We found this configuration in a 1974 publication. Transistors can be replaced with equivalents such as 2N2222. The circuit has a dynamic range of 60 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...