This circuit was obtained in a 1969 Mullard manual. The transistors are from that time. The input sensitivity is 300 mV.
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...