On 3/26/2013 3:03 PM, Bryan Swadener wrote:
I find this interesting, especially Bill K4XS' comments. My comments...
LMR400UF has a thermoplastic elastomer jacket that is good for
"in excess of 10 years" outdoors.
Experience from a number os has come no where near that. Mine was pretty
well shot after less than 6 years and this is Michigan which is not
exactly noted for lot of or intense sunshine.
It certainly does not feel like a thermo plastic, It's quite rubber
like and is a real PITA to strip with regular strippers as it bunches up
and does not cling to the braid/shield. Strips well with a plain old
box cutter.
Most of the other LMR400s use a
PE or PVC jacket that're supposedly good for 20 years outdoors.
Apparently, Times' marketing department is... ahem... stretching
the truth a bit!
So far I've had good luck with the regular cables
I've used the DX Engineering DXE-400MAX and Davis RF BuryFlex400 stuff.
It has a Type III PE jacket and has been fine for nearly 10 years
(so far). In another 10 years, I'll let you know if it lasts 20 years. ;-)
The Davis BuryFlex(tm) has a very tough and slippery jacket and is
almost as flexible as the UF versions of the LMR cables
I've used quite a bit of the BuryFlex and like it. So far it has stood
up well. I've not used any of the DX Engineering cable.
73
Roger (K8RI)
vy 73,
Bryan WA7PRC
Date: Tue, 26 Mar 2013 11:42:22 -0400 (EDT)
From: Bill K4XS
Subject: Re: [TowerTalk] LMR degradation
Back in the early 2000s I had a long conversation with the guys
at Times. The ultra flex on many of my jumpers had cracked after
only a couple of years in the FL sun. His response was the
ultraflex was not supposed to be used outside.
He offered to replace the stuff with regular 400 but I never
took him up on it.
I use the regular LMR 400 on all my jumpers and have had zero problems.
Bill K4XS
Roger K8RI writes:
We've known for years the UF versions of the LMR cables deteriorate out
in the elements. It follows that they'd possibly do so with age as well.
I found that the braid had almost disentegrated in some pieces of
LMR400UF where the jacket "appeared" to syill be in good shape. I
thought perhaps the jacket had become porous, but perhaps not? I wonder
which LMR400 he's talking about.
73
Roger (K8RI)
On 3/24/2013 9:42 PM, Jim Hoge wrote:
Today I discovered that I have had environmental ingress beneath the
outer jacket of some ~8 year old LMR-400.
In the latest (I think) version of his excellent Managing Interstation
Interference," W2VJN notes that he observed degradation in the measured
performance of stubs made of LMR400 that had been sitting in his garage
for a bit less than a decade. He seemed to think it was due todegraded
contact between the foil and braid shields. This was written several
years ago. He may have more to say about it by now.
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