Found in an American 1980s documentation, this circuit compares signals from two TTL sources, providing an output that depends on the frequency difference. The circuit can be used as a shield.
This switching buck regulator with the NE5560 was found in the February 1980 issue of Radio...
This commercial medium and short-wave radio was manufactured in Japan in the 60s. The circuit has...
Unlike the previous one, this circuit uses only one resistor in the base polarization. The...