In article .com,
"Skip Gundlach" wrote:

As further background, we have full rails, with the gates combined
electrically with brass straps belowdecks, attached to the arch, the
pushpit and pulpit. We have about 110 lineal feet of 1" SS tube rail,
unless you count the inner rails, plus the arch. In addition we have
the standard 4" copper strapping leading to a sintered bronze Guest
plane below the boat, and also connected to a 3x5' plate under the
workbench top. I think we have a reasonably good ground.

You will never know if you have a "reasonably good ground", unless
you get yourself an Impedance Bridge, and check it at the frequencies
that you commonly work. Anything that is more than 12" away from the
water, isn't going to add "diddley-squat" toward building a Low Impedance
Wideband RF Ground System, and anyone who tells you otherwise, is just as
uneducated about MF/HF Marine Radio Antenna Systems, as you seem to be.
I have seen all kinds of Systems that looked very impresive, untill they
were evaluated with real insurmentation. 400 Sq Ft of Copper Screen in
the Cabin Overhead was proffered, as a really good RF Ground, by a well
known Boat Builder, 20 years ago. It didn't work any better than
having nothing at all, when tested, in a real radio enviorment. If
you got a Plastic Hull, you are NEVER going to get a Real RF Ground,
UNLESS the hull builder was smart, (they never are) and put 200+ Sq
Ft of screen under the gellcoat down by the keel. Cellulose hulls
are just as bad, and harder to retrofit that Plastic ones.
Like I said in my first reply, Autotuners were invented to allow any
"Dufus" to think he install an MF/HF Marine Radio System, and save
himself all that money he would have paid a Compitant Radioman.
SGC Autotuners are some of the worst of the lot, even if they did steal
the design from the real inventers. SGC couldn't even copy the design
correctly, and "Old PeeAir" couldn't design his way out of a "Wet Paper
Bag".

Me

On Sat, 30 Jul 2005 06:12:33 GMT, Me wrote:

In article .com,
"Skip Gundlach" wrote:

As further background, we have full rails, with the gates combined
electrically with brass straps belowdecks, attached to the arch, the
pushpit and pulpit. We have about 110 lineal feet of 1" SS tube rail,
unless you count the inner rails, plus the arch. In addition we have
the standard 4" copper strapping leading to a sintered bronze Guest
plane below the boat, and also connected to a 3x5' plate under the
workbench top. I think we have a reasonably good ground.

You will never know if you have a "reasonably good ground", unless
you get yourself an Impedance Bridge, and check it at the frequencies
that you commonly work. Anything that is more than 12" away from the
water, isn't going to add "diddley-squat" toward building a Low Impedance
Wideband RF Ground System, /// If
you got a Plastic Hull, you are NEVER going to get a Real RF Ground,
UNLESS the hull builder was smart, (they never are) and put 200+ Sq
Ft of screen under the gellcoat down by the keel. Cellulose hulls
are just as bad, and harder to retrofit that Plastic ones.
Like I said in my first reply, Autotuners were invented to allow any
"Dufus" to think he install an MF/HF Marine Radio System, and save
himself all that money he would have paid a Compitant Radioman.////
Me


Hehe...why don't you tell us what you really think, anonymous poster?

If it takes 200 sq ft of screen under a gel coat to make a good RF
ground, then folks who attempt a similar feat through a hull would
need about 0.5 / 0.05 X 200 sq ft of material - That's 2000 sq ft of
foil or metal mesh (for a 0.05 in gelcoat, and a mere 0.5 inch hull
thickness)

Now THAT would be quite a trick - a square about 100 ft by 20 ft.
Better not tell the folks who use an antenna coupled through a 1/4
inch glass shield - a coupler that can measure 1.5 inch square.
Admitted, this is often for FM radio (say 90 MHz) as opposed to
3MHz (?) on hf. Using these numbers for comparison,
90/3 X 0.5/0.25 X 2.25 sq in = 135 sq in of ground plane, hmmmm that's
1 sq foot in round numbers. Now that *does* look small to me.

I expect the truth lies somewhere between 1 sq ft and 2000 sq ft.
through a half inch hull section. There! How mealy-mouthed is THAT!
:-)

OK, let's get serious: how about locating a bronze through hull,
and connecting a copper foil externally in contact with it.
a square foot THERE, connected internally with good Litz wire might
make a serviceable ground....

