In article . com,
"Boozo" wrote:

Have a 100 foot roll(approx) of used coax cable which has no markings
printed on it.
Can anyone tell me how I can work out what it might be ? e.g. 75 ohm or
50 ohm or ?
Going by the size it looks similar to 50 ohm but I'm not sure.

Any suggestions would be appreciated.

just a note, lots of cable have sold conductors at 50ohms times
microwave and andrews cinta are examples