will make tune up easier. If you want the best possible perfor- mance you should use an audio-signal generator and a frequency counter to verify that the filter circuits are per- forming as designed. Remember that when you change S2 (170-, 425-, and 850-Hz) you are changing the input bandpass filter width. You must make your measurements at IC6 pin 1, which is prior to the NE570 AGC circuit; otherwise the AGC will pre- vent you from seeing the filter's actual response. Potentiometer R23 sets the input level, but the setting is not very crit- ical. If you don't have a scope to check for audio-clipping at the output of the front filter section, just set it to a level where the detector seems to work well. The 20K, ten-turn trim potentiom- eter, R68, on IC32 sets the DC thresh- old voltage for squaring up the AC input waveform (vadj, IC32 pin 1). To set it you must use a frequency coun- ter and a clean sine- wave generator. Set your generator to 1500 Hz and feed about a 1-volt signal into the PMX-200, using the counter as a fre- quency reference. Set the potentiome- ter so that the center LED on the upper row is lit. Normally you will see two LED's lit and, as you approach the correct setting, the two LED's will merge until only one is lit. So. as long as your generator is clean, the adjust- continued on page 88 52 Why Are There so Many Transistors? IT'S EASY TO BECOME overwhelmed by the number of transistor de- vices available . Understanding where they all come from can make it easier to select the one best suited to your needs. Suppose the instaictions in a given project article call for "any general-purpose transistor." So you leaf through the back of Radio-Elec- tronics, or pull out the pile of cata- logs you've accumulated as the result of filling out reader-service cards month after month, and look to see who's got a good deal on general- purpose devices. Let's see, where are they? "RF transistors'?" "Power transistors?" "Small-signal transistors?" "Switch- ing transistors?" Since you're build- ing a little audio amplifier, you proba- bly want "small -signal" transistors; after all it'll be handling only a small signal. Fine. OK, let's see what there is in that category: Hmmra . . . 2N2222, 2N3904, 2N3906, and about 15 other types. Maybe your pro- cured-with-difliculty data book will give you a better idea. Well, that's no help either. With something on the order of 30.000 dif- ferent types of bipolar transistors alone, there are at least 15 pages of small-signal devices, and only one or two also appear in your Jameco or Digi-Key catalog. How do you decide which is the right one? Why are there so many? Transistor classes Even the most confused parts hunt- er will have to agree that dividing Selecting the right transistor for a particular application does not have to be frustrating. transistors into classes according to the purpose makes sense. To use a bulky heavy-duty power transistor that costs several dollars to do a job that could that could just as easily be handled by a smaller, less-expensive version is foolish. The question is. which specifications make it "just right?" Bach class of transistor is designed specifically for a particular type of operation, and those characteristics are what makes it suitable for a par- ticular job. In some cases, the main criterion is the maximum frequency that a device can function at for rated performance, called unity-gain band- width, or / r ; it is the frequency at which the voltage gain drops to one. RF transistors, for instance, can have / T 's of hundreds — or even thou- sands — of megahertz, while good old "general purpose" types get by with a much lower value. Gain is another factor used to di- vide devices into classes. Whether or not a specific transistor has a specific gain can be a matter of either design or practical limitations. Power tran- sistors, for example, are built pri- marily for high-power loads. While their gain may not be as impressive as that of other varieties, they can handle JOSEF BERNARD high currents or voltages without overheating, melting, or exploding. Another important characteristic is breakdown voltage, or the maximum voltage that a particular device can handle. Depending on whether it's in the millivolt, volt, or kilovolt range, the required size, packaging, operat- ing characteristics, and price of a transistor can be affected. There are small-signal transistors designed for only a few volts and milliamperes of current, and power transistors de- signed for massive amperages. Another class of transistor al- together is the switching transistor, or saturated switching device. While switching transistors can be, and often are, used for small-signal ampli- fication (and vice-versa), they're really designed just to turn a low-level current on or off. They do that by- being driven to saturation with a base- emitter voltage beyond the level for useful amplifications. Depending on component type, application, and packaging, transistors can be divided into over three dozen classifications. Where transistors come from No device in a data book slips in by I O 53 SELECT 5 BOOKS for only $495 (values to $133.70) and get a FREE Gift! to CO o 54 For 25 years, your most complete source for electronics books. An Absolutely No-Risk Guarantee. 1S99P 19 IIP 514.95 I867P S17.9S FREE when you join! 15 Easy Electronic Projects s,vu From Delton T. Horn l?«Jl% Projects you can build— some unique, some old favorites — from the author's vast treasury of electronics know-how. -7 Value, ^ Membership Benefits • Big Savings. In addition to this introductory offer, you keep saving substantially with members' prices of up to 50% off the publishers' prices. « Bonus Books. 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Lu-.h if Dfdtt my fifil Huh Selection ai 50%- »fl ihe- Publisher's ptii'U i pin-, shipping li;tn.lkni:i I then need in purcliiise ufllly 2 or more hoofc* wiihin lire ncu 12 munihv Name Address City Stale Zip Signature . Valid for now members only, For&ign applicants will receive special ordering instructions Canada must romii in U-S- currency This order subject lo acceptance by ihe Electronics Book Club RES&0 5 57 o o EC o Q < accident; they're all there for a reason. Many new designs come about as the result of technological advance, or improved manufacturing. For exam- ple, when power MOSFET's became practical to produce in large commer- cial quantities, a whole new product line was launched. That obviously didn't mean that all previous power transistors already in use were now obsolete. Rather, those older products continued to be manufactured be- cause there were many circuits where they performed well in, possibly at lower cost. Take the 2N2222 general-purpose NPN bipolar transistor; it drives re- lays, small audio amplifiers, digital inverters, etc. However, not all 2N2222's are alike, and the four dies in Fig. 1 prove it; a die is an actual chip, minus packaging and leads. When you buy a Digi-Key 2N2222, even though it's electrically identical to all others, its geometry might be any of those shown. Unless you find out which die is used, you'll probably never know the difference. For exam- ple, Fig. 1-c is the type of die typically associated with 2N2222A-ciass tran- sistors. Different die geometries have slightly different operating param- eters. The unity-gain bandwidths for the dies in Figs, \~a-\-d are; f r = 340, 420, 300, and 400 MHz, while their typical maximum collector-base breakdown voltages are: V CBO = 140, 130, 110, and 95 volts, respec- tively. Obviously, parameters like rise time and gain (P) also vary between models. Quite a few new products arise from the requirements of design engi- neers. The calculations for a specific circuit may call for product specifica- tions that can't be met, at least within required tolerances, by any existing device. If a large enough quantity of a new device is required, or if the man- ufacturer sees a general-market po- tential, he'll set his engineers to work, and the product will eventually be manufactured and wind up in the next data book. A small manufacturing company in search of a transistor may take the time to investigate preexisting devices in the hope of finding one for a specif- ic job. Sometimes redesigning a cir- cuit around an existing device to take advantage of its characteristics may avoid the expense of having a special part manufactured. mmM FIG. 1— THIS IS WHAT TRANSISTOR DIES look like under a microscope. The names of the different geometries are: (a) BBC, (b) JGA, {c) DCA, and (d) TNL. However, for a company that antici- pates the purchase of millions of a specific device to request that a part be produced to exact specifications may well be more economical. Taking that route is often cheaper than using a device that may already exist, but of questionable availability. It may be identical in all but one minor charac- teristic to another that already exists, but no semiconductor manufacturer will turn down an order worth mil- lions. He'll produce it, and another part number will find its way into a data book. Adding to the proliferation of de- vice types is the fact that solid-state manufacturing isn't an exact process. It's certainly much less of an arcane art and more of a science than it was many years ago. There are still numer- ous variables, however, that can't be precisely controlled. During a man- ufacturing run, there are always some devices that either fall short of or ex- ceed specified tolerances; examples are gain, breakdown voltage, and power dissipation. Those devices exceeding specifica- tions can be marketed as a premium product for those who need superior characteristics. For example, the mean desired cutoff frequency might be 200 MHz, but a number of devices might be made with much higher val- ues, say 300 MHz. While those could be used by the original buyer, they're really wasted. There are probably other uses for such a high-perfor- mance part, so it's culled out and sold separately — at a premium price. Some devices meeting very high tolerances may be classed as "mil- spec" or "high-rel(iability)" parts. They have to meet stringent test crite- ria and, if they pass, they get their own part numbers. Similarly, there may be a significant number of parts with a cutoff frequency of only 125 MHz. The buyer certainly can't use them, but they're not worthless, and they aren't discarded. Someone is out there with less critical design needs, who can use such out-of-spec parts. Actually, many "general purpose" parts originate that way. 58 FIG. 1— FROM THE SPECS IN SECS menu "Small Signal Devices," option G is "JFET Amplifiers (< 1 MHz)." FIG. 2— IN THE "PARAMETRIC SEARCH mode," the user can select one or more parameters of the desired transistor. The floppy catalog SPECS IN SECS handles all discrete Motorola products, over 7,500 parts; you can then use a databook for specifica- tions. Also, PRECISION DECI- SIONS from Precision Monolithic, Inc. (PMI), accesses a complete line of analog signal-conditioning and data-conversion IC's; both use pa- rametric search methods. To illustrate how such software op- erates, simple parametric search will be shown using both packages. In SPECS IN SECS, the user can select different languages, product catego- ries, and screen colors. On selecting a specific entry in each column, and performing a search, the entries are stored to save time on the next run. Here, "English" (option B), "Small Signal Devices" (option P), and "Monochrome" (option U) were used. On hitting Enter, a menu appears (see Fig. 1); 'JFET Amplifiers (< 1 MHz)" was selected. Another menu (not shown) dis- plays the types of JFET amplifiers. Selecting the "Parametric Search" mode from that menu gives the one shown in Fig. 2. SPECS IN SECS tells whether the values in the menus and prompts are minimum or max- imum, and the limits on the values that can be entered. Figure 3 shows a list of appropriate Motorola devices, with specifications on each. CATALOGS ON FLOPPIES 7b make the job of selecting transistors easier, several companies now let you enlist the aid of a computer. Here are two examples. FIG. 3— A LIST OF MOTOROLA devices satisfying the selected parameters, with some specifications on each. FIG. 4— PRECISION DECISIONS MAIN menu; the user can select from the dif- ferent part types shown. A similar set of examples for PRECISION DECISIONS is shown in Figs. 4—6. Figure 4 shows the main menu; the user can select from the different part types shown. Figure 5 shows the data-entry screen for a pa- rametric search of matched tran- sistors; the parameter values shown are the minimum and maximum per- missible. You can also get data on a specific part, if you know the one you're interested in. Finally, Fig. 6 shows the results of the parametric search from Fig. 5 for matched tran- sistors from the PMI database meet- ing the specified parameters. The SPECS IN SECS Motorola Data Disk floppy-disk component se- lection guide from CyberSoft, Inc., 440 E. Harmony Ave., Mesa, AZ 85204, (602) 962-0075, has signifi- cantly modernized device selection. FIG. 5— DATA-ENTRY SCREEN for the Precision Decisions parametric search for matched transistors. FIG. 6— PARAMETRIC SEARCH results for matched transistors from the PMI database. It has 7,000 devices and 20,000 cross-references in 58 categories, for Motorola's entire discrete product line, including optoelectronics, RF, power, small-signal, and specialty items, and has both part number and parametric search modes. Once sat- isfactory devices are displayed, you can use a catalog for more data. Cop- ies are $2.00 from the Motorola Sem- iconductor Literature Distribution Center, PO Box 20912, Phoenix, AZ 85036, (602) 994-6561 or (800) 521-6274 (part number DK101/D REV-1). Precision Monolithics, Inc. (PMI), also has a floppy-disk catalog called PRECISION DECISIONS, with their complete line of analog signal-con- ditioning and data-conversion IC's, using both part number and param- etric search modes. Packaging, pric- ing, and competitive cross-referenc- ing are included. Available categories are op-amps, D/A and AD convert- ers, matched transistors, voltage ref- erences and comparators, sample- and-holds. analog switches, multi- plexers, military/aerospace prod- ucts, the part numbering scheme, new products, sales offices, surface- mount and extreme temperature range devices, and a user directory. For a free copy, call the PMI Commu- , nications Dept., Santa Ciara, CA 95052, (408) 562-7470. R-E 5 CD CO © 59 10 o z o CE 1- o 11) g < ir The number of devices that won't meet specifications in a given run can be predicted statistically, and there are frequently enough to be included in a catalog as a new product with a sepa- rate part number. That's not to say that quality control or manufacturing are at fault — it's just thai some parts meet specifications and some don't. What's a company supposed to do, just throw them away? The name of the game is profit, and if somebody can use them, why not wring out the maximum profit possible? The case for cases A given part isn't set apart from all others only by ratings and electrical characteristics. The same part can be packaged several different ways, each with its own part number, or with suffixes to differentiate them. Certain applications may need "ruggedized" parts to withstand extreme tempera- ture, humidity, or shock, or special ceramic or metal packaging instead of plastic. A part originally specified for such extremes may be worth produc- ing in a less rugged version for more ordinary use. Bingo, another part number. Power dissipation is another factor that can add part numbers to data books, and can vary according to packaging. A transistor in a plastic TO-92 case may safely dissipate only a few hundred milliwatts. A TO-220 tab-type case may raise that to a few watts, while a heavy duty metal TO-3 case can push it even higher. The con- tents are identical; the point is that cases affect device characteristics. Sometimes the part numbers may be identical, with only the suffix changed to denote the different case, although new cases sometimes get en- tirely new numbers. Some common cases appear in Fig. 2, Size and shape are also important. Someone designing a high-density PC board may need a part in a case of specific shape or size, so he can fit as many devices as possible in a given space. Such custom packaging isn't cheap and manufacturers may deem it worthwhile to make a part available in a cheaper, more conventional case to increase availability. Where do they get them? As you browse through your Jam- eco, Digi-Key, or other catalog searching for parts, the selection of transistors offered by your favorite FIG. 2— TRANSISTORS CASES come in a wide variety. These are a few of the more common versions. supplier is obviously much smaller than the range of offerings from even the smallest manufacturer. How do those people narrow down the choices? The line stocked by a com- pany like those advertising in Radio- Electronics depends on two main fac- tors: availability and customer need, which works out to the familiar law of supply and demand. Manufacturers — both of transistors and equipment that uses them — fre- quently find themselves with more of a particular part than they need. There's no problem with quality, just inventory, solved by selling the ex- cess. There are firms specializing in disposing of excess inventory, taking it off an overstocked company's hands for a price probably less than that originally paid or asked. Sometimes an over- inventoried manufacturer can sell directly to a vendor through an ad indicating his excess stock placed in the classified ads of a trade publica- tion. The low price you may pay isn't a reflection of item quality, but rather the sacrifice that the overstocked manufacturer had to make to dispose of the excess. Many devices in a vendor's catalog are there simply because they're con- sistent best-sellers. As long as people keep buying 2N2222's, they'll keep appearing in vendor price lists. De- pending on supply, their price may vary, but they'll still be there. Some- times, a device is a frequent "special- request." Vendors receive many phone calls and letters from people trying to locate such-and-such a part. On occasion, such requests arise from specific projects that appear in such magazines as Radio- Electronics. The individual responsible for the project may have used an "orphan" transistor he found at the bottom of a junk box. Some people (and you know who you are!) are unwilling (or unable) to look for a more readily available substitute, and so they re- quest the oddball one. If there are enough such requests, a vendor will sec a profit and add the item to his list. Sometimes, albeit rarely, there's no readily available substitute; that, too, is a reason to stock it. Whatever the reason, if there are enough requests for an item, a source will be located, and it'll find its way into a catalog. How do you choose? Selecting the right part may at first seem difficult from the plethora of transistors available; all you need is common sense. First, determine the category. If you're building a huge audio amplifier, you need a power de- vice. If your project will operate at moderate power, perhaps an audio de- vice of some sort such as a small- signal transistor will work. If it'll be oscillating or switching at high fre- quencies, a switching transistor may be needed, although at audio frequen- Continued on page 68 60 TEST S2 ■#■ FIG. 1— SIMPLE RELAY-AIDED non-latch- ing fire alarm using thermostat tempera- ture sensors. ALTHOUGH IT'S UNFORTUNATE. THE chance of being attacked, robbed, or incinerated in your own home is steadily increasing. Fortunately, the odds against those kinds of Jisasters can be greatly improved by taking a few common-sense precautions, like using good locks on all doors and locking all windows at night. The odds can be improved even further with a good electronic home-security system. Home security is a fairly large and involved subject. To understand it, you first need to understand the basic principles of security- system installa- tion, some criminal psychology, and to examine some actual burglar alarm systems. We'll deal with all of those topics here, and continue the subject in future articles. Let's start with some of the basic principles that are involved in a modern home-security system. Basic precautions The disasters most likely to strike you at home are fire and intruders. Most home fires are caused by things like lit cigarettes, pieces of smolder- ing coal or wood falling onto rugs, overheated electric appliances, or cloth igniting from the heat of gas or electric stoves. The first line of defense against fire is common sense, and the second is a fire-alarm system. The latter can be sophisticated, including smoke and gas detectors, or simple, like a number of /Vormally-Open (N.O.) thermostats, mounted