Bob, I don't think I could have explained your issue in a suitable way, but I did try to draw attention to the issue without getting into kirchoff's rules. Kirchoff, wasn't even on my mind, so you're probably right.
I agree that the kirckoff rules apply, but I can't implement the coax feed line with confidence, so I use isolation as a method of removing much of the current effects from the pattern as I can and let the pattern stand as though it was perfect as a result. We've talked many times about doing the isolation bit, and the need to add a choke for the feed line. And if we didn't, such and incomplete setup and the feed line would seem to simply replace the isolated mast idea, and the whole mess would act the same...as if we didn't isolate the mast at all, and the currents would flow right on down the mast radiating as they go. This leaves us with the idea that we have to consider radials. Another topic.
I was just trying to show in a simple way the effects of removing the current path for the mast on these models, as if the models were correct and following the Mr. K's rules maybe. And, without trying to do something that was way over my head, and maybe most others on this forum.
We can easily see that this .625 antenna needs radials, or else connecting the mast directly to the antenna will send the pattern almost straight up and we could only talk to the birds. So I asked the question, on-the-other-hand does the Imax without radials, one that is connected directly to the mast, and not isolated, really performs as badly as the pattern suggest, 1.02dbi @ 8* degrees, vs. 3.83dbi @ 8* degrees compared to the antenna that is isolated? According to the model, would doing this likely produce a difference that many could possibly detect when on air? I think it would.
I think Imax/A99 users will tell us this is not my experience for the way these two work, in other words they just don't work that bad. I just didn't want to get all into some technical details, and not be able to explain.
So, my conclusion would be that maybe the Imax/A99 matching coil device does something special, for the most part, that tries to balance the feed point enough to decouple the antenna from the support, and thus it works without radials. Shockwave suggested the same thing I think.
I'll bet if you took the radials off of your I-10K you would see a big bad difference. I'm not that well schooled on the subject of end fed radiators, but I have read the work of AA5TB, and that is the bases of this idea for how I think the Imax/A99 might work.
Right now I can't even remember what provoked me to do this little modeling project for this discussion. That was back on page #6, and a lot of words have been posted since. However, you're right about that model not being perfect or even near perfect. I first made the antenna without isolation, and the pattern looked terrible, so I made another with isolation and I included both for the guys to consider. I didn't even suggest that these models didn't have feed lines, and that would have to be considered. And if feed lines were included then a choke of some kind would likely also be needed.
I guess the main thing this project might suggest to us is that if the Imax/A99 matching device does take care of the problems that no radials cause in your I-10K, then maybe it might help explain a little for why we see similar results with the Imax type models here, with and without radials. This is not withstanding the model without radials that is not isolated, and having no matching device to help isolate the antenna like a real Imax might have.
Who would have though that to possibly be the case, and do we hear stories suggesting the same,
