Hi Gang

Since the radiation of an antenna is done primarily on the surface of
the elements (or wire) would gold plating the elements increase the
efficiency of the antenna in any way?

Gold sounds expensive, but if thin enough, one ounce of gold could
plate an entire football field. Brass corrods, nickel is usually used
as the first plating before another metal like gold is plated over
that. If the cost for gold over the cost of brass is only about 1
buck per foot of element length, making cost not relavent to the
question. Would a gold plated antenna work better than aluminum or
nickel plated?

TTUL
Gary

Gary V. Deutschmann, Sr. wrote:
Hi Gang

Since the radiation of an antenna is done primarily on the surface of
the elements (or wire) would gold plating the elements increase the
efficiency of the antenna in any way?

Gold sounds expensive, but if thin enough, one ounce of gold could
plate an entire football field. Brass corrods, nickel is usually used
as the first plating before another metal like gold is plated over
that. If the cost for gold over the cost of brass is only about 1
buck per foot of element length, making cost not relavent to the
question. Would a gold plated antenna work better than aluminum or
nickel plated?

TTUL
Gary

Why don't you download the demo version of eznec, www.eznec.com/, model
an antenna with gold, copper, aluminum, etc. and see for yourself how
much difference it makes?

--
Jim Pennino

Remove -spam-sux to reply.

On 16 Apr 2004 11:07:12 EDT, am (Gary V.
Deutschmann, Sr.) wrote:
Since the radiation of an antenna is done primarily on the surface of
the elements (or wire) would gold plating the elements increase the
efficiency of the antenna in any way?

Of Course - you knew that anyway. How much? More than a dB? No.
Less than a dB? Very much less.

-Unless-

Gold sounds expensive, but if thin enough, one ounce of gold could
plate an entire football field.

I know you didn't really have this in mind, but putting your gold into
System loss pays back far more than trying to raise the efficiency of
the radiator from 99.89% to 99.90%

Gold plate your lawn and you could easily recover 1dB in a DX lobe.

73's
Richard Clark, KB7QHC

"Gary V. Deutschmann, Sr." wrote:

Hi Gang

Since the radiation of an antenna is done primarily on the surface of
the elements (or wire) would gold plating the elements increase the
efficiency of the antenna in any way?

Gold sounds expensive, but if thin enough, one ounce of gold could
plate an entire football field. Brass corrods, nickel is usually used
as the first plating before another metal like gold is plated over
that. If the cost for gold over the cost of brass is only about 1
buck per foot of element length, making cost not relavent to the
question. Would a gold plated antenna work better than aluminum or
nickel plated?

TTUL
Gary

The only real downside would be security! :-)
--
--------------------------------------
Diagnosed Type II Diabetes March 5 2001
Beating it with diet and exercise!
297/215/210 (to be revised lower)
58"/43"(!)/44" (already lower too!)
--------------------------------------
Visit my HomePage at http://members.shaw.ca/finkirv/
Visit my very special website at http://members.shaw.ca/finkirv4/
Visit my CFSRS/CFIOG ONLINE OLDTIMERS website at http://members.shaw.ca/finkirv5/
--------------------
Irv Finkleman,
Grampa/Ex-Navy/Old Fart/Ham Radio VE6BP
Calgary, Alberta, Canada

I've seen real-life cases with high-Q microstrip structures where gold
plating actually caused a significant lowering of efficiency. As you
point out, nickel is used as a barrier metal to prevent alloying of the
gold with the underlying copper. If the gold isn't at least several skin
depths thick, significant current flows in the nickel. Nickel is a
particularly poor RF conductor, very much worse than copper, because the
skin depth in nickel is decreased dramatically by its ferromagnetic
permeability. So, if you're able to calculate skin depth, and know what
you're doing, and are willing to use quite a bit of gold (particularly
necessary at HF and below) you can achieve efficiency with gold plating
that's pretty much indistinguishable from that of copper. If you don't
know what you're doing, it is possible to substantially degrade the
efficiency by gold plating. I'm sure somebody could be conned into
buying one, though.

