This circuit switches power loads with audio signals. The circuit is from a Popular Electronics from the 90s. The components can be changed depending on the signal used.
This is the power supply indicated for the previous circuit (CB18905E) providing a voltage of 24 V...
This simple 1-transistor reflex receiver was published in Radio Electronics magazine in September 1959....
In this Radio Electronics from May 1958 we have the now common use of the varicap in a frequency...