This is a simple tubed mixer from the 50's. The circuit does not include the power supply and has 3 inputs with independent controls. The tubes are double and the inputs are high impedance.
Found in documentation from the 1970s, this circuit for resistive loads uses a trigger...
This simple receiver for listening on the phone was obtained in a 1960 documentation. The circuit is...
This circuit was found in the 1989 Radio Electronics Experimenter edition. The circuit has the...