Pivot arm operating drive for model vehicle or satellite receiver

The operating drive has an electric drive unit (5, 8), supplied from a current source (19), a radio receiver (20), coupled to an amplifier (7) and a setting element (15) between the drive unit and the pivot arm. The position of the pivot arm is detected via a LED (16) and a cooperating phototransistor (17), connected in circuit with the amplifier, for supplying the electric motor (5) with current in dependence on the supplied radio signal and the actual position of the pivot arm.