This frequency triple oscillator circuit was found in an American publication in 1967. The FET is current and more detailed information about the coils is not given.
This simple metronome, from 1985 documentation uses only transistors and has two settings. For...
This circuit is suitable for modulating AM transmitters. The circuit is from a 1977 radio amateur...
This flasher was found in an old Hands On, but uses common components. The optocoupler can be...