There sure seems to be a lot of confusion by some people about what
the the "ground side" of the tuner should be connected to.

While it is true that you don't need a "true ground" for an end fed
antenna to work properly, you do need the other half of it or a
counterpoise instead.

A dipole works well if both ends are well above ground and isolated
from ground. If you place one leg of that dipole vertical and the
other leg horizontal you have a vertical with a counterpoise. Provided
the counterpoise leg is well above ground. It will work fine.

However if you have that counterpoise leg on or very near the ground
then it starts coupling to the ground. When it does that it greatly
detunes that counterpoise leg.
Making it a 1/4 wavelength when above ground works fine. As soon as
you place it near ground it is no longer a resonant leg. The
capacitance is much higher than in space. The velocity of propagation
slows way down. Those things make it no longer resonant. It is not
resonant and it is poorly coupled to ground. That is going to give
poor performance of the antenna.

For it to be effective it then needs to be well coupled to the ground.
When it is then it is no longer a resonant counterpoise. Making it a
quarter wave long does little good.

The point is that making a radial a resonant length that is to couple
to ground or is in close vicinity to ground is useless. Because it is
no longer resonant in those conditions.

Likewise something like a ground screen imbedded in the fly bridge of
a boat will not be resonant (maybe at one frequency if you are lucky)
and it is too far away from ground to successfully couple to it.
About the only thing it will do is provide a radiator to couple RF
into the surrounding wiring.

On a boat it is almost impossible to have the room for a resonant
radial that is independent of ground.

A radial needs to be resonant if not coupled to ground.

The alternative is to tightly couple to ground. To couple to ground
you need to get things down close to ground (ground in this case being
the sea)
whether you couple to ground with radials or directly couple with
metal in contact with the water.
Direct contact with the water is the most efficient as the
conductivity of salt water is so high. It makes a much better
conductor than any soil that you could encounter on land.
Because salt water is so high in conductivity you don't need much
surface area to obtain an efficient ground contact.

Once you do have a good ground system you want the ground side of your
antenna tuner to be as close to it as practical.
If you have a long ground lead from your ground system to your tuner,
it will still function as an antenna system.

But one of the problems that you run into first of all is that the
tuner has other things connected to it besides just the antenna lead
and the ground lead.
You have the coax from the transceiver and the control cables that run
the tuner. If the tuner is connected directly to ground then so will
the coax cable and the control cables be at ground as far as the RF is
concerned. But if you have several feet of ground lead between your
tuner and ground system then that puts your coax and control cable
above ground.

That wouldn't matter except that they are tied to the antenna tuner's
ground lead!
Remember that when the ground side of the tuner is not right at ground
it then becomes part of the antenna that radiates. When that happens,
because the coax cable and control cable are tied there they become
part of the antenna!

Your transmitter is being directly coupled to the outside shield of
the coax and to that control cable. These cables may run past many
other wires on the boat. That will induce RF into these other cables
too. It will also make your transceiver hot with RF. You have one big
mess! Also whatever is in proximity to the ground lead to the tuner,
is going to get RF induced into it too.

By keeping the ground lead short you eliminate those problems. You
will get much less RF induced into other wires than you will by
allowing DIRECT coupling to them with the ground floating. Then the
only problem you have left is RF getting induced into other wiring
from the radiation of the antenna itself. Keeping the antenna and lead
as far away from other wiring and objects as possible is the thing to
strive for. Still not 100% but much easier to deal with than ground
induced RF.

At the lower frequencies a moderate length ground lead may work ok or
provide a mild nuisance with stray RF. At higher frequencies where the
long ground lead may be a significant part of a wavelength (even
though it may not seem that long) you may not have any ground at all
at the tuner if it happens to approach a quarter wavelength. With a
lead a quarter wave length long if you ground one end the other end is
effectively an open circuit. In that case you get full power into your
"other leads connected to your tuner rather than a portion of it.

In the days of the 2 mhz AM ship radios, 10 to 15 foot ground leads
were common and worked ok. That is a rather small percentage of a wave
length at 2 mhz. But with the newer equipment operating on higher
frequencies this length becomes a much more significant part of a wave
length and places things much more above ground.

There must be some carryover from the old days as to how to install
radios these days. "If it worked then it should work now". And it
would if you were to limit yourself to 2 mhz!

Looking at steel ships and how it is done on them is irrelevant. On a
large steel ship the whole thing is ground as far as the antenna is
concerned. You can put the tuner anywhere you want to and you will not
be bothered with ground currents in other conductors.