at ceiling height, connected in parallel and ar- ranged so that they trigger an alarm if any of them close. Any fire alarm is better than none at all, provided it's reliable, and a simple thermostat sys- tem like the version shown in Fig. 1 can easily be used with most burglar alarms. HOME-SECURITY COOKBOOK ^^ An introduction to modern home-security systems. k. RAY MARSTON PANIC BUTTONS = FIG. 2— THIS SIMPLE SELF-LATCHING panic burglar alarm with N.O. panic but- tons or pressure pads Is adequate for many domestic applications. Intruder prevention Intruders are a very real menace, and are generally divided into either thugs or burglars. Thugs generally operate by having one or more males attack you either as you open your front door. Sometimes, an attack carM occur late at night after or during a break-in. The first defense against thugs, as with fire, is common sense: have a peep hole and chain on the front door. An excellent second defense is per- manently armed panic buttons near likely attack points, like the front and rear doors, living room, and bed- room, arranged to operate a seif- latching alarm when they're momen- tarily activated, as shown in Fig 2. Panic buttons are ordinary N.O. push- button switches. A simple panic sys- tem like Fig. 2, can easily be used with most burglar alarms. Of course, ON/OFF key switch S4 is an absolute necessity to make the circuit prac- tical, to let it be shut off once it's activated. Burglary prevention Any burglar alarm system can be broken down into the three blocks shown in Fig. 3. The first is the "sen- sor network," which detects an actual or possible intrusion at one or more protected points, and sends a signal to SENSOR NETWORK — * CONTROL CENTER ALARM-CALL GENERATOR FIG. 3— BLOCK DIAGRAM of a burglar alarm system. the "control center," That block checks the sensor signals for validity, and trips the "alarm-call generator" (a bell, buzzer, or siren), when condi- tions are appropriate. Four basic types are available: the radar, ultrasonic, infra-red, and mi- cros witch varieties. The most impor- tant performance characteristic of any burglar alarm system is its reliability, or immunity to false alarms. Many sophisticated systems that give fre- quent false alarms (99% of all alarms are false) will be ignored by both the police and the owner, and are thus useless. Many can be false-triggered by electrical interference from sources like lightning or electric motors. Radar systems generate a micro- wave field over the whole house, and sound an alarm when the field is dis- turbed. Unfortunately, they can some- times be falsely triggered by large vehicles passing by, and may have poor reliability. Ultrasonic alarms usually protect an individual room. They generate an ultrasonic field in the room, and sound ah alarm if phys- ical movement within the room I CD CO O 61 causes a significant Doppler shift. Such systems can be falsely triggered by a draft moving curtains or drapes, or by insects close to the ultrasonic sensors. Infra-red systems normally monitor along an invisible line-of- sight beam, and sound an alarm if the beam is broken by a physical object. Most alarms of that type use single beams, and can easily be falsely trig- gered by insects, as shown in Fig. 4. A few such systems use dual beams, as shown in Fig. 5, activating only when both are broken simultaneously. Those beams are separated by 10-25 cm, to prevent being falsely triggered by insects. CO y z o IT h- O LU Q Q < but consumes 1 mA of quiescent cur- rent via Rl-Ql (in practice, that can be reduced to a negligible level with a more elegant relay driver). It can also be easily modified forN.O. switches, as shown in Fig. 7, In a practical contact-operated alarm system, the sensor switches ac- tually connect to the inputs of a con- trol center, which houses the electronics and battery, plus a number of switches that allow different sys- tem sections to be turned on or off, or to be tested. Ideally, the control center should be housed in a burglar- proof box with a key-operated ON/OFF switch. Figure 8 shows a typical con- trol-center panel with six switches. ♦ d7— INFRA-RED RECEIVER FIG. 4— A SINGLE-BEAM IR ALARM SYSTEM CAN easily be false-triggered by an Insect breaking the beam. INFRA-RED TRANSMITTER LED2 INFRA-RED RECEIVER FIG. 5— A DUAL-BEAM IR ALARM ACTIVATES ONLY when both beams are broken simul- taneously, and can not be false-triggered by small insects. The most popular system type is the electro-mechanical switch variety. These switches can be either micro- switches or reed relays connected to doors or windows, or pressure pads under rugs. They can all be of the A/ormally-Open (N.O.) variety (acti- vate by closing), or the For- mally-Closed (N.C.) type (activate by opening) , or a combination thereof. If N.O. switches are used exclusively, a self-latching burglar alarm can be made by wiring all switches in paral- lel and connecting them to buzzer BZ1 via relay RY1, as shown in Fig. 2. That may involve a lot of wiring, but the circuit consumes zero standby current. If N.C. switches are used ex- clusively, a self-latching burglar alarm can be made by wiring all switches in series and connecting them to BZ1 via a transistor-aided re- lay, as shown in the version in Fig. 6. That circuit uses minimum wiring, 7-0-— < ' *fe 6 OFFC RY1 12V (>)180n P-W BZ1 ON ,12V S3 N.C. S2 N,C. + 12V S1 N.C. D1 -1H4001 R1 ~\W 1ZK ~ 01 2N3704 FIG. 6— SIMPLE BURGLAR ALARM WITH N.C. switches, drawing 1 mA of quiescent current. The main ON/OFF switch is (SI) of the key type, and S2 is a pushbutton that enables the alarm and battery for a functional check. The remaining four switches are toggle types, allow- ing sensors to be enabled or disabled. Figures 9 and I0 show the connec- tions for turning individual sections of the sensor network on and off. Se- FIG. 7— BURGLAR ALARM CIRCUIT using N.C. and N.O. sensor switches. ries-connected N.C. sensor networks can be enabled or disabled by wiring such a series string of N.C. sensors in parallel with SI, as shown in Fig. 9. Here, the sensors are enabled with SI open, and disabled with SI closed. Parallel-connected N.O. sensor net- works can be controlled by wiring such a series of parallel N.O. sensors in series with SI, as shown in Fig. 10. In that case, the sensors are enabled when SI is closed, and disabled when SI is open. Planning a system The most, popular burglar alarm type uses switch sensors. Let's look at the actual techniques of planning such an installation in a house. A building can, for the present, be regarded as a box with an enclosing "perimeter" around a number of interconnected compartments. That perimeter is the shell, containing walls, floors, ceil- ings, doors and windows. To commit a crime, an intruder must penetrate the perimeter, the owner's first line of defense. Once an intruder enters a building, he can niove from one room to the next only along paths determined by internal doors and passages. In doing so, he must pass over or through cer- tain L 'spots," or checkpoints, as shown in Fig. II, the ground-floor plan of a medium-sized mid-terrace house. To move between the kitchen (a likely break-in area in the average home) and the living room requires passing through the kitchen door, ad- jacent point "X," and the living room door. Those "spot" locations repre- sent the owner's second line of de- fense. The house owner can use perimeter 62 FRONT DOOR ON § OFF se ON STAIRS OFF S5 ON ON GARAGE p) AUXILIARY p, OFF OF S4 S3 FIG. 8— TYPICAL CONTROL-CENTER INSTRUMENT PANEL. pressure pad in the hall near the din- ing room door, or one on the stairs. That arrangement makes no attempt to keep a burglar out, but uses "spot" defense to detect him once he's in- side. The approach is highly cost- effective, and gives reasonably good protection. By contrast, Fig. 12 assumes exten- sive perimeter and spot defense. Its owner has decided to try to scare off ON -*s OFF 9 S1 SENSORS | A,H,0. f TO ALARM SYSTEM I FIG. 9— METHOD OF ENABLING/DISAB- ling series N.C. sensor switches by oper- ating S3. OFFq I 5 q ioN \>S1 I SENSORS I h-o. f N.o. y TO ALARM SYSTEM FIG. 10— METHOD OF ENABLING DISA8- ling parallel N.O. sensor switches via 51. defense, spot defense, or a combina- tion thereof. Perimeter sensors in- clude microswitches or reed-relay/ magnet combinations fitted to exter- nal doors and windows, and window foil fitted to the windows on external doors, windows, and skylights. Spot sensors include pressure-pad switch- es fitted under rugs or carpets, micro- switch or reed -re I ay /mag net door switches, and baited traps using an attractive or valuable item (like a clock) placed on top of a concealed microswitch. When planning an installation, you should try to think like a burglar. Nor- mally, a burglar enters from an easy access point obscured from the view of neighbors, like a back door or win- dow. Often, they'll even break in using tools from your own garage, so include the garage in any system layout. Almost invariably, a burglar's first action after gaining entry to your home is to provide for rapid escape by opening a back door, and then to start stealing. FIG. 11— GROUND-FLOOR PLAN OF A MEDIUM-SIZED mid-terrace house with minimal spot and panic defenses. Two examples Figures ll and 12 show alternate ways of installing security systems in the ground floor of a medium-sized mid-terrace house. In both cases, a peep hole is installed in the front door, with panic buttons at three likely at- tack points. The two houses differ considerably, however, in the methods of burglary protection that are used. Figure 1 1 presupposes that a burglar will most likely enter via the French windows of the living room, or the kitchen door or window. If he uses the French windows, he'll be detected by a pressure pad under a mat or carpet, but if he enters via the kitchen, he'll find nothing worth stealing. So, he'll open the kitchen door into the hall, where he'll be detected by another pressure pad. In the unlikely event that a burglar enters the house from the front, he'll eventually be detected by yet another potential burglars by using clearly visible window foil on selected win- dows, both in front and in back. Some foil is really connected into the alarm system, and some is dummy foil. All external and internal doors arc pro- tected by door switches, and two pres- sure pads are on the stairway. Also, baited traps are placed in both the living and dining rooms. That house has excellent protection. Installation notes Pressure pads arc available as small mats; they're excellent spot defense devices, easily hidden under rugs and carpets. Both standard and stair types are available. However, they're fairly sensitive and can be set off easily by large cats and dogs; if you own a pet, make sure it's confined when the pres- sure pads are on. Window foil is adhesive-backed aluminum stripping that bonds to CO <£ O 63 CO o z o DC H O til 6 < cc FIG. 12— GROUND-FLOOR PLAN OF A MEDIUM-SIZED mid-terrace house with a high level of perimeter and spot defenses, plus minimal panic defenses. glass, and couples into an alarm sys- tem using special connector blocks. The strip breaks when a window is shattered. Door and window switches are usually a reed-re lay /magnet com- bination. The magnet goes in the edge of the door or window, opposite the reed-relay installed in the frame, as shown in the version in Fig. 13. When a door or window is closed, the mag- net holds the reed-relay in one posi- tion. When it's open, the magnet moves away, making the reed-relay switch states. Most commercial ver- sions have two sets of output wires in the reed-relay, one giving N.O. opera- tion, and the other N.C. operation. When you plan your installation, don't forget to provide for some means of bypassing the front door, so ^t -t-o- OFF ON ,\, + 12V BZ1 S4 12V KEY SWITCH FIG, 14— THIS CMOS-AIDED ALARM draws only 1 |.iA of standby current. ■ REED- RELAY SWITCH ALARM X MAGNET I+12V you can enter and leave without sounding an alarm. Keep all wiring neat and concealed, and test each sec- tion as it's installed. If possible, fit your system with both internal and external alarms. The external unit should be prominently displayed in front of the house, where it'll act as a deterrent; weather-proof housings are available. Home-security circuits We've already looked at the very simple burglar alarms shown in Figs. 2, 6, and 7. In reality, they need modi- fication to be practical. A major de- fect of the circuits shown in the Figs. 6 and 7 is that they consume 1 in A of quiescent current via Rl-Ql . That can be overcome by increasing Rl to 12 megohms, and using a CMOS inver- ter as a buffer between Rl and Ql , as shown in Fig. 14. That circuit con- sumes 1 u,A of quiescent current. In practical installations, long wires used to interconnect series sen- sor switches tend to pick up spurious pulses and signals, especially during thunderstorms . The purpose of R2-C 1 is to act as a low-pass filter to reject such signals, and minimize suscep- tibility to false alarms. Note that Figs. 2 and 14 each show the left-hand relay contacts being used to provide self- latching action. An alternative is shown in Fig. 15. Here, self-latching is performed by a bistable made from ICl-a and ICl-b, and low-pass filter R5-C2 causes the bistable output to latch low when S6 is first closed. If any sensor switches are then acti- vated, a logic high is fed to pin 2 of the bistable via the low-pass filter R3-C1, which latches high and turns on Ql and RYl, activating buzzer BZ1. In Fig. 15, R2 is in series with the sensor switches, letting the circuit be acti- vated by either the series switches or parallel pressure pads across Rl. That WALL DOOR FRAME RY1 12V NM81 KEY SWITCH Ql FIG. 13— PLANS SHOWING METHOD OF CONNECTING a reed-relay/magnet com- bination fo form a door/window-activated switch. ;> 12011 Q1 2N3904 FIG. 17— PANIC AND FIRE ALARM CIRCUIT that can be added to the circuits of Figs. 16 and 17. makes a very versatile burglar alarm; ideally, the alarm generator (BZl) should be powered by a completely separate supply. Figure 16 shows how Fig. 15 can be modified for auto-turn-off action, so the alarm sounds as soon as an intru- sion is detected, but turns off auto- matically after four minutes. That sensors. In Figs. 15 and 16, Ql and RY1 are permanently connected to the power supply, even when S6 is open and the sensors disabled. That makes adding accessories like fire detectors and panic switches, which must be permanently enabled, easy. Figure 17 shows a practical add-on panic and fire alarm circuit for use OFF -V*V- PRESSURE PADS S3 N.C. S4 N.C. S5 N.C, R2 10K C4 100pF ff R3 R4 10K ' 52 < R1 T O H0 ?12MEG CI .01 <•— t :v via any of a number of parallel panic switches or thermostats. If you com- bine the circuits shown in Figs. 16 and 17, you'll still need an independent IC1 and IC2, since they need separate supplies. A comprehensive system Most of the burglar alarms exam- ined thus far give useful but limited performance. The final version, shown in Fig. 18, gives outstanding performance and has several sophisti- cated features. It uses a + 12- volt sup- ply and draws a few p. A of quiescent current. The + 12- volt power to the CMOS circuitry is smoothed via D3 and C4, enabling the circuit and alarm generator (BZl) to use the same supply Normally, with S7 closed and all sensors inactive, LED1, RY1, and BZl are all off. Low-pass filters R3-C1 and R6-C2 suppress any transients. If any sensor switches activate, the inputs of ICl-a and ICl-b go high, turning on LED1 and RY1, the latter throughQl.ICl-candICl-d.AsRY) turns on it self-latches via the left- hand contacts, and activates BZl via the right-hand contacts. Note that the self-latching relay is permanently wired to the + 12- volt supply, and can be activated at any time by either the panic buttons or thermostats. If key-switch S7 is initially closed, or if pushbutton S6 is pressed and released, the R7-C3-IC1-C network disables Ql for about 100 seconds. At the end of that period, the circuit re- turns to normal operation. That's of D3 1N4001 1H4148 JL ?470K l ^ " i- R10 < R8 . C3 J* 47fl>2.™: ICI-c •I* 4001 B ON S7 KEY SWITCH 04 - 1N4001 J 10 REINTKY S6'9 N.0.4r R9 U 01 3 1N4148 27K * i t 7 1 ICl-a M-J: < ,i4001B V RY1 12V l»12MJ r — =h J~\ 01 «' I 2N3904l__ , IC1-d 4.7K ^r \\ i, t£> ici-b ■M4D01B R5 1K LED1 : 40 DIE? R6 MEG ft sal m.o.L PANIC BUTTON FIG. 18— COMPREHENSIVE HIGH-PERFORMANCE home security system. action is obtained via ICl-a and ICl- b, which act as a monostable that driv- es RYl via Ql , and is triggered via the with the circuits shown in Figs. 1 5 and 16. Here, IC2-a and IC2-b make up a flip-flop that turns RYl on through Q2 great practical value, since when the system is first turned on via S7, LED1 should stay off. R-E ID CO O 65 LU zc o ^ ■ *~i — 1— \_ ■ -g— -. * v— — •^*-r^ ^-,* — *4 — *^st ■ — ^Z *>. ■ — vT ... • •— • *- ^» * I ./ 7r/^* yH^»>»»»» . — -*_a ■ » ■ ■ aja ■ ■ • ■ ■ ■ a a » a a ■— • id ■o o o 0) o £ O HI o • » • M ">• iji a a a a i i^iull _5< t (A 1- oo Z LU LU zc z CJ o 2 0. E SS o o 1 • *J? • It • 1 • • T??ffi r#iiWPr« V h II \\W *!• r I * II* *nf Tl * I T 1 01 O U 0) ■o O CO DC u a _i O w fu^ UNIVERSAL DESCRAMBLER FOIL PATTERN. It's a single-sided board. g z o DC F o UJ Q < IE TRANSISTORS continued from page 60 cies that same small-signal device (most likely a "general-purpose" de- vice) will also do. In most cases you don't even have to look at specifications — unless you're "pushing the edge of the enve- lope," working somewhere out at the outer fringes of a category, almost any transistor in a class will do suffice, tf you want to be more particular, start scrutinizing the specifications, but bear in mind that your application and the specifications don't have to match perfectly. If your amplifier has to handle up to 100 kHz, there's no reason why the cutoff frequencies have to be exact. You can establish cutoffs slightly higher than required, if you follow good engineering practice and over- design. A device usable up to I MHz will work just as well at 100 kHz as it will at the high end of its range. If your application falls within those ex- tremes, you can use the device. And if you get the "higher-quality" part at a bargain price, so much the better. There are several computer pro- grams to simplify electronic design. One has a library of about 12,000 transistors, while another only 200 or so. The rationale behind the seeming- ly small selection in the latter is that there really aren't that many different transistors — it just seems that way. Many are the same device in a dif- ferent package, or behaving slightly differently from its peers when pushed to its limits. If you stick to the middle ground, it's hard to go wrong. Once you're in the ballpark, there's no absolute right or wrong. R-E 68 R-E Engineering Admart Rates: Ads are 2Vi" x 2 r A". One insertion $950. Six insertions $925. each Twelve insertions $895. each. Closing date same as regular rate card. Send order with nittance to Engineering Admart, Radio Electronics Magazine, 500-B Bi-County Farmingdale, NY 11735. Direct telephone inquiries to Arline Fishman, area e-51 6-293-3000. Only 100% Engineering ads are accepted for this Admart. MIDI Project* y. j MIDI PROJECTS BP182— MIDI interfacing enables any so equipped instruments, regardless of the manufacturer, to be easily connected to- gether and used as a system with easy com- puter control of these music systems. Combine a computer and some MIDI instru- ments and you can have what is virtually a programmable orchestra. To get your copy send $5.95 plus $1.25 for shipping in the U.S. to Electronic Technology Today Inc., P.O. Box 240, Massapequa Park, NY 11762-0240. FCC LICENSE PREPARATION The FCC has revised and updated the commercial license exam. The NEW EXAM covers updated marine and aviation rules and regulations, transistor and digital circuitry, THE GENERAL RADIOTELEPHONE OPERATOR LICENSE - STUDY GUIDE contains vital information. VIDEO SEMINAR KITS ARE NOW AVAILABLE. WPT PUBLICATION 979 Young Street, Suite A Wood bum, Oregon 97071 Phone (503) 931-5159 6805 MICROCOMPUTER DEVELOPMENT SYSTEM The MCPM-1 system allows the IBM PC and compatibles to be used as 3 complete develoornerri system For the Motorola MCS8705P3. PS. IB. LB. H3 and RS single chip microcomputers. The system includes a cross assembler program, a simulator/debugger program and a programming board I hat connects to a serial port. Price— $449 00 VISA and MASTERCARD accepted. 