Towertalk
[Top] [All Lists]

Re: [TowerTalk] How Helically Wound Verticals Really Work (was : Vertica

To: "Richard (Rick) Karlquist" <richard@karlquist.com>
Subject: Re: [TowerTalk] How Helically Wound Verticals Really Work (was : Vertical dipoles)
From: jimlux <jimlux@earthlink.net>
Date: Thu, 19 Nov 2009 12:14:29 -0800
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
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
_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk

<Prev in Thread] Current Thread [Next in Thread>