Ultra high gain FET amplifier (CB9065E)

Found in American documentation this circuit has a typical gain of 500 times. Other transistors can be used.

Modified Hartley Oscillator (CB21138E)
This circuit was found in old American documentation. Transistor is general purpose and coil rated...
Solar Oscillator (CB22262E)
This tiny photocell-powered audio oscillator was found in a book on transistors from the 1960s. The...
Tape deck power supply (CB9231E)
This circuit was found in a Hands On Electronics from the 90s. It is intended to supply old tape...