'the msmciss ' COLLASDMtrin IHC. RR#3. BOX 8C Barton, Vermont 05822 Phone (802) 525-3458 RW (802) 525-3451 CIRCLE 185 ON FREE INFORMATION CARD CIRCLE 194 ON FREE INFORMATION CARD OSCILLOSCOPES continued from page 48 The triggering capability of the HP 54501A shows the versatility of DSO's. Users can select a "time- qualified pattern trigger," for exam- ple, where the DSO will trigger only on a glitch. Logic triggering allows triggering only for certain user-de- fined conditions. A user can select a particular pattern of either positive- or negative- going edges to trigger on for each of the four channels. Triggering occurs only when the selected pattern occurs. A user can also specify a pat- tern using any three channels, with the fourth as a clock. A TV/ Video Sync Pod option can capture un- damped video waveforms; the HP 5450 1 A also has an internal TV trig- ger. Figure 7 shows the Tektronix 2432A, with a 300-MHz bandwidth and a 250-megasample/s digitizing rate. The single-shot bandwidth is 100 MHz for band-limited signals. The repetitive mode uses an equivalent- time sampling technique (random and multiple point). The Tektronix 2432A has a number of other useful features, including envelope mode, averaging, and smoothing. Averaging reduces noise on repetitive signals, while smoothing greatly improves Signal - FIG. 8— THE ANALOGIC CORP. DATA 6100 WAVEFORM ANALYZER is much more power- ful than most DSO's, with many accessories, including plug-in front ends from 100 kHz-125 MHz in bandwidth, RS-232C serial and GPIB interfaces, preprogrammed hand- shaking, a programming language, and soft display keys. It's also a two- or four-channel spectrum analyzer, with numerous math functions on the calculator-style keyboard (see text), and can both work in real-time and store up to 32K points per waveform. There's a double floppy-disk drive add-on to store waveforms and programs, and extensive tech- nical support. to-/Voise /?atio (SNR) of single-shot waveforms. One of the most impressive DSO manufacturers is Analogic Corp. of Peabody, MA. Their DSO, the Data 6100 Waveform Analyzer shown in Fig. 8, is much more powerful than most, with numerous accessories, in- cluding plug-in front ends from 100 kHz-125 MHz in bandwidth, RS-232C serial and GPIB interfaces, preprogrammed handshaking, a pro- gramming language, and an incredi- ble array of math functions. There's also a calculator-style keyboard, and soft keys on the display. It's not just a DSO, but a spectrum analyzer. There are two or four inde- pendent channels, letting you display magnitude, phase, real, and imagin- ary parts of frequency spectra simul- taneously. You can add, subtract, multiply, divide, differentiate, and in- tegrate signals, and display power spectra or histograms, do con- volution, auto- and cross-correlation, find fundamental frequency, RMS, pcak-to-peak, mean, standard devia- tion, and rise time, and signal averag- ing, all in real-time, and store up to 32 K points per waveform. There's also a double floppy-disk drive add-on for storing waveforms and programs, and extensive technical support. Since DSO's are here to stay, you should get familiar with them. Most manufacturers provide a tutorial handbook that you should read if you have access to one. R-E CD CO D 69 H ARDWARE H ACKER Cycolor printing secrets Hall Effect Resources Shape Memory Alloys Cycolor Printing Secrets Low Noise Amplification Unusual Mechanical Stuff DON LANCASTER o z o Be \- o w _i LU o Q < IF YOU EVER FIND OUT WHATEVER IT IS WE are doing here, please be sure and let me know. At any rate, this month's goodies include a brand- new color imaging process, low- noise amplifiers, Hall-Effect de- vices, and some unusual new non- electronic items that cry out for hacker use. As usual, all of our refer- enced sources appear in either the upcoming Hall Effect resource side- bar or in the Names and Numbers box. Please check out those side- bars before using the free help line. And please make your product and your literature requests to anyone listed in either sidebar specific, rather than general. Onward and upward... The Cycolor process Color copiers are getting better and better. While they cannot today challenge production color printing or photographic processes for cost or clarity, the handwriting is on the wall. As you might expect, there are now dozens of new color tech- nologies in one stage of develop- ment or another. Several of the obvious needs that any color system must meet are accurate color regis- tration, low materials cost, dense resolution, and the ability to faithfully reproduce an original. One of the candidate systems is called the Cycolor process. That one is in volume production, solves most registration problems in one swell foop, and appears to be emi- nently hackable. The key Cycolor secret lies in the materials used. Figure 1 shows de- tails. Picture three different egg- 1 ike packages called cyliths. Each cylith is around one-third of a mil (0.0003 ") in diameter. Zillions of them are uni- formly spread out one cylith deep over a polyester carrier, similar to a piece of photo film. Each cylith starts out with a soft outer shell. The first cylith type is full of a liquid cyan (process blue) leuco dye. The second cylith type is full of magenta (reddish-purple) dye. The third cylith type is full of yellow dye. The cylith shells are sensitive to different color tight. On exposure, the cyliths will harden. For instance, red light will harden the cyan cyliths but leave the magenta and yellow ones soft. White light will harden all of the cyliths, while black (no light at all) will leave all the cyliths soft. To create a color print or slide, an image is projected onto the de- veloper sheet containing all the cyliths. After exposure, your de- veloper sheet will consist of a mix- ture of hard and soft cyliths. You now have a latent image on your sheet that is somewhat similar to a color negative. The developer sheet is then placed in pressure contact with a suitable paper, slide, or transparen- cy material. The pressure breaks all of the soft cyliths, releasing their in- ternal dyes. The hard cyliths remain intact and do not release their dye. NEED HELP? Phone or write your Hardware Hacker questions directly to: Don Lancaster Synergetics Box 809 Thatcher, AZ 85552 (602) 428-4073 For instance, if you've got hard cyan cyliths and soft magenta and yellow cyliths, then the magenta and yellow dyes will get released and will mix to form a red image. For a blue image, those yellow cyliths harden, leaving the magenta and cyan cyliths soft. Squashing the soft cyliths mixes a magenta and cyan to produce a deep blue. And so on. One more time. Bunches of cylith capsules are on the polyester car- rier. Some of the capsules get selec- tively hardened when exposed to light. A pressure roller then squas- hes the soft capsules, releasing their dye onto a suitable final paper, plas- tic, or slide material. Like stomping on balloons. A brief heating com- pletes the imaging process. Neat stuff. A free and interesting brochure on Cycolor is available through Mead Imaging, while leading com- panies offering Cycolor machines include Brother, Noritsu, Pic- Mount, and the folks at Seiko- Mead. Probably the best way to start off hacking that stuff Is to get free demos of the various machines and then rip off small quantities of the supplies for your own testing and use. I can think of dozens of spe- cialized hacker uses for this new technology. What can you come up with? Low-noise amplifiers The best of new integrated circuit amplifiers now offer noise levels that are much lower than a circuit built from discrete components, and significantly lower than what vacuum tubes used to be able to 70 HARDENS HARDENS HARDENS UNDER RED UNDER GREEN UNDER BLUE LIGHT LIGHT LIGHT POLYESTER CARRIER FIG. 1— THE CYCOLOR PROCESS uses tiny cylith microspheres. Each of the cyliths is initially soft, but hardens under exposure to certain light wavelengths. Crushing the soft cyliths releases a dye that creates the final image. accomplish eons ago. Four of the leaders in the field of ultra-low-noise chips include Linear Technology, Precision Monolitbics, Burr-Brown, and Analog Devices. While all of those sources have fots of free and excellent technical info available, I am most impressed with the Linear Technology offer- ings at the present time. Bui, before we really get into this, let us shatter a few hacker myths involving low-noise amplification. First off, in no way will a low-noise amplifier by itself reduce the noise from an already noisy source. All a low-noise amplifier can do is limit the amou nt of extra noise added by its own amplification process. Second, in the overwhelming ma- jority of hacker circuits, most noise problems are caused by improper circuit layout, sloppy decoupling, instabilities, poor shielding, and un- desired ground currents. Switching from an ordinary amplifier to a low- noise one in such instances will not in any significant way reduce your apparent output noise. It could even make things much worse. Third, the wider the bandwidth, the more noise you are going to have. The wideband circuits are in- herently noisier than narrowband ones. All other things being equal, noise will increase as the square roof of your bandwidth. Most often, if you quadruple your bandwidth, you double the noise involved. Fourth, integrated-circuit noise tends to increase dramatically at ex- tremely low frequencies. If a preci- sion DC response is not needed, you will be better off capacitively coupling an AC or audio amplifier. Fifth and finally, circuit noise is a very strong function of frequency and source impedance. There is no such thing as a universal "low noise" amplifier. In fact, a "low noise" amp run in the wrong frequency range or at the wrong input impedance will actually generate more noise than might a plain old op-amp. Thus, if you want low noise, it is super important that you have all the data sheets and applications lit- erature on hand for the device you want to use, along with a thorough understanding of the options avail- able in other chips. There are two types of noise that the first stage of an integrated ampli- fier can generate. They are voltage noise and current noise. It turns out that current noise is directly propor- tional to the square root of the first stage collector current, while volt- age noise is inversely proportional to the square root of the collector cu rrent. Iffen the right one don't git ya, the left one will. Voltage noise tends to be con- stant with frequency and more im- portant at low impedance levels, while current noise tends to in- crease sharply below a noise corner (or"1/f") frequency in the low audio range. Current noise is more impor- tant at higher input impedance lev- els than low ones. Voltage noise is usually measured in nanovolts per square root of bandwidth (nVVHz), with any value under 1.0 being fairly decent. Cur- rent noise gets measured in picoamperes per_sguare root of bandwidth (pAVHz), again with anything under 1.0 being desirable. Figure 2 shows some possible choices for Linear Technology am- plifiers that will give you the "best" noise performance for a given im- pedance level or frequency range. Of the previous generation devices, the Precision Monoiithics OP-37 is considered the "parent" of the new- er low-noise devices in the same way that the original 741 started the whole op-amp universe. Let's look at a typical device. The Linear Technology LT1115 is an ultra- low-noise and low-distortion audio op amp. It works best when AC cou- pled at higher gains and over an op- timum input source impedance of 30 to 300 ohms. Figure 3 shows you a simple microphone preamplifier that receives balanced inputs (for hum cancellation) and provides a single-ended output with a gain of 300. The total of combined noise and harmonic distortion is under 0.028 percent over a 20-Hz to 20-kHz bandwidth. Should you truly and genuinely need the lowest voltage noise you can possibly get, and already have total and absolute control over all the usual ground, hum, stability, and stray noise sources that usually swamp hacker-circuit first-stage noise figures, there is one sneaky trick you can pull. At least it's the- oretically possible. Simply arrange several low-noise amplifiers in parallel and sum all of their outputs into a second-stage low-noise amplifier. The gain goes up with the number of amplifiers, while the noise only goes up as the square root of the number of ampli- fiers in use. Five parallel amplifiers seems a practical limit, which, in theory, can reduce your first stage noise by a factor of slightly over two. In the real world, that works only for input im- pedances less than ten ohms. Worse yet, circuit strays are likely to eat you alive if you attempt it. More details on the LT1028 data sheet. Unusual mechanical goodies There has been plenty of unusual non-electronic stuff piling up here lately, much of it with great hacker potential. Time for a rundown. First and foremost, if you really want to get a handle on things, pick £ up your free sample kit from ^ GripWorks. g A new material known as Trovicel 8 71 10 kHz > LU O 1 kHz — LU LT LT1028 LT1 037 LT1 001 LT1012 U- LT1115 LT1055 2 3 100 Hz — 3 X < LT1 037 LT1001 LT1012 10 Hi I 50 SOU 5K 50K 500K 5 Meg 50 Meg INPUT IMPEDANCE LEVEL FIG. 2— ANY LOW-NOISE AMPLIFIER has to be specified over a certain input-impedance level and a certain frequency range. Here are Linear Technology's selections for the "best" low-noise op-amps. Note that a misapplied "low-noise" amplilier can actually be noisier than a regular one. looks like a really good board prod- uct for use on everything hacker from cases through prototype mod- els and displays. Trovicel is a rigid foam center plastic sheet that comes in lots of attractive colors and in several thicknesses. It is light- weight, tough, paintable, outdoor rated, printable, pretty, and self-ex- tinguishing. You work it with pretty near any hand or power tool, al- NEW FROM 1 DON LANCASTER HANDS-ON BOOKS Hardware Hacker Reprints II 24.50 Ask The Guru Reprints 1 or II 24.50 CMOS Cookbook 1B.50 TTL Cookbook 16.50 Active Filter Cookbook 15.50 Micro Cookbook vol 1 or II 16.50 Enhancing your Apple 1 or II 17.50 AppleWriter Cookbook 19.50 Apple Assembly Cookbook 21.50 Incredible Secret Money Machine 10.50 LaserWriter Reference (Apple) 19.50 PostScript Cookbook (Adobe) 16.50 PostScript Ref. Man. (Adobe) 22.50 PostScript Prog. Design (Adobe) 22.50 Real World Postscript (Roth) 22.50 UNLOCKED SOFTWARE LaserWriter Secrets (lle'Mac/PC) 29.50 PostScript Show & Tell 39.50 Intro to PostScript VKS Video 39.50 PostScript Beginner Stuff 39.50 PostScript Perspective Draw 39.50 PostScript Technical Illustrations 39.50 PostScript Work In Progress 39.50 PostScript BBS stuff 19.50 Absolute Reset lie & lie 19.50 A pp leWrlter/Lase rwriter Utilities 49.50 tn Enhance 1 or 11 Companion Disk 19.50 o o AppleWriter CB or Assy CB Disk 24.50 FREE VOICE HELPLINE /1SA/MC t- o Hi _l UJ 6 < SYNERGETICS Box 80 9- RE Thatcher, AZ 85552 (602) 428-4073 CIRCLE 83 ON FREE INFORMATION CARD though hacksawing and power shearing are not recommended. You can bond it with ordinary PVC cement, and even grind or weld it. Free samples are available. Should you need any curved plywood in tubes, quarter-round, half-round, or with a radiused end, try some of the Deco Shapes prod- uct from Laminates Incorporated. There seems to be a lot of interest lately in machinable waxes. Besides bei ng obviously ideal for CAD/CAM training and program debugging, the material is well suited for one-of- a-kind mockups, proof-of -concept models, and for "does-it-fit?" prod- uct verification. With a machinable wax, your tools stay sharp, the chips are safe, and you can easily recycle your final OUTPUT 316K 30K L -VM — VM — W/Hi 31 6K 1K 1K I MICROPHONE INPUT FIG. 3— AN ULTRA-LOW-NOISE balanced preamp circuit that uses the Linear Tech- nology LT1115. Combined noise and dis- tortion is under 0.028 percent. material simply by remelting it. The product is available from two to eight inches thick, in cylinders up to nine inches in diameter, and in bulk. You could easily recast their wax into any shape you want to. It melts at 310 degrees Fahrenheit. One good source for machinable waxes is Freeman Supply. Prices start at $4 per pound. The American Safety Razor folks are obviously one sharp outfit. Their catalog lists zillions of different low- cost blades, including ripple ones for cutting potato chips and big mutha ones nearly eighteen inches long! The variety here is amazing. One obvious project around here is a $5 cutter for laser-printed busi- ness cards. I'm wondering if you couldn't use their blades for a clam- ping paper cutter as well. A proper support, of course, would be essen- tial for it to work. In what just might be the most obscure free trade journal in the en- tire world, Power and Bulk Solids covers such things as bin-level de- tectors and similar goodies. Amazingly, several hacker helpline callers per week are asking for that sort of stuff, especially for agri- cultural electronics. A new product called Scotch 9703 Conductive Adhesive Transfer Tape from 3-M has a very unusual proper- ty. It conducts electricity through its thickness but not along its length. From face to face, the resistance is under 0.1 ohms. Yet, along its length, it insulates to the point of allowing 500 volts across a ten mil gap! Embedded silver-plated particles apparently do the trick. Adhesion values are in the 50-ounces-per-inch range for most substrates. Free test samples are available. Finally, short shape metal alloy wire samples are available free from Beta Phase. These magic wires can be bent into any shape at all and will stay that way until heated to hot cof- fee temperatures. Then they'll rapidly spring back to their original size and shape. You can repeat the shape-and-restore process zillions of times. Applications include ev- erything from high-density zero-in- sertion-force connectors to dentis- try. Tellyawhat. For this month's con- test, just dream up an off-the-wall use for any of those unique new 72 NAMES AND NUMBERS American Safety Razor Razor Blade Lane Verona, VA 24482 (703) 248-8000 CIRCLE 226 ON FREE INFORMATION CARD Analog Devices One Technology Way Norwood, MA 02062 (617) 329-4700 CIRCLE 227 ON FREE INFORMATION CARD Beta Phase 1200 Chrysler Drive Menlo Park, CA 94025 (415) 494-8410 CtRClE 228 ON FREE INFORMATION CARD Burr-Brown 6730 South Tucson Blvd Tucson, Az 85706 (602) 746-1111 CIRCLE 229 ON FREE INFORMATION CARD Freeman Supply 1246 West 70th Street Clevelend, OH 44102 (800) 321-8511 CIRCLE 230 ON FREE INFORMATION CARD Grip Works 6916 South Broadway St. Louis, MO 63111 (800) 827-GRIP CIRCLE 231 ON FREE INFORMATION CARD Laminates Inc. 35 Engineers Road Hauppauge, NY 11788 (800) 221-5454 CIRCLE 232 ON FREE INFORMATION CARD Linear Technology 1630 McCarthy Blvd Miliptas, CA 95035 (408) 432-1900 CIRCLE 233 ON FREE INFORMATION CARD Maxim MWK Industries 1440 S State College Blvd, 3B Anaheim, CA 92806 (800) 356-7714 CIRCLE 237 ON FREE INFORMATION CARD Omega Engineering Box 4047 Stamford, CT 06907 (203) 359-1660 CIRCLE 238 ON FREE INFORMATION CARD Power/Bulk Solids PO Box 650 Morris Plains, N J 07950 (201) 292-5100 CIRCLE 239 ON FREE INFORMATION CARD Precision Monolithics 1500 Space Park Drive Santa Clara, CA 95052 (408) 727-9222 CIRCLE 240 ON FREE INFORMATION CARD Raytheon 350 Ellis Street Mountain View, CA 94039 (415) 968-9211 CIRCLE 241 ON FREE INFORMATION CARD Sharp Sharp Plaza Mahwah, NJ 07430 (201) 529-8757 CIRCLE 242 ON FREE INFORMATION CARD Silicon Valley Surplus 4222 East 12th Oakiand, CA 94601 (415) 261-4506 CIRCLE 243 ON FREE INFORMATION CARD Teledyne 1300 Terra Bella Avenue Mountain View, CA 94039 (415) 968-9241 CIRCLE 244 ON FREE INFORMATION CARD 120 San Gabriel Drive Texas Instruments Sunnyvale, CA 94086 PO Box 1443 (408) 737-7600 Houston, TX 77001 CIRCLE 234 ON FREE INFORMATION CARD (800) 232-3200 CIRCLE 245 ON FREE INFORMATION CARD Mead Imaging 3495 NewMark Drive 3-M/Scotch Miamisburg, OH 45342 3M Center Bldg. 220-7E-01 (513) 495-9100 St Paul, MN 55144 CIRCLE 235 ON FREE INFORMATION CARD CIRCLE 246 ON FREE INFORMATION CARD Motorola Trovtcel Huts 5005 East McDowell Road Turner Place Box 365 Phoenix, AZ 85008 Piscataway, NJ 08855 (602) 244-6900 (201) 981-5000 CIRCLE 236 ON FREE INFORMATION CARD CIRCLE 247 ON FREE INFORMATION CARD TgNtTH TURBOSPORT 386 PORTABLE LAPTOP COMPUTER r ■ 60386 32-bit processor. 