Found in a 1964 Electronic Design, this circuit generates pulses based on an avalanche diode of the time. The circuit can be tested with modern equivalent components.
The oscillator shown in the figure keeps its frequency constant in an active cycle adjustment...
For bench use, this circuit functions as a bistable safety switch. The circuit is from a Radio...
In fact, this is the circuit also known as “vox”, that is, a relay triggered by sound. This...