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Author Topic: Cushcraft R8 Vertical add ground radials?  (Read 1143 times)
KA1LMR
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Posts: 13




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« on: December 06, 2011, 04:34:36 AM »

I have a roof mounted R8 vertical wondering if anyone has tried adding ground radials to this antenna when roof mounted  wonderign if this would lower SWR or increase bandwith on lower freeqs like 7 and 10 MHZ? I have a 35 ft RUn down the house is a ground wire at that length of any performance benefit?
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K2QB
Member

Posts: 103




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« Reply #1 on: December 06, 2011, 06:42:24 AM »

The design of the R8 is similar although not as good in my opinion as it's predecessor the R7. Both antennas are designed to work with a counterpoise and not an actual ground radial system. By installing a ground radial system you will actually de-tune the antenna by changing it's feedpoint impedance. If you are having SWR and/or bandwidth issues and you have it mounted per Cushcrafts' instructions you may need to do some adjustments on it as far as length is concerned. If that doesn't correct the problem I would check all the joints to make sure there is good electrical/RF connectivity between them. One other source of a potential problem is your feedline. Make sure that you have a choke wound at the base of the antenna with your feedline as Cuchcraft recommends. I currently have an R7 as a secondary antenna and I opted for a set of ferrite beads at the base on the feedline. Made a big difference once I got these right as far as SWR was concerned especailly on the lower bands.
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