David G. Nagel wrote:
Ken and Gary;

Coax fed auto tuners have a range of about 3:1 SWR. This means that
for
a 50 ohm feed the greatest antenna input that it can match is 150
ohms.

That's roughly true for the usual (lousy) ATUs sold by the likes of
Yaesu as rig accessories. It is most definitely not true in the cases
of most of the third-party "coax-fed" autotuners. My LDG AT-11MP easily
matches the high VSWRs presented by my G5RV on all the HF ham bands
with the exception of 30M. I forget which band it is but the feedpoint
impedance at the shack end of the coax falls outside the ability of my
MFJ antenna analyzer to measure it which means that the AT-11MP is
successfully dealing with a VSWR in excess of 12:1. The servo-tuned ATU
in my old TS-940SAT is almost as good as the LDG autotuner in this
respect.

If you want to feed any type of antenna with a generally unknown
input
impedance you need to use open wire feed line. Using this feed line
you
can auto match a wider range of miss match 10 or 15 to 1. For
matching
absolutely any impedance use a manual tuner.

Dave WD9BDZ

w3rv