>Plug it into the FT-990 and the swr on the rig was 3:1. Antenna tuner was
off. Add different lengths of RG-8, the swr varied from 2.5:1 to 5:1. It
doesn't seem to be wx related. <
I'd suspect common mode currents on the coax outer. Some ferrite rings or clip
on sleeves, plus a couple on the mains lead would be the first place I'd try.
Plus, have you got a good RF ground on the radio? Or still got a good RF ground
on the radio? I ask that because I had a ground on my antenna tuner consisting
of 6 inch wide aluminium flashing running back to the tower. Checked the
continuity last weekend - it was 80 ohms. The aluminium had corroded through
just below the sod.
73
Peter G3RZP
========================================
Message Received: Oct 06 2005, 04:46 PM
From: K7LXC@aol.com
To: towertalk@contesting.com
Cc: W7FPChuck@aol.com
Subject: [TowerTalk] Antenna problem?
Howdy, TowerTalkians --
I've got an antenna problem and I'm stumped. An M2 15M monobander
developed some high swr - 3:1 or more where it used to be 1.1:1.
I took a crane and man-basket up to the feedpoint and measured the swr
with my MFJ at the balun; it was 1.2:1. I next measured at the jumper to the
tower - same thing. Then I measured the end of the feedline in the shack - same
thing. As far as I was concerned, the antenna system was fine.
Plug it into the FT-990 and the swr on the rig was 3:1. Antenna tuner was
off. Add different lengths of RG-8, the swr varied from 2.5:1 to 5:1. It
doesn't seem to be wx related.
Like I said, I'm stumped. Any help out there? Solutions appreciated!
Cheers,
Steve K7LXC
TOWER TECH
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
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