[TowerTalk] Stacking Tribanders

[Lux, Jim]

On 6/21/22 1:06 PM, John Langdon wrote:
> It can tell you how each antenna will do individually but does not calculate the combined patterns exactly.
>
> 73 John N5CQ
>
> -----Original Message-----
> From: TowerTalk <towertalk-bounces at contesting.com> On Behalf Of David Gilbert
> Sent: Tuesday, June 21, 2022 1:01 PM
> To: towertalk at contesting.com
> Subject: Re: [TowerTalk] Stacking Tribanders
>
>
> HFTA should never be used to try to optimize stacking distance.  It simply does not actually calculate the stacking gain as a function of stacking distance like EZNEC would.
>
> 73,
> Dave   AB7E
>
>

I'm not sure the "transform to a single antenna at the mid distance" is 
universally valid - that is, two antennas will have their own set of 
lobes and nulls, and the combination of those will vary with the phasing 
and weight of the two antennas.  I'm not even sure it's valid if the 
only case considered is summing equal amplitudes in phase.

You could probably do HFTA on each one individually, and then work up an 
Excel spreadsheet to combine them.