This voice scrambling scrambler was published in the August 1982 issue of Radio Electronics magazine. The circuit is for old analog telephone lines.
This circuit with 5 times gain was found in European documentation from the 1980s. The input and...
Suggested by Siliconix documentation from the 90's, this circuit uses power MOSFETs according to the...
Other operational amplifiers can be used on this unit gain amplifier. The circuit is from the 1993...