[TowerTalk] properly feeding a tribander stack

Pete Smith n4zr@contesting.com
Sun, 17 Oct 1999 03:17:55 +0100


I have been operating all along on the premise that in feeding a stack it
is sufficient to have equal feedline lengths from a common feedpoint such
as a stackmatch, in order to feed the driven elements in phase.  Now a
local has said that the feedlines should not only be equal in length but
also an odd number of quarter waves in length.  I vaguely recall a
discussion of stacking several years ago on Towertalk in which one of the
established experts said that it was necessary to do this to force equal
currents in the driven elements, for the best possible pattern.

Obviously, having to switch feedlines in order to meet this criterion would
significantly complicate a typical tribander stack.  Does anyone know:

1.  Is this true, even in the abstract?

2.  If it is, quantitatively, how significant is it?

73, Pete Smith N4ZR
n4zr@contesting.com 

Sometimes a tower is just a tower

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