This 5-tube hi-fi amplifier was found in an American publication from 1947; The output is in class B and the circuit uses a source with transformer.
This modulator circuit for AM transmitters was found in a 1960 Sylvania transistor manual. Modern...
circuit is used to increase the sensivity of a relay. A 50 to 100 mA relay can be triggered with...
We find this circuit in an Electronics Now. The indication of the logic level is done on a...