GB754766A - Improvements in or relating to television receiving aerials - Google Patents

Abstract

754,766. Aerials. DAY, A. E., BROCK, C. E., and GOODMAN, G. CRIGHTON-, [trading as WEBMORE (1948) & CO.]. May 16, 1955 [May 14, 1954], No. 14140/54. Class 40 (7). A receiving aerial suitable for use with television frequency signals comprises two flexible elements of a length substantially less than #/4 which are connected together at one end of each by a tunable inductor whereby the aerial may be selectively tuned to receive signals over a particular channel. The other ends of the elements are left open and coupling means to match the aerial to feeder and receiver input, are associated with the inductor. In a preferred embodiment each of the elements 1 consists of two parallel conductors 3 contained within the ends of a dumb-bell sectioned flexible ribbon of insulating material 2. The elements are secured at their inner ends to an insulating base 5 and both conductors 3 soldered to terminal tags 4. A cylindrical pillar 6 supports the inductor coil 8, connected between the tags 4, on its outer surface. The inside of the pillar is screw-threaded and contains a threaded core 9 of bonded powdered iron adjustable in position to tune the aerial. A brass core may be used instead of the powdered iron core for a different waveband, or a composite core, half of one material and half of the other may be used. The inductor serves as the primary winding of a matching transformer, a secondary winding 13 of a suitable number of turns for matching the aerial to the feeder being wound over the top of it and connected to the feeder 15 at terminal tags 14. Alternately a part of the winding 8 may be tapped off for connection to the feeder so that the operation is that of an auto-transformer. A dust cover 16 is provided to enclose the coils and connections.