We found this circuit in a Japanese publication in 1967. The circuit consists of a 15 W audio amplifier with germanium transistors including a voltage indicator power supply.
This configuration is also valid for other operators and the formula for calculating the gain is...
This inductively coupled oscillator was found in an American documentation from the 90's. The...
This circuit was obtained from an Analog Devices manual from the 90's. The integrated circuit is...