[TowerTalk] Blackened Sheild on Belden Coax?

Mike Gilmer - N2MG n2mg@contesting.com
19 Sep 2000 12:38:04 -0700

On Tue, 19 September 2000, K7LXC@aol.com wrote:

> I've heard good logical explainations that the chlorine in 
> the PVC (polyvinyl choride remember) reacts with UV and causes the jacket 
> material migration through the coax shield thus blackening it. That's why 
> RG-213 with a non-contaminating jacket is preferred for outdoor applications.
>     OTOH someone a couple of years ago mentioned an engineer that worked for 
> Belden or other cable manufacturer that claimed it was ENTIRELY due to water 
> migration. I tried tracking the guy down for clarification but was never able 
> to get ahold of him. Maybe someone will do the research and let us know. 

I won't argue about the possible reactions of UV and chlorine.
I found a slit in my coax's (RG213) jacket that had been 
outside, laying on the ground for ~2 years - the black stuff 
was all around the slit, and a few feet up and down the 
coax.  Nowhere else.

PeoplePC:  It's for people. And it's just smart. 

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