Suggested by a 90s Popular Electronics this circuit is intended to receive volleys or whistles from thunderstorms in the wave range below 20 kHz. The coil consists of 300 turns of wire 26 in a ferrite rod.
This amplifier can be used for public-address or other applications. Three transistors of the time...
This circuit was found in a 1967 Electronics World. The circuit uses components of the time that...
This circuit was obtained in a June 1987 magazine Hands-On. It is a circuit that indicates on an...