12/6 MKi (switchable). ■ 40 MS (28ms) hard drive. ■ One 3.5" 1 .4 MB (loppy disk drive. ■2MB RAM (expandable to 3 MB). • MS-DOS 3.21 included. • 100% IBM compatible.! ■ "Page- White" fluorescent backlil LCD display with 1 0.5" viewing area. ■ Supports: MS OS/2 version 1 ,0, Xenix, and aJso Microsoft Windows/386 environments. * Zero wail state. * Socket tor 60387 numeric co-processor. • Internal Hayes 2400 Baud modem. * Serial & parallel printer ports. * Resolution: 640 x 400 pixels. * 79-key lull function detachable keyboard. • "Fast" charge NICad battety pack included. • Dim.: 13.25"W x 14.75"0 X 4,75"H. ■ Wl: 14.7 lbs. ■ One Year Warranty! • Factory New a Perfeetl Due to a special ar- rangement, we were able to obtain a large inventory ol Ihese laptop com- puters. As a result, we can now ofler them to you at HUGE SAVINGS! * Expansion Slot 1 MB Memory, Carry Case, Battery Pack also available. Manufacturer's Suggested Retail $8,499.00 ■ ■MnUsBUdUU $ 2999 s9 Item No. B-1970-128G86 Insured Ship/Hand.: $20.00 FOR FASTEST SERVICE CALL TOLL FREE 1-800-729-9000 MasterCard " . I Q2B DA MARK IKTTEHNATIONAL, INC. 6707 stunojn Creak Parkway. Minneapolis. MN 55430 Customer Service -612-566-4940 Please rush me: Zenith Laptop Computer(s) jsjz(Lcwas FIG. 1 *A5-JL& / TW//($1-A ■f- V /S 2. T/Af/N(JT-A ■/OUTPUT -B /o 3 GROUND -Ot/r/ : 'UT-0 ? Fie. 2 short a pulse and you want to keep the shoulders nice and sharp, you need something other than a 555. The most common way to make accurate monostables is to use a D- type flip flop in combination with an RC network. That is such a routine combination, that special MSI chips were developed for it. Those IC's have been around for a while, and one of them, the 4528 dual mono- stable multivibrator, is a good choice for us to use. You can see the pinouts in Fig. 2. Since that is a dual chip, and each half can be used independently, we can use one section to generate the horizontal sync pulse. As you can see from Fig. 3, it takes only two parts to make it work. The width of the output pulse is determined by the RC product. We're talking about straight multiplication. Due to the fact that we're using a capacitor in the timing chain, there's a delay be- tween the time you trigger the chip and the time the output pulse is generated — but that is more of a drawback when you want to pro- duce long pulses. The problem can be minimized by using small-value capacitors and, since we want a5-jxs pulse, the inherent charge-dis- charge delay in the capacitor won't be much of a problem. The timing circuit we developed produces positive-going signals, so we'll be feeding them to pin 4, the positive trigger input of the 4528. The resistor and capacitor values will generate a pulse width of about 4.7 n-S. The actual value you'll get depends entirely on the compo- nents you use. A metal-film resistor and mica capacitor are the best choices for overall stability but, if you can't get your hands on those, 9 ■t-v £y/VC AULS£ o /b /V CLP /// 78 standard carbon resistors are fine. Try to avoid using a ceramic-disc ca- pacitor since the value stamped on them is usually nothing more than wishful thinking. Should you have any problems, you can add the trim- mer shown in the schematic to tweak the pulse width. The vertical interval Just as the horizontal sync pulse is only one of the signals found in the horizontal interval, a vertical sync pulse is only one of several signals you'll find in the vertical interval, just what sort of stuff will show up there depends on the broadcaster, the area you live in, and the open mindedness of the FCC. The only thing that really has to be there, however, is vertical sync... and a bit more. Several things have to happen during the vertical interval. Things get a bit complicated because the NTSC standard calls for interlaced video. Remember that field one scans all the odd-numbered hori- zontal lines (1, 3, 5, etc.), and field two scans the even-numbered lines. Each field covers the entire picture area on the screen. Both fields con- tain a complete vertical-blanking in- terval and they both have the same information during the interval. But each field carries different picture information so there has to be a way of telling them apart. In the NTSC standard, there are 262 1 /> lines per field (525 lines per frame), and it's that half line that forms the basis for distinguishing between field one and field two. That is evident in Fig. 4 where the two fields are drawn as you would see them on the screen. You can see how the two fields are combined to make up one frame. And, as you might guess, the control signals are exactly the same for both. You must keep in mind that the two fields differ from each other in timing, not signals. The movement of the electron beam in the tube is controlled by the hardware in the TV. The beam's deflection angle as it goes from left to right and back again is not controlled by the signals sentto the TV. It's determined by the hardware in the TV's deflection cir- cuitry. The only control that the vid- eo signal has over the movement of the beam is to make it go to the beginning of the next line on the left START F/£LJ? 7V*£J E/£U3 0A/£. F/EL.0 7JYO £SMD FIG. 4 side of the screen (horizontal sync), or to the top of the screen (vertical sync). If you think of field one as begin- ning with the end of a vertical inter- val, then the first field starts with a full line of video and the second field starts with a half line of video. That means that field one starts at the upper left of the screen and ends at the center of the bottom. It follows that field two starts at the top center and ends at the bottom right. Those differences between the two fields may be evident to the eye but they're not the sort of distinc- tions that are needed to provide a means of electronically knowing which field is being painted on the screen. In order to understand that we have to take a close look at the anatomy of the vertical interval. The first nine lines in each field's vertical interval are shown in Fig. 5 I've put one right on top of another to help you see the difference be- tween them. The two contain the same number of pulses but they dif- fer in their timing relationship (phase) with the rest of the video signal. The beginning of the vertical in- terval is marked by a series of six pre-equalizing pulses (two per line for three lines of video). If you look carefully at Fig, 5 you'll see that the first pre-equalizing pulse for field one occurs a full line after a horizon- tal sync pulse while the first pre- equalizing pulse in field two occurs a half line after horizontal sync. That difference in timing is the mecha- nism used to identify which field is being painted on the screen. It's important to notice that there are no real horizontal sync pulses during the first nine lines of the ver- tical interval. In order to maintain the horizontal sync in the receiver during that period, there are two pre-equalizing pulses per line. Each pulse is half the width of a horizon- tal sync pulse and, since they occur twice as often, they provide the same DC level as one horizontal sync pulse. That is done because the circuitry in your TV integrates the DC level on each line of video to determine what to do with the elec- tron beam. One level will be inter- preted as horizontal sync and, as we'll see in a minute, a greater level will be interpreted as vertical sync. The vertical sync signal is really just an inverted version of the pre- equalizing pulses and that means that each pulse is very wide (92% 5 CD O 79 £0 PULSES 3 L //Y£$ vert sy//c 3 ^./V^5 £

inrr J,J-/M£S £& /VLSE5 3 J.MBS FIG. 5 duty cycle). The result is that the three lines (4, 5, and 6) in which vertical sync appears have a very large negative value — as a matter of fact it's the most negative value in the video signal — and that's exactly what triggers the vertical-deflection circuitry in your TV. By integrating the DC level on each line, the TV can detect the presence of the ver- tical sync signal and move the elec- tron beam to the top of the tube. Remember that when the vertical deflection circuitry in the TV is acti- vated by detecting the vertical sync in the video signal, it only moves the beam to the top of the screen — not the top left corner of the screen. Moving the beam to the left is the job of horizontal sync. Since field one starts at the top left of the screen and field two starts at the top center, you can understand why the TV has to be told which field it's about to paint. In order to build a correctly aligned frame from two fields, the two fields have to be lined up. If vertical sync doesn't appear at the right time, a properly interlaced image is impossible. Figure 5 shows that there are six more equalizing pulses in the three lines (7, 8, and 9) following the ver- tical sync signal. Although they are identical to the pre-equalizing pulses, they're officially the — you guessed it — post-equalizing pulses. In the early days of TV, they were needed to maintain interlace but, as with so many other things, modern technology has made them ob- solete. You'll still find them in the g signal but they're not really used for HE anything at all. Even the distinction § between pre-equalizing pulses and o post-equalizing pulses has disap- j peared. Most people today just con- ^ sider the vertical interval as having 5 two signals: equalizing pulses (sans rr prefix), and vertical sync. Interlace or non-interlace Even though the NTSC standard calls for interlaced video, it's not an absolute requirement for getting images on the TV screen. Broadcast TV is interlaced but a lot of comput- er video is non-interlace. If you want to do non-interlaced video and you also want to paint more than 400 or so lines of video on the screen, it's clear that you have to do something to avoid the flicker that would be caused by having the top part of the o i-t-V A7 5-QK V££7~fCAE Q S2. *n :3 // CJ.A //v ■t-ftf out XCB-b //245Z8 TZ 77 /f /S A3 JZ7&K 6&O fi F - FIG. 6 image start to fade before the elec- tron beam worked its way down to the last line on the screen. That means either using a tube with a high-persistence phosphor (like IBM monochrome monitors), or in- creasing the horizontal scan rate (IBM EGA and VGA monitors). Generating vertical sync A properly constructed video sig- nal will have all the equalizing and sync pulses we've been talking about but, as you can imagine, the circuitry needed to properly con- struct the vertical interval can get to be really complex. You'd need a separate pulse generator for the equalizing pulses (and an inverter to make the vertical sync pulses), and the circuitry needed to make sure they showed up at the correct time would have to be designed as well. That is why most of the early sync generators were really expensive. That kind of stuff isn't designed from discrete parts these days be- cause there are sync-generator chips that do the whole job for you. For our purposes, we can generate non-interlaced video and produce a single vertical sync pulse that's wide enough to be detected by the TV's vertical-deflection circuitry. The only signal we'll need in the vertical interval will be a long vertical sync pulse; the equalizing pulses are un- necessary since we're not going to interlace the image. The field of video we're going to produce will be 262 lines long but some of that has to be reserved for vertical blanking. That is for two rea- sons: The first is that most TV sets overscan the image so that some of the lines fall outside the screen area, and the second is that a certain amount of time is needed for ver- tical sync. We can solve the first problem by not putting any picture information at the very beginning and end of the image; we'll leave the beam turned off. The second problem can be handled by following the NTSC standard and making our long ver- tical sync pulse at least three hori- zontal lines wide. Actually generating the vertical sync pulse is simple since we have half of the 4528 available. By using the values shown in Fig. 6, the chip will output a negative-going vertical sync pulse with a width that's exactly three lines long. As I mentioned ear- lier, you should use metal-film and mica parts to make the pulse as accurate and stable as possible but, once again, add the trimmer shown in the schematic if you're in doubt as to the measured values of the parts you're using. Once you assemble the circuits we've discussed and add them to the circuitry we've developed so far, you'll have a working video-sync generator. I know 1 promised we would get some images up on the tube this month, but it took a bit longer than I had planned on to get this far. Next month we'll produce a real 75-ohm video signal, and we'll put more than dots on the screen — 1 swear. R-E 80 COMPU Just about any observable ac- tivity can be represented as a series of numbers, and, using the techniques described in this article, you can write simple BASIC programs to analyze those numbers in any manner desired. For example, standard elec- tronic waveforms (sine waves, square waves, sawtooth waves, etc.) can be expressed as a series of numbers computed from stan- dard equations. In addition, you can capture that type of series from real-life waveforms gener- ated by an ADC {Analog-to-Dig- ital Converter) or a digital- storage oscilloscope. Not only that, but non-elec- tronic phenomena are also ame- nable to the same types of analyses. For example, you could analyze the Dow Jones industrial average over a period of time, or you could track the performance of any individual stock. Even lot- tery results are candidates for that type of analysis. The point is that each of those phenomena can be thought of and analyzed just like a wave- form, be it an electronic wave- form, a stock "waveform," or a lotto "waveform." More generally, those things can be thought of simply as a series of events occur- ring over a period of time. Any such series of events can be sub- jected to what mathematicians and scientists refer to as numer- ical analysis or time-series analysis. Don't be intimidated by the ter- minology. Time-series analysis is nothing more than basic mathe- matics applied to a series of num- bers. To see how easy it really is, lets look at some examples. Tables To analyze a series of numbers, the numbers need to be orga- nized into some form for easy ref- erence. The most familiar and easiest" form of organization is a simple table of values like the one shown in Table 1. You might rec- continued on page 83 EDITOR'S Work- Bench The Talking PC Speech synthesis on a PC is hard to come by, if not expen- sive — usually. Street Electronics has come to the rescue with the Echo PC + , an under $200 (de- pending on host PC) setup that includes a PC board, an external speaker with volume control, and software. The software (which is supplied on both 5-'A- and 3-'/a- inch diskettes) includes several speech generators, demonstra- tion programs, and assorted mis- cellany. A 50-page booklet ex- plains how to install and use the Echo PC + . Special versions of the card are available for PS/2's with the MicroChannel bus, for Tandy 1000's, and the Apple II. I looked at the PC version. The half-length board plugs into any 8- or 16-bit PC expan- sion slot and has two connectors. One connector (a Vs-inch mini plug) is for the external speaker; the other (a standard 17-pin D connector) is an IBM-compatible game port. The board includes half-a-dozen logic devices (bus buffers, a PAL presumably used for decoding, etc.), an NE558 quad op-amp. an LM380 for au- dio output, and a proprietary speech chip. The board is laid out well, and construction is excel- lent. The software consists of two programs: Talk and Words. Both load as memory-resident pro- grams that capture ASCII text sent to a phantom output device (LPT3, for example). s $ 81 z O 1 LU I LU 6 D < DC Talk and Words Talk is a generic text-to-speech converter that can pronounce any word based on a set of rules stored in the program. Talk's "voice" is synthesized and me- chanical sounding. It is based on the LPC (Linear Predictive Cod- ing) technology used in TI's Speak 'n' Spell games. Words, on the other hand, speaks in a more natural sound- ing way. Words has a limited 700- word vocabulary consisting of the actual digitized sounds of a female voice. Words' vocabulary includes all the letters of the al- phabet, numbers from 0—9, the months of the year, and many common words (electronics, hello, good-bye, you, me, ques- tion, multiply, etc.). There are some strange omissions, how- ever. Boy and man are both in- cluded, but neither girl nor woman is. You can increase Words' vo- cabulary in a limited way by adding one of seven prefixes and suffixes (dis-, ex-, re-, un-; -d, -t, - s) to a word by enclosing the addi- tion in parentheses. For example: I like her. I (dis)like her. I like(t) her. I (dis)like(t) her. The version of the product that I saw doesn't allow you to add to the digitized vocabulary, but around the time you read this, the company should be introduc- ing a DSP (Digital Signal Process- ing) board for about $500 that will allow you to digitize any au- dio signal and convert it to a form suitable for playback through the Echo PC + . Fine tuning Several parameters affect how both Talk and Words speak. For example, you can vary the speech rate of either program by sending this command: *RATE = n where n has a value from (slow) to 15 (fast). The default value is 2. You may find, as you gain experi- ence with Echo PC + , that you can increase the rate somewhat. Other parameters common to both programs include pitch, vol- ume, and delay. Pitch can vaiy from -63- +63, with being the default. Although the external speaker has its own volume con- trol, you can also set volume un- der program control using the Volume parameter, which may range from 0—15 (14 is default). The Delay command allows you to specify a delay between each spoken word; values are specified in tenths of a second, and may range from 0-20. Delay is inde- pendent of Rate; is the default. In addition, each program has several unique performance pa- rameters. Since it has its own limited "intelligence" for decid- ing how to pronounce any given combination of letters. Talk al- lows you a fair amount of control over how it forms its interpreta- tion. For example, the program can operate in either of two basic modes: Word or Letter. In Letter mode, every letter of every word is pronounced separately. In Word mode, however, the product's in- telligence is put to the test. - 1 ECHO! S P ' 1 1 C 11 J> B B C 1 S > M ■ vr, . . , ., Hi FIG.l Within Word mode, there are several punctuation modes: Some, Most, and All. In All mode, every punctuation mark is pro- nounced. In Some mode, Talk tries to pronounce sentences with end-stops (question mark, period, semicolon) correctly. Questions, for example, end in English with a slight rise in pitch. One other mode ("Caps") avail- able in Talk forces words spelled in all caps to be pronounced letter by letter. That mode could be useful in creating an interactive spelling tutorial. Words' special features include the prefixes and suffixes dis- cussed above, and the ability to speak several complete pre-pro- grammed phrases, including disk drive, 1 am, I win, it is, se- lect one qfjol, that is correct, that is right. United States, when was that, you are. and you win. One way of overcoming Words* limited vocabulary is to load both Talk and Words into memory. Then when you send a string to Words, any text that it can't pro- cess it will send on to Talk. How- ever, the two voices are so different that maintaining con- tinuity is impossible. One problem with Talk is its inability to deal with compound words and words that break the "rules" of English pronunciation. For example, Talk pronounces typewriter as tip-eh-writer. How- ever, by breaking compounds up into the component parts, it will often pronounce them correctly. To get Talk to pronounce rule- breakers correctly, you must mis- spell the word. For example, for the first syllable to be pro- nounced ee rather than eh. elec- trolyte must be spelled eelectrolyte. I also had trouble getting the Echo PC+ to pronounce other words correctly. Rigid, for exam- ple, sounded more like a croaking frog than a word. And though it did all right with words like Brian, Jeff. Marc, Carl, Bob, John, Julian, Larry, Kathy, Terry, I had to spell Byron as two words [bie ron), and I was unsuccessful in getting it to say the first sylla- ble of Andre [an dray) to rhyme with the first syllable of father; it insisted on rhyming it with hand. (Sorry, Andre!) How it works Both Talk and Words work by hooking into the appropriate BIOS interrupt and capturing output sent to a COM or LPT port. Then you force the board to speak simply by "printing" the desired text to the appropriate port. For example, if you start Words like this Words lpt3: any ASCII data you send to LPT3 will be interpreted and pro- nounced by the program, if pos- sible. You can set the software up to respond as any legal COM or LPT port. The demo programs allow you to type a line at a time at the key- board and send it to the Echo PC+ . To get it to talk from your own programs, you just PRINT or 82 WRITE the desired string to the appropriate port. For example, the manual supplies the follow- ing BASIC program: 10 OPEN "LPT3:" FOR OUTPUT AS#1 20 PRINT 30 INPUT ''Enter text: ";A$ 40 PRINT #1,A$ 50 GOTO 20 60 END Some versions of BASIC won't let you PRINT in that fashion; the manual includes another exam- ple with some in-line assembler code that does the same thing. Examples are also provided in several varieties of Pascal and C. All