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THE BELL SYSTEM TECHNICAL JOURNAL, JULY 1954 



For waves bound to the helix, Fte * is to be derived from that solu- 

 tion of (24) which tends to zero ar r — > oo. This solution is TFx,o(2a:2r)/ 

 \/2air, and so Fte^*' is given by equation (30) 



1 TV. 



1 _ i /3^ — coVei W^,(,{2a2r) 



Zte Wju q;2(2x — 1) TFx,i(2Q;2r) * 

 Similarly, from equation (23), we have, for bound waves, with E^^ Kq , 



FERRITE 



DIRECTION OF 

 CONDUCTION 



CIRCUMFERENTIALLY 

 MAGNETIZED 



Fig. 11 — (a) Cylindrical helix surrounded by ferrite, (b) Magnetic Reld lines 

 projected onto a plane containing the axis of the helix. 



