Author Archives: clem.law@usa.net

1965 Light Beam Communicator

Screenshot 2025-02-13 11.35.20 AMThe young man in this drawing is now a senior citizen, but in 1965, he was taking part in the school science fair, using a project shown in the Winter 1965 issue of Elementary Electronics. He was communicating with a light beam, with a rudimentary setup consisting of two audio amplifiers. The output of one of them was hooked directly to a light bulb (in series with a 3 volt battery), and the input of the other one was hooked to a photocell.

According to the article, this unit was good for demonstration purposes only, and was only capable of a couple of feet. I’m surprised that they are so conservative in their estimate, since I made virtually the same setup when I was a kid, and it traversed the length of the house without much difficulty.

The only difference in my version was the addition of a transformer to the output of the first amplifier. The primary was hooked to the amp, and the secondary was wired in series with the battery. I used a flashlight, and just sandwiched two pieces of foil, insulated by cardboard, between the lamp and the battery terminal. I suspect my use of a flashlight, complete with its parabolic reflector, was probably an important factor in my success.

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1940 Cane/Seat/Radio

1940MarPSEighty-five years ago, this no-nonsense outdoorswoman is enjoying a hike, but when she stops to rest, she can listen to a favorite program on this combination cane/seat/radio described in the March 1940 issue of Popular Science.

One HY115 tube served as a regenerative detector, with a second serving as AF amplifier.  A final HY125 audio stage powered the headphones.  The cane itself could serve as an antenna, or a convenient fence wire could be used.

As with everything, cane-seats can still be found on Amazon.  The exact instructions for mounting a radio will differ, but we’re confident that our readers can figure it out.

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1976 Grocery Prices

1976Mar6APFor a snapshot of the cost of living in the Bicentennial year, this ad for A&P stores appeared in the Pittsburgh Post Gazette on March 5, 1976.  While the prices look low, this was the era of the WIN button, and there was a lot of inflation in progress.  According to this online calculator, one dollar in 1976 works out to $5.58 in 2025 dollars.  So 59 cents for a five pound bag of flour works out to about $3.29 per pound today.  You can check the current price at Amazon at this link.



Converting Your TV to a Big Screen, 1950

1950MarPSShown here is Popular Science author Robert Gorman upgrading his 10-inch television to a “big screen” 16-inch set. He owned a 10-inch RCA 630-type circuit (which he had built from a kit). That circuit was widely distributed, both by RCA and other well-known brands. It had enough power to run the larger picture tube, and an article in the March 1950 issue of Popular Science showed how to make the conversion.

The new tube had the same pin configuration, and only a few small changes to the circuit were required. The larger tube required adding some wiring to the socket, and the article warned of the importance of using wire insulated for the high voltages involved.

The larger tube required a new cabinet. An accompanying article showed how to make one. The cost of the cabinet was a significant portion of a TV’s cost, so even if you were buying a new TV, you might save money by just buying the chassis and putting it into a cabinet of your own making.



Charging the Battery With Your Toaster

1925MarPS1If you were one of the growing number of Americans who owned a radio 100 years ago, the cost of batteries would soon become a concern, and you would be thinking of ways to run the radio from your lighting current.

In many large cities, the power company supplied 110 volts direct current, and if that was your situation, the March 1925 issue of Popular Science showed you how to power the radio.  Even though the power was DC, the generators down at the power plant generated a lot of ripple, and if you just ran the radio straight from the line, the result would be a loud high pitched whine.  So the filtering arrangement above could be used.

1925MarPS2For the filaments, since you already had a battery, you could just use that, but then recharge it with 110 volts DC, as shown here.  To drop the voltage, you would start with a 60 watt lightbulb in series.  But to finish the job, you would want to lower the current, which meant putting the toaster in series.

If you weren’t sure about the polarity, you could run the simple test below:

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2025 New York As Envisioned in 1925

SciInvMar2025Shown here, in the March 1925 issue of Science and Invention is “a good idea of the probable appearance of New York’s skyscrapers in the year 2025.” It was to include triple and even quadruple-decker streets. The lower level would be occupied by trucks, with lighter vehicles on the upper levels. Sidewalks would be moving. The subways, both long distance and local, would be in multiple layers underground, with daily commutes of a hundred miles, such as to and from Philadelphia, commonplace. The skies being filled with aircraft would be almost quaint, as they were to be there by 1950.

While the image above is not recognizable, the image below doesn’t miss the mark by very much.  You can see a modern view from a similar angle at this link.

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1945 Television Theatre

1945MarRadioRetailingThis idea to promote television appeared in Radio Retailing 80 years ago this month, March 1945. Anticipating a television boom after the war, the magazine suggested that the idea might promote interest in television. Dealers who were equipped with sets could invite neighbors and customers who might be interested but had no set.

The address on this invitation is residential, and undoubtedly the home of O.H. Caldwell and Mildred B. Caldwell. The location is about 30 miles from the Empire State Building, so would pull in a good signal with a suitable antenna.

Caldwell, one of the original commissioners of the Federal Radio Commission, is described as an editor of the magazine.  His home was said to be a home of the future, with many modern electronic devices, including, apparently, the television.



Taking Radio on the Road, 1925

1925FebWirelessMagOne hundred years ago, an entrepreneurial radio dealer in Horsham, England, noticed that interest in wireless was lagging in nearby villages. He took it upon himself, therefore, to equip a motor van with a complete receiving set an hit the road. He paid periodical visits to enable the inhabitants to enjoy a wireless concert, and to bring to their attention the fact that his firm could sell them a set of their own.

In this picture, in the February 1925 issue of Wireless magazine, and it is noted that great pleasure is written upon the faces of the children listening here.



1925 Telemedicine

1925FebSciInvA hundred years ago this month, the cover of the February 1925 issue of Science and Invention gives Hugo Gernsback‘s vision of what telemedicine would look like. Of course, the word “telemedicine” hadn’t been coined yet, but the concept is there: “The doctor of the future, by means of this instrument, will be able to feel his patient, as it were, at a distance. The doctor manipulates his controls, which are then manipulated at the patient s room in exactly the same manner. The doctor sees what is going on in the patient’s room by meads of a television screen.”

The device did have a name, the “teledactyl.” That’s not a type of dinosaur, but instead means that it could feel at a distance.



Loop Antennas, 1940

1940FebNRNEighty-five years ago, this radio listener is showing off her RCA receiver. More specifically, she is showing the loop antenna mounted on the back, manufactured by Consolidated Wire and Associated Corporations. She is on the cover of the February 1940 issue of National Radio News, which devotes several pages to the use of such antennas.

If you see some buyer’s remorse in her eyes, it’s possibly because the small antenna doesn’t work as well as the old aerial that was previously connected to the set.  If the serviceman was approached by a customer wanting the added portability of such an antenna, it was recommended that they explain the shortcomings. As opposed to a longer antenna, fewer stations could be pulled in. But if the receiver was fairly sensitive, the strong local stations could be heard. If the receiver covered the shortwaves, the customer would need to be told that reception would be severely limited.