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.
This circuit was obtained from the 1976 Siemens Integrated Circuits Manual. It is the circuit for...
The circuit is a multivibrator version using two NPN general purpose transistor. This circuit can...
The sensor of this circuit is a thermistor of the same value as the adjustment circuit formed by...