The antenna starts at ground no matter where the tuner is mounted,
whether you like it or not.
Remember, If it isn't ground then it is antenna.

More than I was going to say. You are probably bored long ago.

Regards
Gary

Gary-
The ideas that you are advancing may work...however they absolutely fly in
the face of all conventional wisdom wrt installing an end fed antenna system
on a non-steel boat using a modern antenna coupler/tuner. I have not
personally tried what you are proposing, but I have personally installed
many dozens of systems using the more conventional methods that are reported
in the literature and...these methods work...5 by 9 reports first crack out
of the box.

Do not misunderstand me, I am simply stating that installing the
coupler/tuner as close as possible to the feed point of either a shipboard
vertical or an insulated backstay, when the other half of the system is a
modest counterpoise, yields very satisfactory results.

Do you have any actual results from a system where the coupler/tuner where
positioned close to the counterpoise? If you do, and you achieved good
signal reports, than maybe the actual position of a coupler/tuner is
irreverent.

73-
Charlie
KS4VB

Gary-
The ideas that you are advancing may work...however they absolutely fly in
the face of all conventional wisdom wrt installing an end fed antenna system
on a non-steel boat using a modern antenna coupler/tuner. I have not
personally tried what you are proposing, but I have personally installed
many dozens of systems using the more conventional methods that are reported
in the literature and...these methods work...5 by 9 reports first crack out
of the box.

Do not misunderstand me, I am simply stating that installing the
coupler/tuner as close as possible to the feed point of either a shipboard
vertical or an insulated backstay, when the other half of the system is a
modest counterpoise, yields very satisfactory results.

Do you have any actual results from a system where the coupler/tuner where
positioned close to the counterpoise? If you do, and you achieved good
signal reports, than maybe the actual position of a coupler/tuner is
irreverent.

73-
Charlie
KS4VB

Make that irrelevant not irreverent... ;-)

"Charlie J" wrote in message
...
Gary-
The ideas that you are advancing may work...however they absolutely fly in
the face of all conventional wisdom wrt installing an end fed antenna
system
on a non-steel boat using a modern antenna coupler/tuner. I have not
personally tried what you are proposing, but I have personally installed
many dozens of systems using the more conventional methods that are
reported
in the literature and...these methods work...5 by 9 reports first crack
out
of the box.

Do not misunderstand me, I am simply stating that installing the
coupler/tuner as close as possible to the feed point of either a shipboard
vertical or an insulated backstay, when the other half of the system is a
modest counterpoise, yields very satisfactory results.

Do you have any actual results from a system where the coupler/tuner where
positioned close to the counterpoise? If you do, and you achieved good
signal reports, than maybe the actual position of a coupler/tuner is
irreverent.

73-
Charlie
KS4VB

"Charlie J" wrote in message
...
Gary-
The ideas that you are advancing may work...however they absolutely fly in
the face of all conventional wisdom wrt installing an end fed antenna
system
on a non-steel boat using a modern antenna coupler/tuner. ....

You're both right. Manufacturers of land-based vertical HF antennas (eg
Butternut) mount the radiator very close to the ground (ie, inches) with
radials to properly couple it's image to the soil. The same would be true
of HF verticals on boats were it not for the problem of waves. Ideally, the
ground terminal of the antenna would be touching the water and the antenna
attached to its top, sort of like a "bugcatcher" but we instead have to put
the bottom of the radiator undesireably high to keep it from being
periodically drown - and that's where the compromises begin. These
compromises work, some amazingly well.

Conventional wisdom puts the antenna as high as possible. That's because
most boaters and their tech's are used to VHF, which propagates line of
sight, and thus needs height for max range. But HF is a different beast. It
propagates by ground wave, NVIS and ducting so HF antenna height doesn't
really matter. But don't say that here!! Half the "experts" here believe
that electrons have no mass or inertia (c:

Regards, K3DWW

In article ,
"Charlie J" wrote:

Gary-
The ideas that you are advancing may work...however they absolutely fly in
the face of all conventional wisdom wrt installing an end fed antenna system
on a non-steel boat using a modern antenna coupler/tuner. I have not
personally tried what you are proposing, but I have personally installed
many dozens of systems using the more conventional methods that are reported
in the literature and...these methods work...5 by 9 reports first crack out
of the box.

