stainless steel foil instead of copper for grounding Ham radio?
 

Brian Whatcott wrote in
:

I have silver at 0.0159 microhm meter at 20 degC
copper 0.0168 microhm.meter
gold 0.022 microhm meter

So gold may not be not quite as conductive as the best, but it
STAYS
at that value - no tarnish....

Brian W



I wish you guys would worry much more about "series inductance"
and lots less about how expensive you can make the damned ground
strap.

Look at your ground strap and follow it down to whatever is
supposed to be "ground" on your boat.

1 - Are there any sharp corners or folds back over itself to make
it look really neat, like boaters love their stuff?

This is bad, very bad. Every sharp curve increases the series
inductance, and inductive reactance. If it bends 90 degrees, you
have a 1/4 turn coil in series, raising the ground at the tuner
MUCH more than the total combined resistance of all the metal
chemistry in the circuit, which increases with frequency.

All turns in the ground strap should be as large a diameter as
you can make it and very smooth to reduce series inductance. It
should be routed in as straight a line from the tuner to the
ground as you can make it, for this same reason. This strap is
PART of the antenna. It radiates like mad when you're on the
air, into the bilge wiring, the reason why the LEDs in the DC
panel all light up when you talk. They're detecting the RF
induced into those DC cables in the bilge.

Now, let's put away the periodic tables and go reroute the ground
straps, taking off all the pretty tywraps and making them as
straight as possible, shortening them as much as we can.

Larry W4CSC and other fine old calls since 1957
--
Bruce will be by to inspect your installation, shortly.

stainless steel foil instead of copper for grounding Ham radio?
 

On Sun, 14 Oct 2007 01:39:43 +0000, Larry wrote:


I wish you guys would worry much more about "series inductance"
and lots less about how expensive you can make the damned ground
strap.
....
Larry W4CSC and other fine old calls since 1957


A valid point. But then, running an insulated wire underwater
has rather appreciable series inductance too
(which can self-tune at some frequency -
I wonder what fx that is? :-)

Brian W

stainless steel foil instead of copper for grounding Ham radio?
 

On Oct 13, 8:39 pm, Larry wrote:
Brian Whatcott wrote :



I have silver at 0.0159 microhm meter at 20 degC
copper 0.0168 microhm.meter
gold 0.022 microhm meter

So gold may not be not quite as conductive as the best, but it
STAYS
at that value - no tarnish....

Brian W

I wish you guys would worry much more about "series inductance"
and lots less about how expensive you can make the damned ground
strap.

Look at your ground strap and follow it down to whatever is
supposed to be "ground" on your boat.

1 - Are there any sharp corners or folds back over itself to make
it look really neat, like boaters love their stuff?

This is bad, very bad. Every sharp curve increases the series
inductance, and inductive reactance. If it bends 90 degrees, you
have a 1/4 turn coil in series, raising the ground at the tuner
MUCH more than the total combined resistance of all the metal
chemistry in the circuit, which increases with frequency.

All turns in the ground strap should be as large a diameter as
you can make it and very smooth to reduce series inductance. It
should be routed in as straight a line from the tuner to the
ground as you can make it, for this same reason. This strap is
PART of the antenna. It radiates like mad when you're on the
air, into the bilge wiring, the reason why the LEDs in the DC
panel all light up when you talk. They're detecting the RF
induced into those DC cables in the bilge.

Now, let's put away the periodic tables and go reroute the ground
straps, taking off all the pretty tywraps and making them as
straight as possible, shortening them as much as we can.

Larry W4CSC and other fine old calls since 1957
--
Bruce will be by to inspect your installation, shortly.

Get a steel hull and just run a short wire to the hull. :o)

Grounding straps are for kids.

Joe

stainless steel foil instead of copper for grounding Ham radio?
 

In article .com,
Joe wrote:

Richard...I'm telling you one of the worlds top antenna designers
lives here and I just happened to be lucky enough to get his help
setting up my radios. If he tells me tarnished silver is the best for
HF I take his word for it..If our goverment flys him all over the
earth to design develope and set up the best....that's good enough
reference for me.

