Monthly Archives: February 2024

1939: The Camera as a Sales Tool

Eighty-five years ago, radio repairman Lewis P. Evans of Chicago’s Evans Radio Laboratory brought along a camera on every service call. He would snap a picture of the house, or if he was lucky, a picture of a child, or even the family dog.

He would hold on to the pictures for a few months, and then send them to the woman of the house, with the shop’s address on the back. He reported that a woman can’t resist a picture of her own home or someone in her family. The picture would be saved, or perhaps placed in the family photo album. And when the radio needed service, they would know exactly where to find the shop’s address.

This feature appeared in the February 1939 issue of Radio Retailing. According to this 1936 newspaper advertisement, the shop’s address (presumably the one on the backs of the photos) was 7152 S. Exchange Ave.



1954 Code Oscillator

1954FebQST11954FebQSTThis schematic for a code practice oscillator appeared in QST 70 years ago this month, February 1954. The observant reader will notice that something seems to be missing.

That’s right. There’s no apparent source of B+ power. The only power connection is to the filament of the tube. But it works anyway! According to an editor’s note, the circuit shows 0.2 volts between the cathode and plate, derived from the initial velocity of the electrons.

According to the same note, the only other circuit that works without any apparent plate voltage is a Tri-Tet crystal oscillator,  This is explained in more detail in an article in the May 1941 issue of QST. According to that note, the oscillator “will run merrily without plate voltage from an external source so long as the circuit is complete.”

This code oscillator was designed by long-time ARRL staffer Lew McCoy, W1ICP, who then held the title of Technical Assistant. He noted that the electric buzzer was the traditional method, but “if you don’t live alone, the sound of an electric buzzer may soon grate on the nerves of the family or neighbors.” This inexpensive circuit allowed practice while still preserving peace at home.

The novel method of powering the oscillator meant that it could be built for less than six dollars, less than half the cost of commercial code oscillators. And after licensing, those parts could undoubtedly be put to use in other projects.

McCoy noted that while the circuit worked with all 6J5 tubes he tried, it was possible that a particular tube might not. In that case, the advice was to try another. He noted that the 6F6 pentode he tried, with plate and screen tied together, also worked.

The oscillator took care of the beginner’s need for sending practice. For receiving, he pointed out the W1AW code practice sessions, but also included a list of other stations with scheduled code practice. Many of these were operating on 10 meters. For example, W0BOL was sending code practice on 29.2 MHz Tuesday and Wednesday evenings from 1130 Delaware Avenue, St. Paul, MN.

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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.



Give Your Boy Scout a Brownie, 1924

Screenshot 2024-02-12 12.56.33 PMIf you were in the market for a gift for your Boy Scout a hundred years ago to celebrate the anniversary of the BSA, you couldn’t go wrong by getting him a Brownie camera from the Eastman Kodak Company. And if you were in Omaha, the place to get it would be the Kodak counter of the Robert Dempster Co., 1813 Farnam Street, as seen in this ad from the February 13, 1924, issue of the Omaha Bee.



1949 Radio-Intercom

1949JanPMThis combination radio-intercom system was the latest thing 75 years ago. It could be used as a regular broadcast receiver, from either its own speaker, or the extension unit in another room. And at the push of a button, it could be used for two-way communications. The set had four tubes, said to be quick heating.

It appeared in the January 1949 issue of Popular Mechanics.



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.



The House Wired For Radio, 1939

1939FebRadioCraftEighty-five years ago, the February 1939 issue of Radio Craft shows how to wire your house for radio. And like Mr. Green, you could be serene knowing that there was one in every room. Actually, there was only one radio, a top-of-the-line RCA Victor model U-130. Speakers were mounted in each room. But in addition, the set allowed the use of a wired remote control, so controls were mounted on the walls of most rooms. But if walking over to the wall proved too stressful, there was also an armchair remote, which could be plugged in to a nearby socket.

The installation also incorporated a set of Model 446 Aristocrat “TELECHIMES” by General Kontrolar company, Inc., which could be used to elegantly page family members throughout the house.



1939 Code Practice Set

1939FebPMEighty-five years ago, it was customary to put on a tie before learning Morse code, and this young man honored that custom. He’s practicing with a self-explanatory device shown in the February 1939 issue of Popular Mechanics.

To hear perfect code, he simply runs the test lead over the cardboard cutout over a copper sheet, and the code sends itself. We’ve seen similar ideas before, such as here.



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.