Brian Whatcott Altus
p.s A hint for you: talking about "compitant radiomen" makes
prospective customers nervous! :-)

In article ,
Brian Whatcott wrote:

Hehe...why don't you tell us what you really think, anonymous poster?

If it takes 200 sq ft of screen under a gel coat to make a good RF
ground, then folks who attempt a similar feat through a hull would
need about 0.5 / 0.05 X 200 sq ft of material - That's 2000 sq ft of
foil or metal mesh (for a 0.05 in gelcoat, and a mere 0.5 inch hull
thickness)

Now THAT would be quite a trick - a square about 100 ft by 20 ft.
Better not tell the folks who use an antenna coupled through a 1/4
inch glass shield - a coupler that can measure 1.5 inch square.
Admitted, this is often for FM radio (say 90 MHz) as opposed to
3MHz (?) on hf. Using these numbers for comparison,
90/3 X 0.5/0.25 X 2.25 sq in = 135 sq in of ground plane, hmmmm that's
1 sq foot in round numbers. Now that *does* look small to me.

I expect the truth lies somewhere between 1 sq ft and 2000 sq ft.
through a half inch hull section. There! How mealy-mouthed is THAT!
:-)

OK, let's get serious: how about locating a bronze through hull,
and connecting a copper foil externally in contact with it.
a square foot THERE, connected internally with good Litz wire might
make a serviceable ground....

Brian Whatcott Altus
p.s A hint for you: talking about "compitant radiomen" makes
prospective customers nervous! :-)

Nice thought Brian.... However what you seem to forget is that
capacative couping at RF Frequencies, is determined by three things.
1. Area of the Inside the hull Plate.
2. Distance between the two Plates.
3. Conductivity of the Sea Water Plate.

A 200 Sq Ft Screen in the cabin overhead isn't near (Orders of magnitude)
big enough to be an RF Ground for a MF/HF Antenna System, by itself.
Being located far (relative in capactive terms) from the other plate
(Salt water) means that the Rf couping into the water is what, can you
guess? Less than a few Picofarads. Now calculate the RF Impedance for
such a system at ANY, and All MF/HF Marine Frequencies that you like to
use, if you have enough computer power in your supercomputer. then come
back and explain it all to the rest of the world.


Me

On Sat, 30 Jul 2005 19:58:46 GMT, Me wrote:

In article ,
Brian Whatcott wrote:

Hehe...why don't you tell us what you really think, anonymous poster?

If it takes 200 sq ft of screen under a gel coat to make a good RF
ground, then folks who attempt a similar feat through a hull would
need about 0.5 / 0.05 X 200 sq ft of material - That's 2000 sq ft of
foil or metal mesh (for a 0.05 in gelcoat, and a mere 0.5 inch hull
thickness)

Now THAT would be quite a trick - a square about 100 ft by 20 ft.
Better not tell the folks who use an antenna coupled through a 1/4
inch glass shield - a coupler that can measure 1.5 inch square.
Admitted, this is often for FM radio (say 90 MHz) as opposed to
3MHz (?) on hf. Using these numbers for comparison,
90/3 X 0.5/0.25 X 2.25 sq in = 135 sq in of ground plane, hmmmm that's
1 sq foot in round numbers. Now that *does* look small to me.

I expect the truth lies somewhere between 1 sq ft and 2000 sq ft.
through a half inch hull section. There! How mealy-mouthed is THAT!
:-)

OK, let's get serious: how about locating a bronze through hull,
and connecting a copper foil externally in contact with it.
a square foot THERE, connected internally with good Litz wire might
make a serviceable ground....

Brian Whatcott Altus
p.s A hint for you: talking about "compitant radiomen" makes
prospective customers nervous! :-)

Nice thought Brian.... However what you seem to forget is that
capacative couping at RF Frequencies, is determined by three things.
1. Area of the Inside the hull Plate.
2. Distance between the two Plates.
3. Conductivity of the Sea Water Plate.

A 200 Sq Ft Screen in the cabin overhead isn't near (Orders of magnitude)
big enough to be an RF Ground for a MF/HF Antenna System, by itself.
Being located far (relative in capactive terms) from the other plate
(Salt water) means that the Rf couping into the water is what, can you
guess? Less than a few Picofarads. Now calculate the RF Impedance for
such a system at ANY, and All MF/HF Marine Frequencies that you like to
use, if you have enough computer power in your supercomputer. then come
back and explain it all to the rest of the world.


