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Subject: [TowerTalk] quad driven element tuning
> Gents,
> My 5 band quad uses one feedline for 20-17-15 and one for 12-10. I
attempted
> to zero in the fo of the driven loops yesterday for 20-17-15. All three
> bands are a little high in fo so I added about 4 inches of wire to each
> driven loop. The fo did not change one khz!!!! What is going on????
> Interaction btwn the three bands???? I am not using any type of matching
> network, just fed directly with 50 ohm coax and all three of these bands
are
> parallel fed. Any ideas of why the fo did not budge???
Is your feedline decoupled from your Antenna?? You need a current
(choke) balun at the feed point...
> P.S. I have not attempted to zero in 12-10 yet.
I would group the bands differently... e.g. 20 -15-12 and 17-10..
Less interaction that way.. Seperate feedlines for each band is the best
solution..
Take a peek at http://www.cebik.com/quad7.html
73
John EI7BA
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