[TowerTalk] Re: Force12Talk Digest for 3 Apr 2000 in hour 0:00
K7LXC@aol.com
K7LXC@aol.com
Mon, 3 Apr 2000 09:37:39 EDT
In a message dated 04/02/2000 10:18:11 PM Pacific Daylight Time, list@qth.com
writes:
> I have been up and down my tower like a yo yo and can not get the swr =
> down on 40 .Have moved the tuners in and out ,but swr still 5 to =
> 1..Changed the feed line to the Wireman 1:1 balun and no help there,not =
> really sure what the distance should be on the phone part of the =
> band,had it at 18 in. and in to 5 in..The only other thought I had was =
> maybe the new Balun could be bad? The other bands are great,any =
> thoughts??
It's been my experience that when the swr is high everywhere and it's
not acting like an antenna (no discernible dip anywhere) that it's a feedline
problem.
Are you checking the swr directly at the end of the feedline? MANY
antenna "problems" have been traced to bad jumpers, bad switches, etc. in the
shack.
There are only a couple of things in the system - antenna, balun and
feedline - so by eliminating each one, you'll find the culprit.
Have you tested the antenna AT the feedpoint? I have a PL259 with two
short jumpers and alligator clips to attach directly to the feedpoint. If the
antenna acts like one at that point, then plug your analyzer into the balun.
If it looks okay there, then test the feedline. Since you've already changed
it, you should be getting close.
I've always had the F12 linear loaded antennas have a dip somewhere so
unless there was a mistake in building the antenna, I'd say the problem is
elsewhere.
The problem with a balun is that there is no way to test one. You have
to substitute one to see if it worked or not.
Cheers, Steve K7LXC
Tower Tech
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