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BELL SYSTEM TECHNICAL JOURNAL 



Appendix E 

 Illustrative Example 



The example contained in this Appendix serves two purposes. 

 First, it illustrates the use of two types of the general line-impedance 

 graphs contained in Parts II and III of the paper; second, it illus- 

 trates the first-approximation design of a simulating network by 

 means of the method in Part IV. 



The specific example chosen pertains to a well-insulated open-wire 

 line consisting of two horizontal parallel copper wires, of No. 12 

 N. B. S. gauge, having per loop-mile the constants 



# = 10.4 ohms, 



L = .00367 henry, 



C=. 00835x10 ~ 6 farad, 



the leakance G being regarded as negligible. This particular type and 

 gauge of line was chosen because it is rather extensively employed in 

 practice, and also because its excess impedance is far from being 

 negligible even as regards its resistance component. 



For the illustratve purposes contemplated, it will be supposed that 

 it is desired to evaluate the resistance and reactance components 

 M and N of the characteristic impedance K of this line over the 

 frequency-range from 200 to 2500 cycles per second; and also to 

 design a network for approximately simulating this impedance over 

 that frequency-range, and to determine the simulative precision of 

 such network. 



The procedure and results are indicated by the following table 

 together with the supplementary description coming thereafter. 



The first column in the table is a set of values of the frequency / 

 distributed over the specified range 200 to 2500. 



The columns headed F, x, —y, M, — N, show the successive steps in 

 evaluating the characteristic impedance K — M-\-iN by means of 



