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vhf quarter wave ground plane antenna radial shape?



Does the shape of a ground plane radial matter?
Modeling software deals with lengths maybe even diameter... Ham, commercial, marine antennas - dyi or purchase have tubular or wire radials....
I have a vhf antenna that has (and is the only fault in design) 3 radials maybe 3/8th in diameter.
My plan was to add more radials.. But because of set screws, where I would drill and tap 3 more radials, my plan changed to just widening the existing radials.
I eventually came to the conclusion I could get more width out of aluminum flat stock than wider aluminum tube.
1.25" width x .25" thickness on all three radials. And I could use the original tapped sockets with aluminum bolts to secure them.
I know it won't change the decoupling from the mast,,, but will it change anything, I'm not thinking of?
It's unity gain, so I don't think it will effect take off angle?
It's not that crucial but now the thought is in my head... and now I'm curios .
Any thought's Please and Thank you

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Larger diameter wire/tube tends to increase the bandwidth of the antenna. That's why when you look at a disk-cone commonly used for scanner applications the vertical element has a bunch of wires to increase the bandwidth so its a better match to the feed line.

On a simple 1/4 wave ground plane at mid to high VHF and low UHF 3 to 4 ground radials is usually enough. Adding more won't make much difference. I built a simple 1/4 ground plane, 4 wire radials, out of a BNC socket and 1/16 inch buss wire. I got a 2:1 SWR bandwidth from 430 MHz to 470 MHz after tweaking the element lengths a bit and radial down angle. Looks sort of dumb but works good enough when I went to the Dayton Hamvention a couple of years.Hattenna UHF SWR Scan Results.pdfHattenna UHF SWR Scan Results.pdf

If you want to get into modeling software for antennas try looking at this package. The guy has retired and doesn't feel like providing further support so he just made it license free to use. I've used it a bit on and off since V3. It does a good job in most cases.


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