Category Archives: World War 2

1944 Two Tube Receiver

Screenshot 2024-03-12 12.34.08 PMThe plans for this handsome two-tube set appeared 80 years ago this month in the March 1944 issue of Radio Craft magazine. The author had a broken midget set with a cracked case, one bad tube, and some loose connections, but he was able to use the parts to make this portable TRF set.

For a cabinet, he found some clear plastic. The result, despite wartime parts shortages, was a radio almost as good as the donor.



Parts for the Junk Box: 1944

1944MarPMEighty years ago, these gentlemen are disassembling an old radio to salvage the parts within. There was a war going on, and those old parts would provide many useful materials. The March 1944 issue of Popular Mechanics reminded them to unsolder all fixed resistors and capacitors, rather than clipping the leads. It also reminded them to save the coils, sockets, and screws in separate compartments in their junk boxes.



1944 Automatic Gun Director

1944RadioCraft11944RadioCraft2Eighty years ago this month, the February 1944 issue of Radio Craft gave some description of the automatic gun director system illustrated here. The system consisted of a computer (undoubtedly analog) that directed the gun exactly where to fire. The path of the plane was plotted by two telescopes, whose operators kept the plane in the cross hairs for a few seconds, to plot the aircraft’s location, speed, and direction. Height was measured in a similar manner, and the computer had inputs for wind direction and velocity, muzzle velocity, and air pressure. The result was a gun that was able to aim itself to the spot where the plane would be when the shell arrived.



1944 Time Zone Converter

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If you are looking for a simple analog computer to calculate time zone differences, you can’t go wrong with this one, from the February 1944 issue of QST. It had been sent in to the magazine by one Lt. I.E. Slutzky, who found the need for a simple device for changing time at one location to any other location on the globe. Since this one had scales for “yesterday” and “tomorrow”, it would also simplify those vexing questions surrounding the International Date Line.

In 1944, you would have had to meticulously re-draw the design (or perhaps cut up your magazine). Today, however, you can easily print the image above on two pieces of cardstock. If Junior is in need of a science fair project, this one will allow him or her to construct an analog computer.



R.C. & L.F. Hall, Houston, 1944

1944FebRadioRetailingThe duo behind the counter here are Dick Hall, W5EIB, and his wife Lillian Hall, W5EUG, owners of R.C. & L.F. Hall, 1015 Caroline St., Houston, Texas.

Their business began when they found a lack of interest by local dealers for hams, and Dick began stocking a few parts in his home. As the stock started to overtake their entire house, they moved to a downtown location. As they anticipated American entry into the war, their business focused on industrial and marine parts. When war came, they knew the whereabouts of most amateur transmitters and receivers in the area, and facilitated sales of that equipment to the military.

The Halls discovered that dealers and hams don’t really mix. The dealer, seeking marine and industrial parts, knew just what he wanted, whereas the hams wanted a place that talked their language. They anticipated a big future for their business after the war, as hams came on the air, and as FM and TV stations would create new markets.

The picture and accompanying article appeared in Radio Retailing, Feburary 1944. This eBay listing shows a 1946 ad for their business, which by then had locations in Beaumont, Dallas, and Galveston, in addition to the Houston store, which was then at 1306 Clay Avenue.



While London Burned: Scout Edward John Cox

EdwardJohnCoxThe February 1944 issue of Boys’ Life carried the stories of a number of British Scouts who had demonstrated bravery during World War II. Shown here is Scout Edward John Cox. During a heavy air raid, he was stationed at his post on the roof of St. George’s-in-the-East Church.

His mother and younger sisters had taken refuge in the crypt under the church. Incendiary bombs crashed around him, and he seized sandbags to quickly extinguish them. But as the raid continued, a big bomb blast into the church belfry, which almost immediately became a roaring mass of flames.

One of the men around him realized that eventually, the belfry would collapse, causing the massive bells to fall through the church and into the crypt. He raced down and gasped out the news to the marshal. Together, they started evacuating the mothers and children. Scout Cox kept going back again and again until all of the children were evacuated.

The last person had just been evacuated when the timbers of the belfry broke through the church and into the crypt.

The UK Scout Association awarded Scout Cox the Silver Cross, an award for acts of bravery in the face of danger where life has been at considerable risk.



1944 Intercom

1944JanPSEighty years ago, there was a war going on, but in his workshop, this gentleman had a power supply capable of putting out 250 volts and six volts. He also had a few tubes lying around, so he put together this audio amplifier, which he used as an intercom. The master station was down in the shop by his power supply, and he mounted a speaker in the kitchen. It was fed with a single wire, with water or steam pipes serving as the second conductor.

From the shop, he could monitor what was going on in the kitchen. And when his wife announced that lunch was almost ready, he let her know he was on the way up. The amp could also be used for a phonograph, as shown in the schematic.

The circuit appeared in the January 1944 issue of Popular Science.

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1939 Electrical Prediction

1939JanPracMechEighty-five years ago, the January 1939 issue of the British magazine Practical Mechanics predicted that, someday, appliances will be equipped with three-prong plugs to avoid the situation shown here. In the meantime, I hope British housewives kept one hand in their pocket while ironing.



1943 Code Practice Oscillator

Screenshot 2023-12-18 1.18.48 PMThe December 1943 issue of Radio News carried the plans for this simple one-tube code oscillator. The 117N7 with a built-in rectifier meant that it could be done with a single tube.

The author of the article is one R.C. Zaun, an engineer with the Thorardson Electric Manufacturing Company. Not surprisingly, the most expensive part shown in the schematic is probably the audio output transformer, which just happens to have a Thorardson part number.

As shown here, the oscillator had a pitch of about 1600 Hz.  This could be varied in one of two ways.  First, R1 could be replaced with a variable resistor, although the article noted that this would also affect the volume.  Another method would be to change the value of C4, switching in capacitors of different values to vary the pitch.

If wartime parts shortages meant that the 117N7 wasn’t available, it could be substituted with other versions of a different filament voltage.  Of course, an appropriate dropping resistor would need to be used.

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Pyruma Putty Cement, 1943

Screenshot 2023-12-18 9.18.22 AMEighty years ago in the U.K., there was a war going on, which meant that many Christmas presents might have been unavailable. But Britons were known for keeping a stiff upper lip, and if there were no gifts in the shops, then they could make their own.

This ad for Pyruma putty cement appeared in the December 1943 issue of Practical Mechanics. After making the model, you baked it in the oven and it became stone hard. The compound was also used by the military in making models.