I want to install a ssb radio on my aluminium sailing yacht. The person who
installs the radio says that the grounding plate should be welded on the
inside of the hull. The hull is fully painted with anti fouling. He argues
that the high frequency connection to the see water is made through a
capacitor effect, the hull acting as a big capacitor, the water being the
other side and the antifouling in between is the isolator.

I hardly can believe that this works.

Is this true ?

Can this work ?

Has any one experience with SSB grounding on aluminium hulls.



Alfred

Alfred Bauer wrote:

I want to install a ssb radio on my aluminium sailing yacht. The person who
installs the radio says that the grounding plate should be welded on the
inside of the hull. The hull is fully painted with anti fouling. He argues
that the high frequency connection to the see water is made through a
capacitor effect, the hull acting as a big capacitor, the water being the
other side and the antifouling in between is the isolator.

I hardly can believe that this works.

Is this true ?

Can this work ?

Has any one experience with SSB grounding on aluminium hulls.



Alfred



It's true.

The insulating antifouling is working as a dielectric, with the sea
acting as the other pole of the capacitor.

A properly designed antenna does not rely on an earth connection,
except to provide a local reference against which remote and local
static may be compared and amplified.

A proper antenna has a + and a - terminal and provides a bifilar,
balanced signal, which is totally isolated from local static.

It's difficult to provide a proper balanced antenna at SSB
frequencies on most yachts, so all you can do is work the best
compromise for you. Hint: try a kite! I would even try a mashthead
towline for an outrigger / keel / float / antenna line, or two, one
on each side.

Terry K

Dutch compnay Shiptron has a clever devise to seperate the earth for
aluminium ships wanting to install a SSB tx.
A handy PDF (albeit in Dutch, but the images and diagrams speak for
themselves) can be downloaded from
http://www.shiptron.nl/docs/Lekstroomscheider.pdf
I don't have shares nor interest in this company.
Best regards,
Hielke
alu Habbeké "destination Zanzibar"

"Alfred Bauer" schreef in bericht
...
I want to install a ssb radio on my aluminium sailing yacht. The person
who installs the radio says that the grounding plate should be welded on
the inside of the hull. The hull is fully painted with anti fouling. He
argues that the high frequency connection to the see water is made through
a capacitor effect, the hull acting as a big capacitor, the water being the
other side and the antifouling in between is the isolator.

I hardly can believe that this works.

Is this true ?

Can this work ?

Has any one experience with SSB grounding on aluminium hulls.



Alfred

In article ,
"Alfred Bauer" wrote:

I want to install a ssb radio on my aluminium sailing yacht. The person who
installs the radio says that the grounding plate should be welded on the
inside of the hull. The hull is fully painted with anti fouling. He argues
that the high frequency connection to the see water is made through a
capacitor effect, the hull acting as a big capacitor, the water being the
other side and the antifouling in between is the isolator.

I hardly can believe that this works.

Is this true ?

Can this work ?

Has any one experience with SSB grounding on aluminium hulls.



Alfred



Yes, Alfred there is a Santa Clause,
and he does make MF and HF RF Grounding Systems, out of Metal Hulled
Vessels. You don't need a Grounding Plate welded anywhere on your
vessel, just attach the RF Grounding Stud on your Antenna Tuner,
directly to a point inside the hull, via the shortest possible length of
ground strap. Sounds like your installer has been around the waterfront
for a goodly length of time, and is familiar with MF/HF Antenna Systems,
and the RF Gounds to support them. His explination is "Right On", and
there aren't many Real RadioMen left out there on the docks anymore.
Most of the really good ones, are just about Retirement Age now, and
MF/HF Marine Radio is beginning to be a "Lost Art".


Bruce in alaska
--
add a 2 before @

"Alfred Bauer" wrote in
:

Is this true ?

Yes, he's right. You only need to bond the TUNER ground to the aluminum
hull the shortest way possible with the least bends. It's not DC or low
frequency AC. If anything gets near the hull that conducts, it will couple
the HF signal to it..especially sea water. With that aluminum hull, you
will be able to have a potent signal even if the boat is on blocks in the
parking lot. The tuner needs an RF ground, which is as simple as a 1/4
wavelength piece of wire laid out going nowhere. 1/4 wavelenght back from
the open end of that wire is an "artificial ground", also called a ground
plane. Your local AM radio station uses buried bridge cables that radiate
in all directions out from the base of the tower, which is itself the
antenna on AM radio, out 1/4 wavelength. They bury them so they don't get
tangled up in the lawn mower.


Can this work ?

