[TowerTalk] LMR degradation

[K8RI]

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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