Seventy-five years ago this month, the September 1949 issue of Radio Retailing carried this ad for the GE model 65 clock radio. The radio featured a “slumber switch” which would let you go to sleep to music, and then wake you to music in the morning. But if the music didn’t wake you up, it would soon revert to a buzzer.
The radio featured the familiar five-tube lineup of 12SA7, 12SK7, 12SQ7, 50C5, and 35W4.
Washington Evening Star, Sept 1, 1939.
Today marks the 85th anniversary of the outbreak of World War II, with Germany’s invasion of Poland on September 1, 1939. Within days, Britain and France had declared war.
The outbreak of war meant that the BBC put into place a pre-arranged program to prevent its transmitters from being used by enemy aircraft for direction finding. All broadcasting was moved to two frequencies. Synchronized transmitters throughout the country transmitted simultaneously on those frequencies. During an air raid warning in one portion of the country, transmitters in that area would cease. But since other transmitters were still in operation, the listener would continue to hear the program, with only a modest loss of signal strength. Later in the war, another frequency, 1474 kHz, was added, with low-powered transmitters.
Immediately prior to the War, the BBC’s domestic programs were broadcast on the frequencies, shown at left, as shown in the September 1, 1939, issue of Radio Times:
This consisted of a national program on 200 kHz longwave, and 1149 kHz mediumwave, as well as several regional programs. The following issue, dated September 4, entitled “Broadcasting Carries On,” highlighted the changes. The regional programs were suspended, and a single national program, called the Home Service, covered the whole nation.
The new Home Service would be on the air on 767 (North) and 668 kHz (South), starting at 7:00 AM until 12:15 AM. If important news warranted, there would be broadcasts at 1:00, 3:00, and 5:00 AM. Regional broadcasts were replaced with announcements for the respective regions. London and Scotland announcements would be at 6:15 PM, Welsh and Western announcements at 7:00 PM, Northern announcements at 7:45, and Midland and Northern Ireland at 10:45 PM.
The 200 kHz longwave signal went off the air, although it came back later for foreign broadcasts. The BBC’s television station in London also went dark for the duration of the War. You can read more of this history at the BBC website.
Eighty-five years ago, this gentleman is teaching himself Morse code thanks to a one-tube code oscillator shown in the August 1939 issue of Popular Mechanics.
It used a single 12A7 tube, and for the filament, it used a “curtain burner” line cord to drop the voltage to 12 volts. The article suggested learning the code by sending from the attached chart, and then having someone else, preferably someone already skilled at the code, to send faster and faster.
We’ve previously featured AC power inverters from American Television & Radio Co., of St. Paul, Minnesota. This ad for their products in the August 1954 issue of Radio-Electronics stresses their usefulness in an emergency situation. In addition, it points out how they can be used to power a tape recorder, allowing the busy businessman to dictate memos right from his car, boat, or plane.
Eighty years ago this month, the cover of the August 1944 issue of Radio Mirror featured singer Jeri Sullavan, who, according to the magazine, was known by GI’s as the girl with the pin-up voice.
She was born in Jersey City, NJ, but the family moved to Bremerton, WA, when she was in her teens. Her first singing job was at a Bremerton ballroom, which paid $1.50 per evening, but she was discovered in San Francisco when some friends asked her to sing with the Bernie Cummins band, and she sang “I’ll Never Smile Again.” Her start in radio came on WSM in Nashville, and at the time of publication, she was a regular on CBS. She was in demand as a performer at camps and canteens. According to the magazine, she lived alone in an apartment two blocks from the studio with her four dogs.
Eighty years ago, this New Jersey war worker was doing her part to assemble a 2-1/2 kilowatt transmitter for the U.S. Army Signal Corps. Her factory, Press Wireless, made these large transmitters, which were too large for mass production. Each unit was put together by hand, and the guiding principle was to make them rugged. The photo appeared in the August 1944 issue of Radio News.
She has an uncanny resemblance to Ted Baxter’s girlfriend Georgette, played by actress Georgia Engel.
But it’s actually Margaret Bagley, an employee of Bell Laboratories, and she’s showing off a light-powered transmitter on the cover of the August 1954 issue of Radio Electronics. The FM transmitter is being powered by an electric light bulb thanks to 39 silicon solar cells which had recently been developed by Bell Labs. The two-transistor transmitter circuit is shown below, and it’s being modulated by the RCA turntable, which is presumably running on AC power.
Seventy 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.
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.
Most 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.
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