Eighty years ago, the November 1936 issue of Popular Science carried the plans for this portable 20 watt AM transmitter for 160-20 meters.
The compact transmitter was designed for operation on a 6-volt storage battery, with a motor-generator supplying the B+ voltage. Also included were plans for an AC power supply.
A type 42 tube was used for the crystal oscillator, with a 6A1 final amplifier. Modulation was handled by two 6A6 tubes.
The November 1943 issue of Popular Mechanics carried the plans for this wartime emergency receiver. Built in a cigar box, the set was an updated version of the “Hurricane Receiver” previously published by the magazine and featured here earlier.
The article noted that the set could be used undrer blackout conditions in areas where a power line would be unavailable. Both the filaments and B+ were provided by six volts, which could come either from dry cells, or obtained from the nearest automobile. For portable use in shelter conditions, the article suggested a wood carrying case such as shown here for transporting the battery.
The set was said to be of considerably more volume and greater range than the original model. It employed two 6G6-G tubes, and the article noted that these tubes were commonly found in the junk boxes of radio students, experimenters, and servicemen. The set employed one tube as the regenerative detector, with the second one serving as audio amplifier.
The coil was wound on a cardboard tube, and the wire could be salvaged from a burned out choke or audio transformer. A ground connection was recommended for maximum results, and a 20 foot indoor antenna could be used for local stations, although a longer outdoor antenna would pull in stronger signals.
With this set and a 6 volt battery, the owner would be able to listen to local stations for emergency safety and blackout instructions.
At OneTubeRadio.com, we appreciate one tube radios of all varieties, but in general, the bigger the better.
In 1923, the one shown here was billed as the world’s largest one tube set. The set is being operated by Miss Agnes Leonard, at the Radio Show being held at the Grand Central Palace, New York City. The photo appeared in the November 1923 issue of Radio Topics.
A hundred years ago today, the November 26, 1916, issue of the Chicago Tribune carried this Victrola ad.
For $79.50 (or a dollar a week until paid), you could take home the Victrola, along with 12 selections of music (6 double-sided records). It was offered on a 30 day free trial, and the seller was confident that you would want to keep it as a permanent member of the family.
It was sold by the P.A. Starck Piano Company of 210-212 S. Wabash Avenue, Chicago.
The young men shown here a century ago are training to become wireless operators at the Montreal wireless school operated by the Marconi Company. The school had opened on June 1, 1916, and was under the direction of instructor in charge Mr. Douglas R.P. Coats, who is shown standing behind the back row of students.
In order to make the training resemble as closely as possible actual working conditions, specially designed apparatus and automatic transmitting devices were used. The school also had the latest 17 kW apparatus available, and other installations were to be installed.
The photo appeared in the November 1916 issue of Wireless World.
Happy Thanksgiving from OneTubeRadio.com!
For the 1920’s radio dealer, an important way to get potential buyers in the door was the window display. And Thanksgiving was a tried and true theme for that display. This 1928 store window featured a cutout turkey listening to the radio.
The photo appeared in the April 1928 issue of Radio Retailing.
Fifty years ago, the “Beginner’s Corner” of the November 1966 issue of Electronics Illustrated carried three circuits for basic radio receivers. The first was the crystal set, the second added one stage of audio amplification, and the third was this basic regenerative set.
The tuner was a ferrite loopstick coil, which were available in abundance for experimenters to use in similar circuits. It used permeability tuning by moving the ferrite core in and out. The tickler coil was added on as a winding around the outside.
Seventy-five years ago today, only two weeks before Pearl Harbor, the Pittsburgh Post-Gazette for November 22, 1941, posed the question of whether America could be bombed, and included contradictory answers: Yes, an air raid was possible, but a Coventry-style attack on the Continental United States would be impossible, as long as America or a friendly navy controlled the Atlantic.
The article didn’t mention the Hawaiian or Philippine Islands which would be so obviously in the news in a fortnight. However, it did look at the Pacific situation on the continent. From Japan, air raids could possibly be made against Alaska. If Siberia fell into enemy hands, then most Alaskan bases could be raided at will.
The focus of the article was a traveling exhibit put together by the Science Museum of Minnesota. After being displayed in Minnesota, the exhibit was on tour, and was making its first stop in Pittsburgh.
This simple idea for a code practice oscillator appeared in the January 1944 issue of Radio Craft magazine.
No doubt inspired by wartime parts shortages, the audio feedback loop could be created with an old telephone receiver and microphone placed next to each other. The idea was sent in to the magazine by one Mr. Ivan H. Walker of Mt. Horeb, Wisconsin.
Seventy-five years ago this month, the November 1941 issue of Boys’ Life carried this image of a New York television broadcast featuring scouts from Troop 1, Mendham, N.J. While not identified in the magazine, the gentleman in the center appears to be Troop 1’s Scoutmaster, William “Green Bar Bill” Hillcourt, the prolific writer whose works included three editions of the Scout Handbook.
From the CBS logos on the camera, the broadcast was from WCBW, which later became WCBS-TV. It is the nation’s second oldest commercial station, having gone on the air only an hour after rival WNBT, leter WNBC.
Both stations began commercial broadcasting on July 1, 1941, the first day that the stations then operating under experimental licenses were allowed to operate under commercial licenses.
Troop 1 was founded by the Danish-born Hillcourt in 1935, and chartered by the National Council of the BSA. He was asked to develop scouting in America, and he used Troop 1 to test his ideas. The twelve candles shown in the picture undoubtedly represent the twelve points of the Scout Law.