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[Towertalk] HI SWR during rain - EXP-14

To: <towertalk@contesting.com>
Subject: [Towertalk] HI SWR during rain - EXP-14
From: fdavis@nf.sympatico.ca (Frank Davis)
Date: Thu, 7 Nov 2002 21:19:07 -0000
Last summer I completely refurbished my 20 year old Explorer 14. =20
I cleaned the aluminium contact surfaces and took the traps apart
 and cleaned them and replaced all rusty screws etc.
Recently after a particularly heavy rain and wind storm the SWR=20
went up on 20 and 15 to about 3:1.  10M SWR no change.   After
 a couple of days of drying in the wind the everything has returned=20
to normal......
I cranked the tower over and did a visual inspection and did have=20
to reposition the inside end caps back over the ends of the driven
 element traps.  They had vibrated out of place in the gusts.  I=20
couldn't see any other issues to deal with.=20

Today it is raining and blowing again with a nice helping of wet snow
 mixed in.  The SWR is up again on 20/15   and no change on 10m. =20
I don't recall this happening in the past on this yagi and I wonder what =

is happening.  The obvious answer is water in the traps.....but why=20
didn;t this happen in the past before I took everything apart to =
refurbish ??   =20

Also would the water cause this to happen if it gets into the driven=20
element traps only or would it happen if water is getting into the=20
parasitic traps and not the DE traps??   There is no change in SWR=20
on 10M ...there are no 10M traps in the DE ..... so I am assuming that
the problem must be water in the 20/15 DE traps.   =20

Anyone with any ideas or comments.

Frank VO1HP


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