|What's up with the plain, sharp-cornered styling on this console? I don't know, but it would have appeared modern, or at least very different, to the 1939 buyer, and I guess that's what Philco wanted. Its severe lines and boxy shape presaged console designs of the late 1950s and early 1960s. At the left below is the Mystery Control, a brand new feature introduced by Philco in 1939 for this and two other console models. I believe it was the first wireless remote control ever offered.
The Philco "Mystery Control." It, and the corresponding receiver built into the console’s chassis, can be set to operate at one of five frequencies below the AM broadcast band. The remote has a dial that operates like a rotary telephone and generates radio-frequency pulses corresponding to the desired function.
Approximately 7-1/4 inches / 184 mm wide.
Philco 39-55, 1939
This is a small console, and receives only the AM broadcast band. The one-band design was a harbinger of the end of the shortwave-listening craze of the 1930s.
Approximately 38-1/4 inches / 97 cm tall.
Console Only six of the ten tubes on the chassis are used for the broadcast band receiver: 6J8G mixer/oscillator, type 78 IF, 6Q7G detector, (2) type 42 push-pull audio output, 80 rectifier. The remaining four tubes form a TRF receiver for the Mystery Control pulses: type 78 amplifier, 6J7G amplifier, 6ZY5G AVC, 2A4G thyratron switch.
Many of Philco's earlier receiver designs were technical masterpieces; this one is all flash with little substance. This radio doesn't even have an RF amplifier stage. Why, it's really nothing more than a simple All American Five type design, except with a push-pull audio output stage and the remote control receiver circuitry.
Mystery Control Type 30, pulse oscillator.