A coax choke is not going to significantly effect forward gain unless
you have a bad connection. It could effect front-to-back if the choke is
done incorrectly. If the SWR is OK, then it is probably the angle of
signal arrival. A signal arriving at about 23 degrees will hit a null
on your 85 ft antenna, and it will be many dB down from your 50 ft
antenna (assuming you are on flat ground). Actually the 50 ft antenna
should beat the 85 ft antenna for anything arriving between 18 and 28
degrees on 20 meters.
Jerry, K4SAV
Carol Richards wrote:
>Hello....
>
>I recently put a new rf choke on my 204ba ( 12 turns, 11 inch diameter as per
>the hy gain manual) and 135 feet of 1/2 inch hardline. Swr is good,
>directivity is fine. Problem....the 204ba at 90 feet is 10 to 20 db down on
>the short path to EU as compared to my TH6DXX at 50 feet. (as reported by the
>europeans).
>
>Question....is this just a propagation problem or is there another problem?
>The choke is made of new RG 213 and the short piece of coax to the panel is
>also new RG 213. Any help? I am getting frustrated fast.
>
>
>Carol
>_______________________________________________
>
>
>
>_______________________________________________
>TowerTalk mailing list
>TowerTalk@contesting.com
>http://lists.contesting.com/mailman/listinfo/towertalk
>
>
>
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|