The operational amplifier used is not common today, but the circuit can be implemented with modern operational ones. The gain is 1000 and the source must be symmetrical.
This circuit was found in a 90s Radio Electronics. It is intended to amplify the sound channel of...
This circuit uses a 4020 counter that divides the frequency up to 210, being found in a former...
This circuit was found in a Radio Electronics magazine from May 1967. The circuit has the time...