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Stell, Add about 6-8 21" radials to the A99 at the base just below the tuning rings, then mount it on a 6' x 1"-1.5" fiberglass rod and wrap 5 1/2 turns of your coax in a neat coil about 4" inside diameter around the fiberglass rod about 6" below the mounting tube down the fiberglass. This will both decouple RF from the coax and supply just the right amount of counterpoise for a bottom-fed 1/2 wave, though you might want to try adding 12"-18" to the top of the A99 to bring it up to 17.5" for a full 1/2 wave above the tuning rings. This should give both the best performance and best isolation from RFI.

[QUOTE="Needle Bender, post: 526652, member: 13339"] Stell, Add about 6-8 21" radials to the A99 at the base just below the tuning rings, then mount it on a 6' x 1"-1.5" fiberglass rod and wrap 5 1/2 turns of your coax in a neat coil about 4" inside diameter around the fiberglass rod about 6" below the mounting tube down the fiberglass. This will both decouple RF from the coax and supply just the right amount of counterpoise for a bottom-fed 1/2 wave, though you might want to try adding 12"-18" to the top of the A99 to bring it up to 17.5" for a full 1/2 wave above the tuning rings. This should give both the best performance and best isolation from RFI. [/QUOTE]

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