Category Archives: Radio history

1943 Emergency Blackout Receiver

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 under 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.

World’s Largest One Tube Radio, 1923

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.

1916 Wireless School

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!

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.

1966 One Transistor Regenerative Receiver

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.

1944 Code Practice Oscillator

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.

WLS Chicago, 1946

In this ad from the November 1946 issue of Sponsor magazine, WLS Radio in Chicago reminds its potential advertisers that it is the radio home of tomorrow’s friendly audience.

In July of that year, 2000 boys and girls from every county in Indiana were in the studio audience of the WLS Dinner Bell Time broadcast, “a program familiar in their homes from babyhood.” They were attending the annual 4-H Round-Up being held on the campus of Purdue University.

WLS presented the plaques for outstanding 4-H achievement, all broadcast live over the station’s 50,000 watt Chicago blowtorch. People in Illinois, Indiana, Michigan, and Wisconsin considered the station “one of the family,” and its complete weather, market reports, news, and down-to-earth entertainment expemplified the quiet neighborly way that WLS served both today’s and the future’s friendly audience.

RCA Victrola Model V-215, 1941

This ad appeared in Life Magazine 75 years ago today, November 17. 1941. Victor Record recording artist Rose Bampton is listening to records on the RCA Victrola Model V-215 radio-phonograph console. The nine-tube set provided 12 watts to the 12 inch speaker. In addition to the standard broadcast band, it tuned two shortwave bands, 2.3-6 MHz and 9.3-15 MHz. You can view a nicely preserved example of the set at this link. The set had an original retail price of $214.95.

As the ad points out, the set features the “Magic Brain” automatic changer, and points out that the Magic Brain does all the work–you just sit back and listen. It also points out that the changer has “no needles,” meaning that it had a sapphire stylus and ceramic cartridge rather than “old-fashioned needles,” and that the total weight of all moving parts on the tone arm was “less than the weight of a postage stamp.”

Mezzo-soprano Rose Bampton performed with the Metropolitan Opera from 1932-1950. She died in 2007 at the age of 99.

Emerson Model 330, 1941

This ad for a 5-tube supereheterodyne broadcast radio appeared 75 years ago today in the November 16, 1941, issue of the Pittsburgh Press.

The set sold for $14.95 (complete, no extras), or could be bought on time for a quarter down and fifty cents a week.

The set appears to be model 330, which can be seen at the Radio Attic Archives. It was a standard “All American Five,” with a tube lineup of 12SA7GT, 12SK7GT, 12SQ7GT, 50L6GT, and 35Z5GT. A schematic and more photos are available at the Radio Museum. While the set’s tuning range didn’t extend much above the broadcast band, it was billed as easily receiving police calls, as well as distant stations.

1926 Popular Science Crystal Set

Ninety years ago this month, the November 1926 issue of Popular Science showed how to assemble this crystal set for the radio beginner, and offered a number of possible variations depending on the listener’s location and available stations.

The article noted that millions of Americans lived within five miles of powerful stations, but a surprisingly large number had not yet taken an interest in radio. But this simple receiver was billed as a mighty good way to get started, and predicted that many builders would eventually decide to upgrade and build a vacuum tube set. Parts selection kept in mind that many of the components, such as the variable condenser, could be used in the new set.

The author remarked that he had a friend who had a good five-tube set, but kept the old crystal set around for times when he wanted to listen to the radio alone. The headphones masked outside sounds, and he didn’t have to worry about wear and tear on his tubes.

The article suggested modifications of the antenna coil depending on the location and number of stations. It gave instructions on tuning. While moving the dial, you would adjust the crystal for the first hint of sound. When that was found, you would tune the dial for maximum sound, and then adjust the crystal for maximum volume. The crystal position could usually stay put for weeks. To prevent vibrations, the author suggested placing the set on a piece of cloth.