Me

Oh my! Anonymous poster, it was *YOUR* suggestion that an RF ground
of 200 sq ft of mesh under the (external hull) gel-coat was required
for a satisfactory RF ground at HF.

It was the original poster's suggestion of an elevated mesh that
caught your interest, not mine.

As you asked about antenna testing, I should mention that
a supercomputer is not really necessary: there is a handy dandy
gadget ( from MFJ ) which combines several RF test functions like
antenna bridge, SW ratio etc. It ran about $200 as I recall. I
satisfy myself with an LC meter these days - which gets one into the
ball park at $100.
eBay has an MFJ noise bridge at $25 currently.


Hmmm...the capacitance to ground of a few objects in my vicinity runs
about 45 pF per sq ft. Like me, standing on carpet It is just
possible a hi level ground screen of 200 sq ft might get you 200 X 45
pF = 9000 pF

At 3 MHz that would put the capacitive reactance at
1/2pi.f.C ohms = 6 ohms. Not that great. The actual value might
well be quite a bit higher than that.
But that's just me measuring with an instrument, rather than you
guessing how poor it is.
Another thing: the conductivity of sea water does not vary all that
much - it doesn't have much impact on capacitance. But there I go
again, actually measuring things!

Regards

Brian Whatcott
p.s. I have an FCC GROL+rdr. You?

In article ,
Brian Whatcott wrote:

Oh my! Anonymous poster, it was *YOUR* suggestion that an RF ground
of 200 sq ft of mesh under the (external hull) gel-coat was required
for a satisfactory RF ground at HF.

It was the original poster's suggestion of an elevated mesh that
caught your interest, not mine.

As you asked about antenna testing, I should mention that
a supercomputer is not really necessary: there is a handy dandy
gadget ( from MFJ ) which combines several RF test functions like
antenna bridge, SW ratio etc. It ran about $200 as I recall. I
satisfy myself with an LC meter these days - which gets one into the
ball park at $100.
eBay has an MFJ noise bridge at $25 currently.


Hmmm...the capacitance to ground of a few objects in my vicinity runs
about 45 pF per sq ft. Like me, standing on carpet It is just
possible a hi level ground screen of 200 sq ft might get you 200 X 45
pF = 9000 pF

At 3 MHz that would put the capacitive reactance at
1/2pi.f.C ohms = 6 ohms. Not that great. The actual value might
well be quite a bit higher than that.
But that's just me measuring with an instrument, rather than you
guessing how poor it is.
Another thing: the conductivity of sea water does not vary all that
much - it doesn't have much impact on capacitance. But there I go
again, actually measuring things!

Regards

Brian Whatcott
p.s. I have an FCC GROL+rdr. You?

I am not so "Anonymous" as you would think. There are, certainly, folks
who know who "Me" really is. Some even post here.

I didn't "Say or State" that the above WAS required. I stated that "200
sq ft" would certainly provide a "Low Impedance Wideband RF Ground, on
plastic hulled vessles floating in Salt Water." I also introduced the
discreditied concept of "copper screen in the overhead" into the thread,
if you would go back and actually read the whole thread.

Your testing tools seem to be of the consumer variety. Some one should
teach you a bit about modern RF Antenna Design & Testing Tools, one of
these days. Most compitant folks use both RF Network Analysers, and, or
an Antenna Impedance Bridge feeding a Spectrum Analyser with a Tracking
Sweep Generator. Best you come back after you learn to use the tools,
that "the Big Boys" use.

It is just possible that you don't have much of a clue about MF/HF
Marine Antenna Systems and RF Grounds aboard Vessles.

The above statement about some mythical capacitive reactance at 3 Mhz
really shows that your way out of your league in this dicussion. There
are few 3 Mhz Marine Frequencies, (Mostly in alaskan waters) and most
non-commercial MF/HF Marine Radio Users rarely use any below the Maritime
Mobile 4 Mhz Band. There are many 1.6Mhz, 2.0 - 3.3 Mhz, Marine
Frequnecies used in alaska, by commerical users, and a daily basis, and
have been for many years. When was the last time you actually operated,
or for that matter installed, a Private Coast Station, using any
frequency at all, or for that matter any Maritime Mobile Station of any
kind. I operate a Private Coast/ Alaska Public Fixed Station, on a
daily basis, that I designed and installed 20 years ago, and communicate
with vessels all over the North Pacific. Tell us all, about your great
experience in Marine Communications.

