Sixty years ago this month, the February 1960 issue of Electronics Illustrated carried the plans for this one-tube regenerative shortwave tuner. The article was part 6 in the magazine’s build-it course, and the new tuner was designed to plug into the existing projects, which already included AM and FM tuners. For that reason, this receiver contains no power supply or audio amplifier. The cord with the 8-pin plug was keyed to fit the rest of the project, and the shortwave tuner took the place of the FM tuner.

The circuit used a 6BC5 tube. One notable feature is that the regeneration was taken from the screen grid of the tube, rather than the plate. The regeneration control was a voltage divider which varied the positive voltage to the screen.

Since the article was part of a course, in addition to the exact schematic diagram, it also included a simplified diagram along with an explanation of each part of the circuit.  From most browsers, click twice on the image for an enlarged version.

Here is the actual schematic for constructing the receiver:

This little broadcast set looks nondescript, but it was also something of a holy grail. As the February 1950 issue of Radio Electronics put it, “the one-tube loudspeaker receiver has long been the goal of constructors and experimenters.” And this set fits the bill. And as an added bonus, the addition of a single capacitor turned it into an excellent code practice oscillator.

The circuit, using a 3B7 tube, is described as a “special type of utraudion with a certain amount of superregeneration.” An outdoor antenna was recommended, but near powerful stations, the article noted that 25-50 feet were adequate. In remote areas, a hundred feet might be necessary.

The set used a permeanility tuner, which is likely unobtainium. However, the circuit could probably be modified to use a fixed inductor and variable capacitor.

Sixty-five years ago this month, the February 1955 issue of Popular Electronics carried the plans for this CW transmitter especially designed for the Novice. The rig used a single 6AQ5 tube to put out a signal on the 80 or 40 meter bands. Tuning up was accomplished by using a 6 volt bulb attached to a 1-1/4″ loop of wire. This was held near the transmitter’s coil and the rig tuned for maximum brightness.

To keep the circuit as simple as possible (and keep hum producing components at bay), the transmitter did not contain its own power supply. Instead, it required about 250 volts DC at 1 amp. “Most experimenters keep a small power supply of this type on hand for general use.” For those who didn’t, the magazine suggested that they were cheaply available as surplus. For portable use, batteries could even be used.

One interesting feature was the use of an octal tube socket for the crystal socket. The pins were such that a crystal would fit. The unused pins were used as a terminal strip for other components.