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.
This reflex radio for medium waves and headphone listening was found in Radio Electronics magazine...
This circuit is from a PopularElectronics of June 1992. The magazine no longer exists, but the...
This well-crafted speed game setup for two competitors was found in a 1998 Poptronics. The circuit...