The figure shows the equivalent circuit for the LM381 audio preamplifier IC. The circuit was found in the February 1990 issue of Radio Electronics magazine.
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...