[TowerTalk] Old coax questions.... OK? or NOT OK?

[Jim Brown]

On 10/8/2022 4:57 PM, kq2m at kq2m.com wrote:
> How problematic is the blackened CC?
> What is that whitish/green powdery stuff inside?
> How problematic are the flecks of black on the braid?

These are all symptoms of water intrusion, the result of which is 
increased attenuation. I've had that happen to me on one of my high 
dipoles, as a result of failure of waterproofing at the dipole center 
insulator. Water entered there, and came all the way down to the end 
that plugged into my grounding panel at the shack. I measured the loss, 
which, after only about a year, was elevated from the same coax new. It 
hurts to have to throw away 160 ft of a good RG11, but I bit the bullet.

By contrast, more than ten years ago, I helped N6RZ's widow sell his 
stuff, which included a LOT of top quality coax, all of it at least a 
decade old, much of it older. When NCCC members turned their noses up at 
it when offered free at a meeting, I built stubs from it. All measured 
as "like new" coax; harmonic rejection stubs work by shorting the line, 
so any degradation would show up as poor rejection.

73, Jim K9YC