482 



BELL SYSTEM TECHNICAL JOURNAL 



it is well known for this structure that D is isolated from input at S, it must 

 follow that an input at S will still divide equally betwen Ei and £2 . 



As Null Device (iJX — 4 Arms). We now associate 6" with mesh 1, Ei 

 with mesh 2, D with mesh 5, E2 with mesh 6 (see Fig. 7) which leads to: 



De = 



III— 3.5 



Fig. 6 — 13^ X ring — 4 arm— tap spacing and identification for power division analysis 

 by determinants. 



Fig. 7 — 13^ X ring — 4 arm — tap spacing and identification for determinantal analysis 

 as null device. 



With voltage applied at 6', mesh 1, the minor for current at /), mesh 5 is: 



<^6( 



III— 5.1 



where the 5(^') indicates that the voltage is at S and the current is sought at 

 mesh 5. Corresponding minors for the current in mesh 5(Z>), due to volt- 

 ages at El and £2 are: 



dnB\ 



db(Ei) -~ ~" 



III— 5.2 



III— 5.3 



