[TowerTalk] Evaluating coaxial cable not from a dealer

[Steve K8JQ]

Occasionally someone will post here or on other amateur radio forums 
coaxial cable for sale. Often unused, left over from a project, on a 
reel, pickup only, as-is where-is, cash. If one were to pursue such a 
purchase, what would one look for and/or do to validate that the cable 
is good?

An eyeball physical inspection of the cable is an obvious thing to do. 
One can see the outer layer of cable on the reel and perhaps both ends 
of the cable. Is that enough?

Should one make some electrical tests before handing over the cash? What 
tests and with what test equipment? A few spot frequencies? Wideband 
sweeps? Antenna analyzer? VNA? Transmitter with power meter? Something 
else? What would you do if both ends are not available or do not have 
connectors?

Is it OK to transport a reel with a few hundred feet (or more) of cable 
on its side or should the reel be "standing up" in the bed of a pickup 
truck?

What else to look for, think about, consider?

Steve, K8JQ