in all, considering the price of the product, my complaints are reallyjust nit-picking. If you'd like to add speech to a science- fair project, an interactive demo, or a self-paced, PC-based tu- torial, the Echo PC+ is an excel- lent buy>CD4 War of the Words Word processors have been evolving rapidly over the past few years. Due to my work with different clients, I have checked out all the major con- tenders during the past year or so. Including Word Perfect 5.0, Word 5.0, WordStar 5.5, XyWrite III Plus, and several lesser pack- ages. I can state unequivocally that Word Perfect was my least favorite, due mainly to the lack of any logic in the way its com- mands are assigned. Many peo- ple would claim the same of WordStar, but that's false; Word- Star commands are for the most part well organized, it just takes a while for the system to sink in. And there's no question that WordStar has the best page pre- view of any non-graphical word processor. XyWrite offers a lot of power, but its on-screen display is mighty ugly for this day and age, and its spelling checker is almost more trouble to use than it's worth. (However, a new ver- sion of the program is due out in early spring; we'll see....) That leaves Word. Even though I've only used it a few weeks so far, it has grown on me quickly. It is highly customizable, offers a wealth of display modes (includ- ing, on a VGA. very nice 30- and 34-line graphics modes that do a decent job of displaying italics and boldface text). Like Word Per- fect, its macro facility amounts to a miniature programming lan- guage. One of Word's most fa- mous (and justly so) capabilities is the style sheet, or set of format- ting attributes you can apply to text. Even though you can't see fonts, etc., on-screen, you can enable a so-called style bar along the left side of the screen that provides a one- or two-letter in- dication of the style of each para- graph. The style bar thus gives you the ability to produce nicely formatted documents without re- quiring the expensive hardware resources required by graphical word processors (Word for Win- dows, Ami) and desktop publish- ing packages. Word has many other features, including on-line help, a good spelling checker and thesaurus, multiple windows, support for many printers (including Laser- Jets and PostScript devices), and a document-management func- tion that allows you to create a summary sheet that remains with the document and that specifies the original author, date of creation, and a one-line sum- mary of contents. You can then search for a specific document based on the summary using a special load function. Word also has a built-in outlin- ing function that, although no match for Symantec's Grand- View, is better than nothing, and has the benefit of being built-in, so you can do things like apply styles to different oudine levels. Word naturally stores docu- ments in its own format, but it can also load and store ASCII text direcUy, in both line- and para- graph-delimited forms, That ca- pability is indispensable if you do much work with on-line systems, E-MAIL, etc. There's a lot more to Word, but no space to give it justice. Forme, it seems to have the right balance between formatting tools and text creation tools, unlike much of the competition, which tend to push too far one way or the other, or are simply disorganized con- glomerations of features. Word 5.0 lists for $450, but you can pick it up mail order for little more than $200.|CD* ITEMS DISCUSSED • Echo PC+ ($179.95 (PC), $134.95 (Apple II), $199.95 (Mi- croChannel), $249.95 (RS-232), Street Electronics Corporation, 6420 Via Real, Carpinteria. CA 93013. (805) 684-4593. CIRCLE 256 ON FREE INFORMATION CARD • Word ($450), Microsoft Corp.. 16011 NE 36th Way, Box 97017, Redmond, WA 98073-9717. (206) 882-8080. CIRCLE 257 ON FREE INFORMATION CARD WAVEFORM continued from page 81 ognize it as the solution to a typ- ical beginning algebra problem: For Jive values q/X ranging from zero to two compute a table of values for Y=X 2 . TABLE 1— Y = = X2 Entry X Y 1 2 0.5 0.25 3 1.0 1.0 4 1.5 2.25 5 2.0 4.0 Essentially the same approach can be taken on a PC using any standard spreadsheet program, as illustrated In Fig. 1. In this case, the five values of X have been entered manually in the five cells or elements of column A. The values in column B are ob- s tained by entering the necessary ^ formula in each of the B cells. For jg example, the formula in B 1 would & 83 o o o w Q < r a ■ I c 1 2 0.5 0.25 3 1.0 1.00 4 1.5 2.25 5 2.0 4.00 6 7 Fig. I. STORE DATA FOR Y=X 2 in a spreadsheet program. The X ualties are stored in. column A. and the Y values in column B. FOR t=1 TO 5 LETY(I)=X(I)*X(1) NEXT I ARRAY X ARRAY V X<11 Yd) X(2) 0.5 YI2) 0.25 X(3) 1.0 Y(3l 1.00 X{4) 1.5 Y(4I 2.25 X(5) 2.0 YI5) 4.00 Fig. 2. STORE DATAFOR Y=X 2 in a two- dimensional array in a high-level pro- gramming language (BASIC. Pascal, etc.). be Al x Al, the formula in B2 would be A2 x A2, and so on. The same principles apply when using numeric arrays in any high-level programming lan- guage (BASIC, Pascal, C, For- tran, etc.). We'll show basic techniques in BASIC here ; it cer- tainly wouldn't be difficult to adapt our techniques to other languages. Arrays An array is a set of subscripted variables or elements; you can think of it as shown in Fig. 2. In that figure, array X has five ele- ments (with subscripts 1—5). The first element isX(l), the second is X(2), and so on. Array Y also has five elements, subscripted the same way The nice thing about creating and manipulating an array in a programming language is that the elements of the array can be referred to and operated on with FOR loops. That allows a single general formula to be applied to every element in the array. Enter- ing five items of data in a spreadsheet is not so bad, but think about entering (and per- forming calculations on) 500 items by hand! To gain a better understanding of how the problem might be gen- eralized and attacked using BASIC, consider the program in Listing 1. The first few lines of the pro- gram prepare an array of the de- sired size. The statement in line 10 specifies that arrays are num- bered from one (1), not zero (0), because computations are usu- ally easier. Line 20 asks you to enter the number of values you want to calculate, and line 30 uses an INPUT statement to as- sign the desired number to varia- ble n. Now that the program knows how many numbers you want to process, the arrays for storing those numbers are cre- ated with one or more DIMension statements. Getting the data in Typing data into the program gets old fast; it would be nice if we were able to bring data into the program directly. For example, a digitizing os- cilloscope could be a source of data. The data would be a series of numbers representing the am- plitude of a waveform captured at discrete points in time; each val- ue is stored in the scopes memo- ry Then, if the scope has an RS-232 interface, the data could be transferred to a disk file on your PC and subsequently read into a numeric array of the type discussed earlier. The waveform data could then be processed just like data typed in by hand. Of course, the method of transfer- ring data to the PC depends on the scope, data-capture software running on the PC, etc. However, most digitizing scopes provide transfer utilities for dealing with their scopes data format. LISTING 1 10 OPTION BASE 1 20 PRINT "ENTER THE NUMBER OF X VALUES TO PROCESS. " 30 INPUT N 40 DIM X(N), Y(N) 50 FOR 1=1 TO N 60 PRINT "ENTER THE ";I;"th VALUE OF X. " 70 INPUT X( I) 80 NEXT I 90 FOR 1=1 TO N 100 LET Y(I)=X(I ) *X(I) 110 NEXT I 120 FOR 1=1 TO N: PRINT X(I) ,Y(I): NEXT I 130 END The next step is to get some numbers into those arrays for processing. Lines 50—80 handle that chore by requesting values from you n times, one at a time. The process of squaring each ar- ray value occurs in lines 90—110. Last, line 120 prints all X and Y values. Even though that program is quite simple, it contains all of the essential steps necessary for ar- ray processing: 1. Dimension the necessary ar- ray variables. 2. Input the values for use in computations. 3. Do the element-by-element array computations. 4. Output the results of the computations. For some applications (purely theoretical analyses, for exam- ple), input data can be generated by a program. For example, the program in Listing 2 can be used to generate a sine wave (SWAVE) composed of any number of points (n) and cycles {cy) that you choose. A plot of the data generated by that program is shown in Fig. 3, The plot was created using a pro- gram called Graph-in-the-Box, which captures data printed to the PC screen. Of course you could write your own custom graphics routine, but Graph-in- the-Box works well with many types of programs. As a point of interest, the sine wave in Fig. 3 was generated with 84 LISTING 2 10 OPTION BASE 1 20 PRINT "ENTER NUMBER OF POINTS TO USE.' 30 INPUT N 40 DIM SWAVE(N) 50 PI=3. 141593 60 PRINT "ENTER NUMBER OF CYCLES DESIRED. 70 INPUT CY 80 FOR 1=1 TO N 90 SWAVE(I)=I-1/N 100 SWAVE ( I ) =CY*SWAVE( I ) 110 SWAVE(I)=SIN(2*PI*SWAVE(I)) 120 NEXT I 130 OPEN "0",#1, "B: SWAVE, DAT" 140 FOR 1=1 TO N 150 WRITE #1,SWAVE(I) 160 NEXT I 170 CLOSE 1.5 1.0 A I A 0.5 / \ A O.D : / f \ I 1 \ \ / \ -0.5 \ / \ 1 -1.0 V \ J -1.5 ^™Sine Dave Fig- 3. THIS GRAPH REPRESENTS two cycles of a sine wave. The data was generated fay the BASIC program shown in Listing 2. 64 equally spaced points over two full cycles. There is no "frequen- cy" inherent in that representa- tion. Frequency enters the pic- ture only when you assume that each point represents some in- crement of time, which could be picoseconds, microseconds, sec- onds, minutes, months, or what- ever you choose. For example, let's say you want Fig. 3 to represent a sine wave of 1 kHz. Then you would assume that each point represents an in- crement of 1 ras (the period, '/iooo Hz) divided by the number of points covering one cycle (32 points/cycle in this case), giving 0. 03125 ms per point. The amount of time per point is gen- erally referred to as the sampling interval. Simple analysis operations Once you have an array of data — however you get it — you can begin analyzing it with wave- form-processing techniques. For example, you might want to scale the data upward or down- ward in value. Let's say you want to double the value of every array element. That can be done by multiplying the array by a con- stant as shown in Listing 3. Or say you want to know the average (mean) value of the data stored in an array with n ele- ments. That's a simple computa- tion. Just add up all the values in the array and divide the result by n. For the sine wave in Fig. 3 , that would be done as shown in List- ing 4. The RMS (root-mean-square) value of that waveform could be computed in a similar manner as shown in Listing 5. When computing average, RMS, or similar values from waveform data arrays, keep in mind the definitions of the cal- culations and how they apply to the data. For example, you would expect the average value of a sine wave [or similarly symmetric waveform) to be zero. But that will be the case only if array SWAVE contains an integral number of sine wave cycles. If SWAVE contains a nonintegral number of cycles, say 1.5 cycles, the average value of the array would be nonzero by an amount determined by the extra half cy- cle. To get the correct value in that case, you would have to re- strict the calculations to just the array elements covering an integ- er number of cycles. LISTING 3 200 FOR 1=1 TO N 210 SWAVE(I)=SWAVE(I)*2 220 NEXT I LISTING 4 300 AVG=0 310 FOR 1=1 to N 320 AVG=AVG+SWAVE(I) 330 NEXT I 340 AVG=AVG/N 350 PRINT AVG The key point here is that your program simply operates on the numbers that you give it. nothing more, and nothing less. It makes no assumptions about the meaning of those numbers. Calculus made simple The greatest attribute of array or waveform processing is that it dramatically simplifies what would otherwise be extremely dif- ficult calculations. Take calculus for example. Pencil-and-paper in- tegration of anything but the simplest functions can be a nightmarish task. But with array 5 ID O 65 LISTING 5 400 AVG=0 410 FOR 1=1 TO N 420 SWAVE(1)=SWAVE(I)*SWAVE(I) 430 AVG=AVG+SWAVE(I) 440 NEXT I 450 AVG=AVG/N 460 RMS=SQR(AVG) 470 PRINT RMS processing, any function repre- sented by a series of numbers can be quickly and easily integrated or differentiated. Integration, for example, is the process of computing the area under a curve. In array process- ing, that means multiplying each element of the array by the sam- pling interval value (e.g. the time increment represented by each samplej. Integration is then com- pleted by computing at each point the sum of the samples pre- ceding that point. Listing 6 shows one example. In that program segment, FUNC is the array containing the waveform or function values to be integrated, and INTEGRAL is the array containing the results of integrating FUNC. If, for exam- ple, FUNC has 30 elements (n = 30), if all elements are equal to one (1), and if the sample inter- val is one (dt=l), the computed values for INTEGRAL will be 0, 1, 2, 3,... 29. The computation as- sumes that there are no values (and thus zero area) preceding el- ement number one. Hence, ele- ment one always has a value of zero and element two equals the first incremental area (0 + 1). Al- ternatively, you could assume that the first element of INTE- GRAL should contain the first in- cremental value of FUNC, in which case the FOR loop should start incrementing from one rather than two. To differentiate a function, you simply compute the point-by- point slope (rise over run) of the array values. The general for- mula is: m = (Y 2 -Y I )/(X 2 -X 1 ). Listing 7 shows one way to make the computation. If FUNC is a ramp of values run- ning from to 29, as obtained from the preceding integration example, the values computed for DIFF will all be equal to 1 . That is to be expected since the dif- ferentiation operation is the in- verse of integration. As a point of interest, notice that the differentiation routine uses a FOR loop running from 1 to n — 1. The reason is that for n points, there are only n — 1 inter- vals between those points over which slopes can be computed. Also, there isn't a final interval for computing the value of n. To get around that problem, the last val- ue (the value for n) is assumed to be equal to the preceding value tn-1). A sampling of statistics Until now all of our examples have been of calculations on ar- ray values. Sometimes, however, especially in statistics, the analy- sis may be more a matter of searching out specific array val- ues or rearranging array values to cast a new slant on the data. For example, after accumulat- ing a large array of data, you may need to find the maximum or minimum value of data and its location in the array. Finding maximum, minimum, and mid- point values is a common re- quirement when analyzing pulse waveforms for rise time, fall time, width, etc. Maximum, mini- mum, and midpoint values are also useful in analyzing stock market data. Listing 8 shows how to search an array (X) for its maximum value. In that example, MAX will con- tain the maximum value found in the array and MAXPT will con- tain the array element number where that maximum was found. If you want to find the minimum value, simply change the less- than sign in line 820 to a greater- than sign. (You'll probably want to change the variable names to MIN and MINPT as well.) It should be noted that, in the LISTING 6 LISTING 8 600 PRINT "ENTER SAMPLE INTERVAL VALUE" 800 MAX=X{1) 610 INPUT DT 810 FOR 1=2 TO N 615 SUM=0 820 IF MAXS TV-SCOPE PSM RESEARCH. Box 3M3 ■1 1 1 tMBPort, P» 17701 An Inttrsstlng and worth- Mhlla project. IMs EASY- TO-BUILD circuit lota you use Liiiy regular TV set as a sluplo OSCILLOSCOPE. Ho riKxil Meat Sana to TVI Tiny, sv battery powered. Goes anywhere I Order newL Ask for our FREE CATALOG of other plans and kits I SURVEILLANCE transmitter kits are available to (aw enforcement agencies that operate on frequen- cies they prefer. Four models of each; telephone, room, combination telephone'room transmitters tune from 65 to 305 MHz. Send S1.00 [overseas airmail $2.00) for catalog. Included is Popular Communications book review of "Now Hear This! Electronics Eavesdropping Equipment Design" by Winston Arrington. Book contains 58 transmitter schematics. SHEFFIELD ELECTRONICS, 7223 Stony Island Ave., Chicago, IL 60649-2806. I N V E STI G ATO RS, experim enters — Quality plans. Micro and restricted devices. Free catalog. Self ad- dressed stamped envelope required. KELLEY SE- CURITY INC, Suite 90, 2531 Sawteiie Blvd., Los Angeles, CA 90064. ^ NEW HE NE V^. LASER TUBES $35 ^^ Dealer Inquiries Invited, Free Catalog! MEREDITH INSTRUMENTS: 6403 N. 59th Ave. Glcndale, AZ B5301 • (602) 934-9387 "Tht Sourctfor Laser Surplus" CB Tricks II book. Power amplifier design and theo- ry, UHF CB tune ups. Send $19.95 MEDICINE MAN CB, PO Box 37, Clarksville, AR 72830. DETECTION — Surveillance, debugging, plans, kits, assembled devices. Latest high-tech catalog $5. DETECTION SYSTEMS, 2515 E Thomas, #16-864F, Phoenix, AZ 85016. DESCRAMBLING, new secret manual. Build your own descramblers for cable and subscription TV. Instructions, schematics for SSAVI, gated sync, stnewave, (HBO, Cinemax, Showtime, UHF, adult) $895, S2.00 postage. CABLETRONICS, Box 30502R, Bethesda, MD 20824. CABLE-TV BONANZA! -CALL FOR AVAILABILITY Name Address State □ Cashier's Check Acct # Signature Zip □ Money Order City . Phone Number) ) □ COD □ Visa Exp. Date ITEM 1 UNIT 10 OB MORE HAMLIN HCC :iOOU36COnOEC HEMOTE CONVERTER. >f:'' I yi 25 00 ■ a i a PANASONIC WIRELESS CONVERTER lour nrsl t)„yi 9B0O 79 00 STAR GATE 2000 68 00 >-,9 00 ■JEPiROLD 400 COMBO 169 00 ; ■ !) oo JERROLDJGO HAND REMOTE CONTROL 29 00 ■■ ; ■>.; ■JERROLD J«) COMBO 1 99 00 139 00 JERHOLD 450 HAND REMOTE CONTROL 29 00' IS 00 .: . i :■ ■: ;. :■: ■-•:.'[.' ■ ■* 99 00 0] CO -JERROLO SB-ADD-ON WITH THIMODE 109 00 75 00 "M-35 B COMBO UNIT iCh 1 oulpol only, 99 00 70 00 ■M-35 B COMBO UNIT WITH VARISYMC 109 00 7', 0-3 ■MINICODE IN-l?i 99 00 fi? :•: ■MINICOf- '- '- >'■ rn VARISYNC 109 00 65 00 "MINICODE VARISYNC WITH AUTO ON-OFF US 00 105 00 ECONOCOOE inninicodo su tan lulu i 69 00 4200 ECONOCODE WITH VARISYNC '■- :<: 46 00 ■MLD-1?O0-3 iCh 3out pl ,n i-j .- 62 00 'MLO- 1200-2 iCh 2oli1b :!j"ly 2JO0 U 00 EAGLE PD-3DESCHAMBLER iCr, :if)iit|lul wily. 1 1 9 in 6'; 1(0 'SCIENTIFIC ATLANTA ADD-ON REPLACEMENT DESCRAMBlER 119O0 65 00 Quantity Item Output Channel Price Each TOTAL PRICE SUBTOTAL from shipping any cable descrambling unit to anyone residing in the state of California. Prices subject to change without notice. Shipping Add $3.00 per unit COD & Credit Cards — Add 5% PLEASE PRINT TOTAL d Mastercard 8 FOR OUR RECORDS: DECLARATION OF AUTHORIZED USE — I, the undersigned, do hereby declare under penalty ol penury that all products purchased, now and in the tutu re. will only be used on cable TV systems with proper authorization from local officials or cable company officials in accordance with all applicable federal and Slate laws. FEDERAL AND VARIOUS STATE LAWS PROVIDE FOR SUBSTANTIAL CRIMINAL AND CIVIL PENALTIES FOR UNAUTHORIZED USE. Dated: Signed : Pacific Cable Company, Inc. 7325% RESEDA BLVD., DEPT. R-5 • RESEDA, CA 91335 (818)716-5914 • No Collect Calls • (818)716-5140 IMPORTANT: WHEN CALLING FOR INFORMATION Please have the make and model # of the equipment used in your area. Thank You ? IP to 91 UNICORN YOUR I.C. SOURCE COLLIMATOR PEN Alow power collima- tor pen containing a MOVPE grown gain guided GaAIAs laser. This collimator pen de- livers a maximum CW output power of 2.5 mW at 25 °C. These colli mated laser sources are designed for industrial applications such as data retrieval, telemetry, alignment etc. The non-hermetic stainless steel encapsulation ot the pen is specifically designed for easy alignment in an optical read or write system, and consists of a lens and a laser device. The lens system collimates the diverging laser light. The wavefront quality is diffraction limited. The housing is circular and precision manufac- tured with a diameter of 11.0 mm and an accuracy between + and - 11»im. ■ucTnniGc$mo.on price $39.99 Quality Components — Low Prices Since 1983 LASER DIODE Designed for general industrial low power ap- plications such as read- ing optical discs, optical memories, bar code scanners, security sys- tems, alignment etc. The gain guided laser is constructed on a n- type gallium arsenide substrate with a Metal Organic Vapor Phase Epitaxial process (MOVPE). The device is mounted in an hermetic S0T14BD (diameter 9.0 mm) encapsulation. The SB1053 is standard equipped with a monitor diode, isolated from the case and optically coupled to the rear emitting facet of the laser. This fast responding monitor diode can be used as a sensor to control the laser optical output level. i i~Trrii'~n|iflnnn price $9.99 We Carry A Full Line ot Components CALL FOR FREE CATALOG EPROMS STUCK » PINS OESCIIPTItlN 1-!4 25-W W- INK zra zraa 27I6 nmi matins 1024 1 8 450ns 1024 x8 450ns 2048 x 8 450ns 125vf 2048x8 358m (25v) 3 39 5.79 3.99 3.19 3.39 3.79 3.41 5.50 4.95 3.79 341 3.03 2.73 3Z2 2.90 1MSZ718 2-) 2040 x8450ns 629 59fl 53(1 Z7C1B 24 2048 X 8 450ns (25I/-CWSI 3.59 341 307 Z73Z 24 4095 X 8 450ns &Si) 379 3 SO 324 Z73ZH-Z 24 4098 X 8 200ns {21 V) ■i.m :i60 324 Z73ZH n 4095 X 8 250ns 121 v) 369 351 3.16 Z73ZH4 24 4095 X 8 450ns BU) :i« 294 J65 TMS2S3? 