Found in an ancient American documentation, this circuit can generate signals up to 40 MHz for a Z80, microcontroller widely used at the time. The circuit must be powered with 5 V and also serves as a shield.
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...