Wattmeter (T1351E)

This circuit is from a February 1949 Radio Electronics magazine. The circuit uses 3 tubes and includes the power supply.

Megaphone (CB14802E)
We found this traditional configuration of a megaphone with a coal microphone in an American...
2 6GHz Oscillator (CB21198E)
Found in Popular Electronics from the 90s, this circuit is intended for a radar emitting pistol. The...
Headphone wireless Transmitter (CB7817E)
Found in 90s Popular Electronics, this circuit produces a modulated infrared beam for a remote...