"M.M." wrote:
wrote:
I disassembled my CT-3 trap (20/30 meters) and found absolutely nothing
wrong with it ... is there supposed to be a capacitor in
there, ...
I believe the capacitor is the capacitance between the inner tube(s) and
the outer tube. I found on mine that the connections at the ends of the
coils in the traps corrode and then make a poor connection to the tubes.
IIRC, they're riveted so I drilled out the rivets and replaced them with
sheet metal screws. I also applied some anti oxidation paste meant for
aluminum wiring...I got it at Lowe's. That seemed to help. You might
check all aluminum-to-aluminum joints and and connections and clean them
and apply the paste. It seems to help mine to do that periodically. You
might also check inside the box. A close lightning strike a few years
back wrought havoc on the matching box on mine.
The R7000 is definitely not Cushcraft's best piece of work. It has been
a PITA ever since I bought it several years ago from the estate of a SK
who belonged to our club. The 14AVQ I bought 35 years ago was a lot
better antenna, as was the Butternut I had before the 7000.
You wouldn't happen to be the guy who bought the trap from K0FL, are
you? I bought the box & other two traps...
73... Mark AA7TA
Yes -- the capacitance between the inner rod and the outer form a variable
(or at least adjustable) cap, just like a 'piston trimmer'. This is used
to bring the trap to resonance. Before you spend
a lot make sure the connections at the end of the coils, as Mark suggested,
are good. This is a simple fix and will save a lot of money and grief.
--
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Diagnosed Type II Diabetes March 5 2001
Beating it with diet and exercise!
297/215/210 (to be revised lower)
58"/43"(!)/44" (already lower too!)
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Irv Finkleman,
Grampa/Ex-Navy/Old Fart/Ham Radio VE6BP
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