The plans for this handsome two-tube long wave receiver appeared in the Fall 1960 issue of Radio-TV Experimenter.

The AC-DC set used two dual tubes. The two halves of the 6AN8 served as RF amplifier and regenerative detector. Half the 6AU8 was used as audio amplifier, with the triode section pressed into service as rectifier. The set covered 85-550 kHz, and with modification (addition of a coil) could be pressed into service on the broadcast band.

The article addressed the kinds of signals that could be heard on the long waves. At the time, they included the old A-N aviation beacons we’ve previously described.

We’ve previously shown ideas for homemade microphones, but unlike this one from75 years ago, none of them were made out of a walnut.

This one, from the October 1945 issue of Radio Craft is, indeed, housed inside a walnut. In addition to the large walnut shell, the required components are “a cord, a little cotton batting, a piece of tinfoil, and a few odds and ends.” The heart of the condenser mike is a diaphragm made of thin copper or tin foil, specifically, “the stiff kind, such as used to be used on cards of buttons.”

The foil is stretched carefully over one half of the shell. Through the other half of the shell a cork is inserted, and a brass screw passes through to a washer which is held in place just next to the foil. The article includes a circuit for a preamplifier. The author notes that the completed microphone “needs plenty of amplification, but the quality is as good as that of any commercial microphone I have ever heard.”

Eighty years ago this month, these students toured the facilities of CKY radio in Winnipeg.  The photo appeared in the October 1940 issue of Manitoba Calling,
the station’s program guide. The students were from the Riverbend School, and were being given a tour of the station by Mr. A. McLean, the station’s official guide. According to the magazine, great numbers of attentive students visited the station. Schools interested in arranging a tour were encouraged to call the station’s public relations department.

If you asked the author of this 1960 article whether he had Prince Albert in a can, he would tell you no, that he let Prince Albert out and instead installed a one tube radio.

The former tobacco tin houses a radio using a 117N7GT tube. The filament of this dual tube ran right off line current, with half serving as rectifier. The other half of the tube, a pentode, was “reflexed” to serve simultaneously as RF and AF stages, with a solid state diode serving as detector. The simple circuit could pull in stations up to 70 miles away with loudspeaker volume.

The article concluded that the chassis of the set was “hot.” It warned that care should be taken to make sure the line cord was plugged in the right direction, or all of the internal ground connections should be isolated from the can.

The circuit appeared in the Fall 1960 issue of Radio-TV Experimenter.