The conductivity of Seawater isn't in dispute in this thread on it's
own, what is in dispute seems to be how it compares to fresh water, RF
Grounds used in MF Commercial Radio Stations, and other mediums. What
you fail to understand is that capacative coupling to SeaWater is
extremely Frequency Sensitive, and to design an effective Low Impedance,
"Wideband" RF Ground on a plastic, or cellulose hulled vessel, requires
a very effective coupling to the Seawater over a Wide Frequency Range.
That is the crucks of the problem.

Again, "It is the RF Ground, sonny, the RF Ground"...


Me 1st Class RadioTelegraph, with Seatime Endorsement, Radar
Endorsement, and, wait for it.... Aircraft Endorsement...

On Mon, 01 Aug 2005 20:23:23 GMT,
the not so anonymous Me wrote:
///
Most compitant folks use both RF Network Analysers
///
Me

Whatever you say, Me....

Actually, I am getting this vast sense of relief, that the big boys
are throwing a little abuse my way. I was feeling *so* left out.

:-)

Brian W

"Me" wrote:

There are few 3 Mhz Marine Frequencies, (Mostly in alaskan waters)
and most non-commercial MF/HF Marine Radio Users rarely use any below
the Maritime Mobile 4 Mhz Band.

I don't claim to be any sort of expert, but on the radio course I took, we
learned that 2182 kHz is "the international distress, safety and calling
frequency for radiotelephony". As far as I can see that is well below 4MHz,
and commonly used even outside Alaska.

-Heikki

You seem to be saying that sea water (which is one heck of a lot less
conductive than copper -- I mean orders of magnitude less conductive) is
the only rf ground (return path) that works? And that the only way to
utilize it in a fiberglass hull is with capacitive coupling?

By your reasoning, radio communication from a vessel on fresh water is
impossible.

Or, as a corollary, radio communication from a vessel on the hard is
impossible because the capacitive coupling to the sea is over a distance
of more than 12".

And of course, for VHF, we all use the equivalent of copper that is not
capacitively coupled to the sea. Since we all agree that VHF works fine
that way, can you tell us at what frequency the laws of electromagnetic
radiation "jump ship" and no longer work the same as at VHF? A reference
would be most welcome. The issue here is radiation, not propagation.

Can you also provide a reference to the published and repeatable testing
of 400 sq. ft. of copper ground that didn't work any better than having
nothing at all? Radio stations thousands of miles from the sea would be
amazed to learn that their ground systems don't work better than nothing
at all.

Why not post your theory on rec.radio.amateur.antenna and see how it is
received there?

Suggest you reef those sails a tad, Me.

Chuck



Me wrote:
In article .com,
"Skip Gundlach" wrote:


As further background, we have full rails, with the gates combined
electrically with brass straps belowdecks, attached to the arch, the
pushpit and pulpit. We have about 110 lineal feet of 1" SS tube rail,
unless you count the inner rails, plus the arch. In addition we have
the standard 4" copper strapping leading to a sintered bronze Guest
plane below the boat, and also connected to a 3x5' plate under the
workbench top. I think we have a reasonably good ground.


You will never know if you have a "reasonably good ground", unless
you get yourself an Impedance Bridge, and check it at the frequencies
that you commonly work. Anything that is more than 12" away from the
water, isn't going to add "diddley-squat" toward building a Low Impedance
Wideband RF Ground System, and anyone who tells you otherwise, is just as
uneducated about MF/HF Marine Radio Antenna Systems, as you seem to be.
I have seen all kinds of Systems that looked very impresive, untill they
were evaluated with real insurmentation. 400 Sq Ft of Copper Screen in
the Cabin Overhead was proffered, as a really good RF Ground, by a well
known Boat Builder, 20 years ago. It didn't work any better than
having nothing at all, when tested, in a real radio enviorment. If
you got a Plastic Hull, you are NEVER going to get a Real RF Ground,
UNLESS the hull builder was smart, (they never are) and put 200+ Sq
Ft of screen under the gellcoat down by the keel. Cellulose hulls
are just as bad, and harder to retrofit that Plastic ones.
Like I said in my first reply, Autotuners were invented to allow any
"Dufus" to think he install an MF/HF Marine Radio System, and save
himself all that money he would have paid a Compitant Radioman.
SGC Autotuners are some of the worst of the lot, even if they did steal
the design from the real inventers. SGC couldn't even copy the design
correctly, and "Old PeeAir" couldn't design his way out of a "Wet Paper
Bag".

