This 4-tube circuit was found in an American publication from 1947. It is intended for audio distribution lines using a transformer source.
This circuit was found in an old American optoelectronics manual. The circuit makes use of an...
Waking up to a loud and clear sound from an audio oscillator, after up to 5 hours of sleep, or...
We found this circuit in Motorola's 1990 Linear Databook. The component used is unusual. The...