[TowerTalk] Modelling a basic stack

[Pete Smith]

At 06:11 PM 5/9/2004, N4CW at aol.com wrote:

>I've never modelled a stack before. I have successfully modelled yagis, and
>in this case, I want to model a stack of two Cushcraft A50-5S yagis, 
>spaced 1/2
>wavelength apart, with the lower yagi being 40 feet over real ground.
>
>I'd appreciate being guided to some good references regarding stacking before
>I get in too deep :~)
>

This really isn't tough, Bert -- all the usual programs will model a stack 
like this just fine.  I suspect you will find that 1/2 wavelength is a 
little close for optimum forward gain.  You can build models of these 
antennas in any modeling program that incorporates taper corrections, 
simply by entering the length and diameter of each step in each 
element.  Feed the two sources in phase and you're home free.

I've done a lot of stack modeling, so if you run into specific issues 
please let me know and I'll try to help.


73, Pete N4ZR
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