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 new AMS device consists of a digital color sensor and proximity sensor that also incorporates an infrared...
This amplifier was found in an old publication of 1990. With the changes, it may still be...
This circuit was found in a May 1981 Radio Electronics magazine article. The circuit is offset...