ROUTE SELECTION AND CABLE LAYING 323 



Since the cable equalization built into the repeater differed appreciably 

 from the final determination on laid cable, it was found necessary at a 

 comparatively late stage to introduce an undersea equalizer into the 

 center of the sea section. This was intended to eliminate a flat peak of 

 loss of 3.5 db, expected at about 100 kc. So that the last repeater should 

 not he too near the beach at Sydney Mines, a network simulating 9 miles 

 of cable was also inserted in the undersea equalizer. 



The repeaters were spliced into the cable lengths on board Monarch 

 and tests were made at every stage of the buildup of the system. The 

 eciualizer was permanently jointed to the first half section of 7 repeaters 

 and left with an excess length of tail which could be cut as desired during 

 the laying operation to further improve the equalization. The first and 

 second halves of the system were temporarily connected through power 

 separation filters so that the whole system could be energized just prior 

 to laying. 



The test routine carried out included attenuation measurement at 5 

 frequencies in each direction of transmission, noise, pulse and loop-gain, 

 supervisory measurements, dc and insulation resistance and capacitance. 

 Monarch test room contained, therefore, two sets of terminal equipments 

 similar to those installed at Clarenville and at Sj^dney Mines. 



It was decided to energize the system continuously during the laying 

 except for the few hours when power had to be removed to make the 

 equalizer splice. This enabled a continuous order (speaker) circuit to be 

 operated over the cable and minimized the number of energizing and 

 warm-up periods. The only disadvantage, considered to be slight, was 

 the necessary omission of insulation resistance and capacitance measure- 

 ment during laying, except in the course of the equalizer splicing 

 operation. 



The plan was to lay from Terrenceville in the direction of the high- 

 frequency band and to test the system to Monarch during the laying 

 from this shore station. The overland section between Clarenville and 

 Terrenceville, which contained two repeaters, was connected on with 

 appropriate equalization after the submarine section had been satisfac- 

 torily completed and tested. 



At Terrenceville, after the cable end had been taken ashore and the 

 beach joint completed, the system was energized from Monarch with 

 a dc power ground at Terrenceville for the necessary 4 hour minimum 

 warming up period. The first set of routine measurements of the laying 

 operation was then carried out. Thereafter, a complete set of measure- 

 ments on the Terrenceville half of the system was made after every 10 

 miles of cable laid. An occasional check set of measurements was also 

 made on the Sydney Mines half of the system in the tanks. 



