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.
Found in National Semiconductor documentation from the 90's, this circuit has an output current of...
With this circuit it is possible to raise the characteristics of a transistor by checking its gain...
The circuit presented is from the Linear Applications Handbook of the National Semiconductor of...