the vertical section was still suppressed and the top 29' was resonating.
With this in mind I decided to run a shunt wire from the top to see where
the antenna resonates. Here's what I found..>>>>
I was afraid the tower was messing up the L. This is what happens when they
are are nearly resonant.
You can't measure tower resonance with a drop wire. The drop wire is a stub
or shorted transmission line in parallel with the common mode impedance
presented by the drop wire and tower combination. It is just a mess of stuff
going on.
<<<
The MFJ read 380 ohms at 1825 and the X is way off the scale. I inserted an
EF Johnson 10-160pf air variable capacitor at the base.in series.and was
able to tune the antenna to 60 ohms and the X=22. If I played with the cap
there was a real sharp drop in reactance showing X=12. The air variable was
about ¾ meshed.>>>
Reducing the lenth (tap point height) of the drop wire is a better way to
get impedance right. Or, better still, use a multiple wire drop to make the
drop diameter look larger. That will reduce Q, require more C, and should
reduce impedance.
You are so close at 60 ohms I would not worry. Adjust the cap for lowest
SWR. What is the SWR??
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