Eighty years ago this month, the March 1938 issue of Popular Science carried the plans for this transceiver, which it billed as the world’s smallest two-way radio. Weighing less than ten ounces, the set could be carried in a coat pocket. The set shown here was for the 3/4 meter band, but could also be built for the 1-1/2 meter band. The heart of the circuit was a 955 acorn tube.

A DPDT switch was used to switch from transmit to receive. In the transmit position, the circuit was an efficient oscillator, and in receive, a grid leak and condenser were added to the circuit to produce a sensitive receiver.

The external batteries were acually larger than the radio. Two 3-volt flashlight batteries were used for the filaments, with a 45 volt battery providing the B+.

In order to make sure the radio was operating within the amateur band, the article described a simple wave meter, consisting of a flat U-shaped loop of No. 12 wire hooked to a galvanometer. The transmitter was held close to the loop and moved along until the highest current rating was shown. The transmitter wavelength was equal to the distance along the wire to the meter.

The construction article reminded readers that an amateur license was necessary to use the transmitter. But for those considering trying for the license in the near future, the construction of the set would teach many of the radio fundamentals that would be on the test.

The circuit here is similar to this WERS transceiver shown here previously. In case you’re wondering, the 955 tubes do seem to be readily available on eBay.

This one-tube shortwave portable was featured 85 years ago this month in  the February 1933 issue of Short Wave Craft.

The set was awarded honorable mention in a contest sponsored by the magazine, and had been designed for a trip by the author to northern Michigan, where neither AC power nor replacement batteries would be available. Therefore, the main design consideration was low battery drain.  The set was built in the venerable cigar box, which housed all of the parts, including batteries and  antenna.

The author noted that the set could also be used as a shortwave converter with a broadcast receiver by running a wire to the phono input of the radio.  The author reported pulling in W1 and W4 stations at Detroit using only a copper screen in the lid of the radio as an antenna.

Seventy years ago this month, the February 1948 issue of Popular Science showed how to put together this handsome one-tube converter to pull in shortwave signals with a standard broadcast receiver.

The simple circuit, by S.T. Van Esen, W2OXD, was built around a 6BE6 pentagrid converter tube, and tuned 6-16 MHz.  The radio was set to an empty spot on the dial near 1500 kHz, and tuning was accomplished with a tuning dial on the converter.  A second variable capacitor was used to peak the mixer section.

For power, you could tap into the power supply of a transformer set.  Or if the proper voltages were not available, or if an AC-DC set was being used, the schematic for an appropriate power supply was also included.

The article promised the ability to pull in London, Lima, Sydney, Johannesburg, and other sources of news, information, and entertainment that were pouring out of foreign skies.

This month eighty years ago saw the beginning of the short-lived run of Rural Radio magazine with the February 1938 issue.  That issue’s cover, shown above, depicts a modern progressive farm family listening to the modern version of the party line, with an image of the old-fashioned version also shown.

The magazine was published by Rural Radio, Inc., of Nashville, which, of course, just happened to be the home of WSM. Edwin Craig, the President of the company that had founded WSM, in 1934 invited fourteen other clear channel stations to a meeting in Chicago where an organization called the Clear Channel Group was formed to lobby on behalf of the powerful stations. One result was the magazine, designed to promote the interests of the clear channel stations to their rural listener base.

The magazine lasted less than two years, since the editor, Ed Kirby, was wooed away by the National Association of Broadcasters to head its public relations department. The magazine was left in the hands of the printer, and was merged into Radio Varieties in 1939.

Morse Salisbury

The first issue carried an article, “What Radio Means to the Farmer,” penned by Morse Salisbury, the Radio Chief of the U.S. Department of Agriculture. Salisbury was the host of the “Farm and Home Hour,” which was heard over 93 NBC stations for an hour each weekday.  (A script of a 1937 broadcast is available at this link.)  Salisbury noted that farm families, in addition to having access to the same entertainment, culture, and news as their city counterparts, also relied upon radio for “quick and close contact with knowledge that is important in a business way.”

He noted that the nation’s six million farm families did not have the capability of gathering the scientific and economic information necessary to their livelihood, but the Government provided that information through the Land Grant Colleges, extension services, and now radio.

Eighty-five years ago this month, the February 1933 issue of Short Wave Craft carried the plans for this two-tube shortwave set dubbed the “Band Spread 2.”

The set, designed by George W. Shuart, W2AMN/W2CBC, featured a type 58 tube serving as regenerative detector, with a 47 pentode amplifying the audio sufficiently to drive a speaker. The case consisted of an aluminum can measuring 5x6x9, which were said to be readily available. To facilitate easy changing of the coils, the author suggested that the can be purchased with a hole punched in the top, with a cover to fit. All parts were mounted on a metal shelf, held in place from the bottom by 7/8 inch spacers.

One variable capacitor was mounted directly on the coil form for rough tuning, with the main tuning control serving as a bandspread. Coil winding data was shown for the 40 and 20 meter ham bands.

A “long low wire” was recommended for the antenna, although it was pointed out that many foreign stations were pulled in with just a ten foot antenna.

A hundred years ago, the February 1918 issue of Popular Science showed this simple method for code practice without the need for a battery. A short length of wire was wrapped around the light circuit (the article noted that it wouldn’t work with a DC light circuit), through the key and headphones, and grounded. The result would be a convenient source of a 60-cycle tone.