[TowerTalk] Bumps in coax

[Roger (K8RI)]

F.R. Ashley wrote:
> Hi all,
>
> During my regular inspection of my coaxial cables, I noticed 2 or 3 hard 
> bumps along the length of the cable.  These bumps or pimples, do not break 
> through the outer jacket, but look as if they are on the verge of doing so.
> These bumps, or whatever, are small, about 1/8th inch or so.   Any idea what 
> they are, or what causes them?
>
>   
Man, a guy who runs enough power to melt the coax.<:-))
Had any nearby lightning strikes?
I take it that you are sure these were not there at the installation 
time so are not an artifact of production?
First thing I'd do would be to put an analyzer and/or a TDR on the coax 
to make sure it's OK.
Then, if you are willing to replace the coax if you make a mistake, 
clean the jacket thoroughly with a solvent, then carefully cut the top 
off a bump, one thin layer at a time. This will help to see if there are 
any pin holes in the jacket as well as the condition of the shield at 
this point. If it all checks out OK I'd then put a piece of MMM large 
flooded heat shrink over the area in question.  (It will fit over PL-259s)

The only things I can think of are either lightning, something causing 
high current in the shield, or a production anomaly, but out of 
curiosity I'd have to peel at least one off to see what it is.

73

Roger (K8RI)
> 73 Buddy WB4M 
>
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