I don't know what I would expect to see Bob, but if I was to guess, I would probably expect to see something like Donald describes. However, that would require some proof that I don't think we will ever see...even if we "think outside the box."
I doubt that CST can even show us the proof, and if it does it will not be noted in the image we see posted. For one thing the color scheme suggest that everything in red has 2.37 amps/meter. Because these colors are not discriminating enough to show us the nity-grity details in this far field pattern, it is suggested we see the current distribution of 2.37 A/m...from one end of the top 1/2 wave to the other. At best the value of 2.37 A/m is mostly in the center portion of the pattern, and its magnitude declines as we go out toward the ends to a really small value. Bob, IMO none of this jives with theory, but it is fun to look at.
The cone does not present a coaxial ratio that would perform like coax. As soon as the radials (shield) started to move away from the monopole (center conductor) the wires would start to radiate in an unpredictable fashion. This is why it is suggested to keep coaxial pig tail connections as short as possible...in order to help us minimizes as much undesirable RF as possible at the feed point.
Your EzBob image of the open sleeve antenna I posted above does not show 3 currents flowing in the area of the radials. My Eznec does not show 3 currents either, and I'm not sure what CST shows, but in my opinion it does not show 3 currents flowing there either.
Bob, what I see in the CST model is almost full cancellation inside the cone with a little difference in magnitudes between these two out of phase currents. If you compare the tops of both colors inside the cone I think you too will see this difference in magnitude. I see the blue color showing a bit more current than the red, and that is what my Eznec model shows. Check this point out and compare about 1" down from the top of the two radials where the color shade begins to fade in several little V shaped looking areas. The blue shows more current than the red and looks to me to be a bit thicker at the base as we might expect from a 1/4 wave element.
Note, the red shows to be the longer of the two which shows less current.
I also see this small difference radiating in to the far field and that difference can be constructive or destructive, but either way the RF is so small as to be meaningless. I also see these currents rising right up the outside of these radials, just like is does inside the cone. If we were seeing CMC flowing as you might suggest...we would see the current outside of the radials flowing down the radials. If you can find a slower motion of this image that the banned guy posted in another thread...you would see these currents are coming from the base of the cone, and going up to the top or out with horizontal radials...like all radials attached to a vertical monopole do whether slanted up, slanted down, or horizontal.
Tell me what you would expect if you somehow got 3 currents flowing in the cone area.
