GB349029A - Improvements in or relating to high frequency composite transmission systems and cables or conductors therefor - Google Patents

Abstract

349,029. Cables. STANDARD TELEPHONES & CABLES, Ltd., Columbia House, Aldwych, London.-(Assignees of Quarles, D. A. ; 273, Robin Road, Englewood, New Jersey, U.S.A.) Feb. 19, 1930, No. 5537. Convention date, March 30, 1929. [Class 36.] In a wired-wireless system, one side of the transmission circuit comprises a specially provided conductor or conductors, which are surrounded by a plurality of conductors in parallel forming the return side. The system may be linked to a short length of multiple cable in which case the special return lead is connected to the inner lines of the cable and the live-wires to the outer, (Fig. 7, not shown), or with longer cables it is preferable to provide a special conductor at the centre of the cable surrounded by enough insulation to sufficiently reduce its capacity relative to the other conductors (Fig. 8, not shown). When a cable of this nature becomes too long for carrier transmission a specially designed cable may be used, constructed as follows. The inner and outer conductors 110, 120, Figs. 11, 13, 14, and 16, are formed as cylinders of braided copper wire, the inner diameter of the outer being about four times the outer diameter of the inner, and the inner cylinder is supported relative to the outer by suspension cords 130 of silk, cotton, hemp, &c., arranged tangentially to the inner cylinder and braided in a continuous length into the structure of the outer. The whole structure is stiffened and waterproofed by impregnation. The cable may be supported by hooks 131, Fig. 11, from a line 132, the hooks being provided with a cradle 133. Various protective armours may be used, for instance copper tape 125, Fig. 13, may be wound on and a steel armouring 136 superposed, consisting of interlocking grooved ribbon. Alternatively a lead sheath may be used. The armoured cable may be supported by a rod 140, Figs.14 and 15, which is bent into a hook 141 arranged round the inner conductor. An insulating bush 142 over the rod 140 bears on the inner conductor, and is provided with a shoulder 144 which supports a band 145 round the outer conductor. In a third arrangement a short section of the outer conductor is removed and the inner conductor wired to an insulator 147, Fig. 16, a split insulating plug 149 being used to close the exposed end and secured by a strap 150 and set-screw 151.