Electronics Now articles from July 1993

Electronics Now archives from July 1993

Channel mapping. (cable network channel system) (Video News)
July 1, 1993... Complicating the problem of TV-cable interface is a new practice by cable systems, becoming increasingly widespread, known as "channel mapping." This is a system whereby channel numbers assigned by cable systems to the various programs they...

AVCOM PSA-37D spectrum analyzer and PTR 25-A portable test receiver. (Eqiupment Reports)
July 1, 1993... It's possible to install a satellite-TV system without any test equipment--but it's not recommended for any professional installer who intends to stay in business very long! Test equipment can help an installer adjust a satellite. system for...

Build Your Own 486/486SX and Save a Bundle, 2nd Edition.
July 1, 1993... If you'd like to own a computer with the power and efficiency of top-of-the-line models, without shelling out the money required to purchase one, you don't have to resort to theft. This book shows how to assemble a high-powered...

Speakers for Your Home and Automobile: How to Build and Enjoy a Quality Audio System.
July 1, 1993... It doesn't matter how good your stereo components are, if you don't have decent speakers. This book shows do-it-yourselfers and technicians how to build quality speaker systems for use in the home and the car. With clear instructions and...

The AutoCAD 3D Companion: The Illustrated Guide to AutoCAD's Third Dimension for Release 12.
July 1, 1993... Mastering AutoCAD Release 12's powerful 3D capabilities doesn't have to be difficult. This book teaches everything needed to draw effectively in 3D. Special emphasis is given to the 3D Toolkit, with 52 ready-to-load AutoLISP programs...

The Experimenter. (computer peripheral circuit)
July 1, 1993... Build the Experimenter, and put your personal computer to work doing interesting and useful real-time tasks. JUST IMAGINE WHAT WOULD HAPPEN if your personal computer had the ability to sense real-world events taking place around it and...

Combustible gas alarm. (design, construction and use)
July 1, 1993... MOST PEOPLE TODAY ARE AWARE OF the dangers of a home fire, and depend on smoke detectors for an early warning. However, fires caused by combustible gases can be avoided by detecting the gases before they ever reach toxic levels or ignite. A...

Precision digital scale. (design, construction and use)
July 1, 1993... AN EASY-TO-READ PRECISE SCALE with a liquid crystal display (LCD) will permit you to put the right poostage on your letters and packages, carry out experiments that require precise measurements, and maybe even improve your cooking because...

Thumb drum. (electronic drum instrument)
July 1, 1993... Let your fingers do the tapping with the ThumbDrum. LAST MONTH WE WENT OVER THE theory on how the ThumbDrum operates. Now let's build it and get it working. Getting it together Step 1 is to decide what you're going to build....

Printer Minder. (design, construction and use of printer power controller)
July 1, 1993... DO YOU DEBATE WHETHER TO TURN your printer on and off--or do you simply leave it on all the time? Perhaps you've got a remote data-logging or control application in which the printer need be on only occasionally. Either way, Printer...

Analog Multiplier IC's. (integrated circuit)
July 1, 1993... Learn how to multiply, divide, square, and get square roots of analog variables with an analog multiplier, and put that skill to work in your experiments and projects. MONOLITHIC ANALOG MULTIPLIERS can multiply, divide, square, and...

LC filters. (inductive capacitive filters)
July 1, 1993... THE PRIMARY APPLICATION FOR RESonant inductive capacitive (LC) filters these days are in high-frequency circuits. These filters, like resistive capacitive (RC) filters can easily be designed to perform low-pass, high-pass, bandpass, or notch...

Maximum power transfer. (computation of maximum power transfer curve) (Hardware Hacker)
July 1, 1993... Suppose you're using an electrical or electronic generator and that it happens to provide a one-ohm source impedance and is outputting a one-volt signal. What is your "best" load resistance? As Fig. 1 shows you, there is no "best"...

SETI resources. (Search for Extra Terrestrial Intelligence) (Hardware Hacker)
July 1, 1993... NASA has recently started a new and very aggressive SETI (search for extraterrestrial intelligence) program. In the first few hours of its operation, more frequencies have been observed in more ways than they have in the entire history of all...

Some reader suggestions concerning our SSAVI descrambler and something completely different. (computer code cracking) (Drawing Board)
July 1, 1993... Over the years, a lot of the projects we've worked on together have needed odd-ball decoders. I've said over and over again that my preferred solution is an EPROM. I've used EPROM's for everything from custom character generators to state...

Loudspeaker power ratings: midrange and woofer probelms. (Audio Update)
July 1, 1993... Everything that I said last month about tweeter power ratings also applies, to some degree, to midranges and woofers. Except, unlike theh situation with tweeters, the heat dissipation problem of the larger drivers is eased by heavier voice...

A bit meter in every basement. (computer technology and society) (Computer Connections)
July 1, 1993... Last month we discussed how the computer, telecommunications, entertainment, publishing, and consumer electronics industries are converging. One way to view this convergence is to think of society as a big information-crunching machine (ICM)....