Barry wrote:
<< Hoping to get some tips from folks who have been there with their F12
C3/4 tuning on 10m. My C3S 10m resonance refuses to go lower than 28.8,
even with the 10m driver extended "one hole" beyond factory drilling....>>
Hi Barry,
I just put a C-3E together. I also went with one hole exposed on all the 10m
elements. The best resonance is down near 28.350 or so.
Be sure to use a balun when test tuning, and raise the antenna high off the
ground when testing.
My balun is 6 turns at about 7.5" OD , made from RG-213 (did it on a one
gallon paint can). I started with 8 turns, but after reviewing data posted
here on the reflector, I went back to six. The leads to the feedpoint screws
(where the shield and center separate) were only 2.5" long. SWR curves on
all bands are beautiful.
To test tune, I rigged a tram line to the tower, connected a temporary coax
extension to the balun and pigtail, and raised it about 50 feet off the
ground.
Seems to me there was a post recently about how the resonance gets lower as
the antenna gets away from ground. Steve, pop in here and correct me if I
got that wrong.
Good luck Barry,
--...MARK_N1LO...--
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