Yes, with the proper reducer one could use RG-58U and or RG-8X (or as it
is sometimes called RG-8u modified) the 8X is much better than the
58U. A tad thicker
than 58u but much heavier center conductor and a better shield. This can
handle much more power also. I use it all the time. The reducer needed
is UG-176/U (8X is the thickness of RG-59U that is used on cable
systems)
cheers!
73
======================

"Airy R. Bean" wrote:

It would appear that even if one purchases PL259's intended
for large coax, that there remain differences, eg, if there is
a shoulder just below the screwed portion where the reducer
might go in, then it is intended for the slightly smaller large
diameter coaxes. Is this the case?

(Never had this problem when we all used Belling-Lee
connectors and UHF TV coax!)