Metal Detector (CB21929E)

This two-transistor metal finder was found in a Raytheon manual from the 1950s. The transistors are germanium from the time.

Megaphone (CB22487E)
Found in a 1999 documentation, this circuit makes use of a power germanium transistor and a...
Regulated 5V 5A Power Supply (CB25374E)
We found this circuit in the March 1991 issue of Radio Electronics magazine. The integrated...
Constant speed regulator (CB7177E)
This Motorola circuit, found in old documentation, keeps the voltage applied to a load by a triac...