Radio-Electronics (classic USA print magazine)

UNIVERSAL DESIGNER: Here is the dreamed -of solderless-breadboard development system featuring six of the most-often-needed peripheral circuits shop and home designers seek! Circuit designing now can be more fun.

LED TACHOMETER: An analog display is still the best method of engine speed indication for your automobile. Our designer-award project offers either an advancing LED dot or a circular LED bar to graphically point out rpm's to the driver.

BINARY TO HEX DISPLAY VIA THE JUNK BOX

Using some mental and TTL logic, you can pulse binary to visual hex display to ease debugging procedures. The cost of this project is greatly reduced by using old junk box LED displays and TTL chips.

DISCO LIGHT ORGAN CONTROL: Boogie to throbbing music amid the blinking of synchronous stringed lights -one strand each for bass, mid-range and treble tones. Simplex design and construction lets you discoize the lighting in your party room.

COMPU-SOUND: Hear the zap and zizzle of aliens impacting on your nuclear laser fields as your space battle crafts dodge muon missiles. This little project ties into the cassette out- put of your microcomputer with- out modifying the expensive hardware, or for that matter, damaging it.

TV TO VIDEO MONITOR: Here are the tips and techniques to convert a television receiver to video monitor for your computer. But, before you pull off the back cover, read this article to discover that the conversion is not that easy!

JUNK BOX METAL DETECTOR: A one evening project that will provide many weekends of fun locating planted (salted) or real buried treasure. A few small parts and a transistor radio will get you beeping on the beaches.

TRACER TONE: Think of the many times you tried to chase twisted pairs through hidden cables in equipment and buildings, and spent too many hours that normally takes a phone company line- man only minutes. His secret tool is this handy project that you can assemble in a few hours for a few bucks.

BEAT-FREQUENCY OSCILLATOR: If your problem is too much monkey talk on the upper portion of the channels on the CB band, you can tune them in for listening purposes as picture taking re- ports on your CB AM transceiver.

XTAL SPOTTER: Shortwave listeners and ham operators the world over have one common problem-pinpointing the frequency of the incoming radio signal. This one-evening project picks out multiple points of frequency reference on the dial making frequency estimation from surplus crystals accurate.

FLASHMETER FOR YOUR STROBE: Shooting in standard size rooms is easy work with good results since the strobe bounce and camera settings have been worked out in the photographer's mind. But, "rules of thumb" are out the window when an amateur resorts to outdoor shots and snaps taken in a barn-like room.

SMART POWER SUPPLY: Most regulated power supplies automatically regulate voltage and make French fries when the external circuit goes bad. Our educated unit senses overloads and shuts down faster before a fatal temperature build-up.

CUT-OFF TIMER: The local bandit tries to rip off your car but the alarm goes off in your driveway at 3 in the morning. You snore away till dawn as your neighbors form a vigilante group to deal with your alarm. With our cut-off timer installed in your car the alarm is silenced minutes later automatically.

REMOTE CONTROL OUTPUT MIXER: Here's a project that can turn on or off up to four electrical appliances in any combination you select. There are 16 possible combinations. You supply the hex input signal and the device by its internal relays will switch in or out four line circuits.

OPTO POWER SWITCH: One of the first facts we learn in electronics is that a small current can be used to control large cur- rents. This gadget lets a little 12-20 mA LED flip the switch on an external circuit rated for 5 amps, and provides line isolation.

LOCK-OUT: Now you can play quiz games at home and know who had the answer first! Expandable circuit allows from 2 to 8 players trigger a circuit as they race each other to the button with the questioner getting a positive readout as to who was first. A bit of innovation permits the builder to expand the circuit of this project to include many more contestants-all losers.

LIGHT SEQUENCER: The light-chaser moving effect seen on theater marquees for many years is an attention getter you can now employ for your sign and window displays. Easy-to-build gadget lets you innovate unusual and creative designs.

DUAL VOLTAGE POWER SUPPY: Add test -bench punch to your project building and troubleshooting with an inexpensive dual -regulated, common -ground power supply that wilt get more use than squeals in a pigsty. It's so inexpensive and easy to build. Why not start now?

CB MODULATION METER: Talk about modulation or talk power-its all the same thing when you are trying to get a pip-squeak signal out of your CB set and the RF din and clamor on the CB 2hannels is enough to make a grown man cry. Don't give up because this handy project aids you in getting out.

WIRELESS CW KEYING MONITOR: Is your "fist" good or bad? You will never know unless your best friend tells you-and your best friend is this desk -top project. If you can't hear the di's and da's you are transmitting, your skill will diminish without a friend.

AIR BURST ETCHING: Here's a project you may scoff at, but you'll change your tune the first time you use it. This device bubbles air through the etchant solution as you etch the foil of a PC board. You gain in saving time and on the first try.

TEMP-SENSOR: Now you can plug a handy temperature sensing probe to your digital voltmeter and read out temperatures from -132°F to 302°F with an overall accuracy of ± 1 percent. Or do you prefer the Celsius, Rankine or Kelvin scales? Select what you want and the readout is accurate.

GLITCH STRETCHER: If fate tosses you a glitch you cannot see, here is a project that will stretch it and let your oscilloscope put it on the screen for all to see. Now you will be able to track down these pulses that are too thin to trigger.