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.
The circuit shown is from an old European publication. In it we have the way to activate a relay...
We found this circuit in a European publication from the 1990s. Transistors are still common types...
This circuit was found in an American documentation and can be added to common amplifiers of any...