Quote:
"that's only one of many reasons why the ZeroFive antennas operate so well when ground mounted because the earth ground reference + radials is "more perfect" than an elevated radial system with fewer radial elements operating independently of earth ground. when you choose to operate it in an elevated mode you've just created more work and expense for yourself because to fully uncouple the radials from earth ground the feedpoint will have to be raised quite high above the ground, especially at the lower operating frequencies.
Stray capacitive coupling between earth ground and an above ground radial system is still quite noticable at heights up to just under one wavelength above ground, not to mention the fact that now you have a support structure that will conduct common mode current where in a ground mounted antenna there is no such path. if you still want to use it in an elevated fashion i suggest that you take all of this into consideration and calculate the height above ground at one wavelength at the lowest operating frequency you intend to use and see just what you're getting yourself into."
The reason I am mounting my Zerofive 43 multiband vertical in an elevated position, is because I have no other choice. My property allows no other possiblity. And I definitely do not have the real estate necessary for a low-band horizontal antenna. No way to even use an 80 meter inverted V here. My only choice is the vertical, and my only choice is to mount it on 20 feer of pipe (mast) bracketed to the eave at the end of my house. I will be able to use a decent number of radials for all bands (except 160), and only a few for 75/80.
Tom at Zerofive told me that I should make a radial for 80M about 87 feet long, to make the antenna act like a vertical off-center-fed dipole. (43 foot antenna +87 foot radial = 130 feet) A half wavelength on 80 meters. I don't know if this would be better, or whether it would be better to add several 65 foot (quarter wave) radials for 80M. What do you think?
But one thing I'd love to FINALLY understand, is HOW does one isolate the support mast from the antenna base? See, Bob even says this again:
"i isolated the a99 from the conductive pole then added 2 wire 1/4wave radials and an ugly balun at the feedpoint"
But he doesn't say HOW he "isolated the A99 from the conductive pole". This is driving me nutz! I've asked this question dozens of times, on various forums, and STILL cannot get anyone to explain this (seemingly) simple concept.
Bob.. (or anybody)... HOW did you "isolate" the antenna from the pole? Electrical tape?
How?
