Described in an article in the March 1979 issue of Radio Electronics magazine, this generator was used in an audio test station. The frequencies are given by the capacitors.
This simple transistor tester circuit was found in the February 1968 issue of Radio Electronics magazine....
This powerful inverter provides a high-quality sine wave signal. I found it in a Radio Electronics issue...
This squelch is activated by its own noise, acting automatically. It is used in communications...