This 5 W transistor amplifier for the car was found in an English documentation from 1969. The transistors are from that time and the transformer is of a special type.
Found in a 1965 Radio Shack documentation this oscillator can be used with modern general purpose...
In the figure we have the way to use a single control voltage to act on two varicaps...
Found in a 90s documentation, this switch that is also sensitive enough to operate capacitively uses...