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[Towertalk] Coax questions

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Subject: [Towertalk] Coax questions
From: ogden@us.ibm.com (Bill Ogden)
Date: Tue, 29 Oct 2002 12:49:29 -0500


Several people helped me understand coax selections a little better,
and I appreciate the efforts involved.  My selections appear to be:

1-  LMR600, LMR600UF, or LMR600DB    (most expensive, more difficult to
use)
2-  RG-213   (least expensive, easy to use)
3-  9913FX    (middle of the road ?)

For various reasons I am not interested in N connectors.  I will stick with
PL-259s.

I am looking at a run of 175', with part in a conduit under ground and part
exposed
on the tower.  As mentioned earlier. I like to work 10 meters near the
noise level.
(When the band is *really* quiet, it is difficult to tell the difference
between my
current antenna and my dummy load.)  Losing a little transmitted power does
not bother me -- I can always turn on the amplifier -- but I like to hear
well.

Questions:

1. Water exposure.  How sensitive are these three types to water
problems?  I attempt to seal my connections, but I am not perfect.  (Once
upon a time, a long time ago when I was a novice, there was seldom any
mention
of coax and water in the literature.  I simply opened the ends of RG58 and
connected this to dipoles.  It worked find for years.)

2. There was a discussion somewhere about the difficulty of putting
connectors
on LMR600.  If the center conductor has the slightest nick the connection
will go bad quickly.  Is this correct?  I *hate* working with coax
connectors
and would probably nick something.

3.  There was a lot of discussion about foam.  Is there a problem letting
LMR600 dangle 60' from a crankup tower?  It would seem that this is
likely to bend/crimp/squeeze/pull the coax holding point at the top.

4. 9913FX does not appear often in these disucssions.  Is there a problem
with it?

Is the 1.3 db difference between LMR600 and RG213 really worth bothering
about?

Bill
W2WO


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