Voice Scrambler (CB22462E)

We found this circuit in a Popular Electronics from 1992. It consists of a voice scrambler used in telephone transmissions.

Night Switch (CB12701E)
The circuit shown in the figure activates a small indicator lamp that will start to flash when the...
LM3900 Voltage Controlled Current Source (CB14211E)
The circuit shown is from National Semiconductor's Linear Applications Handbook. The LM3900 is a...
Oscillator for Bias and Erasing Recording Heads (CB1516E )
This circuit was found in a 1976 documentation. It can be used with old tape recording mechanisms for...