Repeater Design for the Newfoundland-Nova Scotia Link

The British Post Office has engineered many shallow-water submergedrepeater systems, 1 and there has been a progressive improvement in design techniques and in the reliability of components which has been reflected in a growing confidence in the ability to provide long-distance systems having an economic life. The seven-repeater scheme from Scotland to Norway laid in 1954 introduced for the first time repeaters which would withstand the deepest ocean pressure together with an electrical circuit which embodied improved safety and fault-localizing devices. Also, since a repeater is only as reliable as its weakest component, much greater attention and control was directed at this stage to the design, manufacture and inspection of all components, both electrical and mechanical. This repeater design was, in fact, envisaged as a prototype for a future transatlantic project. * British Post Office. 245 248 T H E B E L L SYSTEM T E C H N I C A L J O U R N A L , J A N U A R Y 1957 under all working conditions.2 Factors involved in assessing these margins and in planning the equalization and level diagram for the system are as follows: (a) Temperature. -- The final assumed sea-bottom temperature was 2.3°C, with a maximum annual variation of ±3°C. The maximum change in attenuation might therefore be ±4 db at 552 kc. The land section change would be ±3 db at 552 kc due to a possible ±10°C change on a mean of 7.5°C. The effect of these seasonal changes would be reduced by the provision of manually adjusted equalization at Clarenville, Terrenceville and Sydney Mines.