SYSTEM DESIGN — NEWFOUNDLAND-XOVA SCOTIA LINK 231 



input and output of the amplifier respecti\-ely ; these losses must, effec- 

 tivel}', be added to the loss in the cable. 



Two other pieces of information are necessary before the repeater 

 system can be planned — the permissible transmitting and receiving 

 levels at the shore stations. The transmitting equipment provided at 

 Clarenville can be operated at channel levels up to +20dbm, and it is 

 logical to allow the same recei\dng level at the shore end as at inter- 

 mediate repeaters. 



On the above basis it is possible to construct a curve (Fig. 8) relating 

 the total circuit noise to the number of intermediate repeaters, and it is 

 seen that the minimum number is 15, each of which must have an overall 

 gain of 59 db (amplifier gain, 64 db) at 552 kc. The actual provision is 16 

 repeaters, each having a gain of 60 db at 552 kc, the additional gain 

 being absorbed in fixed and adjustable networks at points along the route, 

 as indicated in the follomng section. 



Level Diagram 



The actual level diagram (planning levels are shown in Fig. 9) differs 

 somewhat from that which can be deduced directly from the preceding 

 because of the following considerations: 



(a) The location of the first repeater from Clarenville (i.e., on land) 



-100 



10 



12 14 16 18 20 



NUMBER OF REPEATERS 



Fig. 8 — Variation of circuit noise with number of repeaters. 



