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 low power circuit for the FM band was found in a spy book from the 90s. The tunnel diode is...
This circuit was found in Radio Electronics magazine from June 1958. The maximum distance depends on...
The circuit presented is from a 2006 documentation. It can turn a set of lamps on or off when...