Found in a 1966 American publication, this circuit generates a 25 MHz rectangular signal for testing flip-flops. Transistors are from the era. No information is given about L1.
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...