Roy Lewallen, W7EL

Gary V. Deutschmann, Sr. wrote:

Hi Gang

Since the radiation of an antenna is done primarily on the surface of
the elements (or wire) would gold plating the elements increase the
efficiency of the antenna in any way?

Gold sounds expensive, but if thin enough, one ounce of gold could
plate an entire football field. Brass corrods, nickel is usually used
as the first plating before another metal like gold is plated over
that. If the cost for gold over the cost of brass is only about 1
buck per foot of element length, making cost not relavent to the
question. Would a gold plated antenna work better than aluminum or
nickel plated?

TTUL
Gary

Hi Roy;
It's worse than that: Copper will diffuse throught the gold and pile up on
the surface.
I showed that with an Auger microprobe at Motorola decades ago.
So to go to a gold surface, nickel is mandatory, then a thick gold coating;
Too expensive!
It's not like the switch from aluminum to copper, which is a 2x resistivity
improvement.
You just can't beat plain old copper.
73
H.
NQ5H

"Roy Lewallen" wrote in message
...
I've seen real-life cases with high-Q microstrip structures where gold
plating actually caused a significant lowering of efficiency. As you
point out, nickel is used as a barrier metal to prevent alloying of the
gold with the underlying copper. If the gold isn't at least several skin
depths thick, significant current flows in the nickel. Nickel is a
particularly poor RF conductor, very much worse than copper, because the
skin depth in nickel is decreased dramatically by its ferromagnetic
permeability. So, if you're able to calculate skin depth, and know what
you're doing, and are willing to use quite a bit of gold (particularly
necessary at HF and below) you can achieve efficiency with gold plating
that's pretty much indistinguishable from that of copper. If you don't
know what you're doing, it is possible to substantially degrade the
efficiency by gold plating. I'm sure somebody could be conned into
buying one, though.

Roy Lewallen, W7EL

Gary V. Deutschmann, Sr. wrote:

Hi Gang

Since the radiation of an antenna is done primarily on the surface of
the elements (or wire) would gold plating the elements increase the
efficiency of the antenna in any way?

Gold sounds expensive, but if thin enough, one ounce of gold could
plate an entire football field. Brass corrods, nickel is usually used
as the first plating before another metal like gold is plated over
that. If the cost for gold over the cost of brass is only about 1
buck per foot of element length, making cost not relavent to the
question. Would a gold plated antenna work better than aluminum or
nickel plated?

TTUL
Gary

silver is a better conductor than gold, but will tarnish very easily, might
now be a good idea for what you are intending

just my two cents


"H. Adam Stevens, NQ5H" wrote in message
...
Hi Roy;
It's worse than that: Copper will diffuse throught the gold and pile up on
the surface.
I showed that with an Auger microprobe at Motorola decades ago.
So to go to a gold surface, nickel is mandatory, then a thick gold
coating;
Too expensive!
It's not like the switch from aluminum to copper, which is a 2x
resistivity
improvement.
You just can't beat plain old copper.
73
H.
NQ5H

"Roy Lewallen" wrote in message
...
I've seen real-life cases with high-Q microstrip structures where gold
plating actually caused a significant lowering of efficiency. As you
point out, nickel is used as a barrier metal to prevent alloying of the
gold with the underlying copper. If the gold isn't at least several skin
depths thick, significant current flows in the nickel. Nickel is a
particularly poor RF conductor, very much worse than copper, because the
skin depth in nickel is decreased dramatically by its ferromagnetic
permeability. So, if you're able to calculate skin depth, and know what
you're doing, and are willing to use quite a bit of gold (particularly
necessary at HF and below) you can achieve efficiency with gold plating
that's pretty much indistinguishable from that of copper. If you don't
know what you're doing, it is possible to substantially degrade the
efficiency by gold plating. I'm sure somebody could be conned into
buying one, though.

