It may be tinned copper - giving it the silver color - and making it easier
to solder..
here's what a ham normally does : TIAS (Try It And See)

If you can find the Manufacturer's name, you may be able to look up the
'loss per mft' for different freqs on their website.


silver coloured and not copper. Any one know if this coax is of good
quality not?

I want to use some for the Cobwebb antenna and I want to make some coaxial
traps for my wire antenna with it.

Thanks