GB641810A - System for long distance radio transmission - Google Patents

Abstract

641,810. Radio signaling; receiving systems; aerials. STANDARD TELEPHONES & CABLES, Ltd. Aug. 8, 1947, No. 21922. Convention date, Oct. 29, 1946. [Classes 40 (v) and 40 (vii)] A radio communication system between two points on the earth's surface comprises means for transmitting signals towards the moon and means for selectively receiving echo signals reflected from portions of the moon's surface. The receiver for the reflected energy may comprise a paraboloidal reflector 6 with screen 7 in its focal plane carrying three spaced dipole aerials 8, each connected by diversity reception channels 15 to a common output. The screen 7 is adjustable by linkage 9 to correct position as viewed by visible light through a central reflector aperture 14, and the dipoles also may be adjustable. The reflector may be adjusted to face in any direction by drive means 12 and rotated by a clockwork drive 13 to follow the moon. The reflector alternatively may be annular or in two partannular sections, each formed of individually set up and adjustable portions. In the sytem of Fig. 7 duration or phase-modulated pulses are used and the receiving antenna comprises concentric series of dipoles 32-35 connected so that their energy is additive and applied to separate channels of a receiver containing delay networks and phase adjusters whereby allowance is made for the different times of reception of signals reflected from different concentric areas of the moon. The delay networks retard all signals except those from the outer series of dipoles, the latter receiving only from the remoter area of the moon. A common oscillator 39 beats with the signals in the respective channels. Four separate receivers for diversity reception may be provided corresponding to each quarter circle area in the focal plane of the reflector, with the dipoles in each quadrant separately connected to a receiver.