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.