24 40mx8450ns(25v) 5 79 550 4.95 27C3Z 24 4090 x 8 450ns &5V-CMOS) 4.19 39ft 358 2784 20 a 8t92xt200nst21v) 3.99 3.79 3.41 Z7M a 8192 x 8 250ns I21«) 359 3.41 307 Z 764* 20 a 8192 x J 200ns I12.5v) 399 379 3.41 2764* a 8192 X 8250ns I12.SV) 3.33 341 3 07 ™S2S&! a 8192 x 8 250ns t25v> 6/9 645 S>81 HI2MH a 16.384 x 8 200ns 121 v) 5 79 5.50 4.95 Z7128 u 18.304 x 8 250ns I21v) 4 79 4.55 4 10 ZTCI2S 2E 16.384 X 8 250ns 121 v) 539 5.1Z 4 61 27R6-20 m 32.758 X 8 200ns I12.5VI 593 509 512 Z725S 21 32.7Mx82Sanstl2.5v) 4.99- 4.74 4.27 zrezM a 32.768x8 250ns <12.5v-CM0$l i'fl 5 HI 51? 27512-21] m 65.536 X B 200ns 112J5V) 10.49 8 9/ 8.97 27512 a 8i.5Xx82SSai12.5v) 949 902 6 '.2 27C512 M 55.536 x 8250ns (I2.5v-CM0S) 999 949 654 2701024 32 131.072 x 8200m »Im. ■!■> ^ A Htikml PuUiatiu Ft Jht Rgg AM Sttimf OfBtetmie fiwjwg BEST BY MAIL Rates: Write National, Box 5, Sarasota. FL 34230 MONEYMAKING OPPORTUNITIES EARN SM,0OO + . OBTAIN 100 bankcards. Send stamp. Universal. 3010 Wilsriire. #J14. Los Angeles, CA 90010. BUY BONDS MASTERCARD AND VISA are now accepted for payment of your advertising. Simply complete the form on the first page ot the Market Center and we will bill. EDUCATION & INSTRUCTION LEARN IBM PC assembly language. 80 sample programs. Disk $5. 800k $18. ZIPFAST, Box 12238, Lexington, KY 40581-2238. MAGIC! Four illustratecf lessons plus inside infor- mation shows you how. We provide almost 50 tricks including equipment for four professional effects. You get a binder to keep the materials in, and a one- year membership in the International Performing Magicians with a plastic membership card that has your name gold-embossed. You get a one-year sub- scription to our quarterly newsletter "IT'S MAGIC!" Order now! S29.95 for each course + $3.50 postage and handling. (New York residents add applicable state and local sales tax). THE MAGIC COURSE, 500-B BiCounty Boulevard, Farmingdale, NY 11735. Computer Kits Theirs Fun, Easy to buEld, |BU Compatible, [ducaltonal h Powerful wilfi Wholesok Prices. All Kits inciude a Free Assembly Manual Free Software, One Yeor Warranty and 24 hour Phone Supp-ort Line Ask for cur Free Catulog (516) 9B1-9473 General Technics Quality Compultar Syitem; F.O, Box 2676 ■nbly fc Tailing AMallnbhi t_ a fe # Ronltonltoma, KY 11779 92 CIRCLE 1B6 0N FREE INFORMATION CARD CABLE TV EQUIPMENT SATELLITE TV Converters, Remote Controls, De scramblers, CD Players. JERROLD- OAK-SCIENTIFIC ATLANTA-HAMLIN ZENITH MANY MORE CALL TODAY! V Only quality products sold t/ Easy to use "v Satisfaction guaranteed V Knowledgeable sales staff V Most orders shipped within 24 houis CALL FOR YOUR FREE CATALOG 1-800-228-7404 B MAKE THE CONNECTION WITH NLI-TEK ELECTRONICS |l 51 14 Balcones Wood Dr.#307 DcpL298 Austin, TX, 7S7S9 BE a recording engineer; Train at home for high paying — exciting careers. Free information AU- DIO INSTITUTE, 2174 Union St., Suite 22K. San Francisco, CA 94123. BASIC cleaning and maintenance TV one half hour, VCR one hour $38.00 each. JAMES BRADFORD, PQ Box 38359, Detroit, Ml 4B238. FREE subscriptions to over 200 major computer and business magazines — guaranteed. Write for free information: SEABIRD, 4N Militia Drive, Lex- ington, MA 02173, FREE catatog - Do-it-yoursell save 40-60%. Lowest prices worldwide, systems, upgrades, parts, all ma- jor brands factory fresh and warrantied. SKYVI- SION, INC., 2009 Collegeway, Fergus Falls, MN 56537. 1 (800) 334-6455. DESCRAMBLER: Build our low cost video only, s ale 1 1 ite TV d escf am bier for most satellite channels. Uses easy to get, everyday parts. Board & plans $35.00 US funds. Board, plans & parts $99.00 US funds. Wired & tested unit $169.00 US funds. Send check, money order or Visa to: VALLEY MICRO- WAVE ELECTRONICS, Bear River. Nova Scotia, Canada BOS 1B0 or phone (902) 467-3577. 6am to 4pm eastern time. Note: educational project only. Not to be used illegally. CABLE TV secrets — the outlaw publication the cable companies tried to ban. HBO, Movie Channel, Showtime, de-scramblers, converters, etc. Sup- pliers list included. $3.95. CABLE FACTS, Box 711- R. Pataskala, OH 43062. T W ( -fc-K-fc-K-KpRESENTING***** CABLE TV DESCRAMBLERS ***** STARRING ***** JERROLD, HAMLIN, OAK AND OTHER FAMOUS MAIM UFACTUREHS • HNCTWAMAftnT PROGRAM MAILABLE • LOWEST RETAIL/WHOLESALE PACES NV U.i. • OrtDE RS &H1FTEQ FrfOM STOCK UrITHIJV H HQLfflS FOR FREE CATALOG OMv 1-100-345**927 FOB ALL INFOS MA7JON 1 -S IS-7T6-59T4 PACIFIC CABLE CO. IMC. IJTS-t RESfOA BLVD. DtPF flEl 89 3 FORI SPECIAL ON SUB-MINIATURE VOICE FN! TRANSMITTERS. KITS CONTAIN PC BOARDS 'FMX-1 LONG RANGE (3 Ml) ULTRA SENSITIVE FM VOICE XMTR with fine tune, range control plus $29.50 •TELX-1 TELEPHONE FM XMTR (3 Ml) auto- matically operates when phone is used. Crystal clear clarity with fine tune and range control. Non detectable $29,50 ■ATR-1 AUTOMATIC TELEPHONE RECORDING DEVICE tapes telephone conversation all automatically $19.50 ALL THREE OF ABOVE FOR $59.50 CALL OR SEND VISA, MASTER CHARGE, MONEY ORDER, ETC. TO A MAZING CONCEPTS. BOX 716, AMHERST, NH 03031. (603) 673-4730. MAAQV 1/ r#r/»TD/l A/!/**" !*#/• CATALOG & INFORMATION (21 3) 888-8988 /nrl#|J% w CLCv lt\vnl UJ, ffwv. order toll free 800-423-3433 IN CALIFORNIA 800-521 -MARK QUALITY COMPONENTS * COMPETITIVE PRICING FAX (21 3) 888-6868 a Beginner 11 Intermediate AAA. Advanced * Fully Assembled a indicates the level of difficulty in the assembling ofour Products. •*' 91 iX / ! % J «C*7T5 '" TA-1 - m nm§ km* \ _. SM-666 *MF> '1r»W TA-2200 ™ We provide transformers for most of our Mark V amplifier kits. AMPLIFIERS kit ASSMIB MODEL DESCRIPTION TA-28MK2 Digit*! Voice Recorder ** 30.00 TA-50A/B Multi-Purpose Melody Generator A 11.84 S 18.58 TA-SOC Multl-Purooa*. Malodv Generator A 12 65 17 71 TA-120MK2 35WCIsss"A" Main Power Mono Amp A A 17. 18 38.81 TA-300 30V7Multl-Purpoae Single Channel Amp A 20.00 29.00 ta-302 eow stereo Power Booster 50. oo 70.00 TA-323A 30Wx2 Stereo Pre-rnsin Amp. A 29.50 38 35 TA-377A HI-QUALITY FET Stereo Pre-Amp-AAA 59.95 75.00 TA-400 40W Solid State Mono AmpA 28.00 34.03 TA-477 I20W Moslei Power Mono flitipAA,. 88.00 85.00 TA-SOO 8OW-I-80W DC Pro-Main* Power Amp. A A 60.92 '9 20 TA-802 8OW-I-80WDC Stereo Main Power Amp. A A 45.94 59 72 TA-820A 80W-+ 6QW OCLDC Pre-Main StereoAmp. AA . 40.39 49.37 TA-1OG0A 100W Dynamic Claw "A" Main Power Mono Amp. 59.69 60-88 TA-1 5O0 1O0Wx2Clasa'"A"DCStereoPre-MalnAmp*,AA73.70 95.81 TA-2IOO FF-TSuper class "A DCPreAmp. AAA 47.70 5B.24 TA-24O0A ElectronicEchoS RovelationAmpA A A* 83.30 116.80 TA-2500 HOFre-AmD. w/ 10 band □ roDhic oaualiier* ... 90.80 TA-2BOO be-fet IC Pre-Amp. w/3 way ion* control AA ..... 48.90 63.57 TA-3OO0 Stereo Simulator i For mono TV or any mono aourcelsO^O 41 3B TA-38O0 3O0W HQ HI-FI Power Mono Amp. AAA 79.00 103.00 POWER SUPPLIES KIT ASSMB TR-100A Q-15V 2A Regulated DC Power Supply (w/casej AAA 59.50 69.50 TR-355A Ct-1 5V 5A Regulated DC PowerSupply A 14.55 20.76 TR-355H O-30V 3A Regulated DC Power Supply A 14. SS 20.76 TR-503 O-S0V3A Regulated DC PowerSupply A A 15.75 J2.65 vtn# > * OOOA Cabinet MODEL TY-23B TY-25 TY-36 TY.3S TV-41 MKV TY-42 TY-43 TY-4S TV-47 SM-222 SM-328 SM-333 SM 666 SM-43 SM4B SM-48A SM-49 SM-100 FC IOOOA MODEL LO- 1 273 LG-1664 LG-1 B24 LO-1925 LG-1983 TA-2500 .MLSCKLLANKOrS KIT ASSMB . DESCRIPTION 3 Channel Color Lrghl Controller AAA* 3 58.04 S74.50 Stereo Loudspeaker Protector A--..*"»-.» ..... 12 65 18 88 AC/DC Quartz Digital Clock A 18.00 25.20 Sound/Touch Control SwitchA..... 12.00 Inlared Remote Control Unit w/case AAA 20.00 35.00 Bar/Dot Level Meter A A.. - 24.1 5 3 v.- Digital Panel Meter A 29.00 38. 00 20 Stepa Bar/Dot Audio Level Display A A .... 36.45 46.14 Superior Electronic Roulette A A 19.46 27.24 7 Band HI-FI Graphic Equalizer AAA* - 26.80 38.80 4 Channel Professional Color Light Controller * 150.00 And io/ Video Surround Sound Processor AAA* 62.00 83.00 Dynamic Noiaa Reduction A 26.00 34.00 INSTRUMENTS KIT ASSM B. 3' ■ Multi-Functional Led D. P.M. (w/ABSplasticcase)AA34.SQ 43.00 4V> Hi-Precision D.P-M. AAA 38.00 48.00 4Va Hl-Precision D.P.M. w/ABS clastic case AAA 41.20 52.00 3Vj Multi-FunctionalLCDD.P.Mlw/holdfunction] AA 38.0O 44.50 150 MC Digital Frequency Counter AAA 7900 90.00 1 GHz Frequency Counter * ' 179.00 METAL CABINETS WITH ALlT.MI.NI'M PANEL: H'ir.I D MATCHING 3" 12" 7" TA-2800, TA-37 7A 4" 16" 8" TA 322i. TA-323A. TA-377A 4" 19" llVi" TA-802, TA-820A. TA-1500. TA-120, TASOO, TA-1000A 5" 19" IIW TA-477, TA800. TA-1 5O0. TA- 1000A -WE ACCEPt MAJOR CREDIT CARDS MONEYORDERSANDCHECKS- BUSINESS* SHOWROOM HOURS (PACIF1L TIMEi MOf. FBI 9:30AM 500PM. SAt 1000AM- 500 PM TERMS $1000 MIN ORDER SiOMIN CHARGE CAHDORDER WE SHIP UPSGROUND* ADD ICfleOF TOTALORDERiMIN S300I FOR SHIFPINGOUTSIDE USA ADD SffVlMIN 55 001 TRANSIT INSURANCE ADD5\,0F TOTALiOUTSlUE L1SAONLYI.CARES1DENTSADDSALESTAX' ALLMERCHANUISE SUBJECT TOPRIORSALE PRICES ARE SUBJECT TO CHANGE WITHOUT NOTICE ■ WE ARE NOT RESPONSIBLE FOR TYPOGRAPHICAL ERRORS MARK V ELECTRONICS, INC. — 8019 E. Slauson Ave., Monicbello. CA 90540 CIRCLE 93 ON FREE INFORMATION CARD O 93 CABLE TV CONVERTERS & EQUIPMENT * ONE 10+ UNIT UNITS PANASONIC WIRELESS CONVERTER 85.00, . . 69.00 JERROLD 400 COMBO W/REMOTE (DHX3DIC) 134.00. . . 95.00 JERROLD 400 OR 450 REMOTE HAND UNIT £4.00... 15.00 JERROLD JRX 3DIC 84.00. . . 65.00 JERROLD SB ADD ON 74.00... 55.00 JERROLD SB ADD ON WITH TRI-BI 95.00... 70.00 OAK M-35 COMBO 79.00. . . 50.00 OAKMIN[CODE[N-12) B4.00 59.00 HAMLIN MLD 1200 64.00. . . 45.00 SCIENTIFIC ATLANTA SA-3 ADDON 109.00... 75.00 INTERFERENCE FILTER (CHANNEL 3 OR 6) 24.00... 14.00 NEW SCIENTIFIC ATLANTA COMBO 275.00. . 215.00 PIONEER DESCRAMBLER . 250.00 200.00 TOCOMVIP 200.00.. 175.00 ZENITH FLASHING 175.00.. 150.00 ZENITH SSAVI 125.00... 90.00 EAGLE PD-3 95.00. . . 75.00 VIDEO-LINK Enterprises, Inc. 520 GLENBROOK RD.. SUITE 202 STA MFORD, CT 06906 ORDERS: 1-800-622-9022 CATALOG & INFO: 203-975-7543 MONDAY - FRIDAY 1 AM — 5:30 PM, E.S.T. IMPORTANT: Have make and model # of the equipment used in your area. QTY ITEM OUTPUT CHANNEL PRICE EACH TOTAL PHiCt NG CONNECTICUT SALES. II SUBTOT. is not the Intent of \ to defraud any pa operator and we wi any company or i 1DEO-UNK i television Shipping $3 /Unit dividual In COD: Add 5% PLEASE PRINT: TOTAL □ CASHIER'S CHECK NAME_ ADDRESS □ M.O, D C.O.D. CITY/STATE/HP PHONE SIGNATURE WAIVER. Since I, iho undersigned, fully understand that the ownership of a cable decoder does not give the owner of the decoder the right 10 decode or view premium cable channels without proper authorization from their local cable company, hereby declare under penalty of perjury that all products purchased, at any time, will only be used on cable TV systems with proper authorization from local officials or cable company officers in accordance with all applicable federal and slate laws. Federal and various stale laws provide for substantial criminal and civil penalties for unauthorized use. Daied: Signed: CONSOLIDATED EL E T R O N I C S < DC CIRCLE 64 ON FREE INFORMATION CARD THE ULTIMATE ELECTRONICS CATALOG Order your 260 page catalog and price Hit with over 14,000 money Buying electronic parti and equipment! Send $3.00 in a check or money order, or call 1-800-543-3568 today and me your Maitercard or Vila. Consolidated Electronic i , Incorporated 70E Watcrvliot Ave., Dayton, Ohio 45420-2699 Name Addreti_ City _3tate_ _Zlp_ CIRCLE 70 ON FREE INFORMATION CARD SATELLITE descrambiers, all types, reasonable prices. Catalog $4.00. SKYWATCH, 238 Davenport Road, Toronto, Ontario, Canada, M5R 1J6. VIDEOCIPHER II manuals. Volume 1 — hardware. Volume 2 — software. Either $32.45. Volume 3 — projects/software — $42.45. Volume 4 — repair — $97.45. Volume 5 documentation — $42.45. Vol- ume 6 — Experimentation — S42.45. Cable Hacker's Bible— $32 45. Clon e H acker's Bible — $32.95 CODs: (602) 782-2316. 220+ Megabytes IBM-PC/XT software — catalog-$3,00. TELE- CODE, BOX 6426-RE, Yuma, AZ 85366-6426. ATLANTIC GROUP ENTERPRISES INC. Buy sat- ellite equipment. Dealing directly with the seller. We can show you how. Toll free 1 (800) 446-4033. VIDEOCYPHER II descrambling manual. Sche- matics, video and audio. Explains DES, EPROM, CloneMaster, 3Musketeer, pay-per-view (HBO, Cin- emax. Showtime, adult, etc.) $1 3.95, $2.00 postage. Collection of software to copy and alter EPROM codes, $25. CABLETRONICS, Box 30502R, Beth- esda, MD 20824. CABLE TV DESCRAMBLER LIQUIDATION! Major Makes & Models! Will match or beat anyone's prices! Dealer discounts at 5 units! Examples: HAMLIN COMBOS $44 ea. (Min. 5) OAK ADD/ON $40 ea. (Min. 5) OAK M35B $60 ea. (Min. 5) WEST COAST ELECTRONICS For Information: 818-709-1758 Catalogs & Orders; 800-628-9656 CABLE T.V. CONVERTERS WHY PAY A HIGH MONTHLY FEE? All Jerrold, Oak. Hamlin, Zenith, Scientific Atlanta, Magnavoxand all specialized cable equ ipment available for shipment within 24 hours. For fast service MC/VISAor C.O.D. telephone orders accepted (800) 648-3030 60 Day Guarantee (Quantity Discounts) 8 A.M. to 5 P.M. C.S.T. CLOSED WEEK- ENDS. Send self-addressed Stamped enve- lope (60c postage) for Catalog. 3_ P.O. a™ soon miDUJeST Sl! i, B w (m BUSINESS OPPORTUNITIES EASY work! Excellent pay! Assemble products at home. Call for information. (504) 641-8003 Ext. 5192. MAKE $50^hr working evenings or weekends in your own electronics business. Send for free facts. INDUSTRY, Box 531, Bronx, NY 10461. YOUR own radio station! AM, FM. TV, cable. Li- censed/unlicensed. BROADCASTING, Box 130- F5, Paradise, CA 95967. GIT l\ \mt 0\ I III. SI 2 IUU10N A YEAR COMPUTER SERVICE INDUSTRY LEARN HOW TO CLEAN/ LifiM] MAINTAIN/REPAIR PRJHTERS... viej:"!. «H»m-mmm»t rnumm fttsio iko mmutwam ACTION-PACKED PAGE!) imut scaurs OF PRINTER REPASR . WITH YOUR AYEflASf MECHANICAL ABTLIT* V)E CAN SHOW roil HOW 10 BEPAIB UP TO »% OF ALL PRINTERS - STMT fin HI KG EXTRA CASH IN OATS' ■ HUGE UNTAPPED MAHKE1! • lERIOUI LACK OF TMIKED TECHNICIANS . . . OVER 31 MILLION PC'S IN USE . . APPROXIMATELY IS* HAVE* HUNTED AT TAC HEO , . M tTHMBMTr OF PB ID TEH I RSA ro OWN S * RE CUE TO SIM PLE MECHANICAL OR ELECTH0-MECHANICAL FAILURE OK WHITE TO IIEJ0 MMUCM1MM 3EI0 , removes lead vocal from standard stereo Li records & CD's! Unlimited Supply of \ ^^6>.BackgTou nd Musict Eaii |y Record or \ / ^i Perform with riie Backgrounds. Used ' Professionally, yet connects easily to home component stereo^ Manufactured and Sold ExcrtiikiiwJy by l.T Sound. For Free Brochure & Demo Record. Call: LT Sound , Dept. I i L ■ 1 . 7981 LT Parkway, Uthonia.GA 30058 (404)482-4724 24 Hr. Phony Dc mo/Info Request Line: (40 4)462-2455 WANTED INVENTORS! Confused? Need help? Call ihpac (or free information package. In US and Canada: 1 (800) 225-5800. _^__^ INVENTIONS/new products/ideas wanted: Call TLC! lor free information 1 (900) 4E8-7200 24 hours' day - USA/Canada. COMPUTER BOOKS DISCOUNT computer books. All titles available. including recent releases. Please call or write lor our latest catalog. BOOKWARE, 147 Campwlle Road, Northfield, CT 06778. 1 (800) 288-5662. TELEPHONE CALL SCREENING REAL telephone call screening! Protect tele- phones, Fax, computer, hearing impaired, day sleepers. Eliminate wrong numbers, prank and sales calls. Ptugin unit provides variable ring cadence signaling. True unlisted number on any touchtone private line. Automatic call routing. Send 513.95 for complete theory and con- struction manual. ELECTRONIC CONTROL SYSTEMS, R.D. 2 Box 3308, WernersviKe, PA 19565. CABLE TV "BOXES" Converters — Desc ram ble rs Remote Controls — Accessories * Guaranteed Best Prices * * t Year Warranty- CO s t • Immediate Shipping * * FREE CATALOG • Callor Write TRANS- WORLD CABLE CO. 1 2062 Southwest urihCoun. Suite lis Miami. Florida 33186 l-BOO 442-933 i INVENTORS INVENTORS! Can you patent and profit from your idea? Call AMERICAN INVENTORS CORPORA- TION for free information. Over a decade of service 1 (800) 338-5656. In Massachusetts or Canada call (413) 568-3753. TUBES - 2000 TYPES DISCOUNT PRICES! Early, hard-tofrnd, and modern tubes. Also transformers, capacitors and parts for luPe equipment. Send $2.00 for 24 page wholesale catalog. ANTIQUE ELECTRONIC SUPPLY 688 W. First St "Tempe, AZ 85281 "602/894-9503 [NfttARJUJ l-KPrXTOFt KIT titttf fm rTipmvl In «|l FTr"n v$ mh4T>\ \\ •■<>•. m. ifrTMK* LHWirrnlVrt ind l.l'On lv r'LhPuf -if: imiaJ iivl Ijchntuj I ll>l[h| rfl I.I II Gmi ?■■' tn-.-.J Lr.l *fiJu*rKin uf Lufpimij orri>| t.i\ km »m ufetra if* 1 1 Jim ui 1'rHij f*|>rtrt.1 to I I if it l. ■Mm iJUll iWr l4l Wltrftlt. (nvpi^f Dm'. fflinlbfc, r*fttt*rtiw n> Ii -i titan. He. hie ilrrrui uptM h***, (» • ■• I Vn* rtillllUn irtii Ifirum, n-ii>"i- vi.n,li-» <:** . nl ii- wnb » i in-uii. I mn> I. in jiWpfKrmnj to in-nrv—i > uf , i ■ u. nntv U"n |" l,]f.rnrn f-r,m nulrfHi ►>■" r l«M.r IrttluiVlr, WHh *n run kM PC I-jjm! 20* *aoi MdcKu amp mi Tw«i inrpiir ii'rh - 6 o- rtw , oifmlfQ, H*8 «-c Lh •••- - inrpi nn "i 1 FC (tojrd t ii-ft irap hii in. ■&»* Irirl can Mi>l inJ Irujm OUT Jit IfiJcvJibli JO fftHu ft*i r-C,1gltFt rtll C f □ "i>n" imlifitcn "rrJ low JiiiejriOji n.r a*\trj tfru firrro hTirr imf foi p/Ditr TO KHinill tViEfBI. lir pith In' >r * " * '» Lip*Mr Hr h|n.1'ir| n rrim M » op um»f. *"fc'i'n* Jf h i f^442 119.95 H>H +-10WBTE&EO WIPKIT Wfltlhl M lh< imp jbm< iHilt :hn m< put* 'ii ! a wain KM% w mi, Ii rfitirtrl lllgrn ■ "■r- liTvrl ,.irMrril ihv *K u> n in IhhH . hj-^r^i. jr.l crJ It'li 'W Hrwl.ru, if Um i'i-s imp wim jmjr ,*ul',>. id beiju rin u i'i i;-. i-l ii i-r, :.,!,i.,. <, r m ji|.»i.r> 1u Evlr ilth ipppi filhrnj vnlumr- i^'Hn from laVlM tA-iili i5l njrti mu f- I ■■->■ i.l <:6443 IIA.95 50 WAIT KMS MtWO AMP KIT Mhth Jtrn^l irtip [Of Yifi'.'U h hlKtiltr tk>m Bihfrriu™. iJhiiri iiYn-yjf »nit * run piaititrti inJ hii wrf Imr Ji (ffc M hmj. Afflfhlififr ki4 c/tl J.PD "flu"' ji.Virilrw inJ « |l bwHl JPiy tMirn^ rjjtani. (.mrircf, CD plitrr ■■> ihhii fslUrhj inTluim« i-j: «J T nut ifrnkfc! Ojp«rU Utt.i: ■ CIRCLE 179 ON FR EE INFORMATION CARD When You Need Resistors, We Sell You Resistors (And Gravy), But Not Printed Matter! Resistors ore one of the most common of electronic component parts and having a good reliable source for them Is a necessity. For years we have been the lowest price leader in this (and many other) areas, and the following price comparison table proves that although we ask for o yearly Membership Fee of $35,00, you can recover your Investment quickly after purchasing just a few thousand resistors, and what you will save on more than 1 0,000 additional items that we stock, is the so-called 'gravy' part of the whole deal. Resistor Type 1/4 Watt, 5% Carbon- Fllm (Bulk) V4 Waft. 1%, Metal- Film (Sulk) Quantity 10 1D0 1.000 10,000 10 100 1.000 Electronic Buyers Club $ 0.77 4.76 43.20 0.32 1.14 S.2S Digi-Key® (No Discount) S 0.50 1.70 8.10 72,00 1.00 3,90 20.00 Digi-Key® (Max Discount) S 0.375 1.275 fl.10 72.00 0.75 2.925 20.00 Jameco Electronics® S 0.50 2.50 11.95 99.50 3.29 17.95 JDR Microdevices® S 0.50 2.00 15.00 Sintec® S4.00 12.00 8.00 30.00 12 Months Saving Guarantee We will refund tlie first year Membership Fee of any member who has purchased $300 or more worth of products from Electronic Buyers Club and has not saved an amount greater than the first year Membership Fee, if buying the same items elsewhere. It is not that these other firms are trying to rip you off. the fact is that advertising in several Trade Magazines each month and printing and mailing hundreds of thousands of virtually the some catalog every few months cost a lot of money and they have to charge more. Call us today and start receiving components for your money instead of printed matter. 30 Days Money Back Guarantee We will refund the full Membership Fee of any new member of Electronic Buyers Club who within 30 Days after receiving the Membership Binder, returns the Binder to EBC and asks for the cancellation of Membership. lectronic rguyers ©lib A Division of InEertutionalCampanealx Corpcrtuicci 1803 N.W. Lincoln Way • Toledo, OR 97391 PHONE (All 50 States & Canada): 1 -800-325-0101 FAX: (503) 336-4400 • Hours: 6:00 AM - 6:00 PM PST MasterCard to to o CIRCLE 1B7 ON FREE INFORMATION CARD 95 AMERICAN DESIGN COMPONENTS COMPUTER BUFFS HOBBYISTS, AND SHARP SHOPPERS Smart shoppers always look for compo- nents & parts that are hard to find, easy to use, and ridiculously low In price. 