That match was a pain in the... well... you know... I'm glad I was able to get it done though, hell, that alone took me half a day to figure out. I think I have it figured out for the most part now so doing it again shouldn't be to bad.
I to have noticed the horizontal component in the radiated field. This isn't the first model I made that has both components, and I attribute most of it to the trombone style matching section, and a small part if it to the small current mismatch in the radials. I made a linear loaded 5/8 wavelength antenna about a week ago that uses a horizontal linear loading section that also had this effect.
When it comes to the feed point, I did mine a little different. I definitely did not simply put it at the base of the vertical radiator, that would defeat the purpose, and possibly make the antenna nearly impossible to tune within the modeling software. Instead I connected mine across the matching section, essentially, one side of the feed point is directly attached to the radials, in this case with a one segment wire, while the other side is tapped into the middle part of the trombone section. The matching wire like yours is one segment long, but is also connected different. I got it as close as I could to the pictures I saw which clearly had a tapped trombone section.
My radials are also symmetrical, I was unaware that there was a difference in the actual I-10K antenna's radials to begin with... I can understand the need for such a difference, although at the same time it isn't at a point that will make a huge difference.
I have yet to do any cmc testing with the model, that will come. This antenna has a full set of radials, do I don't see common mode currents being that big a deal. I have another project to play with first, and that is seeing what length, once tuned for, will the antenna produce maximum gain. Another model that used linear loading instead of a trapped trombone section produced maximum tuned gain with its tip .58 wavelengths above the radials. This was a surprise to me. It was a very similar design to the I-10K, just the matching system was a bit different.
I really want to make a Maco model as well, but I haven't figured out how to account for the capacitor hidden in its design... If anyone has the capacitance of that part I would need it to make such a model and tune it properly...
The DB