Sure wish such a great ground were easy to get to in a fiberglass sailboat.
Our Icom M802's AT130 tuner is strapped to the engine block and uses the
boat's ground system from there. Works fine. I worked Japan on the ham
bands from Charleston, SC. That's about as far as you can get.


Has any one experience with SSB grounding on aluminium hulls.


You won't be on the air long enough or be running enough power when you are
to eat holes in the hull from the RF current of such a small transmitter.
A Canadian fishing trawler was being outfitted here as a pirate radio
station with a 70KW shortwave transmitter. The US government's FCC swept
down on them and confiscated everything before it got to sea. One problem
they didn't solve was the huge RF current from such a big transmitter into
the seawater was eating holes in the bottom of the steel boat! Their first
indication something bad was happening is when they got up for breakfast
one morning and the fresh water system was salt water....


--
Larry W4CSC

"Bruce in Alaska" wrote in message
...
Sounds like your installer has been around the waterfront
for a goodly length of time, and is familiar with MF/HF Antenna Systems,
and the RF Gounds to support them. His explination is "Right On", and
there aren't many Real RadioMen left out there on the docks anymore.
Most of the really good ones, are just about Retirement Age now, and
MF/HF Marine Radio is beginning to be a "Lost Art".


Bruce in alaska
--
Bruce
I can't collect SS retirement for another month. (There is no truth to the
rumor I crewed for Noah on the Ark either!)
73
Doug K7ABX (USN Retired)

"Doug" wrote in
ink.net:

(USN Retired)


Admiral Halsey?

--
Larry

You know you've had a rough night when you wake up and your outlined in
chalk.

In article . net,
"Doug" wrote:

"Bruce in Alaska" wrote in message
...
Sounds like your installer has been around the waterfront
for a goodly length of time, and is familiar with MF/HF Antenna Systems,
and the RF Gounds to support them. His explination is "Right On", and
there aren't many Real RadioMen left out there on the docks anymore.
Most of the really good ones, are just about Retirement Age now, and
MF/HF Marine Radio is beginning to be a "Lost Art".


Bruce in alaska
--
Bruce
I can't collect SS retirement for another month. (There is no truth to the
rumor I crewed for Noah on the Ark either!)
73
Doug K7ABX (USN Retired)



Well some of us did take "Early Retirement", but only because we could
and we also could see the "Handwritting on the wall".........


Bruce in alaska
--
add a 2 before @

Bruce in Alaska wrote:

snip
Well some of us did take "Early Retirement", but only because we could
and we also could see the "Handwritting on the wall".........


I'm like Doug (and we knew each other in the Navy), my early retirement
was from the Navy in 1990 and I started getting my SS at age 62 last year.

I worked from 1990 until 2001 but mostly at things that I wanted to do
and when I wanted to do them.

If you crunch the numbers on starting at 62 or waiting until 65 and
getting more money, it will take about 13 years for the increase at age
65 to make up the amount you would have already received if you had
started at 62. That means you are not "ahead" until you are 78. I
looked at the smaller amount sooner, thought about the actuarial tables
(i.e, the odds of still being alive at 78), and took mine at 62.

Retirement is lovely, I'm getting the best allowance I ever had! And
seven Saturdays a week is fun thing.

Jack


--
Jack Erbes in Ellsworth, Maine, USA - jackerbes at adelphia dot net
(also receiving email at jacker at midmaine.com)

Hello Alfred,

You've received some interesting comments. Let me toss an additional
consideration into the water. While it is true that RF will easily pass
through the capacitor formed by the hull and the seawater, I doubt that
it will matter much on a large aluminum vessel. The resistance (both RF
and DC) of your hull is probably orders of magnitude less than the
effective resistance of the seawater "ground" system around your
antenna. Seawater makes a better RF return path than dirt, but one that
is much poorer than aluminum. Moreover, I imagine that your hull may be
at least 40 ft in length. So not only is your hull a low-resistance
"ground" but it is a fairly efficient one as well.

As Larry pointed out, because of this, you will find that your SSB works
fine even when you are on land.

By all means, connect your tuner ground to the hull. It will definitely
not hurt and is likely to improve your SSB signal.

Good luck.

Chuck

Alfred Bauer wrote:
I want to install a ssb radio on my aluminium sailing yacht. The person who
installs the radio says that the grounding plate should be welded on the
inside of the hull. The hull is fully painted with anti fouling. He argues
that the high frequency connection to the see water is made through a
capacitor effect, the hull acting as a big capacitor, the water being the
other side and the antifouling in between is the isolator.

I hardly can believe that this works.

Is this true ?

Can this work ?

Has any one experience with SSB grounding on aluminium hulls.



Alfred