Me

When you talk of capacitive coupling, frequency does matter. (Xc =
1/[2*pi*F]) There's two orders of magnitude difference between HF at 1.8
MHz and VHF at 180 MHz.

"Ground" is one of those elusive concepts that get more magic/conundrum (aka
BS) than it deserves. A full dipole needs no ground. The whip or backstay
needs a ground plane so that its "virtual image" creates a full dipole.

Note that aircraft use HF communications with a half dipole antenna
(trailing wire) with no ground plane. Of course they do have an excellent
antenna height. (Don't hold the end in your fingers to test on the surface.
When your boss hits the transmit key, it hurts, for weeks.)

Antennae are magic.

Roger

http://home.earthlink.net/~derbyrm

"chuck" wrote in message
ink.net...
You seem to be saying that sea water (which is one heck of a lot less
conductive than copper -- I mean orders of magnitude less conductive) is
the only rf ground (return path) that works? And that the only way to
utilize it in a fiberglass hull is with capacitive coupling?

By your reasoning, radio communication from a vessel on fresh water is
impossible.

Or, as a corollary, radio communication from a vessel on the hard is
impossible because the capacitive coupling to the sea is over a distance
of more than 12".

And of course, for VHF, we all use the equivalent of copper that is not
capacitively coupled to the sea. Since we all agree that VHF works fine
that way, can you tell us at what frequency the laws of electromagnetic
radiation "jump ship" and no longer work the same as at VHF? A reference
would be most welcome. The issue here is radiation, not propagation.

Can you also provide a reference to the published and repeatable testing
of 400 sq. ft. of copper ground that didn't work any better than having
nothing at all? Radio stations thousands of miles from the sea would be
amazed to learn that their ground systems don't work better than nothing
at all.

Why not post your theory on rec.radio.amateur.antenna and see how it is
received there?

Suggest you reef those sails a tad, Me.

Chuck



Me wrote:
In article .com,
"Skip Gundlach" wrote:


As further background, we have full rails, with the gates combined
electrically with brass straps belowdecks, attached to the arch, the
pushpit and pulpit. We have about 110 lineal feet of 1" SS tube rail,
unless you count the inner rails, plus the arch. In addition we have
the standard 4" copper strapping leading to a sintered bronze Guest
plane below the boat, and also connected to a 3x5' plate under the
workbench top. I think we have a reasonably good ground.


You will never know if you have a "reasonably good ground", unless
you get yourself an Impedance Bridge, and check it at the frequencies
that you commonly work. Anything that is more than 12" away from the
water, isn't going to add "diddley-squat" toward building a Low Impedance
Wideband RF Ground System, and anyone who tells you otherwise, is just as
uneducated about MF/HF Marine Radio Antenna Systems, as you seem to be.
I have seen all kinds of Systems that looked very impresive, untill they
were evaluated with real insurmentation. 400 Sq Ft of Copper Screen in
the Cabin Overhead was proffered, as a really good RF Ground, by a well
known Boat Builder, 20 years ago. It didn't work any better than
having nothing at all, when tested, in a real radio enviorment. If
you got a Plastic Hull, you are NEVER going to get a Real RF Ground,
UNLESS the hull builder was smart, (they never are) and put 200+ Sq
Ft of screen under the gellcoat down by the keel. Cellulose hulls
are just as bad, and harder to retrofit that Plastic ones. Like I said
in my first reply, Autotuners were invented to allow any "Dufus" to think
he install an MF/HF Marine Radio System, and save himself all that money
he would have paid a Compitant Radioman.
SGC Autotuners are some of the worst of the lot, even if they did steal
the design from the real inventers. SGC couldn't even copy the design
correctly, and "Old PeeAir" couldn't design his way out of a "Wet Paper
Bag".

Me

Thanks for the comments, Roger.

While I don't disagree with what you have said (except that antennae are
magic), I don't believe your remarks touch on the issues here.

The typical marine VHF antenna, for example, does not depend upon the
sea for its operation. I am assuming the usual quarter-wave ground plane
vertical atop a mast. Do you believe that because VHF and HF antennas
involve different frequencies the underlying theory is different?

