This circuit comes from a 1966 NASA documentation. The circuit makes use of discrete components and is suitable for generate 455 kHz IF signals.
Using SCRs, this circuit from a 1967 General Electric manual allows full wave load control with SCRs....
This interesting circuit from a publication from the 1970s, measures the intensity of the sound...
This simple NPN and PNP transistor tester configuration can use the low current range of a common...