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 is a circuit published in the January 1962 Radio Electronics magazine. The circuit is for...
In the figure we have the simple way to implement the NO-OR or NOR function with common diodes and a...
This timer for short intervals was found in a documentation from 1966. The transistor is made of...