GB552395A - Improvements in and relating to remote control systems - Google Patents

Abstract

552,395. Remote control of radio apparatus. STANDARD TELEPHONES & CABLES, Ltd., and NEWTON, G. Sept. 30, 1941, No. 12661. [Class 40 (i)] The tuning element of a wireless receiver and a tuning indicator at a distant control point are operated step-by-step under reciprocal control, fine tuning between steps being provided by a potentiometer or condenser at the control point for adjusting the frequency of the heterodyne oscillator in known manner. In one arrangement, Figs. 1 to 3 (not shown), the control unit comprises keys for continuous movement and keys for single steps in either direction. In addition, a fine-tuning element is mechanically coupled to the scale of the tuning indicator. It may be arranged that the set can be controlled by a second set of keys in the neighbourhood of the receiver either at any time when the other keys are not being operated or only after the operation of an emergency switch. In a modification, Fig. 4, the control handle rotates a commutator disc 53 and a pointer 63, and the tuning element of the receiver and the arrangement shown for driving an indicator pointer 59 control each other to step in one or other direction until a wiper 50 driven by the stepping mechanism is again on the insulating portion of the commutator disc. As in the other arrangement, a fine adjustment is provided by a potentiometer coupled to a cam device 61, 62 which adjusts the indicator scale. In both cases, the indicator pointer and the main tuning element of the receiver are held in definite positions at each step by a notched disc co-operating with a detent 65. In a further arrangement, Fig. 6 (not shown), push button selection is provided in addition to the control provided by the control knob 64.