Roy Lewallen, W7EL

Gary V. Deutschmann, Sr. wrote:

Hi Gang

Since the radiation of an antenna is done primarily on the surface of
the elements (or wire) would gold plating the elements increase the
efficiency of the antenna in any way?

Gold sounds expensive, but if thin enough, one ounce of gold could
plate an entire football field. Brass corrods, nickel is usually used
as the first plating before another metal like gold is plated over
that. If the cost for gold over the cost of brass is only about 1
buck per foot of element length, making cost not relavent to the
question. Would a gold plated antenna work better than aluminum or
nickel plated?

TTUL
Gary

"S" wrote in message
et...
silver is a better conductor than gold, but will tarnish very easily,
might
now be a good idea for what you are intending

I thought that silver oxide was a decent conductor, which is why it is
sometimes used as a plateing material.

jim
N8EE

On Fri, 16 Apr 2004 20:40:53 -0400, "JLB"
wrote:


"S" wrote in message
. net...
silver is a better conductor than gold, but will tarnish very easily,
might
now be a good idea for what you are intending

I thought that silver oxide was a decent conductor, which is why it is
sometimes used as a plateing material.

Hi All,

It hardly matters unless you are speaking of switch contacts.
Insulated wire's insulation is absolutely unconductive, and yet in the
context of antennas it doesn't impact the wire's capacity to carry
current.

Oxidation products only become a problem at interfaces where they
either resist current between the joined conductors, or create a
semiconducting barrier.

The technician is taught to clean surfaces of tarnish to bring bright
metal into contact. Then crimp them (or twist the wire - same thing)
for a gas tight seal. Then solder them to weather proof the seal
(solder is never meant to be a mechanical join or the conductive
path). Common practice allows for solder to provide more
functionality than what I describe - this does not elevate the method.
Barring the final solder, switch contact faces must meet the same
conditions of bright metal and gas tight seals. This is often
achieved by pressure (some mistake the so-called "wiping" action as
meaning to scrub the oxide away - a useful metaphor but only that;
otherwise switches would self demolish in very few operations) and a
sustaining current (wet vs. dry contacts).

73's
Richard Clark, KB7QHC

Hmmm...My book says aluminum's resistivity is about 2.6 microohm-cm,
and copper's is 1.7, only a 1.5:1 ratio--though it may not be quite
that good for commonly used aluminum alloys. OTOH, copper also
suffers from being alloyed. But in any event, it's good to keep in
mind that the RF resistance ratio for non-magnetic materials goes as
the square root of the bulk resistivity ratio, because higher
resistivity materials have larger skin depth. So a 2:1 ratio at DC
ends up being only 1.41:1 at RF, and 1.5:1 at DC is only a bit over
1.2:1 at RF.

Since both copper and aluminum have good conductivity, it's just not
worth sweating in practically all cases, unless the antenna is very
short (and thus has very low feedpoint radiation resistance).

Actually, what I thought Gary might be getting at is the protection
from corrosion that gold might offer, as compared with bare copper.
I'd say that it IS worth worrying about protecting your antenna from
corrosion. Maybe you just have to think about it long enough to
understand that you are lucky to live in a place where corrosion isn't
a problem, or maybe you live next to the ocean where salt spray will
get the best of almost anything metallic. But like Roy says, gold
over nickel is probably a bad idea. Unplated stainless steel antenna
wire is probably a bad idea. Painted copper pipe, or anodized
aluminum tubing, will probably work well for a long time.

Cheers,
Tom


"H. Adam Stevens, NQ5H" wrote in message ...
Hi Roy;
It's worse than that: Copper will diffuse throught the gold and pile up on
the surface.
I showed that with an Auger microprobe at Motorola decades ago.
So to go to a gold surface, nickel is mandatory, then a thick gold coating;
Too expensive!
It's not like the switch from aluminum to copper, which is a 2x resistivity
improvement.
You just can't beat plain old copper.
73
H.
NQ5H