Found on 80's Popular Electronics this circuit operates at 455 kHz. The explorer coil is formed by 10 turns of yarn 26 in a 4 inch shape. The indicator is a microammeter.
We found this circuit in a 1997 publication. It produces pulses of excitation whose intensity can...
This simple circuit uses a car ignition coil. The circuit appeared in the 1983 Radio Electronics Annual...
This circuit is from a Radio Electronics from February 1970. The circuit selects the input...