This battery-powered micropower supply was shown in Radio Electronics magazine in 1991. The maximum current is 170 mA. and the integrated circuit is the MAX655 from Maxim.
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...