Do not misunderstand me, I am simply stating that installing the
coupler/tuner as close as possible to the feed point of either a shipboard
vertical or an insulated backstay, when the other half of the system is a
modest counterpoise, yields very satisfactory results.

Do you have any actual results from a system where the coupler/tuner where
positioned close to the counterpoise? If you do, and you achieved good
signal reports, than maybe the actual position of a coupler/tuner is
irreverent.

73-
Charlie
KS4VB

Charlie,
What you say above, does not constitute any real objective
information about the operation of an "End Feed Wire Antenna System.
First off, Gary is ABSOLUTLY Right on everything he stated in the
Post. All one has to do is go back to the days of Marine Radio
Design and Installation BEFORE autotuners came into the picture.
Now maybe your experience doesn't go back that far, but back when
it took a REAL Marine Radio Tech, to install and tune a Marine
Radio System aboard a vessel, and there were a bunch of BASIC Rules
for getting a System to work RELIABLY on multiple frequencies,
when connected to a single Endfeed Wire Antenna. Gary laid them out
very well. Now that we have Autotuners, it doesn't take a REAL
Marine Radio Tech to install the system, but it does take following
the RULES in order to make the System RELIABLE on multiple frequencies
when feeding a single antenna. Ever wonder why there are multile
MF and HF Antennas on Large Ships? Why would one need more than one
antenna if things are as easy as you seem to imply? And this on Metal
Hulled Large Ships, where ground isn't the problem.
Just because you got a 5-9 from your first contact doesn't mean
SQUAT, about how well your antenna/ground system is working. If
the band is open for that distance at that frequency, a "Wet Noodle"
would allow for the recived signal report. I've received Good Signal
Reports from KMI in California, while testing SOLAS Required System
in harbors in Alaska, with the radio connected to a Dummy Load.
That type of eveidence is not meaningful.
The Laws of Physics haven't changed since Autotuners were invented.
The same BASIC Rules still apply to Installation and operation of Marine
Radio Systems. The only thing that has changed is that the installer no
longer has to sit for a couple of hours trying to get a BAD Rf Ground
System to tune a marginally installed Endfeed Wire Antenna across the MF
& HF Marine Radio Channels. With Autotuners, all the installer needs to
see is the TUNED Annuciator come up on the Radio Display, and he
considers himself Done. What he doesn't see, is exactly how the
autotuner has decided to actually tune the antenna it is hooked to, and
where the Rf Energy is going now that the tuner says that it is done.
If you had ever done any REAL Testing of Autotuners, you would know
their very REAL Limitations on what they can tune for, and what drives
them to find the equivelent of a Dummy Load, as the TUNED condition.
I have spent many hours doing testing of autotuners for SEA. (now
defunkt) I have worked with the two guys who designed, built, and tested
ALL of the SEA SSB Radio's they ever built including a number that were
never marketed. We all worked at Northern Radio Company, back in the
70's when Marine Radio, and MF/HF Point to Point Systems were the Primary
Communications Links in the State of Alaska.
What you don't understand is that your "Conventinal Wisdom" comes
from a bunch of guys who have little or no REAL Experience in Marine
Radio Technology, but have installed a few radios on a few small vessels
and have been able to communicate with them to some degree or another.
Guy's like Gordie West and that ilk. Their "Convertinal Wisdom" has
always been suspect, by the Professional Techs, who actually do go out
in the REAL world and keep Mariners communicating 24/7 no matter if the
band is open or not, and not just for the "Weekend Worrior's" in their
Plastic Hulled boats.

Bruce in alaska
--
add a 2 before @

In article ,
"Vito" wrote:

You're both right.

Well not really. There is a "Giant Difference" between Land Based HF and
MF Rf Ground systems and those that can be constructed aboard ANY Vessel.
Radials in a Land Based Antenna System aren't designed to "properly
couple it's image to the soil." They are to provide that image for the
antenna system. The soil has very little to do with the Rf Gound System
in a conventional Marconi Antenna System. If it were otherwise one
would expect to see a lot more "Soil Remediation" going on around such
Antenna sites, like adding Salt to the area, or Chicken wire, bonded to
the radial system. Waves also really don't have a lot to do with
Antenna systemm in the Marine Enviorment.

"Conventional wisdom puts the antenna as high as possible."

