In article ulztc.40$Y21.34@lakeread02,
"Jack Painter" wrote:

"Bruce in Alaska" wrote in message
"Jack Painter" wrote:

who referenced a steel ship, which is my reference as well. I have seen
hardline (still 50ohm coax) in shipboard installations using the same
Sunair
ATU that I use, connected to the wire HF antennas. It appears (to me) no
different that the ungrounded dipole that I feed with coax from my land
station tuners. I have also fed a longwire with that same tuner/coax
combnation, however the longwire was a grounded antenna, and not simlar to
a
insulated backstay of a sailboat.

Coaxial Cable is the WRONG Stuff to be feeding and EndFeed Longwire
Antennas with, even should you not ground the shield, which would be
disasterous in any case.
What is needed is good old GTO15, which like others have
plainly stated, High Voltage - Super High Isulation Wire. In a pinch
I have used the Center Insulation and Feedwire from RG8 or similar
coax with the shiled and jacket stripped off, but this is still not as
good as GTO15.
Yes there are a bunch of Installers who ran around using Hardline
to feed USCG MF/HF SunAirs Antenna Systems from their AutoTuners a few
years back, but the folks who had to maintain those systems 24/7 up
here in alaska, ripped all that **** out and replaced it with
conventional PhospherBronze Antenna Wire with insulators, when it was
determined that the original installations were STONED DEAF compared to
a one transistor radio.
How do I know this you ask? I was the FCC Resident Field Agent
for Southeastern Alaska, and watched it all happen.

Bruce, I am asking why there is apparently such difference between feeding
an ungrounded dipole with coax from an ATU (my shore station) and feeding an
insulated (hence ungrounded) backstay from an ATU? I work Alaska bareback
in the summertime with that setup and I just can't understand what GTO-15
does that hardline doesn't. If you could explain or reference a document
that specifies the reasoning I would try to correct my misunderstanding.

Thanks,

Jack Painter
Virginia Beach, Va



The fellow that followed your post did a good job in his reply.
The thing that get most of the rookie marine installers in trouble
is that they think of an antenna and tuner as if it only worked
at one frequency. They design the system for that frequency and think
they have a good system. Well it does work for one frequency but when
they try another band, things go very wrong and things just don't work
anymore. This is exactly why tuned counterpoises are an absolute JOKE
in the Marine Radio Service, but we still see them touted as the
greatest thing since canned beans. A good antenna system for a Marine
Radio Installation needs to be as efficent as possible across the whole
MF/HF Spectrum. Given a Wood or Plastic hull, this is a very daunting
challenge for the worlds best RF Engineer, let alone the SuperHam turned
Instant Expert Marine Radio Installer in a day. What is required is:
1. The Best RF Coupled Ground system one can afford to install onboard.
2. No compromise on the RF Ground System.
3. It is the RF Ground that makes the Radio work.
4. An antenna that is long enough to have a reasonable antenna
effeicency at the lowest frequency that the radio will operate at.
(this means about 75 Ft or more for 2182 Khz)
5. No compromise on the installation because of the wifes astetic
senseabilities. (build it to work, not just look good)
There are more but I think you get the idea. Just because you can
get a signal report on 12 Mhz during the day from the other coast
doesn't mean squat, about how good your Radio system is really doing.
If the band is open a 10watt TX on a dummyload can be heard on the other
coast. What makes a good system is carefully planning the installation
of the RF Ground System and then not compromising the antenna length
because you can't figure out how to install what is needed to make the
system work. All autotuners did for the industry is allow any fool to
install something that looks good, but radiates about as well as a wet
noddle. Back when all the tuners were setup by the installing Tech, he
had to actually make the system work, or he didn't get paid. Now there
is a novel thought.

Ok now I'll get off my soapbox......

Bruce in alaska
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