GB1261731A - Aerial for transmitting and receiving radio signals - Google Patents

Abstract

1,261,731. Aerials. G. A. PARTRIDGE. 27 Jan., 1969 [26 Jan., 1968], No. 4344/68. Heading H4A. An aerial comprises a winding consisting of a closely helically wound wire, that is, with adjacent turns touching if the wire is insulated or with the pitch of the winding not exceeding the wire diameter by more than 5 % if the wire is bare, with a ratio of axial length to diameter of at least 20 : 1, and non-ferromagnetic support means arranged to support the winding with its axis in a straight line, including a conductor extending from one end of the winding for connection purposes. As described, a tube 20, Fig. 3, made of fibreglass or polythene, contains a helical aerial constructed by winding bare or enamel insulated copper wire on a rod-like former, introducing the wound former into the tube, releasing the ends of the wire so that it springs against the inner wall of the tube, and removing the former. The tube 20 is filled with foamed plastics material, which may be loaded with lossy material to increase the operating band-width, and closure caps are fitted. Support clamps 31, 32 are provided and the aerial is extended by means of a connection 29 to the inner conductor of a coaxial cable 30. The outer conductor of the cable 30 is connected to a ring 28 from which extend radial members 26, 27 of different lengths, constituting an earth screen. By suitably placing the said members (for example, as shown at 26a and 27a) the aerial may be matched to the cable. In another embodiment, an aerial (12), Fig. 1 (not shown), is wound upon a rod (11) and one end is connected through a tuned circuit (14), comprising an inductor (15) and variable capacitors (16), (17), to a coaxial socket (19). A whip aerial may extend from an end of a helical aerial of the kind described. Use on a ship in association with a long down lead is mentioned, and also that several aerials may be arranged radially to form an array.