This is one of the first radios with an integrated circuit. The circuit is from a Radio Electronics from November 1969. The circuit is powered by a 9 V battery.
This two-stage circuit has a voltage gain of 100 times, with a high input impedance. The circuit is...
Four amplifiers are used in this circuit, which uses a magnetic pickup to obtain the pulses whose...
This simple circuit was obtained in a Portuguese publication in 1979 but can be easily assembled with...