Found in the September 1972 issue of Radio Electronics magazine, this signal injector is based on the HEP580. The circuit is powered by two batteries and its frequency is basically given by C1.
This circuit uses one UJT (Unijunction Transistor) to produce three different tones in a...
This circuit for the medium wave range was suggested by a Popular Electronics from the 90s. The...
AEM's FM12 (QPL) series components are included in the latest edition of the European Space...