it's either from exposure to UV, or salt, or a combination of both.
The problem of water and moisture getting into the coax along the brade and 
under the brade is something to think about, but your sealing job should let 
you use the thing for at least another year or two if you have to.
with mag mounts being so cheap these days, and even the really good square 
NMO type maggy mounts, the best is to just replace it...to buy the coax and 
a new connecter for the existing magnet mount, would probably be actually 
more costly than perchasing a brand new one.
You can change the coax though...you just have to pry off the outer shell 
and take out the mount assembly.  it can be done, but then you have to 
reglue and make sure the whole thing is sealed and soldered properly and so 
on...more of a headache than a 15 dollar replacement is worth hi hi.
73
Colin, V A6BKX
----- Original Message ----- 
From: "tom behler" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Monday, March 07, 2011 5:37 PM
Subject: Re: splicing coax


>    Hi, all.
>
> So, here's a related question:
>
> I use a mag-mount on our vehicle for 2 meters and 440, and tonight, I just
> noticed that the outer jacket on part of the coax feedline was becoming 
> hard
> and inflexible, and has even split in one place.  As a temporary repair, I
> wrapped where the outer jacket of the coax is split with electrical tape,
> then put coax seal over the tape, and wrapped the connection again with an
> outer layer of electrical tape.
>
> I suspect that this fix will not last forever, and that I may be looking 
> at
> buying another magmount at our next local swap.  If I could, I'd take the
> magmount apart, and just replace the coax, but it is all molded together,
> and won't come apart easily.
>
> Any thoughts on this situation, and what I have done, would be 
> appreciated.
>
> Someday, maybe someday, all of my antennas will be working again without
> problems.  It certainly has been a rough few weeks for a number of us on 
> the
> list as far as antennas are concerned!
>
> 73 from Tom Behler:  KB8TYJ
>
> ----- Original Message ----- 
> From: "Pat Byrne" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Monday, March 07, 2011 6:28 PM
> Subject: Re: splicing coax
>
>
> Chris,
> I wouldn't do it.  You would have to retain the coaxial part of coax
> and that would be very difficult.  Also, whatever insulation you
> placed around the center conductor would probably have different
> dielectric properties than what the cable has and that would screw
> things up as well.  You could place connectors on the ends of the
> pieces and use a barrel connector to connect them.  That would work fine.
> Sorry to rain on your parade.
> Pat, K9JAU At 03:27 PM 3/7/2011, you wrote:
>>Hello,
>>Is it a good idea to splice coax?  I wouldn't consider it for an outdoor
>>run but what about indoors?
>>
>>Chris
>