[TowerTalk] How Helically Wound Verticals Really Work (was : Vertical dipoles)

[Roger (K8RI)]

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. 
But a center loaded vertical has a high profile, high wind drag, and is 
more fragile than the helically wound vertical.
Some times that is a problem and sometimes it is not. If not, then the 
decision is easy, if it is a problem then the helically wound is the 
solution. The center loaded can also be recognized from over a 1/4 mile 
while the helically wound is rather inconspicuous. A "Stealth" mobile 
antenna, if you will.

73

Roger (K8RI)
>  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?
>
> Rick N6RK
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