Ok, first thing, NONE of the Lumped Constant Binary Switch Tuners like
SGC's Knockoff of the SEA Design, will tune ANYWHERE within a few
percent of the Natural Halfwave Point of the antenna. So you must
design
the Antenna, so as to move that Halfwave Point to a section of the
HF Spectrum that you NEVER plan on using. Second thing, none of the
SGC
Employees around today, were around when this Tuner and it's Operating
software was designed, and most don't have much experience with actual
operational considerations.
Thirdly, After a lot of experimentation with the SEA1612b Series
Tuners,
from which the SGC's were plagiarized, when using them to drive a
dipole, there are two schools of thought. One school says that you
should add a 1:1 Balun on the output of the tuner between the RF
Ground
Stud, and RF Output Connection to make your Balanced Feed. Second
school
says to take the Feedline Coax, Dc Power Lines, and Tuning Feedback
Wire, and wind them, in a Bifilar fashion on an appropriate Torriod
to decouple the Tuner from Radio Feed and connect the dipole to the
RF Ground Stud, and the RF Output Connection.
I have used both Systems on Maritime Mobile Limited Coast Stations,
around Alaska, and find that they both work about Equally Poor. It
should be noted here, however that Alaska is notorious for not having
any kind of decent RF Grounding Soil, so usually this type of Antenna
System works much better than an type of Longwire antenna that needs a
good RF Ground, to work against. Where a GOOD RF Ground is available,
(Salt Water) the Longwire Antenna outperforms the Tuner Driven Dipole,
ever time, but without that GOOD RF Ground, the Tuner Driven Dipole
works better than just about anything else, especially over a wide
range
of Frequency Bands available, in both the Maritime and Amateur Radio
HF
spectrums.

Bruce in alaska


Bruce,

Thanks for the response to my query. I have a couple comments to
these. One, we already own a new SGC-237 coupler, so that is what we
will use. Two, thanks for the info on the SGC personnel.... that
might explain why some of their responses to my emails didn't seem to
make sense... especially their comments about NOT needing any balun.
Three, and more direct to my initial questions, it appears we will be
using coax between the coupler output and the antenna feedpoint.... up
to 20 feet of low loss... we'll just eat the loss. But more
importantly, I had intended, and will proceed along the lines of your
comments on baluns, by installing a 1:1 balun at the input to the
tuner. This will, at least, keep the RF out of the building and our
station location.

thanks.

Ed