RG-393/U
M17/127
I use this cable in most runs in the transmitter buildings to and from each
station since it has the dual silver shields, I don't have dissimilar metals
to worry about.
And can handle 1.8kw @950Mhz it works out great.
Brent KF4TNP
 
 
 
 
  _____  

From: Repeater-Builder@yahoogroups.com
[mailto:[EMAIL PROTECTED] On Behalf Of skipp025
Sent: Saturday, May 10, 2008 12:10 PM
To: Repeater-Builder@yahoogroups.com
Subject: [Repeater-Builder] Re: Best coax for short jumpers in repeater
cabinet?
 
> I think the LMR400 is a double shielded with each shield 
> different metals. One braid and one foil. This is a no-no 
> for duplexed repeaters for the higher TX RF will generate 
> noise getting into receiver. 

Just to be clear... 

The dissimilar shield metals is the potential problem source, 
not the braid - foil combination. And notice I used the term 
"potential problem source". It's not always automatic gremlin 
101 right out of the starting gate... Some years back I used 
a fairly large amount of LMR-400 feed line in various new radio 
& repeater system (applications) until I sourced more than an 
unacceptable number of antenna system "train wrecks" specific 
back to the LM-400 (and LMR-600) cable. 

Sometimes the problem took months and even years to develop... 
but from memory I've never had an installation of conventional 
antenna hard-line or coax feed sabotage a radio system like the 
many examples I've had to ferret out from or back to LMR-400. 

No more LMR-400 for me or any antenna system I'm involved 
with. 

The other cute dissimilar metal shielded coax problem is how 
physical cable movement can easily be a noise generator. There 
is a potential for LMR-400 coax moving in the wind to be noisy... 
and I have seen that demonstrated in an actual installation. 

cheers, 
skipp 
skipp025 at yahoo.com 
www.radiowrench.com 
 

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