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Henry, I basically put a sibilance of an end fed 1/2 wave above the beam and added a mast, but had to insulate it from the AT to get Eznec to accept the input, so this whole exercises was just quick and dirty.

I just wanted to see if I could get the model to work and if either pattern went to hell in a hand basket with the AT's close together. This model in no way is meant to duplicate precisely such a setup, and I was surprised at the lack of affect that resulted.

I also did not take time to model the 1/2 wave by itself and at that height, but it looks pretty close I think. I did not tweak the models for SWR or resonance, but they both would need matching for sure. I do not know why the beam's pattern skewed as it did in the back only. However the vertical sits much closer to the reflector and that might be the difference for the beam. Maybe the mast and A99 needed to be set more to the middle of the boom and that might minimize the shewing noted, or the radials need to be shifted in direction...as BM suggested. That would be a lot of work I think.

This only suggests to me to not be too concerned with such a setup. I was pretty sure this is what I might find based on my personal experience with my 4 element horizontal with both an A99 - 1' foot above and a Starduster - 10' feet above, but I wasn't sure. As best I could tell, I did not notice any negative results with either setup.

<blockquote data-quote="Marconi" data-source="post: 299360" data-attributes="member: 903">Henry, I basically put a sibilance of an end fed 1/2 wave above the beam and added a mast, but had to insulate it from the AT to get Eznec to accept the input, so this whole exercises was just quick and dirty.&nbsp;I just wanted to see if I could get the model to work and if either pattern went to hell in a hand basket with the AT&#039;s close together. This model in no way is meant to duplicate precisely such a setup, and I was surprised at the lack of affect that resulted.&nbsp;I also did not take time to model the 1/2 wave by itself and at that height, but it looks pretty close I think. I did not tweak the models for SWR or resonance, but they both would need matching for sure. I do not know why the beam&#039;s pattern skewed as it did in the back only. However the vertical sits much closer to the reflector and that might be the difference for the beam. Maybe the mast and A99 needed to be set more to the middle of the boom and that might minimize the shewing noted, or the radials need to be shifted in direction...as BM suggested. That would be a lot of work I think.&nbsp;This only suggests to me to not be too concerned with such a setup. I was pretty sure this is what I might find based on my personal experience with my 4 element horizontal with both an A99 - 1&#039; foot above and a Starduster - 10&#039; feet above, but I wasn&#039;t sure. As best I could tell, I did not notice any negative results with either setup.</blockquote>

[QUOTE="Marconi, post: 299360, member: 903"] Henry, I basically put a sibilance of an end fed 1/2 wave above the beam and added a mast, but had to insulate it from the AT to get Eznec to accept the input, so this whole exercises was just quick and dirty. I just wanted to see if I could get the model to work and if either pattern went to hell in a hand basket with the AT's close together. This model in no way is meant to duplicate precisely such a setup, and I was surprised at the lack of affect that resulted. I also did not take time to model the 1/2 wave by itself and at that height, but it looks pretty close I think. I did not tweak the models for SWR or resonance, but they both would need matching for sure. I do not know why the beam's pattern skewed as it did in the back only. However the vertical sits much closer to the reflector and that might be the difference for the beam. Maybe the mast and A99 needed to be set more to the middle of the boom and that might minimize the shewing noted, or the radials need to be shifted in direction...as BM suggested. That would be a lot of work I think. This only suggests to me to not be too concerned with such a setup. I was pretty sure this is what I might find based on my personal experience with my 4 element horizontal with both an A99 - 1' foot above and a Starduster - 10' feet above, but I wasn't sure. As best I could tell, I did not notice any negative results with either setup. [/QUOTE]

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