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 is from the 1971 Motorola SCR Power Control Fundamentals. The circuit can be made...
In the figure we show another configuration for a crystal-controlled overtone oscillator using a...
This circuit was found in the 1990 Motorola Linear Databook and can use almost any operational...