Station-storing cct. for communications receiver - has comparator controlling station-tuning potentiometer drive motor

The station-storing circuit, for communications receivers tuned with varactor diodes, makes the voltage of a fixed set of potentiometers equal to that of a variable potentiometer. The fixed set of potentiometers has each of its pots. corresponding to one transmitter or station and each of their sliders are connected by switches in turn to a comparator that compares their voltages with the voltage of the variable potentiometer's slider. The comparator's output is used to drive the motor that sets the positions of the fixed potentiometer's sliders. The motor, or motors, stops when the comparator's inputs are equal.