Joe

Your Designer Friend is certainly speaking from experience. The
Experience of a Job that has little monitary consideration. The rest of
the non-commercial boaters of the world may not need the "Money is no
Object" design, where the difference between Tarnished Silver, and
plain old Copper Foil, could possibly be significant, to the RF Ground
for their MF/HF Antenna System. Larry's observation that the Series
Impedance of the RF Ground, is considerably MORE significant, than the
Resistance difference, between Tanished silver and Copper Foil, in
the Total RF Ground Impedance of the Antenna System.

Bruce in alaska who has designed and installed RF Ground Systems
for LF/MF/HF Radio Stations on Land and at Sea
for the last 40 Years.... and inspected them
for Regulatory Agencies, in the past.....
--
add path before @

stainless steel foil instead of copper for grounding Ham radio?
 

On Sun, 14 Oct 2007 01:31:49 +0000, Larry wrote:

Your "tarnished" silver-plated ground strap is fine....mine, too.

It is well known that copper is somewhat soluble in sea water. After
all it was used to cover ships bottoms to retard marine growth. Had to
be in solution to be toxic. Silver is not very subject to attack. They
use it for medical work: I have silver wire in my jaw.
So, silver may well outlast copper in the ground. Life of either
should be long enough, in any case. They often ground electrical
transformers with a six foot or so copper rod driven into the ground
at the base of the pole. Fairly heavy conducters running down the
poles. I wonder if people steal them. They do get killed trying to
steal energized wire. You are supposed to ground your end of the
neutral, but whatever.

Casady

stainless steel foil instead of copper for grounding Ham radio?
 

Brian Whatcott wrote in
:

which can self-tune at some frequency

The only reason the boat has a tuner is we can't make an antenna
"self tune" but on a couple of frequencies.

All my ham antennas at home are "self tuning". No tuner is
required or wanted as they are so lossy.



Larry
--
You can tell there's extremely
intelligent life in the universe
because they have never called Earth.

stainless steel foil instead of copper for grounding Ham radio?
 

Joe wrote in
oups.com:

Get a steel hull and just run a short wire to the hull. :o)


You guys should see how well a Butternut HF9VX vertical ham antenna
works clamped to the handrail of the flight deck of the USS
Yorktown (CV-10) in Charleston Harbor....one of the "World's
Largest Ground Planes".

Her call is WA4USN, thanks to Senator Thurmond. The base of the
antenna is about 80' off the harbor surface.

Larry
--
You can tell there's extremely
intelligent life in the universe
because they have never called Earth.

stainless steel foil instead of copper for grounding Ham radio?
 

On Thu, 11 Oct 2007 21:25:14 -0500, Brian Whatcott
wrote:

Yes but it's relatively high-resistance compared with copper, silver
plate, or (preferably soft) aluminum sheet.

Funny you should mention soft. It is true that anything that hardens
copper or aluminum will increase electrical resistance. In the case of
work hardening, you beat dislocations into the crystal structure. Even
that has a very slight effect on the electrical properties. If you
have a joint between copper and aluminum immersed in the bilge water,
you may perhaps have some trouble with corrosion.

Casady

stainless steel foil instead of copper for grounding Ham radio?
 

On Sun, 14 Oct 2007 17:17:34 GMT, Bruce in Alaska
wrote:

Impedance of the RF Ground, is considerably MORE significant, than the
Resistance difference, between Tanished silver and Copper Foil, in
the Total RF Ground Impedance of the Antenna System.

No trouble believing that. Note that silver has ninety percent of the
electrical resistance, other things being equal. Thing is, there is no
reason why things should be equal. Make the copper foil ten percent
thicker and it will have the same resistance. I think a wide strap for
a conductor, to reduce inductance, would be helpful, but I don't
really know.

Casady

stainless steel foil instead of copper for grounding Ham radio?
 

On Sun, 14 Oct 2007 21:35:49 +0000, Larry wrote:
[Yorktown, CV-10]
about 80' off the harbor surface.

I guess people fall off of carriers and sometimes survive. Eighty feet
is a long drop. Good chance they won't find you, if it is moving. At
night, forget it.
Casady