A SUBMARINE TELEPHONE CABLE WITH SUBMERGED REPEATERS 



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articulated assemblage of composite lucite cylinders, each about five inches 

 long, successive units being held together by a spring assembly. Each lucite 

 cylinder contains the related electrical elements of a particular part of the 

 repeater circuit. The groups of smaller elements are mounted rigidly in a lu- 

 cite form which slides into an insulating envelope consisting of two close 

 fitting lucite shells and is held in place by end pieces of lucite. Eight copper 

 tapes laid in axial slots between the shells and extending over several sections, 

 where necessary, permit electrical interconnection of the various parts. A 

 representative assemblage is shown in Fig. 4. In the case of the Key West- 



Fig. 3 — View of repeater assembly. 



Havana repeater the complete assemblage is eighty-four inches long and com- 

 prises fifteen sections. 



Circuit Elements 



Early in the development general principles were developed regarding the 

 type of circuit best suited for underwater repeaters and on this basis require- 

 ments were established on the characteristics necessary for the circuit ele- 

 ments, including electron tubes, and on their arrangement in the repeater. 

 Decisions in such matters could not be arbitrary of course, but had to be 

 carefully worked out in order to freeze designs as early as possible so as to 

 facilitate the start of significant life tests. 



The electron tube is the most important of the elements. Work had been 



