SD'r, when I first noticed that your radials were on the inside and mine were on the outside of our bent hubs, I wondered why the difference.
I went out with binoculars and checked my TopOne out, and it's just like the picture of the hub I posted. So, I have two hubs that look alike. I had a thought that if your radials were on the opposite side of the hub from mine that maybe it changed the center to center spacing between the radials, with your's being closer than mine. If it did, then that might account for your low frequency, because I was sure that my TO was resonant at 27.205, but I didn't say anything as you were already getting questions. I also realize that you noticed some misalingment at this point and you were looking close, so your idea is valid too, if the spacing did not change in the process.
At some point I took a closer look at my Antenna Work Sheets and noticed that my AP had also shown a low resonance at 27.005, when using a tuned 1/2 wave line. So, with that I figured---if there was a little difference in the spacing, it probably made no difference. Now, I'm wondering that this might be an issue that needs to be explored further. Maybe you could measure your modified AP, center to center, and see if it equals 6", and maybe Bob could measure his knockoff hub too? This is not much of a difference, but it could be critical for the impedance based on how current distribution works.
SD' I know I can change the hardware on my knockoff to either side if there is room, Bob could verify this also. Can you change your hardware to the other side? This might be worth testing.
Boy this project seemed so simple at first, and now it's turning into a can of worms with more questions than answers.
