In this phase shift circuit, the transistor can be any general-purpose transistor. The circuit is from an Electronics Now issue of June 1993.
Found in a 1967 Electronic Design, this transistorized circuit compresses and then expands a pulse....
This squelch is activated by its own noise, acting automatically. It is used in communications...
This is the battery-powered version of the previous circuit. The circuit is from the same Radio...