This 1 kHz TTL oscillator uses 3 inverters of a 7404 integrated circuit. The circuit is from a Popular Electronics from the 90s.
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...