Found in a 1965 Radio Shack documentation this oscillator can be used with modern general purpose transistors like the BC558. The transformer is the output type for transistor radios.
With two cascading tunnel diodes, this circuit found in a 196 General Electric documentation...
Found in General Electric's 1969 documentation, this circuit uses two Foto Darlingtons to control...
This circuit is used in the analog part of the telephone lines. The same circuit can directly...