GB774026A - Improvements in or relating to telecommunication submarine cables having repeaters installed at intervals - Google Patents

Abstract

774,026. Telephone transmission systems. SIEMENS & HALSKE AKT.-GES. Jan. 28, 1955 [Jan. 29, 1954], No. 2712/55. Class 40 (4). A submarine cable comprising transistor amplifier is specially constructed to withstand pressure. All holes or empty spaces in the transistor and its associated protective sleeve are exhausted and then filled with liquid insulating material of the type which subsequently solidifies. The transistor is then enclosed together with the other amplifier components in a non-pressureproof sleeve and the intervening space filled with liquid, semiliquid or highly viscous material. Alternatively the whole transistor circuit may be embedded in an insulating liquid which subsequently solidifies though remaining flexible. This may be done by spraying or dipping. Alternatively the transistor amplifier may be fitted into the sleeve which is then filled with the liquid insulator which subsequently sets. This is preferably performed in vacuo. The sleeves may comprise separate housings for the components or the housings may be dispensed with if the components are embedded in a non- hygroscopic insulating mass. The sleeves containing the amplifiers may be included in the middle of relatively short cable sections. These are tested physically and the gain/frequency characteristics of the amplifiers then measured. During the laying of the cable these may then be selected for insertion in accordance with the characteristics of the cable being laid. In the case of a coaxial cable the outer conductor thereof may extend over the repeater. If the outer conductor is stranded one or more of the strands may then be passed through the sleeve to make connection with the repeater.