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[TowerTalk] Fwd: How Helically Wound Verticals Really Work (was : Vertic

To: towertalk@contesting.com
Subject: [TowerTalk] Fwd: How Helically Wound Verticals Really Work (was : Vertical dipoles)
From: hanslg@aol.com
Date: Fri, 20 Nov 2009 00:43:40 -0500
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>


Funny you mentioned it; how much better is a coil (or helical) be if it 
is made of ribbon wire instead of round wire, or is it worse?

Hans - N2JFS

Richard (Rick) Karlquist wrote:
> Dan Zimmerman N3OX wrote:
>> I don't see anything in there that is a reason for implicit mistrust 
of the
>> model.  A helical is better than a high Q base loaded vertical.  
Helical
>> winding is worse  than a lumped mid-loaded antenna.    Doesn't seem
>> particularly strange to me.  It's somewhere in between.  The 
effective coil
>> height *IS* higher than with base loading, so you get a more 
favorable
>> current distribution.    It's non-optimum in terms of wire length 
(and hence
>> loss) but there's no reason to assume it's going to be worse than 
***all***
>> possible lumped loading coils in various locations.
>
> The point about HWV's is not "do they work?" but "are they worth the
> trouble to build?".  If you can cover the entire antenna with 
windings,
> you can just a well, with a lot less work, cover the center 1% with
> windings and have a center loaded vertical.  So we have shown that it
> is easier to make a center loaded vertical than a HWV.  We agree that
> the center loaded vertical is at least as good and probably better.
> Can anyone present a "value proposition" to justify the HWV?
>
>
Not for self construction.

However, if one were in the antenna selling business, helical winding
could provide a discriminating (and potentially patentable) feature.
Company A could say: we're selling helically loaded verticals.  Company
B could say, Our helical loading (unlike those lame ones from A) has a
non uniform winding pitch.  Company C could say, Our helical winding is
made from silver ribbon, reducing the ohmic losses from those lame As
and Bs.

Jim
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