This circuit was obtained from a Radio Electronics issue from January 1989. The indicator is a ceramic transducer, and the frequency of the emitted sound is given by C3.
This circuit generates 50, 100 and 200 Hz signals from a 2.2768 MHz TV crystal. The circuit can be...
This small power amplifier makes use of an output transformer given its design time. In fact, the...
This resistance meter with the CA3130 was found in an English publication from 1977. The circuit has...