This VCA was found in the July 1988 issue of Radio Electronics magazine. It uses an OTA op amp and has its gain adjusted by the voltage at the gain input.
You can measure capacitances across a large range of values using the AC Power line frequency as...
This circuit had its assembly described in a Radio Electronics from March 1963. The circuit uses 2...
This transmitter for the 2-meter range with a power of 1.5 W was found in a magazine 73 for radio...