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 simple circuit was found in Popular Electronics. It can be built with any JFET. Galvanometers from...
This circuit, with printed circuit board included, is from a Radio Electronics magazine from July...
This circuit for FET was obtained from a 1977 Radio Handbook. The input impedance is 150 ohm. The...