[Antennas] Full legal Limit cable

[Robert Lay]

Dear Jim,

There is no good answer to that question, because it DOES depend on
frequency as well as VSWR and power level. You will find hams operating at
the legal limit using RG-58, but the next guy may not get away with it.
There are some complicated ways of measuring the impedance of a given sample
of cable, but it's a little tricky and not much fun. The best thing to do is
assume that it's 50 or 52 ohms. Terminate it in a dummy load of 50 ohms and
look into it with an SWR meter, an antenna analyzer, your rig, or whatever
and see what kind of SWR is on the line. If it's 1.25:1 or less, then you
undoubtedly have a 50 or 52 ohm line. Otherwise it is more than likely 75
ohm line

Bob Lay (W9DMK) in Dahlgren, VA
http://www.qsl.net/w9dmk