Nope, not really. The antenna just needs to have sufficent length,
so as to be able to resonate at the Lowest Frequency, of desired
communications. Likely 2182.0 Khz for most folks. That would be a bit
longer that 75 Feet, for most common Endfeed Wire Antenna tuners built
since the early 70's. Now stringing 75 feet of wire and whip means
going up very high on most small vessels, and that is why "As High as
Possible" is the CV for MF systems.

Other than that, you are in the Ball Park.


Bruce in alaska
--
add a 2 before @

On Tue, 27 Jan 2004 04:03:24 GMT, "Charlie J"
wrote:

Gary-
The ideas that you are advancing may work...however they absolutely fly in
the face of all conventional wisdom wrt installing an end fed antenna system
on a non-steel boat using a modern antenna coupler/tuner. I have not
personally tried what you are proposing, but I have personally installed
many dozens of systems using the more conventional methods that are reported
in the literature and...these methods work...5 by 9 reports first crack out
of the box.

Do not misunderstand me, I am simply stating that installing the
coupler/tuner as close as possible to the feed point of either a shipboard
vertical or an insulated backstay, when the other half of the system is a
modest counterpoise, yields very satisfactory results.

Do you have any actual results from a system where the coupler/tuner where
positioned close to the counterpoise? If you do, and you achieved good
signal reports, than maybe the actual position of a coupler/tuner is
irreverent.

73-
Charlie
KS4VB



Placing the tuner at an elevated point above ground flies in the face
of common antenna theory.

The problem is that "modern antenna tuners" can make anybody a radio
technician. I say this with no disrespect to you Charlie.

You can hook them up to almost anything and they will "work".
I see time and again reports from people that say "I installed it and
was heard loud and clear". Yes this means that the radio does work.

Auto tuners have allowed many bad installations to get by on boats.
Just hook up a few wires and you are done. It will usually work in
some manor. And this is how most manufacturers want you to view it,
very simple to install and make work.

In years past I have seen guys install radios in the Ft Lauderdale
area and call WOM for a signal report. They would most always get a "5
9 report". That would be the end of the installation. It worked fine
as far as they were concerned. Never mind that the WOM receiving site
was only a few miles away from where the boat was.

You may have an excellent installation or a very marginal one. How do
you know. The radio is happy, the tuner tunes and you hear noise.

Comparisons with other boats near you talking to the same distant
stations is the real test.

If you want to get some indication of what different types of ground
systems do, place an RF ammeter in the antenna lead at the tuner. Note
the antenna current obtained and try different ground hookups. The
more current you can put into the antenna the better your system is.

The tuner is going to tune just about anywhere you install it. How
efficient the system is another story.

The other big factor in where the tuner is located is determines how
much RF is introduced into other things on the boat via the ground
connections.

Regards
Gary

"Bruce in Alaska" wrote

Well not really. There is a "Giant Difference" between Land Based HF and
MF Rf Ground systems and those that can be constructed aboard ANY Vessel.

Yes

Radials in a Land Based Antenna System aren't designed to "properly
couple it's image to the soil." They are to provide that image for the
antenna system. The soil has very little to do with the Rf Gound System
in a conventional Marconi Antenna System. If it were otherwise one
would expect to see a lot more "Soil Remediation" going on around such
Antenna sites, like adding Salt to the area, or Chicken wire, bonded to
the radial system.

On the contrary. They (buried radials) provide coupling. The soil itself
provides the image. That's why there is, in fact, a lot of "Soil
Remediation" - like adding salts and chicken wire and grin even radials.

Waves also really don't have a lot to do with Antenna system in the Marine
Enviorment.

Unless they put the bottom xx feet of the antenna under water (c:


"Conventional wisdom puts the antenna as high as possible."

Nope, not really. The antenna just needs to have sufficent length,....

Trouble is few boat owners or installation techs understand what you are
saying. They believe higher is better as a matter of faith. Thus .....

Bruce-
I have read your many posts with interest and respect your experience and
your opinion. I have also observed that respecting others' opinions and
experience is something you have a hard time doing. Rather than beat on
your chest and berate all of those that did not have your exact career path
as being somehow inferior...reread what I was trying to clarify in my
original post.

Gary was proposing a significant departure from "conventional wisdom" in
recommending the placement of the antenna coupler/tuner closer to the
counterpoise/rf ground than is conventionally done. I asked if there was
any objective evidence that showed that placing the antenna coupler/tuner
immediately adjacent to the counterpoise half of the antenna system truly
offered measurable improvement, on a non-metal pleasure boat... today.

I thought this was a forum for discussion...not a competition.

73-
Charlie
KS4VB