Dee, I took the day off today and put up a 20 meter dipole and I can
"match" like a dandy. This would lead me to believe that there might, in
fact, have been some slight change in my 10 meter dipole that I just
can't see. This change, if it exists, could be the problem.
My dipole is indoors up in the upper most apex of my attic. I had
hoped that this would put off any weather related problems but it just
may be some sort of normal corrosion that's the problem.
The 10 meter dipole antenna will "match" on 28.3 and 28.4, but ceases
to "match" at 28.5 and above.
I never actually saw the carbon that was blamed for the previous
"match" problem. I just took the repair shop at their word. When I took
out the tuner this time and gave it a good inspection, I saw no evidence
of arcing or carbon build-up.
I have tomorrow off as well, so I think that I'll just start with 2
new connectors on my feed line and work from there. If this fixes
things, I'll respond to this newsgroup with the good news and a
follow-up report.
Thanks for your input on this. I never even considered an antenna
analyzer. I have to check them out in the MFJ catalog.
I'm kind of a 10 meter addict and this is the time of year that I get
to curl up in my shack on the weekends and indulge myself.
Thanks again, Dee.

Charlie Shaw
KB3BTO

Dee D. Flint wrote:



Even though nothing obvious may have changed with the antenna, get hold of
an antenna analyzer and check it. The connection of the feedline to the
antenna may have deteriorated. If you are using coax, water may have gotten
in the line. The joints of the connectors to the line may have
deteriorated. The MFJ antenna analyzer lets you check the impedance and
loss of the line itself. You have to disconnect the line from the antenna
when you are checking the line only.

Note if you had a carbon buildup before, that indicated something else was
wrong with your system. Carbon occurs when something burns. Quite possibly
your tuner has been arcing because something is off with the antenna and has
always been off. Then when the carbon builds up, it won't work.

If you are using a properly cut 10m dipole on 10meters, you really shouldn't
need the tuner at all unless you are at the extremes of the band. What is
your SWR reading when you don't use the tuner?

Dee D. Flint, N8UZE