Donald while I was waiting for DB to post the modeling details for his Vector model, where he claims the nice gain that you have suggested for a long time, and that is supported by the reports in Siro's specifications for the NV4K...I was reading over this thread to maybe see if I missed anything.
For those of you that really care about this issue and will speak out...I suggest you read Donald's email quote from Sirio's engineer noted in bold above...very carefully. You might have to click on the quote to show it all.
I have never seen or heard this information before, and for me it describes what I've been saying for some time now...the bottom cone area does radiate a little...but it is not much. I've also suggests that their NV4K design may show signs of CMC on the attached mast.
In my real world testing that I did some years ago on my S4, in collaboration with Bob, we discussed the CMC's on the feed line that I was experiencing, and Bob described this as a transforming effect that allowed the feed point impedance change some. Right Bob?
I was changing feed line lengths, and saw this happening, just like many others have reported over the years, but they had no explanation...and were likely wondering if they were tuning the antenna,,,as many talk about.
It is also a fact that I have described the 5/8 wave radiator as an alternative example of what I see going on in the S4 design. In those cases, however, I said the bottom portion of the antenna does nothing to cancellation the bad effect from the bottom 1/8 wavelength out of phase area of the radiator, and thus all it effectively does is just raise up the maximum current point up a bit...compared to a 1/2 wave radiator.
