We found this circuit in a 90s Popular Electronics. The circuit uses a pickup coil that consists of 100 to 200 turns of wire 28 around the cable to be monitored.
This circuit was found in the Electronics Experimenter Handbook of 1961. The circuit uses door...
The basis of this circuit is a National Semiconductor operational amplifier that functions as a...
This two-transistor amplifier can be used as power stage for intercom, experimental receivers,...