Shockwave, I don't have a clue what is really going on with NB's setup, but in your post #53, last paragraph, you talk about a collinear 5/8 wave, albeit the 3db advantage you suggest is not near the 2 Sunits that Needle Bender has experienced. Maybe that is what is going on over at his location---among other things to make the improvement he sees.
It may be coincidence, but NM5K, look him up on the Internet, here in Houston builds a 5 radial GP kit for his 5/8 radiator and he claims similar and remarkable collinear free space gains of 5.1 dbi, at least according to modeling. I have posted all of his 10 meter 1/4, 1/2, and 5/8 wave work in my picture album here on WWRF if you want to take a look at what he says.
Personally, I am dubious about such gains too, but here is a claim that supports close to what NB says.
NB, talks about different insulators and maybe I don't understand the distinction, but maybe he as actually created a collinear gap between these two 5/8 wave elements. Typically this will require some kind of coil to connect the two elements, but none was mentioned. But again, if the Sigma IV/Vector 4000/your stuff makes a collinear shift in phase without this gap, then why not in this case.
NB, can you post some pictures? I can tell you if your's looks like NM5K's. His setup is very slanted to the ground and is less than 30 degrees.
BTW NB, what do you mean when you post 5-9 radials?
