HIGH-SPEED OCEAN CABLE TELEGRAPHY 



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voltages of constant frequency as low as 2.5 cycles per second and of 

 very pure wave form. 



To determine the various electrical parameters of the laid cable 

 wholly from measurements at its terminals was practically impossible 



Fig. 13 — String oscillograph 



on account of the complicated manner in which the resistance and 

 also to some degree the inductance and leakance vary with frequency. 

 However, by combining the results of factory measurements with 

 the results of measurements made at the cable terminals it was 

 possible to determine the fundamental characteristics of the laid 

 cable with a fair degree of accuracy. The method consists essentially 

 in measuring, at a number of frequencies ranging from 5 cycles per 



