[TowerTalk] Site Elevation and TOA

[David Gilbert]

One caveat with regard to using HFTA for planning stacks.  HFTA 
overstates the stacking gain for narrow spacings.   Choose your stack 
spacings based upon other more commonly accepted criteria or model it 
with some version of NEC before loading the stack into HFTA.

73,
Dave   AB7E



On 6/18/2014 9:35 AM, john at kk9a.com wrote:
> 69 feet and 138 feet are usually very good heights for 20m. I use similar
> stacking heights and I have numerious 20m contest plaques. I have never
> used HFTA, does it model stacks properly?
>
> A 200' high 10m beam can be a very good antenna however there are many
> nulls so there will be times that is a poor antennas.  This should not be
> your only 10m beam.
>
> John KK9A
>
>
>
> To:	 "Cqtestk4xs at aol.com" <Cqtestk4xs at aol.com>
> Subject:	 Re: [TowerTalk] Site Elevation and TOA
> From:	 Jorge Diez CX6VM <cx6vm.jorge at gmail.com>
> Date:	 Wed, 18 Jun 2014 10:45:06 -0300
>
> Really is nice to see HFTA suggestions
>
> For a project to put two 20M5 in a stack, I was told by several friends to
> put
> them at 69/138 ft
>
> HFTA show that this is not the best height and they must be not to high,
> 59/118
> seems to be better
>
> Anyway the practice show me that high antennas are good:-)
>
> Most of the people told me that a 10 mts antenna at 200 ft hight will not
> work,
> but really this antenna pay off all the work
>
> So now, about the 20 mts stack project, I am in doubt if I need a 118 or
> 138 ft
> tower, not sure what to do :-(
>
> 73,
> Jorge
> CX6VM/CW5W
>
>
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