This circuit from the 1980s uses an operational amplifier that is uncommon today. The circuit can be designed with modern operators. The gain is 40 dB.
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...