This programmable sound circuit was found in the July 1978 issue of Radio Electronics magazine. It uses an integrated circuit of the time dedicated to producing effects.
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...