This 5.1 MHz circuit was found in a 1980s documentation. The frequency is given by the crystal and general purpose transistors can be used.
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...