A backstay "vertical" antenna may or may not depend on the sea for its
return path. Me has unequivocally asserted that it always depends on the
sea and thus its ground must be coupled to the sea. (400 sq. ft. of
copper is no better than nothing at all he believes)

Conventional antenna theory suggests that a backstay "vertical" could
utilize a counterpoise or other return path element (like a horizontal
dipole half) with no coupling to the sea at all.

Me asserts this is false: that such an antenna will not work.

I attempted to present a "reductio ad absurdum" argument showing that if
Me is correct, his reasoning leads to absurd results. There is no magic
here.

I would be pleased to reconsider any of my comments if they appear
incorrect or incomprehensible.

Regards,

Chuck








Roger Derby wrote:
When you talk of capacitive coupling, frequency does matter. (Xc =
1/[2*pi*F]) There's two orders of magnitude difference between HF at 1.8
MHz and VHF at 180 MHz.

"Ground" is one of those elusive concepts that get more magic/conundrum (aka
BS) than it deserves. A full dipole needs no ground. The whip or backstay
needs a ground plane so that its "virtual image" creates a full dipole.

Note that aircraft use HF communications with a half dipole antenna
(trailing wire) with no ground plane. Of course they do have an excellent
antenna height. (Don't hold the end in your fingers to test on the surface.
When your boss hits the transmit key, it hurts, for weeks.)

Antennae are magic.

Roger

http://home.earthlink.net/~derbyrm

"chuck" wrote in message
ink.net...

You seem to be saying that sea water (which is one heck of a lot less
conductive than copper -- I mean orders of magnitude less conductive) is
the only rf ground (return path) that works? And that the only way to
utilize it in a fiberglass hull is with capacitive coupling?

By your reasoning, radio communication from a vessel on fresh water is
impossible.

Or, as a corollary, radio communication from a vessel on the hard is
impossible because the capacitive coupling to the sea is over a distance
of more than 12".

And of course, for VHF, we all use the equivalent of copper that is not
capacitively coupled to the sea. Since we all agree that VHF works fine
that way, can you tell us at what frequency the laws of electromagnetic
radiation "jump ship" and no longer work the same as at VHF? A reference
would be most welcome. The issue here is radiation, not propagation.

Can you also provide a reference to the published and repeatable testing
of 400 sq. ft. of copper ground that didn't work any better than having
nothing at all? Radio stations thousands of miles from the sea would be
amazed to learn that their ground systems don't work better than nothing
at all.

Why not post your theory on rec.radio.amateur.antenna and see how it is
received there?

Suggest you reef those sails a tad, Me.

Chuck



Me wrote:

In article .com,
"Skip Gundlach" wrote:



As further background, we have full rails, with the gates combined
electrically with brass straps belowdecks, attached to the arch, the
pushpit and pulpit. We have about 110 lineal feet of 1" SS tube rail,
unless you count the inner rails, plus the arch. In addition we have
the standard 4" copper strapping leading to a sintered bronze Guest
plane below the boat, and also connected to a 3x5' plate under the
workbench top. I think we have a reasonably good ground.


You will never know if you have a "reasonably good ground", unless
you get yourself an Impedance Bridge, and check it at the frequencies
that you commonly work. Anything that is more than 12" away from the
water, isn't going to add "diddley-squat" toward building a Low Impedance
Wideband RF Ground System, and anyone who tells you otherwise, is just as
uneducated about MF/HF Marine Radio Antenna Systems, as you seem to be.
I have seen all kinds of Systems that looked very impresive, untill they
were evaluated with real insurmentation. 400 Sq Ft of Copper Screen in
the Cabin Overhead was proffered, as a really good RF Ground, by a well
known Boat Builder, 20 years ago. It didn't work any better than
having nothing at all, when tested, in a real radio enviorment. If
you got a Plastic Hull, you are NEVER going to get a Real RF Ground,
UNLESS the hull builder was smart, (they never are) and put 200+ Sq
Ft of screen under the gellcoat down by the keel. Cellulose hulls
are just as bad, and harder to retrofit that Plastic ones. Like I said
in my first reply, Autotuners were invented to allow any "Dufus" to think
he install an MF/HF Marine Radio System, and save himself all that money
he would have paid a Compitant Radioman.
SGC Autotuners are some of the worst of the lot, even if they did steal
the design from the real inventers. SGC couldn't even copy the design
correctly, and "Old PeeAir" couldn't design his way out of a "Wet Paper
Bag".

Me