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BELL SYSTEM TECHNICAL JOURNAL 



quency is held fixed, or alternatively to give responses at more than one 

 frequency when the tuning is held fixed. In either event they lead to 

 ambiguity and confusion, and their effects must be reduced to the point 

 where this cannot occur. 



a 



O 0.7 



< 0.6 



Fig. 4 — Mode-shai)e factors ( C^t ) as a function of diameter to length ratio ( 7- ) for ci 

 cular c_\linder resonator — TE modes with / > 0. 



A si)ecial tyi)e of interfering mode is the 7'£01(/; + 1) mode. In the 

 nature of things, it is virtually impossible to suppress this mode without 

 likewise suppressing the desired TE 01;/ mode. The width of the operating 



