This small transmitter appeared in the March 1989 issue of Radio Electronics magazine. The two-transistor circuit used an electret microphone and had a range of a few dozen meters.
We found this circuit in the April 2013 issue of Electronics Now. Any JFET can be used. Note the...
Using a component of the era, this 1968 Mallory circuit uses an output transformer whose...
This space mark demodulator for FSK signals was found in an American telecommunication...