MriC.U. IXlHCT.IXCIi IX if.iir. III.II.RS o.t 



riilier (H>siti\o or lu-^ative. ('()iisi'(|iu'n(l\', llirro coils haviiij; nuitiial 

 iruluctanci' iHMwt't'ii i-acli of tlu-m and ha\'inK only three arcessihie 

 terminals offer no ^'■•■'•i'*''' l)<)ssil)ililies than rio two coils lia\in>j nnitiial 

 itidiictance Iwlvveen them and havinjj three terminals. In liolh 

 cases the structure is etiiiivalent to a 7'or w mesh composed of three self 



Fig. 35 — Equivalent Filter Sections, With .mil Without Mutual Iiulurtanrc 



inductances, at least two of which must be positive. With specific 

 relations between the various self anfl mutual inductances, it is possi- 

 ble for the three coils with mutual inductance between each of them 

 to be equivalent (as in the case of two coils with mutual inductance) 

 simply to an L network composed of two positive self inductances. 

 Since either two or three coils with mutual inductance between 

 them are, in general, equivalent, at all frequencies, to a T or v net- 



