This circuit was found in the September 1984 issue of Radio Electronics magazine. The frequency is given by the capacitors. The diodes help in the starting process.
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...