This circuit of dozens of watts uses germanium transistors and the critical components are transformers. The circuit is from the 1960 Mullard transistor application manual.
Found in a Popular Electronics from the 80's, this circuit triggers an SCR keeping an LED on when...
Found elsewhere in this section, this circuit is from the April 1971 Radio Electronics magazine. Note...
This circuit works with practically any tunnel diode, transmitting signals in the FM range with a...