Built in ATUs are OK but remote auto-tuners work better.
I question this statement, because it seems to be built on the
assumption that excess loss in the mis-matched transmission line matters
a lot more than it often does. I suspect that most hams using remote
auto-tuners have a poor quantitative understanding of that loss, and may
also be fooling themselves into believing that their antenna "works
better" if they see a 1:1 SWR. I also suspect that many (most?) hams
using remote auto tuners to tune wildly non-resonant antennas would be
better off either by making those antennas closer to resonance, or by
using a bigger coax between the antenna and the shack, or both. To get
that quantitative understanding, study the family of graphs showing
excess loss due to SWR in the Transmission Lines chapter of the ARRL
Handbook.
Another point -- how well a built-in ATU works depends a lot on its
design. The TT rigs I've owned have not had them; the tuners in the
Icom, Kenwood, and Yaesu rigs have been mediocre, but the tuners in the
Elecraft K2 (their first), K3, and KX3, as well as their KAT500, are all
quite good. Again, I believe that's because Wayne Burdick has always
been a backpacker, so he understands what a tuner needs to be.
73, Jim K9YC
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