For about a week now, since this thread started, I have been interested in the topic. I have been redoing my M103 to make sure the specs are correct as noted in the manual.
I have also reconfigured this same horizontal model in the vertical field to insure everything is the same as the horizontal model.
I have a full comparison presentation between the Gizmotchy3 and the M103, that I'll post soon. I took the vertical M103c from this project to make the post below showing the effects with the mast attached and without, so you guys can see what my Eznec suggests when I remove the mast from the antenna. Will the results be as bad?
Shockwave it right, the mast does effect the pattern, but I'm not sure we could casually notice this difference...just using our radio.
You might also notice that the model with the mast
does not show a significant amount of CMC on the feed line or the mast, so I take that to suggest there is likely enough decoupling going on at this particular height (feed line length)...even though I did not model the feed line into the model.
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