In article ,
"TomS" wrote:

1. Does anybody have experience on making a SSB ground system on a carbon
fibre hull?
2. Has anyone used sheets of metal (stainless stainless or copper) glued to
the inside of the hull instead of laminating copper starps to the hull?
Dynaplates or similar can not be used due to the drag that they create,
neither can they be recessed into the hull as cutting in to the hull is not
an option due to directinal fibres in the hull.

My idea is to use 4pcs of 30cm by 50cm 0,5mm thick AISI316 plates glued to
the inside of the hull as groundplane. Any ideas or experience?

In theory the hull could be my ground plane, as carbon is a pretty good
conductor, but dont know..?!

How does carbon fibre work as a dielectric? Just wondering how the
capacitive coupling would work.

Regards, and Merry Christmas to you all
TomS



It is SURFACE AREA of your conducting RF Ground system, and dielectric
distance to the water, that matters. What is the conductance of your
Carbonfiber hull? Is it anywhere near that of steel? If so then
your looking at the same as having a metal hull. If not, then figure
your hull is the same as fiberglass or wood.

Bruce n alaska
--
add a 2 before @

TomS wrote:

1. Does anybody have experience on making a SSB ground system on a carbon
fibre hull?
2. Has anyone used sheets of metal (stainless stainless or copper) glued to
the inside of the hull instead of laminating copper starps to the hull?
Dynaplates or similar can not be used due to the drag that they create,
neither can they be recessed into the hull as cutting in to the hull is not
an option due to directinal fibres in the hull.

My idea is to use 4pcs of 30cm by 50cm 0,5mm thick AISI316 plates glued to
the inside of the hull as groundplane. Any ideas or experience?

In theory the hull could be my ground plane, as carbon is a pretty good
conductor, but dont know..?!

How does carbon fibre work as a dielectric? Just wondering how the
capacitive coupling would work.

Regards, and Merry Christmas to you all
TomS



Consider using lifelines and pulpits for your "ground". Insulate
them all around. The hull is an insulator, so they are likely
insulated already. Test it. Some fear electrocution if the shrouds
or mast are live, connected to the backstay / antenna element at the
masthead. You could loft an insulator on the backstay. Try it
uninsulated first, or later. A sheath of garden hose would protect
deck apes from radio burns. You could test for danger, but I suspect
you would search frequencies for a long time to find a dangerous
tickle.

Worked for me on C.B.

I doubt anyone will gaurantee much improvement in radio range by
papering the hull with tinfoil or mesh or even plate for use as an
"Earth Ground," whatever. A full length insulated antenna element in
the bilge might do well as a radio counterbalance for the "official"
antenna feed. The battery ground leads to the radio, and elsewhere
beyond the battery probably also figure as part of the antenna array.

You want counterpoise, not neccessarily a radio ground. There is
really no such thing as a long range radio ground. Consider a
metallic bootstripe, keelson or heavy aluminium foil tape bonded
just under the hull deck joint. The sea ground, keel or plate, may,
but shouldn't affect local radio noise interference. You will want
one for a lightning protection ground, and could test to see. If it
works good, couple to it with a .01 micro Farad high voltage
capacitor. More alternatives exist.

Only a properly oriented and phased antenna array will improve
propogational efficiency.

You need a low resistance connection to the sea for lightning
dissapation. Are you using a carbon fibre mast? Conductive shrouds?
Conductive elements in mast, like a VHF antenna coax, lights, wind
instruments, or better?

Reduce radio noise at it's source, usually the alternator and video
devices, even flourescent tubes and depth sounders, anything with a
processor or diode in it. You will probably never eliminate it all.

You should not consider antennae or rig without regard for lightning.

Nor should you ignore galvanic corrosion. It is only enabled when
connections exist between dissimilar parts immersed in the sea. Do
not automatically connect all metal parts.

Terry K

"Bruce in Alaska" wrote
"TomS" wrote:

1. Does anybody have experience on making a SSB ground system on a
carbon
fibre hull?
2. Has anyone used sheets of metal (stainless stainless or copper) glued
to
the inside of the hull instead of laminating copper starps to the hull?
Dynaplates or similar can not be used due to the drag that they create,
neither can they be recessed into the hull as cutting in to the hull is
not
an option due to directinal fibres in the hull.

My idea is to use 4pcs of 30cm by 50cm 0,5mm thick AISI316 plates glued
to
the inside of the hull as groundplane. Any ideas or experience?

In theory the hull could be my ground plane, as carbon is a pretty good
conductor, but dont know..?!