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An entire year's membership is just $29,95, (We pay the postage.) Send your check or money order to: Crossword Puzzles of the Month Club 629 Green Bay Road, DepL 701 Wilmette, Illinois 60091 Or call toll-free: 1-8004334386 L and charge it to your MasterCard or Visa, o — 24 hours a day. 7 days a week — Your satisfaction is guaranteed. SPECIAL FROM ETT SAVE $$ TODAY D2617T— BUILD A RE- MOTE-CONTROLLED ROBOT regular $9.95 SPECIAL $8,95. Fool- proof Instructions for putting together your own full-size work mg robot at a ft action ol the commercial cost. MIMOTl CONTROLLED ROBOT roe woo ssti □ 2645T— 117 PRAC- TICAL IC PROJECTS YOU CAN BUILD regular $10.95 SPECIAL $9,95. Dozens of fully tested ready-lo-Purld circuils you can put together from read- ily available, low-cost ICS. □ BP53— PRACTICAL ELECTRONICS CAL- CULATIONS AND FOR- MULAE regular $6.95 SPECIAL S5.95. Si- basic sections: Units and Constants, Direct Current Circuits. 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Box 240 Massapequa Park, NY 11762-0240 SHIPPING CHARGES IN USA AND CANADA SO.01toS5.00 ...J1.25 S30.01 to S40.00 S5.00 S5.01 to 10.00 ...52.00 S40.01 to $50,00 S6.00 S10.01 to S20.00 S3.00 S50.01 and above S7.50 120.01 to $30.00 S4.00 SORRY, No orders accepted outside ol USA and Canada Total price of merchandise S Shipping (see chart) S Subtotal S Sales Tax (NYS only) S Total Enclosed t Name Address , City _State . .Zip. WORKBENCH continued from page 88 Notice in Fig. 5 how values are computed simply by stating an equation or function equiv- alence. For example, the average or mean value is subtracted from array PULSE by simply stating: pulse := pulse -mean{pulse) In the same manner, the max- imum value in array PULSE can be assigned to variable mx by: mx : = max(pulse) MathCAD is thus simple, quick, and clean, even for sophis- ticated functions such as the fast Fourier transform (FFT), which is the numerical-analysis equiv- alent of a spectrum analyzer, ex- cept that this spectrum analyzer can be applied to any array of nu- merical data. In fact, Fourier techniques and FFT's have been used to define and extract busi- ness-cycle information from eco- nomic indicators, stock market data, and weather data. Analysis packages such as MathCAD offer a wide range of capabilities from simple to so- phisticated. 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CABLE TV DESCRAMBLERS 10 Lol ,„ in JERROLD™Tri.B,MoA;.S105,00 185.00 CO fi JERROLD IM SB-3 0R2 SS9.00 $65.00 O ^_ bi LL1 KsmlinMUMMO SW.95 $6200 Z C ? — Oak N-12W/V.S.. 199.95 JSZOO Q < °- rsl OJt-M-JS-B W/V J S99.00 J7S.00 QT -r- D < OAKE-13 - „.. $99.95 $5S.O0 1— Q W O Zenith SS A VL $183.00 $145.00 O f- !5 J Eagle FD-3 $120.00 $85.00 UJ < \- S Scientific Allan. SI 29.93 $105.00 yj 2 ffj — SA-Conibo's. CALL $C!I - -J ^ I Tocctn. 1350.00 $295.00 Q ^ £ I— Oik N-12W/ Aula $140.00 $105.00 ^ & rf Z IcrroldSarmmCSV.... 5139.95 Cill ~ *NEW STARGATE 2000 CABLE CONVERTER 1-S89.00 10-S69.00 100-Call Last channel recall- Favorite channel select- 75 channel-Channel scan- Manual line tune- One year warr anty-surge protection- H FtC &Stand- ard switchable- and much more. Cfllt Todtiv! INFORMATION(402}554-041 7 Orders Call Toll Free 1-800-624-1150 M.D. ELECTRONICS 115 NEW YORK MALL SUITE 133E OMAHA, NE. 681 14 M.C. VISA mm, CIRCLE 53 ON FREE INFORMATION CARD i/f Parts //express fff m International Inc. EMINENCE .SN^ ® MOTOROLA PolydaX 1-800-338-053 1 M pioneer- 3-WAY 100W CROSSOVER la dBfoctave tollotf. SOOHx SODOHr, crossover points. 6 ohm. 100 Wltls RMS. $12.50 #260-210 *j. 9 ) t& go-up) SPEAKER CONTROL PANEL Fane] with 90 watt L-pads for tweeter and midranye and built-in LED power meter. 8"jt 2 W 100 watt version available $14.50 #260-235 (1-S) $12.90 (6-up) 12" POLY WOOFER Super duly, 40 or magnet. 100 wins M, 145 warts max. 4 and S ohm compat- ible (6 ohm), 2" voice coil- Is- 25 Hi\ QTS =.166, VAS^lO.Scua Response: 35-1500 Hi- Net weight; 9 lbs. Pioneer #A30GU40-S1D #290-125 ^M° «0 $34.50 (4-up) 15" WOOFER Original Sanyo woofsr. Paper cone wilh vented dust cap and treated doth surround. 12 02, magnet, 60 waits RMS, 85 watts max. A ohm. Resonance: 26 Hz. Response: 25- 2,500 Hi. #29T-155 $23" (1-5) $21 m (S-up) PIONEER HORN TWEETER Mylar done. ZM oj. barium forxite magnet. 8 ohm. Response: 1600- 30000 He. 39WRMS, BOWroai. (s-aOOOHl, SFL-lOSdB. Pioneer #AH£60-51F 4 #270-050 m $5.90 (10-up) /l- par is 'express 340 E. Fot< Si,, Dayton, Oho 43402 loctt l-Si-3-222-0173 FAX S13-Z&4&44 ' SSdtymoMT hack guarareM "Jt5.CC JTuTisiuri «d max- *" ntmd. Potydax p*n #DTWlOOTi2S. S27.50 #270-041 (i-9) ft- $24.80 (10-up) GRILL FRAME KIT With thus lot you can make spcaiter grtU trames up to 3Cjs40r. Kit includes 4 corner pieces, 2 T brackets, and 7 frame bars. Grill mounting kit Included. #260-333 CIRCLE 56 ON FREE INFORMATION CARD Mm Ordar ElfcrlniniCS ■ World* >df ameco ELECTRONICS 24 Hour Order Hotline 415-592-8097 - ^ _ SIP & SIMM MODULES Pari Ho. Function Price SiWr SSfPSS >«-saSt.iE3<;- 1BMPS-2 icons iMEGi 9 SIMM |2each| ,368.95 412S6A9A-10 262.144.9 100ns 256K X 3 SIP (Has Leans) . 44.95 412S6A9B10 262.144x9 (Ore 256K ■ 9 S MM 49.95 431OC0A6B.1G 1.04fl.576xa 103ns I MEG * 3 SIMM —.109.95 42IDO0A94.J0 I.C4<.576>9 Mrs IMEGx 95IP(Hlsl.t»3sl .. 124 95 421000A9B10 1.04t576x9 TOns 1MEGx 9 SIMM... 11985 "Upgrade lor Voaols 30, 50Z and 60 7400 PjllifcL 7400..- 7402 7404 7405 7406 7407 7408 7410 7411 7414 7416 7417 7420 7427 7430 7432 7438 7442 7445 7446 7447 7473 59 .19 59 .19 .35 .25 .39 .29 .39 29 35 .25 .29 35 .49 .29 .35 ,25 35 .25 .29 19 29 19 .29 .19 39 59 39 59 .49 39 75 .65 .69 .79 .89 .79 39 59 7474... 7475... 7476... 74S3 7486 7436 39 59 .49 .39 .45 .59 .45 7489 555 2.15 .49 ,45 .59 59 39 7490. 7493 7495 74107 74121 74123. ,49 74125. 49 74147 1,99 1,89 74150 135 1.25 741S1 39 .29 74154 135 1.55 74161 -. .69 .69 74174 59 .49 74176 59 .49 74193 79 .69 74LS 74LS00 74LS02 74LS03 741S04 74LS05 74LS06 74LE07 74LS08 74LS09 74LS10 74LS11 74LS14 74LS20 74LS21 74LS27 74LS30 741535 74L53S 74LS45 74LS47 74LS73 74LS74 74LS75 74LS7B 74LS83 74LS85 74LS86 74LS90 74LS93 74LS123... 74LS125... 74LS132... 74LS138. -26 58 .29 58 58 .59 .59 28 .18 28 .26 .29 .49 28 .29 35 .23 .28 35 .49 .8a 39 35 39 39 55 .55 59 .49 .49 .49 3a .49 39 .49 45 74LS139... 74LS151... 741-5153... 74LS154... 74LS157... 74LS161... 74L5153... 74LS164... 74LS165... 74LS166... 74LS173... 74LS174... 74LS175-. 74LS191... 74LS192... 74LS193... 74LS194... 74LS221., 74LS240... 74LS241. 74LS244... 74LS215... 74LS257... 74LS259... 74LS273.. 74LS279. 74LS367. 74LS373.. 74LS374. 74L5393. . 74LS541. 741S590- 74LS588- .49 39 .49 39 .49 33 1.29 1.19 .45 35 .49 39 .49 33 .59 .49 ,75 .65 .69 .79 .45 35 39 .29 39 29 ,59 .49 .69 .59 .69 .59 .69 59 69 59 .59 .49 .59 .49 .59 .49 .79 .69 .49 39 .99 £9 .89 .79 .49 39 .49 .39 .79 .69 .79 .69 ,89 .79 1.291.19 5.95 5,85 2.39 229 74S/PROMS' 74S00 25 745188' 74S189 745240 74S244 74S2B7* 74S2B8\„„ 745373 745374 74S3B7" 745472",..,. 745571' 1.49 74S04 25 1.49 1.39 74S74 74S115 74S124 74S13B 25 .25 1,25 49 99 1.49 1.49 .99 74SI63 .75 139 74SI75 . .'. 39 . . 149 MICROPROCESSOR COMPONENTS CD-CMOS CD4001 ... CD 4002... CD4O07... CD401! ... CD4012 C04013 . CD4015 CD4016 CO4017... CO40I8 CD4020- CD4021.. CD4024 CQ4027... CD4028... CD4029... CD4030 .. CG4040... CEJ4042 .. CD4043. CD4046.. CD4047.. CD4049 CO4051 ... CO4052, CD40S3 CD4060... C 04066... CD4069 . CD4070... CD407I . CD4072 . CD4073.. CD40B1 . CD4093 . CD4094 CC4503 . CD451I. CEM51S... CD4520 CD4522. CD4526 CD4538 CD4543. CD4584 CD4585-. .69 59 59 .65 59 55 59 .19 ■i .19 19 35 99 33 S3 .75 65 75 69 ,79 .79 .49 NEC V20 & V30 CHIPS Replace the 8086 or 808S In Your IBM PC and Parley Increase lis Speed Py op IP 30* priM UPD70108-5 (5MKz) V20 Chip 5.55 UPD7010S-8 ISMHl) V20 Chip 6.9S UPD701Q6-1Q (10MHz) V20 Chip 10.95 UPD70116-8 (BMHl) V30 Chip 7.95 UPD70116-10 (10MHI) V30 Chip 13.49 ZS0, ZB0A, ZBOB, SEH1ES RM.Hb. . Ensa Z80ACTC- -.. Z80ADAHT Z80A PIO 1.65 4 95 ...1.89 ...395 Z80BCTC 3.95 Z8400HBI CPujwhj 1 .95 8000 SERIES 8031 3.95 80C31 .6.95 8039 8052AH BASIC SOBOA 80B5A ... 1 .59 24 95 ...1.95 ....1.95 B08SA-S 8066 80B7 iSMHz) 8087.1 (10MHz) 8037-2 |6MHz) 8088 15MHz) 80B8 2(BMHz) 8165 ..,,3.59 ...3.95 .89.95 169.95 129.95 ...4.95 ....6.95 ....2.49 BOM SERIES Continued Part No. Price 81C55 455 8212 1.99 1 39 8243 1.95 8250A . ...4.95 82S0E (For lt!M. 5.95 8253 . .. 1.89 82535 ,. 1.95 82C535 3.95 B254 4.95 B255A-5 295 B2C5SA-5 .... 4.49 9256 1195 B2595 2 25 B572 3 49 6274 4.75 85795 .. 2 95 8284A 1.95 STATIC RAMS Pan Wo. 2015-12 2102 21 r2 2114N 2II4N-2L 21C14 5101 6116P-1 6116P-3 61161P I SlWi.P-3 ;v;j» ■.; 6264P-15 6264LP 10 6264LP12 6264LP15 6514 43255-1DL 43258- 15L 62256LP-10 62256LP-12 6225SLP15 Funcllon 2041IS 1024>1 25614 1024x4 102414 1024x4 255i4 2048x8 5W0xi 2KS.S 2W8x! il92li 0192x1 8192i« ei92i« 0192^1 102414 32766.6 32.709x9 32.769x6 32768x8 32.768x8 150ns — 350ns 20D<15 Lew Fwer. 200ns (CWOSI. .. . 450rs!CMOSI 100ns (16K) CMOS 150ns (16Ki CMOS 100ns (I6K| LP CMOS . 150rs(16KILPCMOS... IOOns(S4KICMOS 150ns |64K| CMOS 100ns|6*KtLPCMOS... !20rs(64K>LF>CMO5. 150ns 164KJ LP CMOS ... 3.50ns CMOS- Pnce — 2.95 99 ._5 49 ..- 99 ..-.-1.49 49 —.1.95 3.19 ,...5.79 3 59 3 09 ...6.75 -..,.4.95 100ns |256K| Low Power . I50ns l256K(LWP LP CMOS. ■ 2tkB 129CKI LP CMOS .. . 15Qn5 1256X1 LP CMOS ...655 .. 6.49 ... 4.95 ...3.25 1995 -.995 .1195 .11.25 .10.95 DYNAMIC RAMS TMS441612 1MS4416 15 4116-15 4)28-15 4164 1D0 4164-120 4194-150 41255-6: 41256 39 4I256-103 41256-120 41256150 41264-12 i 1.164 60 4148412 41484-15 51256 10 511000P10 511000P-10 514256P-10 514256-10 16.384x4 16.364x4 16 384x1 131.07211 65,536x1 65.536x1 65,536x1 262144x1 262.144x1 295.144x1 262.144x1 282.144x1 64Kx4 6653614 65.53614 65.53914 262.144K1 1.048.57611 1.048.57611 262.14414 2G2.144i4 129ns 150ns . 150ns (MM529Wi-21 ,. 150ns (PKHrTOCkl IHlB. 120n« 150ns.,.. 60ns tOOns lynnn .. ,. ISOfis 120ns V^«(WM Sons... ,~~.....~„ IMns... 150ns.. 3 96 .3.75 ,.1.09 .4.49 ,.2 75 .2.39 lDOns Sialic Coiiim 90ix(IMeg) IDIhS(IMec); irjossrlMMj— 100ns Slibc Column.. _2.tS ....555 . 375 ..-3.15 295 .. ,559 .. 10-95 5.95 3 95 ... 3.5S 895 ...12.95 12 35 12.95 56 95 EPROMS TMS2516 TM52532 ™S2532fl TMS2564 TMS2716 1702* 2701 2716 27161 27C16 2732 2732A29 27C32 2764.25 27S4A-20 2764A25 27C64-15 2712820 37128 25 2712BA-15 27128A-20 27C12855 27256 15 2725650 27256-25 27C256-15 27C256-25 27512 25 27C512-15 27C512-25 27C01D-15 66764 6J766-35 204S1B 4096i8 4098x6 1192x6 2048x6 25S»8 1024x8 2048x8 2048x8 2048x8 4096x6 4098x8 4098x8 8192il 8192x8 6192i8 3192.6 16.384x6 1638416 16384x8 16.384x8 16.384x6 32.768x8 32.788x8 32 768x8 32.768x8 32.788x8 65.536x8 GS.S355 I2SVI (Chip EnsWe! 14 95 64X350ns(25'JI (0/n/ E^stfn 15.95 1501B 1125V) „ 2«ta5 112.5V) 250IH 121V) CMOS... 150«s (12.5V) 200ns (125V) 250ns (12 5V| .. , 160rts(l2SVICMOS 250ns (12.5V | CMOS 250ns ri26V). EEPROMS 2Bl6A-252048x8250ns(91MSV)5VRea35V.... 69 POTENTIOMETERS Values available (insert ohms into space marked "XX"): 5001J. 1 K. 2K, 5K, I OK. 20K. 50K. 100K. 5O0K, 1MEG 43PXX3«Watl.i5Tum ,99 [ 63PXX i5Wali Hum .89 TBANSISTORS AND DIODES PN2222 .13 .29 .69 .. .12 PN2907 2N4401 1N270 -'■,7rV ... .13 .15 .25 ... ,15 2J12222A 2N3055 2N3904 1N4148 1N4735 C106BI .... .07 3$ 49 SWITCHES JMT123 SPDl-O-on 1.25 1 206 8 Sflsr. le.pix DIP 1.19 MPC121 SPDT.Q1QTO! 155 I MS103SPS7 Munum^y 39 D-5UB CONNECTORS 0625P Male. 25-oin 69 | OEaSS Fsn-jle 25-r»n .75 LEDS .151 XCS56GTi".Gro 74HCT245 2S 74HCT373 ;;) 74HCT374 LINEAR Part Mo, TL071CP TL072CP TL074CN TL061CP TL0B2CP TLOB4CN LM307N LM308N LM309K LM310N LM311N LM317T LM318P) U4319N LM353K LM354N LM335Z LM336I LM337T LM33SK LM339N LF347N LM349N LF351N LF353N LF356N Ll?57tY ... LM358N i l.':53^N LM3B5II.2., LM386N.3... LU393N LF39SN LF411CN LF412CN NE555V,..., XRL555 , LM5545N „ LM565N LM566CPI ... LM567V LM723CN ... LM741CN... LM747CM ... LMM58N.... LMU88N,,,, .69 .79 .99 59 .59 .99 .45 .65 1.49 ■ :'•> 1 49 ■ ?s 49 an r,H 59 1 l» 99 1.59 1.19 3.49 • :-\ .39 36 1 49 1.JS 1.09 .99 1 >N 1 «) 4.49 455 .49 .39 1.49 1.25 m .59 49 .39 59 49 SB 79 99 89 .59 .49 .89 .29 1./5 149 . .89 .79 .45 39 1 95 : ,-. 79 69 1 VI 1 19 . .35 ■ai ,. .75 , .49 . .99 .1.29 . .75 „ .49 . .35 .. .59 .. .39 .. .49 PO'IM, _LS Ifil □S14C8et1 LMI489N DS14C89N LM1496N LM1871M LM187214 ULN2003A ULN2004A ... 26LS29 26L53I 26LS32- -... 26LS33 ULN2803A LM290IN LM2907N LM2917Nr6(.n| MC3470P- MC3479P MC3486P MC3487P LM3900N LM3905N LM3909N LM3914N NE5532 NE5534 7805K 7S12K 7S15K 7805T 7808T 7812T 7815T.... 7905K 7905T 75113 76150 75154 76174 75175 75176 „, 75451 „. 75452 75492 MCI45406P... 1.19 1.09 .49 .45 1.19 1.09 69 .59 1.95 1,75 .195 1.75 .79 .59 .79 69 .295 2 75 .1 19 99 .1.19 .99 .1.75 1.49 .1.19 .99 . 39 59 .1.29 1 19 1.75 1.49 1 29 1.19 .3.95 3.75 1.29 1.19 .159 1.19 .49 .45 1.29 1.19 .89 .79 .1.95 1.75 89 79 . 89 .79 1.29 1.19 .129 1.19 .159 1.19 49 45 .49 .49 . .49 1.49 . .55 I 39 .1.29 .29 1.19 .295 2.75 .2.95 2.75 .525 1.95 45 39 . 45 39 . 89 .79 .2.95 2.75 PARTIAL LISTING OVER 4000 COMPONENTS AND ACCESSORIES IN STOCK! RAMS ARE SUBJECT TO FREQUENT PRICE CHANCES CALL FOR QUANTITY DISCOUNTS CIRCLE 114 ON FREE INFORMATION CARD Now Available.. Jameco's NEW Flyer 142 with 48 pages of Computer Peripherals & More! jilloscope Probes situation: xt/x10 J radiance 80)i IBOpF )F:(LF210): ** ' r /17pF V"-*- ■/ 80 40MHz Osci 1 I escape Probe $19.95 10 100M Hi Oscilloscope Probe S29.95 TEST EQUIPMENT dSi.tr 20MHz Oscilloscope 1 1GHz Frequency Counter ■Hgh GS7020 •ge 6" rectangular display ritivity: 1 mV/drv '020 Oscilloscope $399.95 ■506 ■50 Prototype Design Stations WM2 i . WM1 & WM2 Features: * Removable solderless bread- board • Variable and fixed DC power supply * Multi- frequency signal generator • Analog multimetef ■ 8 bicoi- or LEDs (red £ green) * & logic switches * Logic probe * Lighted power switch • Fuse overload protected • Sturdy ruggedized case WM1 Special Features: ■ 4 potentiometers ■ Built-in speaker WM2 Special Features: * Pulse Generator ■ Binary coded decimal (BCD) lo 7-segmem decoder/driver ■ DB25 connector * Frequency counter (1Hi to 1MHz) WM1 Analog Prototype Station .... $199.95 WM2 Digital Prototype Station $249.95 IBM h Compatible JEJ012 Cases and d ■ I Power Supplies n r i ^JL JE1O30 ^&&^ JE1O10 Ftp "op SB-BlrtPClTC JX ..$3935 I $39,95 1 JE103Q lKMMKMCTPoMrSurt -.$5935 ....$89.95 1 JE1032 200*11 °*y at Bom S*ey - JE1035 300«lAlPwret5ucrtf ...H39J6 I JE201 1 Ve-KJ Case ti'-cm tm, Sum- — ...$249.95 i JE2012 Ito vera case waxhVFW.5UQpy ...SI49.S5 I JE20H Rip- Top Baby CTTuoiCis..,.,, ....$69.95 | J&2019 RpTajBi^ATCw ..... $69.95 J: | let ex Digital Multimeters ex General Specs: ndheld. high accuracy (DC Vollage. ACJDC ent. Resistance. Diodes, iinuity, Transistor hFE nual ranging w/overload jction SO, 3550B & U4SS0 only: o measure Itequency and capacitance SO only: » Data HakJ Swilch * 4.5 Orgit 10 3.5 Dgii Multimeter .....$49.95 ■50 3.5 Digit Multimeter wiTiequenGy S Capacitance ... .,.,..,......,..,., ,.$59-95 Same as M3S5Q wjtjargrapti.. ..$74.95 4.5 D-3H ^.frequency, Capacitance and Data Hold SwffiH ..$99.95 IBM PC/XT/AT Compatible Keyboards PROTOTYPING PRODUCTS imeco Solderless Breadboards JE23 Contact Binding '"■w Poinu Posh puce II !3 '.i a <-$ a 3.2512.125 6,5x2.125 6.513.125 6.6 1 4.25 5.875x5.75 7.25 1 7.5 400 833 1,389 1,663 2,399 3.220 $4.95 $6.95 2 J1Z.95 3 $17.95 4 S22.35 4 $32,95 JE2017 J E 20 1 5 &4 ■ Key SlarslariJ AT Style Layout $59.95 1 FK84700 1 1 - Key Enlianced Layout with 12 Function Keys $69.95 | JE2016 m-Key Enhanced wiihsmai Power cd Calculator.. $79.95 JE2017 104-Key Enhanced «* Trackball (Microsoft Compatible) ,,,,$99,95 ' '■ ' = 3.5" and 5,25" Floppy Disk Drives MFF11 Pictured eaMB^B^n^iiM Sony MPF1 1 3 5- 720Kb internal Drive.... $49.95 SMK 5.2S" Installation Kil w Faceplate .. SI 4,95 TEAC FD55B 5.25" 360Kb Hall H I $89.95 FD55G 5 25" i 2M& nan Ht . ..... . $99 .95 Mitsubishi MF353B 3.S - 720Kb Hall Height ...$99.95 MF355B 3.5- 1.44Mb Hall Height $119.95 MOTHERBOARDS XMkJH only $620.95! ■ AIIW/0KRAM JE3520 Plclurw JE1001 jimm < ?t-8mhi sma (P«ti $89.95 JE30D5 Janwca Baby 8 12MH1 Bases iati .... $1 99,95 JE3010 j>mcBjeaor". , i6HHi)a!K[ATi.,.. $299.95 JE3011 jinws 9asy UOMhi 102(E i« n . . .. $389.95 J E3025 Mil Baby 20MHI kme 41 199.95 J E3026 mii Full -Sji ami 10316 $1 899.95 JE302B ami Fill sis othi so3I6 $2299.95 JE3520 Jarnato Baby 2DMHz J03B6 $529.95 J E 3525 janweo Duty ismm! 10316 $1 199.95 JE3533 Januco amy 33MHi 80316 $1 899.95 EGA & Multiscan Monitor Packages Casper 14" EGA monitor and EGA card package (720 x 350 max. resolution) JE1059 EGA Monitor S EGA Card $459.95 Relisys 14" Multiscan monitor and EGA card package (800 x 600 max. resolution) JE2057 Multiscan Monitor & EGA Card $559.95 = A.R.T. EPROM Programmer • Programs all current EPROMs in the 2716 to 27512 range plus the X2864 | EEPROM • RS232 port • Software incl. EPP $179.95 ■ Erases all EPROM's ■ Erases 1 chip in 15 Min. and 8 chips in 21 min. • UV intensity: 6800 UW/CM 2 DE4 $69.95 "C Soldering and Desoldering Stations 60 Watt Analog Display Sobering Station • Electronic lemperature control liom 200" to 878'F ■ Cartridge healing element for a longer life ol the sotdering lip XY1 683 $59.95 SO Watt Analog Display Soldering Station * Electronic lemperature control from 200' lo 878°F ■ Ceramic heating element for a steady temperature and long tife XY2660.. $89.95 60 Watt Digital Display Soldering Station - Electronic temperature control (torn 200' to B7B°F ■ Temperature displayed on easy to read .560"H 3-digit LED readout ■ Nicftrome heating element XY960 ..■■■■■ $99.95 30 Watt Electronic Temperature Coniielled Desoldering Station ■ Eleclronic temperature control from 212° to SAVf • Self- contained high rotary vacuum pump XY999 $279.95 Hard & Hard/Floppy Disk Controller Cards MFM Ut;d JlDpp v RLL HuiTiopp* CpmpularType arppxt)gi:i t02Bli[*T>3l6eMI«l«lmt aaatt«r>-3a6@i:i Pan Mo. ( Price i-303VMm.J139.55 IM6VWM1.?l4asS Part No. . Price lOOJVSRI.'SHS.aj Part No. (Price I0O3VMUJSHSS5 Part No, i Prlea ■:;:-.5=rs'7=r: toKVSHZ^igags 6 Sttoreway Road mont. CA 940 02 Hour Order Hotline (41 S) S92-8097 Cs (415) 592-2503 or (415) 595-2664 3-x 176043 - Ans. Back: Jameco 9lmt a Sheets - 50c each xSS2.00 Postage lor a FREE BO-Pege Calslog 990 Jameco Electronics 5/OT is a registered trademark 01 rnatibnal Business Machines v&r 24-Hour Order Hotline (415) 592-3097 • Customer Service 150.00 Minimum Order - U.S. Funds Only CA Residents Add 6%, 6.5% or 7% Sales Tax Shipping - Add 5% plus St -50 Insurance [May vary according to weight and shipping method) Terms; Prices subject lo change wiibout notice. We are not responsible For typographical errors. Wo reserve the righl to suostiluta manufacturers. Items subject to availability and prior sale. Products pictured may only be represenlatlve. Complete list of lerfnsNvarranlies is available upon request The Following Services Are Also Available Through (415) 592-8097 From 7AM ■ 5PM P.S.T.: magmaBm * a me co ELECTRONICS Technical Assistance + Credit Department ■> All Other Inquiries CIRCLE 114 ON FREE INFORMATION CARD INTEGRATED CIRCUITS AK, Puerto flico - Z18-5B1 6674 INTEGRATED CIRCUITS 1-800-344-4539, FAX- 219-681 33BD TWX - 9103668982 D1GI KEY CORP SILICON TRANSISTORS "HFJH 3.f HH?I 14 WHO : 1 1*IJI JE mi]] ?J ruilJI mm* man ii ntjuj h 11)111 PANASONIC SU SERIES L: ■ I '■ gjEEB g r" p» 1 10G DO U49M tt.W * »0 DO HMW . i »

