This circuit is from a 1968 Motorola power circuit manual. The circuit uses transistors of the time. The passing band is 45 Hz to 100 kHz.
This ohmmeter can be made with a scrap milliammeter used for continuity tests or even resistance...
This circuit was found in the November 1992 issue of Radio Electronics magazine. The circuit has...
Found in an English Maplin documentation from 1983, this circuit generates separate frequency...