How does carbon fibre work as a dielectric? Just wondering how the
capacitive coupling would work.

Regards, and Merry Christmas to you all
TomS



It is SURFACE AREA of your conducting RF Ground system, and dielectric
distance to the water, that matters. What is the conductance of your
Carbonfiber hull? Is it anywhere near that of steel? If so then
your looking at the same as having a metal hull. If not, then figure
your hull is the same as fiberglass or wood.

Bruce n alaska
--
add a 2 before @

Excerpts from the National Lightning Safety Institute on Carbon Fiber
Compounds:
--
For carbon fiber compounds (CFC) the resistance is up to 1000 times greater
than that of metal. Ohmic heat becomes important; and the arc heat is also
higher because the burning voltage is higher due to carbon contamination.
Conditions are also different because CFC has properties (for example,
electrical and thermal conductivity and coefficient of thermal expansion)
which are different for the long-fiber and cross-fiber directions. Arc root
damage to CFC usually is manifest in the "tufting" of the fibers due to
vaporization of the resin matrix and delamination due to inter-lamina stress
resulting from differential expansion.

For dielectric materials there is no arc attachment, but punctures may occur
through high voltage breakdown. If the arc root parameters are insufficient
to cause the melting of metallic skins or burn through damage to CFC panels,
a hotspot still will be formed on the under surface
--
Pretty clear that a plate on the *inside* of the hull could be catastrophic
in the event of a lightning strike. That leaves the keel for a best location
of through-hull grounding electrode conductor. The mast would be stepped on
a bonded copper plate that uses heavy copper or aluminum cable to make
sea-contact through some nearby point in the keel where a dyna-plate can be
smoothed-in and eliminate drag as an issue.

Jack Painter
Virginia Beach, VA

1. Does anybody have experience on making a SSB ground system on a carbon
fibre hull?
2. Has anyone used sheets of metal (stainless stainless or copper) glued to
the inside of the hull instead of laminating copper starps to the hull?
Dynaplates or similar can not be used due to the drag that they create,
neither can they be recessed into the hull as cutting in to the hull is not
an option due to directinal fibres in the hull.

My idea is to use 4pcs of 30cm by 50cm 0,5mm thick AISI316 plates glued to
the inside of the hull as groundplane. Any ideas or experience?

In theory the hull could be my ground plane, as carbon is a pretty good
conductor, but dont know..?!

How does carbon fibre work as a dielectric? Just wondering how the
capacitive coupling would work.

Regards, and Merry Christmas to you all
TomS

Tom, what frequencies do you intend to operate, and what
ranges are you looking at?

Chuck

TomS wrote:
1. Does anybody have experience on making a SSB ground system on a carbon
fibre hull?
2. Has anyone used sheets of metal (stainless stainless or copper) glued to
the inside of the hull instead of laminating copper starps to the hull?
Dynaplates or similar can not be used due to the drag that they create,
neither can they be recessed into the hull as cutting in to the hull is not
an option due to directinal fibres in the hull.

My idea is to use 4pcs of 30cm by 50cm 0,5mm thick AISI316 plates glued to
the inside of the hull as groundplane. Any ideas or experience?

In theory the hull could be my ground plane, as carbon is a pretty good
conductor, but dont know..?!

How does carbon fibre work as a dielectric? Just wondering how the
capacitive coupling would work.

Regards, and Merry Christmas to you all
TomS

I used 1/2" copper tubing the ridged type and peen the ends
together and ran them along the keel up next to the hull and
connected them at the stern with a brass bolt and connected
the ground to it. It worked great.
"chuck" wrote in message
...
Tom, what frequencies do you intend to operate, and what
ranges are you looking at?

Chuck

TomS wrote:
1. Does anybody have experience on making a SSB ground
system on a carbon
fibre hull?
2. Has anyone used sheets of metal (stainless stainless or
copper) glued to
the inside of the hull instead of laminating copper starps
to the hull?
Dynaplates or similar can not be used due to the drag that
they create,
neither can they be recessed into the hull as cutting in
to the hull is not
an option due to directinal fibres in the hull.

My idea is to use 4pcs of 30cm by 50cm 0,5mm thick AISI316
plates glued to
the inside of the hull as groundplane. Any ideas or
experience?

In theory the hull could be my ground plane, as carbon is
a pretty good
conductor, but dont know..?!

How does carbon fibre work as a dielectric? Just wondering
how the
capacitive coupling would work.

Regards, and Merry Christmas to you all
TomS