532 



BELL SYSTEM TECHNICAL JOURNAL 



of the system terminated at the far end in an open circuit. Impedance 

 curves 180° out of phase with those obtained by the last method de- 

 scribed can be obtained by using what is equivalent to one half of the 

 system terminated at the far end in a short circuit. The circuit ar- 



3.0 



2.5 



« 2.0 

 o 



z 



o 



o 



liJ 1.5 



<2 



_/ 

 _i 



2 1.0 



0.5 



300 



X 



o 



200 



100 



+ 200 



+ 100 



10 



I 



o 



-100 



-200 



400 



800 



1200 

 FREQUENCY 



1600 



2000 



Fig. 5 — Computed curves illustrating method of Fig. 4. 



rangement for such measurements is given in Fig. 6. When the 

 system being considered is balanced, the connections can be made as 

 shown on the left. However, when the system is completely un- 

 balanced, for example, a network built with no apparatus in one side 



I 



