Found in a 1969 documentation, this circuit for the 20 MHz band does not use a transformer. The circuit is a phase detector that makes use of the transistor of the time.
This circuit produces a IR beam with a frequency adjusted by the 100k pot. The circuit can be used in...
This voice scrambler and descrambler circuit was found in a Radio Electronics from July 1963....
This transistor source was found in a 1990 documentation. 2N3055 transistors must be equipped with...