This voice scrambler and descrambler circuit was found in a Radio Electronics from July 1963. Transformers are common types at the time with impedances according to telephones and line.
The basic idea of this circuit found in a 1988 documentation is to transmit a signal modulated using...
This configuration, found in other circuits on this site, was obtained in an English publication from...
Several analog TV channels operate with stereo audio signals, but the vast majority of receivers are...