doae. RATEO: 0.1 amp ewiiching. 0.25 amp cony current. P.C, mount CAT*PB-B SStoach ■ lOkxte.co 100 lor $50.00 SPOT PUSHBUTTON Marquardtf 1843 Rated 6 ampd £> 125/250 Vac. Slack plastic pushbutton. Sullch body: 52" X .84" X «". CAT* PB-1B 11.65 60. ■ 10 [or (15 00 PUSHBUTTON SWITCH QC/Thomsent 35-420 JHL S.P.S.T. norniafly open momentary ^^ pushbrjiun switch. Red plasnc ^q actuator 0.57" diameter. Chrome l pJ bezel 0.AS" diameter. Threaded bushing nvxinu in .50" diameter hole. Rated 3 amp @ 250V4C. Solder loop terminals. CAT* P8-20 (1 .00 each WALL TRANSFORMERS ALL PLUG Dtt«6ft.T HT0 120 VAC OUTLET 12Vdc^SCOmt'CaTJ DCTX-123 fa.H t v* » 200 ma cati ucnr-sM ius S> Vdc $ 1 amp CAT! DCTX-M1 15.00 24 Vac » s» ma. CAT! ACTX-24S2 t3.2S SERVO MOTORij 3 Vdc aervo wfth pc+erK tometer . Waal for roboUce or tameae comrcr medal aapanmentaLSoe. Rotates w«. 140 degreee. Pot connected to motor wiea Irom alt* SCO lo 3000 a-ma. 1 jir X 0.9S* X 1 jSS". O.ST' dlamecer njbber whaaJ aaachatt la motor I haft c*i ba medal acapetancr can be aaaSy nanwad . Prepped wUh capadon, chofcae and afce leads. CATiSVO-2 21brt1.n0 0-6 HOUR AUTO SHUT-OFF TIMER M.H. Rhodes, Inc. MarX-Time* 90007 Wall-box timer fits standard 3' deep wall box. Rated 20 amps t§ 1 25 Vac. Turn knob to desired time. Includes hardware, beige wall plate, and knob. UL and CSA listed CAT* TMC-6 $5.75 each *< a' NICKEL-CAD BATTERIES ■{RECHARGEABLE) AMSIZE >i.»e*ch 1 .2 «a 1 80 mAB CATa NCB AAA AASEE 12.C0aach 1 .25 *otl 500 mATi CATa HCB-AA AAStZE K.ajenn WITH SCXnER TABS CAT* HCB-SAA C SIZE H .25 each 1.2voti 12COmAh CAT* NCB-C D SIZE H.50 each L3>wta 12O0 mAh CAT* HC9-D XENON TUBE 1 ■ erg iua iftfi* mm j irz- tad and Black laada. Uaal lor electronic flash or strobe projecte. CATa FLT-1 21wS1.00 RELAYS £3 S-fi VDC SIP REED RELAY EkKBOl *Bba3ayf BBS1AKA10 Mi Vfc r £00 Ohm COI.S.PJ5J, fW ■ miJrj-optK. r**d mLvy. 0,5 *JTp COTttKtl, SiP ixntaoMBSfL rx jTs-xj, CATa F1RLY-SIPJ tl.lOaach ■ lOtortiaOO © I VDC LATCHING RELAY HSL2C-5V SPOT. dual coll iatcmrg lela*. BVdc l70ohmeoHi. l amp.TTL Wa, UL and CSA ractjjr sea. O.TOr X 0.3U' X 0.W CAT* LP.LY.iDC S3 .SO wen II VOLT D.C. CML S.P.D.T. 33S0hmooA. Suoar cube alza. .ar X A3? X j«' hasKPJC mount with pine on DIP apadng. CAT* RLT-Tt? H .SO audi INSTRUMENT ENCLOSURES High quality mddttf ABS Insttunwn tKrCknuma. Integrated PC bovd a tarnfcrf.1 and two sols of vwtcaJ rrxHinting slots (or front and rtar tub panel i _AIJ BnctosuTw are aTwvo>X6 1«" deep. Choiw trf itrw hetghta. IntiLidet ivnskkl rubber Feet and hardwar*. Avaiiabla in baige, ivny, black, and blue. P*nol ht. CAT* 1.9 1IVM 21/4' CATfMB-A *7.50eacn 10tort$S,00 2&ST CATfHB-B S7.7S oacri l0tX$ESj0D 3" CATfMB-0 »a.0Oeacti 10 for 170.00 PIum f«atona hour proiecL CAT* AEC $6.50 each SPECIAL PLtRCHASEZlO MFD 300 V PHOTOFUSH CAPACITOR Rubicon CtE photorlash capacitor, 0.79" da. X 1.1" high. These are new capacitors that have been propped with 1 4" black and red wire leads soldered to the terminals. CAT* PPO210 $2.50 each 10for$22.50 - 100for$200.00 22/44 PIN CONNECTOR IIHUIH TITTT ,156" pin spacing, O.£O0" between double rows p gold contacts, P.C. mounting. SPECIAL. Same as AMP# 2-530655-6. CAT* EBC-1G $1.00 each ■ 10 tor $8.00 ELECTROmC QAME BOARD Tr« rr*f wartkagi Ct m »4«ctrwic Sa«bbta q*it». Op#r**w e<\ e V()c. *dig(iafeh4H)L>rr-»rtc nadaut, 45 butlofi hoypitf. 14 liwwhdm, 2 1.Ci. 1 pteio it im r n and ovw goodktt. Top and boftorn row e> tvyptf butuni in luTKSlon k*yi, mMd** 3 row* «j# ilphifatlkL No lAttrucuoM avaUMfe. r X 4^S". CATi 5T-4 fUSfisdl 10 for $15.00 TELEPHONE CQUPEJHQ TBANSFORWEB Hull Product! IrriwnidonaM A1BNHO-.CV1 PriTury: KM ohn, Sacondary: flOO/eoO ohm 077- X OUtT X OAT high. S p.c. phu on o.iar Mntwi.. Primary Muctanca: 300 mH mki., at ]Wz. 1 wM. CAT#TCTX-1 (l^Seach < I0lbrtii,00 RECHARGEABLE BATTERY PACK (USED) Four AA nickel cadmium batteries connected in series to mate a 4.8 volt nack. Batteries are in a 2X2 con figuration with a 2 pin connector attached. The (our batteries can be separated into single AA size solder lab nickel cadmium batteries or resoktered Imo other configurations. SPECIAL SALE PRICE NOW $3.00 per pack • 1 packs for $25.00 CAT# NC8-41AAU LED'S STANOAnO JUMBO OFFUSED T 1.3/1 alia a RED CAT* LED-1 B 10lorA1.5o <100lorl13CO W CDC EH CAT* L£D-2 1 1 10k*S?.CO' 1 CO (dtS 17.00 11 YELLOW CAT* LED -3 lOrar^OO -lCO'nr *1?00 FLASHING LEO , a*h bull In flaabiig drajfc *" oparaiaa on s volta... HES tl.OOeach M CATa LEDJ IOIocM.SO Tl ■EM tl.Maadi I CATa LELMG lOlorW.w'l Bl-POLAR LED M UJte RED ona d^actkxi, W GREEN Ha obiar. t«q laada. I CAT* LED.0 2 tor tl. 73 LED HOLDER *» II Tan piaca holoar. ty A CAT! HLEO lOtoceSa 10 AMP SOLID STATE RELAY ■3d ElECTFWLt 521 71 COHTHOL: flaw) M B 10 Vdc rat* operate on 3-32 Vdc). LOAD; 10 amp @!<0 Vac 2 wf x i at* 1 x 7/r. CAT* 9SRLT-10B la 50 aa. CUAHTTTV DISCOUNT 10 fer tK.OO • 25 lor J175.00 SO tor S300.00 * 100 lor S5OO.0O OPTO SENSOR U ahJpad pactaea ir3"cc*img. w mounting earn. CAT! OSU4 SOtaadi 10 tor ta.ic - ™ tenant) A.C. LINE CORDS Btadtett.. IS/2. SPT-2 I S WON POLARIZED PLUQ CATfLCAC 2 tor tl. DO 1O0 !Ki> toolatM.OO C4Lt OR WRITE FOR OUR FREE 60 PAGE CATALOG outside the ils.a. OVER 4000 SEND $2.00 POSTAGE PA R TS! eoH * CATALOG!* ORDER TOLL FREE 1-800-826-5432 MAIL ORDERS TO; ALL ELECTRONICS P.O. BOX 567 VAN NUYS, CA 91408 L.E.D. FLASHER KIT T«o LEJM Daeh h unaon whan This W( InclLKiw i p.e. baart. ^p,.— ^ Qm parta and irAtLKiioni Q^- 1 ^ bo mifci a »HTpkvvflaih*r drcutt. A quldt and Miy pra|tct lor anjofvi wttii buc iold»f it%j tUta. CAT#t£DKIT ti.TSporkn LOOK WHAT $1.00 WILL BUY A *! z* 3 *! 200 ASSORTED 1/4 WATT RESISTORS Bert laada. carbon conp, and cartjon INm. CAT! GBEB 11.00 par aaaonman SM ASSORTED /~ i h raUHy 4 roctor HAAfa, Ourcth^oa, CATf GRAB&W $200 par aWorlnwA INFO: (818)904-0524 FAX; (818)781-2653 MINIMUM ORDER $10.00 QUANTITIES LIMITED CALIF. ADD SALES TAX USA: $3.50 SHIPPING FOREIGN ORDERS INCLUDE SUFFICIENT SHIPPING, NO C.O.D. as»»V#^* CIRCLE 107 ON FREE INFORMATION CARD 101 DYNAMIC RAMS PART* ♦164-150 4184-120 4164-100 THS4464-15 TU54464-12 TMS4464-10 41156-150 41256-120 41256-100 ■11256-80 41256-60 414266-160 414256-80 1 MB- 120 1 MB-1DO 1 MB-00 SIZE 65536s! 65536x1 65536*1 6553614 65S36x4 65536>4 262144(1 262144x1 262144x1 262144x1 262144x1 262144x4 262144x4 1046576x1 1048576X1 1046576x1 SPEED 150ns 120ns 100ns 150ns 120ns 100ns ISOrs 120ns 100ns 80ns 100ns sens 120ns 100ns 60ns SIMM/SIP MODULES PART* 41256A9B-12 41256A9B-80 42TQOOABB-10 4210O0A9B-1O 421000A9B-80 256KX9SIP-80 256KX9SIP-60 1MBX9SIP-80 PART* HM6116LP-2 HM6264LP-15 HM6264LP-12 HM43256LP-12 HM43256LP-10 SIZE 256Ks9 256Kx9 IMSxB 1MBx3 1MB i 9 256Kx9 256Kx9 1MB «5 TYPE SFMM.PC StMMTPC SIMM/MAC SIMM/PC SIMM-PC SiPfPC SIP/PC SIP/PC PREE 36.95 49.95 109.95 11395 119-95 54.95 64.95 124.95 STATIC RAMS SIZE 204SXS 6192x3 81 92x8 32768x8 32768x8 SPEED 120ns 150ns 120ns 120ns 100ns MATH COPROCESSORS 8-BIT COPROCESSORS 0087 5 MH: 39.95 8067-2 8 MH; 129.95 9087-1 10 MHz 169.95 16-BIT COPROCESSORS 8028? : l.'li: 139.95 60287-6 8MH; 209,95 B0287-10 10 MHz 239.95 BOC2S7 12MH* 299.95 32-BIT COPROCESSORS 60367-16 16 MH; 359.95 60387-SX 18 MHz 319.95 60367-20 20MHJ 399.95 80387-25 25MHI 499.95 60387-33 33MH* 649.00 5 YEAR WARRANTY INCLUDES MANUAL & SOFTWARE GUIDE 74 SERIES LOGIC 7400 74LS00 74LS02 7404 74LS04 74S04 7406 7409 74LS0S 7432 r cp.u "S 3000 8052AH BASIC 34.95 6098 5,99 6250 6.95 8251 A 1.69 8253-5 1 35 8254 9.9] 8255-5 2.49 6741 9,95 8748 7.9S 6749 9.95 S75S 14.98 6500 65C02' 7.95 6522 2.95 17-20 V20 6.98 V20-9 6.95 V20-10 11.95 1 V30 13.95 74LS32 74LS73 7474 74LST4 74S74 74LS138 74LS155 74LS163 74LS240 74LS244 MISC DAC0800 3.29 1 793 9.98 COM8116 6.95 MC14SS19 5.95 MM5S157 9.95 INS8250 6.95 NS16450 10.95 LM317T .69 NE5S5 .29 LM741 .29 7805T .49 781ZT M 75150 1-95 75154 1,95 14411 9.95 CRYSTAL OSCILLATORS 1.0MH2 5.95 1.8432 5.35 20.0 4.95 21.0 4.95 74LS245 .79 74LSZ73 .79 745288 1.69 74LS322 3-95 74LS367 .39 74LS373 .79 74LS374 .79 74LS393 .79 74LS682 3.20 74LS588 2.40 ', PALS 16LS 2.9 16H4 2.95 16R6 2.95 16H8 2.95 20L8 4.9S 20R4A 4.95 20P8 4.9S 20 H fl 4.95 20X9 4.95 PAL KIT AN ENTRY- LEVEL | PAL DEVELOP- MENT KIT FROM CUPL. FULL SUPPORT FOH 16L8.16R4.16RB. 16R6, 20L8. 20R4, 20R6. 20RS. AND 20X8 MOD-MPL-SOFT M9.95 D&rfc&'s HIGH-TECH I SPOTLIGHT Ciillaur BBS [40S1559 U253 lur more mio in Slti 1ilp"Hllpth" FOf :^o Hm* flow JDR. OOCl n*Oc(y a II 1h o c ompy I a>. Induim/, hove titled Norton SI and Landmark bene hmarfc fr{]Ur»f in hhair cdYO.-tiiomonts. One Of tt» ftal Itilng* | Joe* at whan comparing. ccmpuler* It their benchmark latlngs. As relative measure* ol speed bolw ocn varfoui sy ilomi. ThoW ratings Will gonemlty toll yO*J which Ls Ihft la**Wt h but I hay con mislead and hicta Information H .he buyer doemi pay clote ortivnlron to the compreti> sytfero- Th* rating numbers only indicate th* amount oi worit mot Ihe processor I; able to da In a pertod of time. Because the program thai touts tor iprad ti very small. It n unable to evOkl- at* th* tyslarm response In many real world 1 rttuatkjrit. J usl at you would select speakers rated compatible with yOUr stero Crnplrfjer. molchlng corn pule system's compo nenls to each other and 1o the lob to b* performed It th* k*y. So compare ipa*d rotlngiL, and look tor thtj# f*alur*s: Memory Typo: 1 Mb RAM fct mora CQtt *ff*cHva ttion ?HK RAM Infw ia g vfciff lntarl.«av*g r memory rum l f awar waft jiaia* Memory Cdcho: Bigger ri batter, but mora oxpoflirvo Cocha Design ; 4-way sat auoclattY* l» batter than 2- way, which li bettor than ai reel mapped Dorick Moore, Direclor eA Engineering EPROMS PARTf 2716-1 2732A 2764 2764-250 2764-200 27C64 27128 2712BA-200 27256 27256-200 27C256 27512 27C512 27C1D1-20 SIZE 2048x8 4096x6 8192x3 8192x6 8192x8 8192x6 16384x8 16364x8 32768x8 32768x8 32768x8 65536x8 65536x8 131072x8 SPEED 350ns 260ns 450ns 250ns 200ns 250ns 250ns 200ns 250ns 200ns 250ns 250ns 250ns 200ns vpp 26V 21V 12.5V 12.5V 12.5V 12.6V 12.5V 12.5V 12,5V 12.8V 12.5V 12.5V 12.5V 12.5V PINS PRICE 24 3.95 EPROM ERASERS DATARASEll *39.9S •SHIRTPOCKETSIZEI ^fc*>^>^ •AU SIZES UP T04 ATA TIME • * ^5*5 - ERASES MOST EPROMS IN 3 MINLTTES^BJ DATABASE II SPECTROHICS CORPORATION ""^ Model T1m*f Chips Inlomlly (uW Cm' i Unll Coil PE-140 'PE-140T PE-240T PL-265T NO YES YES YES 9 9 12 3d 8,000 8,000 9,600 3,800 $89.95 1139.95 SI 89 .95 1255.95 POWER SUPPLIES 13S WATT FOR 80SS ■ I I0-220V SWITCH • UL APPRVD. - •5V@15A, *I2V@4.2A, ■5V@ EA. -12V@.5A PS-135 S59.95 PS-150 150W{8088] S69.9S PS-200X 200W (6063) S89.95 PS-200 200W (26&386) $89.95 PS-250 250W (2B&386) J129.9S FAX SWITCHER ROUTES CALLS FROM 1 PHONE LINE TO PHONE. FAX. MODEM i. ANSWERING MACHINE - FOR SINOLE OR MULT I- LINE SYSTEMS - AUX PORT FOR MODEM. COHDLESS PHONE. ALARM. ETC. F AXM-SWITC H 5J1 09.95 PROTOTYPE CARDS FB-4 EPOXY OLASS LAMINATE WITH COLD PLATED EOGECARD FINGERS AHD SILK SCREENED LEGENDS FORXT JDR-PR1 MTH.5VANDGROLINDPLANE 27.95 JDR-PR2 ABOVE WITH W DECODING LAYOUT .29.95 JDR-PR2-PK PARTSKITFORJDRPR2ABOVE 8.95 FOR AT JOtVPRl 1 6-BIT WITH l» DECOD ING LAYOUT .. „ 34.95 JDR-PR10-PK PARTS KIT FOR JDR-PR10 ABOVE 12.95 FOR PS/1 JDR-FR32 32-BIT PROTOTYPE CAHO 69.98 JDR-PR16 16-BIT WITH \IO DECODING LAYOUT ..49.95 JDR-PR16-PK PARTS KIT FOR JDRPR16 ABOVE _.._ 15.95 JDR-PR16V 16 BIT FOR VIDEO APPLICATIONS 39.95 EXTENDER CARDS SIMPLIFY PROTOTYPING AND TESTING EXT-S088 (.BIT FOR 8088 MOTHER BOARDS . 29.95 EXT-B0266 1 6-B IT FOR 286>386 MOTH ERBOARDS .. 39-95 EXT-1S MICROCHANNEL 16BIT 69.95 EXT-32 MICROCHANNEL 32-BIT 99.95 PC BREADBOARD-ON-A-CARD • 82 BUSLINES • USE UP TO24 14-PIN ICS • 1940 TIE POINTS - DH25 D-SUB CONNECT, PDS-604 S49.9S SOLDER STATION ■ UL APPROVED I ■ ADJUSTABLE HEAT SETTING \ ■ TIP TEMPERATURE READOUT / • REPLACEMENTTIPSeS2-95 ^0C J I 1 6B-3C S59.95 mm IC SOCKETS/DIP CONNECTORS SOLDERTAIL a PIN ST 14 PIN ST 16 PIN ST 16 PIN ST 20 PIN ST 24 PIN ST 28 PIN ST 40 PIN ST 11 8 PIN WW .69 11 14 PIN WW 69 12 16 PIN WW .69 'T[PU ■ 320 DPI RESOLUTION lUUTltbn -SERIAL PS/2 COM PATI BLE. LOGC9 SERIAL MOUSE $98.95 LOGC9-C SERIAL (NOT PS/2 COMPATIBLE) $79.95 LOGC9-P SERIAL MOUSE WITH PAINTSHOW ... $109.95 LOGC9-PC SERIAL MOUSE WITH PAINT/CAD $1 54.95 LOGB9 BUS MOUSE $69.95 L0GB9-P BUS MOUSE WITH PAINTSHOW $1 04.95 LOGB9-PC BUS MOUSE WITH PAINT/CAD $149.95 JDR MICR0DEVICES, 2233 BRANHAM LANE, SAN JOSE 95124 LOCAL (408) 559-1200 FAX (408) 559-0250 TELEX171-110 RETAIL STORE: 1256 S. BASC0M AVE., SAM JOSE. CA (408) 947-8881 HOURS: M-F 9-7 SAT. 9-5 SUN. 12-4 i Bnii£ Minimum Order StQ.QQ. For shipping £ h.in,rilE! nl tor |he pittqutiI CA r r 1 s i flt 1 1 *' =. musl include applicable sales la« Prices subiacE lo change wJlhoul nolice We are not r tifJQ rts-iulc [Or lyp&GjTapriical errOii. W" 10 MmtE ■ ; i,n 'i|m . and To substilyte rnanutscturcr. All merchiandise suhit'Ct topnttt sales A lull copy q1 out lerms. is availably up an rcttucsi. Uoflis- pictured may only be r£>prr>scnla|ive. ORDER TOLL FREE 800-538-5000 CUSTOMER SERVICE TOLL-FREE 800-538-5001 • TECHNICAL SUPPORT TOLL-FREE 800-538-5002 CIRCLE 113 ON FREE INFORMATION CARD DEALERS CIRCLE 17D OH FREE INFORMATION CARD 103 ADVERTISING INDEX RADIO- ELECTRONICS does not assume any responsibility for errors that may appear in the index below. 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Electronics 93 — McGraw Hill Book Club 28 61 Microprocessors Unltd .87 1 17 Mouser 25 — NRI Schools 18 192 Optoelectronics i 5 — Pacific Cable 91 56 Parts Express 97 101 Pomona Electronics 23 78 Radio Shack 17 197 SCO Electronics 77 188,189 Sencore 33, CV4 196 Smith Design 34 — Star Circuits 27 83 Synergetics 72 194 TECI 69 198 U.S. Cable TV 77 186 Unicorn 92 64 Video-Link 94 184 Viejo Publications 26 185 WPT Publications 69 Gems back Publications, Inc. 500-B Bi-County Blvd. Farmlngdale, NY 11735 1-516-293-3000 Fan 1-516-293-3115 President: Larry Stockier Vice President: Cathy Steckler For Advertising ONLY 1-516-293-3000 Fax 1-516-293-3115 Larry Steckler publisher Arline Fish man advertising director Lisa Strassman credit manager Denise Haven advertising assistant SALES OFFICES EAST/SOUTHEAST Stanley Levitan Eastern Sales Manager Radio-Electronics 259-23 57th Avenue Little Neck. NY 11362 1-718-428-6037, 1-516-293-3000 Ml DWEST/Texas/ Arkansas/ Okla. Ralph Bergen Midwest Sales Manager Radio- Electronics 540 Frontage Road — Suite 339 Northfield. II 60093 1-312-446-1444 Fax 1-312-446-8451 PACIFIC COAST/ Mountain States Marvin Green Pacific Sales Manager Rad io - El ectro n ics 5430 Van Noys Blvd. Suite 316 Van Nuys, CA 91401 1-818-986-2001 Fax 1-818-986-2009 104 CIRCLE 113 ON FREE INFORMATION CARD DEALERS CIRCLE 170 ON FREE INFORMATION CARD Electronics Paperback Books GREAT PAPERBACKS AT SPECIAL PRICES □ BP248 — TEST EQUIPMENT CON- STRUCTION S5.&5. Details con- struction of simple, in- expensive, but ex- tremely useful test equipment, AF Gen. Test Bench Ampl, Au- dio Millivoltmeter, Tran- sistor Tester and six more. i_j BP267— HOW TO IUSE OSCILLO- SCOPES AND OTHER TEST EQUIP- MENT $6.95. Mas- tering the oscilloscope is not really loo difficult. This book explains all the standard controls and functions. Other equipment is also de- scribed. "] BP265 — MORE ADVANCED USES OF THE MULTI- METER $&S&.U9e these techniques to lest and analyze the performance of a vari- ety Of components. Also see how to build ad-ons to extend multi- meter capabiliiies. 1.1 BP256— INTRO TO LOUDSPEAKERS AND ENCLOSURE DES3GN $5,95. We explore the variety of enclosure and speaker designs in use today so ihe reader can under- stand the principles in- volved. O BP263— A CON- CISE INTRO TO dBASE S6.95. The dBASE series Of pro- grams are probably the best known database programs for micro- computers. This book is designed to help you get started working with them. D BP260--CONCISE INTRO TO OS/2 ..... $5.95. It you are a mul- titasking! PC user and wani to gel the most out of your computer, then you must learn its OS/2 operating sys- tem. This book shows you just how to do that, quickly and easily. □ BP249— MORE ADVANCED TEST EQUIPMENT CON- STRUCTION $5.95. Eleven more lest equipment con- StruClion projects. They include a digital voltmeter, capacitance meter, current tracer and more, ~] BP245— DIGITAL AUDIO PROJECTS $5.95. Practical cir- cuits to build and ex- periment with, in- cludes A/O converter, input amplifier, digital delay line, compander, echo effect and more. D BP247— MORE ADVANCED MIDI PROJECTS $5.95, Circuits included are a MIDI indicator, THRU box. merge unit, code generator, pedal, pro- grammer, channel izer, and analyzer. BP257— INTRO TO AMATEUR RADIO $6.95. Amateur is a unique and lascinating hobby. This book gives Ihe newcomer a com- prehensive and easy to understand guide to the subject. □ pernor— DIGITAL LOGIC GATES AND FLIP FLOPS $10-00. Thorough treatment ot gales and Hip-flops tor enthusi- ast, student and tech- nicians. Only a basic knowledge of elec- tronics is needed. I i BP251— COMPUT- ER HOBBYISTS HANDBOOK SS.95. A wrapup of ev- erything the computer hobbyist needs to know in one easy lo use volume. Provides a range of useful refer- ence material in a sin- gle source. ^PCP102— INTRO- DUCING DIGITAL AU- DIO $9.95. Covers all kinds of digital re- cording methods — CD, DAT and Sam- pling. Bridges the gap between the technician and the enthusiast. Principles and meth- — ods are explained, D PCP10B— COM- PUTERS AND MUSIC $9,95. Explains the basics ot computers and music with no pre- vious knowledge of computers needed. Covers types ol music soltware and explains how to set up your own computer music stu- dio. D BPI95— INTRODUCTION TO SATELLITE TV...„ $9.95. A definitive introduction to the subject written for the professional engineer, electronics enthusiast, or others who want to know more before they buy. 8 x 10 in. □ BP1 90— ADVANCED ELECTRONIC SECURITY PROJECTS $5.95. Includes a passive infra-red detector, a fiber-optic loop alarm, computer-based alarms and an unusual form of ultrasonic intruder detector. D BP235— POWER SELECTOR GUIDE .....$10.00. Complete guide to semiconduc- tor power devices. More than 1000 power handling devices are included. They are tabulated in alpha-numeric sequence by technical specs. Includes power diodes, Thynstors, Triacs, Power Transistors and FETs. □ BP234— TRANSISTOR SELECTOR GUIDE $10,00- Companion volume to BP235. Book covers more than 1400 JEDEC. JIS, and brand-specilic devices. Also contains listing by case type r and electronic parameters. Includes Darlington transistors, high-voltage devices, high-current devices, high power devices. G 8P99— MINI-MATRIX BOARD PROJECTS $5.50. Here are 20 uselul circuits that can be built on a mini-matrix board that is just 24 holes by ten copper-foil strips. PI BPB2— ELECTRONIC PROJECTS USING SOLAR CELLS $5.50. Circuits with applications around the home that are powered by the energy otthe sun. Everything from radio receivers, to a bicycle speedometer, to timers* audio projects and more. D BPH7— PRACTICAL ELECTRONIC BUILDING BLOCKS— Book 1 $5.75. Oscillators, Timers. Noise Generators, Rectifiers, Comparators, Triggers and more. □ BP164— INTRO TO 66000 ASSEMBLY LANGUAGE $6.95. The 68000 is a great new breed ot microprocessor. Programming in assembly language increases the running speed of your programs. Hare's what you need to know. □ BP179— ELECTRONIC CIRCUITS FOR THE COMPUTER CONTROL OF ROBOTS .... $7,50. Data and circuits lor interfacing Ihe computer to the robot's motors and sensors. CHECKOFF THE BOOKS YOU WANT □ BP239— GETTING THE MOST FROM YOUR MULTIMETER $5.95. Covers basics of analog and digital meters. Methods of component testing includes transistors, thyrislors, resistors, capacitors and other active and passive devices. □ BP97— IC PROJECTS FOR BEGINNERS $5.50. Power supplies, radio and audio circuits, oscillators, timers, switches, and mere. If you can use a soldering iron you can build Ihese devices. D BP37— 50 PROJECTS USING RELAYS, SCR 5 & TRIACS $5.50. Build pri- ority indicalors. light modulators, warning devices, light dimmers and more. D RADIO— 100 RADIO HOOKUPS $3.00. Reprint of 1924 booklet presents radio circuits of the era including regenerative, neulrodyne, reflex & more. □ BP42— SIMPLE LED CIRCUITS $5,50, A large selection ot simple applications for this simple electronic component. H BP1 27 HOW TO DESIGN ELECTRONIC PROJECTS,.... $5.75. Helps Ihe reader to put projects together from standard circuit blocks wilh a minimum of Irial and error. P BP122— AUDIO AMPLIFIER CONSTRUCTION $5.75. Construction details for preamps and power amplifiers up through a 100-watt DC-coupted FED amplifier H 8P92— CRYSTAL SET CONSTRUCTION $5.50. Everything you need to know about building crystal radio receivers. H BP45— PROJECTS IN OPTOELECTRONICS $5.50. includes inlra-md detec- tors, transmitters, modulated light transmission and photographic applications. L! BP1S5-™ ELECTRONIC SYN- THESIZER CONSTRUCTION $5.95. Use Ihis book lo learn how lo buitd a reasonably low cost, yet worthwhile monophonbc synthesiser and leam a lot about electronic music synthesis in the process. ELECTRONIC TECHNOLOGY TODAY INC. RO. Box 240, Massapequa Park, NY 11762-0240 Name Address City SHIPPING CHARGES IN USA AND CANADA .State . -Zip . RE-590 S0.01toS5.00 . S5.01 to 10.00 .. E10.01 to S20.00 $20.01 to $30.00 $30.01 to S40.00 $40.01 to $50.00 $50.01 and above .SI. 25 .$2.00 . $3.00 ,$4.00 .$5.00 . $6.00 ,$7.50 SORRY Na orders accepted outside of USA & Canada Number of books ordered | | Total price ot merchandise S . Sales Tax (New York State Residents only) S . Shipping (see chart) S . All payments must be in U.S. funds Total Enclosed Introducing The SG80 AM Stereo-FM Stereo Analyzer '"' Now For The First Time, A High-Performance AM Stereo (C-QUAM) • FM Stereo Analyzer Integrated into One Unit, Allowing You To Performance Test Troubleshoot, And Align To Manufacturers' Requirements jr^iooF^s R MF»MS1GNM- WIT * "" W^OUTPW^w***^ •• . : , ■# -.-"is: a cc ... j^ers**^ 5 ,^.*®" i^^^H^k «"m $3,535 Patented Licensed Under Motorola Patent No. 4,218,586 SE Complete AM Stereo-FM Stereo Analyzer— exceeds manufacturers' requirements. Patented FM analyzing signals isolate any FM receiver detect. Exclusive integrated AM Stereo C-QUAM analyzer. Digitally accurate performance tests meet EIA/IHF requirements. Exclusive, tuneable FM-IF Sweep and Markers-aligns all IF stages. Expandable FM features for future service needs, plus SCA compatible. Twice the capability for less than 1 II tl C-QUAM is a re BHiiH 32 DO Sen co re Drive, Sioux Falls, South Dakota 57107 Cain-800-SENCORE Ask About <73&W73y AW Day circle 1 39 on free INFORMATION card Video Preview tape'