This circuit is from a March 1978 Radio Electronics magazine article that showed how to build it. The circuit is TTL based and is powered. The components used can still be found.
This small FM transmitter for clandestine listening has a good range and should be powered by a 9...
This circuit has a high input impedance and provides a good signal at its output. The power must...
This traditional metronome configuration uses unusual transistors in the original version, but it...