MEASUREMENTS AT TELEPHONIC FREQUENCIES, 125 



equivalent n in Fig. i6c. The " mutual impedance " of the network 

 for these pairs of terminals is 10.48605 Z 95°. oo'.47" ohms, and the 

 mutual admittance 0.936265 X io"^Z 34°.59'.3i" mho. 



'13-i'oi>'iL77'o'-32\j,miOllTli!>}^ZZ'-Ul^'l^'c/,m 



'^■iOi-iM\-J1^0'nn.lw 



M 



7-ii']l.jL^°u.i.'ii-",^c 



0' 



-o C 



g-. 



Fig. 16. Alternating-current network with its equivalent T and n. 



In any actual network, it is theoretically easy to determine the 

 elements of the equivalent T experimentally. It suffices to measure 

 EcD and I^^ in order to determine R^,. A measurement of the 

 sending-end impedances at each pair of terminals in turn, will then 

 serve to evakiate r^ and n- Similar treatment applies to the experi- 

 mental determination of the IT, if this is preferred. 



