Shockwave, you're right about the in-phase issue a while back. I think when I got to modeling my version, there was not question in my mind that we concluded wrong back then, and the bottom is in phase with the top portion just like the Sirio model shows. I wrote Bob that he was right. We were all confused by how Eznec handles and smooths the depictions of currents. I don't know why that is or even if I'm right, but that is what I think.
I tend to agree with Shockwave. If we could get further back from the model that SW posted, then I think we would see a larger RF pattern that is complete from bottom to top with no nulls across the entire Sigma radiator including the base. For me this larger tear drop shaped lobe shows the pattern in the far field. That part is also like CDX007 suggests about the full radiator working on the Gain Master.
I also think if we weren't looking at a collinear affect in this antenna, we would see such a far field pattern. Also notice that the pattern show does not indicate much if any skyward RF. If this is Sirio's model of the New Vector 4000, then I don't see how it can be beat unless better tuning would put more current into the segments. SW, do you know if Sirio is showing us a tuned model? Did you get any more output of their model that would show they included mast, feed line, and/or matching of some sort? That would also be great for us to ponder. I think Bob may be right however, it looks like a free space model again. For Sirio's purposes, that may be all they consider relevant to their antenna designs. How bad could a good free space model turn out to be, pattern wise, just by placing it over the real Earth feature in the software?
I would like to see a 3D view of that model.
