This 2-quadrant modulator circuit was found in the May 1988 issue of Radio Electronics magazine. The CA3080 is an OTA operational amplifier.
The frequency of this oscillator can be set in a range from 5000 to 1. We found it in an old...
This filter was found in Radio Electronics, and its configuration can be applied to any...
The keyboard for this organ is made by small metal plates where the probe touches when in...