On Feb 1, 2:05*am, eddy wrote:
... which of the three methods are considered more reliable ?

I assume you are trying to configure a 1/4WL 75 ohm piece of coax to
interface to your ~100 ohm loop. What I would do is cut it a little
longer than 1/4WL with the velocity factor taken into account. Connect
it to the antenna and trim for lowest SWR on the MFJ258B. Why bother
with an exact 1/4WL when you can trim for lowest SWR using the actual
antenna?