1954 Two Transistor Regen

1954AugRadioElecSeventy years ago, the August 1954 issue of Radio Electronics showed how to make this two-transistor regenerative receiver. It used two CK722 transistors, one for the detector, and another for one stage of audio amplification. It was said to provide ample volume on stations hundreds of miles away.

The set was billed as a preparedness device, as it made “a reliable receptor for emergency use during a power failure should a sudden air attack occur.” Since it was an emergency receiver, the antenna requirements were flexible. Two separate antenna connections were provided, one for a long antenna, and one for a short antenna. The short antenna could include “the shell of a floor lamp or table lamp, the shell of a telephone box, or to one side of an a.c. outlet. No ground connection is made if any of the above antenna substitutes are used. This precaution is necessary because of the possibility of a short in C1.”

The author noted that there was some variation in transistors, and for that reason, it was a good idea to hook the circuit up breadboard style to test them in operation before final assembly.

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1924 Novelty Crystal Sets

A hundred years ago this month, the August 1924 issue of Science and Invention offered these variations on the crystal set. One was built into a teapot, one into a coconut shell, and one was a ring. They had been demonstrated in Chicago and were found by experts to pull in the stations.



Pelmanism, 1939

PelmanismMost of our readers will recognize the figure shown in this ad from the August 1939 issue of Practical Mechanics as Lord Baden-Powell, the founder of the Scouting movement. But the ad reveals that B-P was also a proponent of Pelmanism, what the ad calls the Science of Success. It was a system of brain training, which was said to develop the mind just as physical training strengthened the body.

The ad invited you to write in for details of the course in Pelmanism. But thanks to the magic of the Internet, you can now download the entire course for free. If you prefer hard copies, reprints are available at Amazon.



Some links on this site are affiliate links, meaning that this site earns a small commission if you make a purchase after using the link.

1924 British Radio Workers

1924AugWirelessWorldA hundred years ago, these British workers (other than the watchful foreman standing at the rear, all women, as far as I can tell) are assembling tuning coils at the works of Igranic Electric Co., Ltd. The photo appeared in the August 1924 issue of Wireless World.



1944 British Wartime Civilian Receivers

1944AugPracWirEighty years ago, the August 1944 issue of Practical Wireless announced the introduction of the bare-bones Wartime Civilian Receiver. With British industry concentrated on wartime needs, civilian radios were getting hard to find. And since the government recognized the need to be able to provide information and entertainment to its subjects, it authorized this design.

Two sets were available. Since domestic longwave broadcasting had been suspended during the war, they tuned only medium wave. The plans were made available to all manufacturers, and the sets were dubbed Utility Radios.  In fact, “Utility” was almost a brand name, since they got that moniker from the government’s earlier venture into clothing, which used the Utility brand name,

The mains-powered set retailed for just over thirteen pounds, with the battery set selling for just under twelve.

 



Wiring the House Up for Radio, 1924

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The kids seem to have their doubts, and Dad is showing some signs of frustration, but he was wiring his house for radio, following the plans in the August 1924 issue of Popular Science. Perhaps his frustration came from not heeding one of the warnings in the article about the proper hookup of remote speakers:

“Ordinary electrical appliance outlets are excellent and reasonable in price. The loudspeaker must be supplied with a corresponding plug and all outlets have to be identical. But here care must be used that all radio outlets are marked with some unmistakable sign, lest a loud-speaker be plugged into an electrical socket by mistake, with disastrous results.”



Radio Swimming Lessons, 1924

RadioWorldAug161924Radio has been used over the years to provide instruction in many different disciplines. But for some reason, this one never caught on. A hundred years ago today, the August 16, 1924, issue of Radio World carried this photo showing radio being used to give swimming lessons.

The photo shows one Mary Gustin, and the swimming instructor is one E.C. Dalton, who is behind the microphone of New York station WEAF.  She is about to plunge into the water, where she will listen in to her instructions.



World’s Largest Radio, 1939

081539BCEighty-five years ago, the world’s largest radio represented KSL, Salt Lake City, in the city’s parade honoring the entrance of the Mormon Pioneers in 1847. Equipped with a powerful public address system, the float furnished music along the 3 mile parade route. The float measured 22 by 9 by 8 feet, and was featured in the August 15, 1939, issue of Broadcasting magazine.



Starting a Home TV Repair Business, 1974

1974AugPEFifty years ago, the August 1974 issue of Popular Electronics offered some pointers for hobbyists thinking of going into business for themselves repairing televisions. It reminded that in some jurisdictions, a license was required, and that high voltages were present, so you had to be careful. But for those who wanted to ease their way in, the initial investment might be as little as fifty dollars for a set of tools, and the most common tubes. As you eased your way in to the business, you could upgrade, and the magazine gave recommendations for the parts, equipment, and chemicals you should keep on hand.

The magazine also reminded that in some cases, the experience and test equipment required might be out of your league. Therefore, if possible, it was wise to make a deal with a full-time service shop to tackle the jobs you couldn’t handle.



1964 Negative-Resistance Oscillator

1964AugPEIf you have a 600 volts power supply lying around (perhaps from an old television), you can loan it to Junior, who will love making this science fair project. It uses lethal voltages, it lights up, and it makes noise! He or she will love it, and it’s bound to take home the blue ribbon.

The project appeared 60 years ago this month in the August 1964 issue of Popular Electronics. It is simplicity itself–you simply apply a high voltage to the fluorescent tube, and it lights up. But past a certain voltage, the current decreases with an increase in voltage, meaning that the resistance is negative. This phenomenon can be used to put the device into oscillation, and sound comes out of the headphones. The device can be used as a code practice oscillator, or simply to wow the judges at the science fair.

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