Found in an old American documentation this FM modulator makes use of a varactor diode. The circuit can be easily implemented given the small number of components used.
This circuit was found in a 1977 Radio Shack documentation. The unijunction transistor can be...
This circuit was found in a 1968 Hughes documentation. The transistors are from that time. The coil...
This circuit uses NO sensors and was found in an American publication in the 90s. The supply must...