This circuit was found in the January 1989 issue of Radio Electronics magazine. The circuit sends audio signals by modulating a low-frequency carrier through the power grid.
This audio oscillator is from a 1957 Raytheon publication. The tone generated depends on C2 and C2...
This common circuit with two transistors was found in an old French publication. The supply can be...
This circuit was found in an American 1980s documentation. It is a circuit that can be used to...