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 sinusoidal oscillator was found in Radio Electronics in 1989. It uses a 741, but other...
This is the circuit of a commercial flash from the 60’s. The circuit was published by the march...
This circuit is suggested by Motorola in its 1990 Linear Databook. The integrated circuit is no...