<IMHO it might be just a problem of SWR-measurement... because of the
inevitable stray pick up of the relatively long vertical I'd never try to
match a low band vertical using an MFJ-type SWR-bridge, but by a
reflectometer-type SWR-meter at the input of the ATU (i.e. at the base of
the vertical) using just enough power for reliable readings...
presumably, Jim has meanwhile solved the problem after so much good advice!?
regards
Uli, DJ2YA>
Uli,
Just to close the loop on this issue, I'm both delighted and embarrassed to
report that the SWR problem with the Titanex V160S vertical turned out to be
very simple to fix. Without thinking much about it, at the time I added more
radials, I had also shortened the wire connecting the tuning unit to the
vertical, on the theory that it was best to keep all connections as short as
possible. Pete, N4ZR, made a comment to me which got me thinking, so I went
back out and lengthened the connection between the tuning unit and the antenna,
and the end result of that process was an SWR of 1.1:1 at 1825 khz. It was a
pretty elementary mistake, so I felt more than a little dumb, but at least that
problem was solved.
By the way, the MFJ measuring device worked fine, giving me very accurate
readings as to the resonant point. From the comments of others, I gather I was
lucky there were no nearby sources of interference to distort the results, but
in any event it work according to specs.
That's the good news. The bad news is that despite an optimum SWR, plus 32
radials (most 130', with some shorter ones at the suggestion of George, K8GG),
the vertical is producing some very disappointing results. There are a number
of possible reasons -- the vertical is only about 40' from the tower (that's
the best I can do, given the size of our property), there are trees all around
the vertical, and the ground is probably somewhat lossy -- but the bottom line
is that while I am hearing very well, I am not being heard well at all, even
with an amplifier. I'll try more radials, but I'm afraid I'm not going to be
able to duplicate the performance of the Titanex verticals that I heard being
used on dxepeditions (of course, they were in salt water) that caused me to
want to use this vertical.
73, Jim W1YY/7
-----Original Message-----
From: topband-bounces@contesting.com
[mailto:topband-bounces@contesting.com]On Behalf Of Ulrich Weiss
Sent: Thursday, December 02, 2004 8:16 AM
To: KEN SILVERMAN; topband@contesting.com
Subject: Re: Topband: Vertical SWR problem
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