Found in a 1966 publication, this circuit is a simple version of a field strength meter. The diode is a general-purpose germanium type.
This circuit uses a capacitor to store energy. The capacitor is charged by closing S1 by a moment. Them,...
This circuit is both a signal injector and a signal follower. A key selects the operating mode. The...
The difference between this circuit and the previous one is that it uses PNP transistors. The...