[TowerTalk] properly feeding a tribander stack

n8ug@juno.com n8ug@juno.com
Sun, 17 Oct 1999 14:12:00 -0400


Hi Pete - Your query brings to mind a few words from  Walt Maxwell. in
"Reflections,"
"All power fed into the line, minus the amount lost in line attenuation,
is absorbed in the load regardless of the mismatch at the antenna
terminals"

This gives credence to your operating premise, in agreement with others
of W2DU's ilk qualified to speak.
 
I would suggest that your "local"  watch for Walt's new book, due out by
years end, or, if he really wants to tell it like it is, find a friend
who will loan him a copy of "Reflections" in the meantime.

73,


Press Jones, N8UG, The Wireman, Inc., Landrum, SC, 29356
Sales (800)727-WIRE(9473) or  orders@thewireman.com
Tech help (864)895-4195 or  n8ug@thewireman.com
http://www.thewireman.com  and the WIRELINE news 
and bargain page.  Our 22nd year!
 

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