Walterb thanks for the report. I won't be testing a real SP 500, but I started modeling one at: http://www.worldwidedx.com/cb-antennas/123067-marconis-penetrator-500-eznec-model.html
I told Bob that I was finished tweaking my SP 500, unless I got some real specs. Now after doing this I-10K above, which is not finished, I may try the matching network on the HyGain also, if I can get some good measurements that I can confirm with some measurements I already have.
Thus far about the best info I've gotten are some general ideas about the overall length being 22' feet...from the very bottom to the very tip, but I don't know if the source for this info tested it somehow or just said it...because it was in his manual. I'm not sure about the radial lengths either.
The manual shows one radial at 105" from the inside of the mounting bracket to the tip, but inside of the mast side of this bracket is off center, and the other three radials are not described. IMO, all three could have different lengths since this bracket is not centered to the radiator with this measurement. The radial bracket is centered and it will easily allow the radials to be symmetrical around the radiator, so I don't know why HyGain didn't described the install better using that bracket. They could have meant to do that, and that would make sense, keeping everything balanced and symmetrical. For me, that would be good, because I believe symmetry is important.
How did you do your radials? Did you record any dimensions, like the overall length, note the best SWR frequency as installed, and did you check and record the SWR or analyzer bandwidths for less than 2.0:1 using an analyzer or and in line meter? I could use such information against the details in my model.
Any info you have and can share would be appreciated. I had to guess on some of my SP 500 dimensions, and I don't have a matcher included yet. Trying that will be next.
Marconi
