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BELL SYSTEM TECHNICAL JOURNAL 



dependent, however, since, for each value of F, Fi for instance, there 

 exist k relations of the form (16) which the corresponding set of 

 constants Aw, A21, ■ ■ ■ Aki must satisfy. The remaining 2k inde- 

 pendent constants can then be determined from a knowledge of the 

 conditions at the terminals of the conductors. 



It is important to observe that the transmission characteristics of 

 a system of coaxial conductors are influenced to a great extent by 

 the manner of connecting the various members of the system. 

 Anomalies in the impedance of a complicated network such as a 

 submarine cable with several conducting sheaths in the return path, 

 may often be traced to lack of proper connections between the sheaths, 

 or to faulty joints. 



Ill 



The submarine cable armored with a continuous coaxial sheath, 

 as shown in Fig. 2, is a particular case of the foregoing, and one which 

 presents a clearer idea of the physical significance of the various steps 

 in the general theory. There are only two groups of conductors, the 



Copper Conductor - 



Insulator 



Fig. 2 



first consisting of the core conductor, and the second comprising the 

 iron sheath and the sea water, the two groups being separated by the 

 insulating material and the layer of jute. Consequently, there is 

 only one mode of propagation, and the analysis is considerably sim- 

 plified. 



The jute is assumed to contain sufficient sea water so that although 

 it conducts practically no current axially, it maintains equality of 

 potential between the outer surface of the gutta percha and the inner 



