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Old April 13th 04, 12:56 AM
Gene Fuller
 
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Cecil,

No, it won't work.

Mercury, being a liquid at normal temperatures, is subject to
hydrodynamic wave action. The RF couples into the hydrodynamic modes,
and the resulting interference energy waves cause cancellation of the
antiglare properties at the ends of the tube. The RF then leaks out and
does not launch into the desired radio waves.

Of course the mercury has high local proton density, so it has been
claimed that even small amounts of proton decay can negate the RF to
hydrodynamic coupling, thereby allowing the essential glare properties
to be maintained.

8-)

73,
Gene, W4SZ



Cecil Moore wrote:
Forget about the feasibility of this question for the moment.
Could a column of mercury inside a tube of glass be used as an
antenna?
--
73, Cecil, W5DXP



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Old April 13th 04, 01:15 AM
phoneguy99
 
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Cecil,

I asked this question about a year ago in some other group but the
posting went unanswered. Here's (more or less) what happened about 4
years ago during a conversation I had with a fellow who emigrated from
Russia many years ago. (It was a Sunday morning coffee shop ritual where
my wife and I would walk to a nearby Starbucks and meet with a small
group and discuss life, the universe, and everything as we overdosed on
several venti lattes with two extra espresso shots...) He once mentioned
a Russian text that detailed a mercury filled collinear antenna. It was
not completely filled with HG but had electrodes at the ends that
connected to cylinders of mercury. The article claimed wideband
performance and low noise. I asked him to sketch out the illustration
(bear in mind he's not a radio guy) and he sketched a collinear antenna.

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This is the best (crude) ascii rendition of the sketch on the napkin,
but you get the picture.
He described the ends were electrodes protruding into a cylinder of HG.
I have yet to build the thing, but I do have a source of HG if I need
it. he claimed the book was a KGB cold war technical manual (obviously
written in russian) that he happened upon. I cannot testify to the
authenticity of the article nor its origin, but I reiterate, he was not
a radio literate fellow, but very well read in a broad field of mainly
business, economic and political topics. When he sketched the
illustration from memory, he even said "I'm not even sure it this is
right, but this is how I remember it..." and yet the scribble was accurate.

I still intend to try it out, but as usual, procrastination rules!!!

Pat

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Old April 13th 04, 01:37 AM
HUMBUG
 
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On Mon, 12 Apr 2004 23:56:34 GMT, Gene Fuller Wrote :
Cecil,

No, it won't work.

Mercury, being a liquid at normal temperatures, is subject to
hydrodynamic wave action. The RF couples into the hydrodynamic modes,
and the resulting interference energy waves cause cancellation of the
antiglare properties at the ends of the tube. The RF then leaks out and
does not launch into the desired radio waves.

Of course the mercury has high local proton density, so it has been
claimed that even small amounts of proton decay can negate the RF to
hydrodynamic coupling, thereby allowing the essential glare properties
to be maintained.



Thanks for that. I just knew someone here would know for sure why it
would, or would not, work. And a simple explanation...



--

Humbug
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Old April 13th 04, 01:39 AM
Richard Clark
 
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On Mon, 12 Apr 2004 20:52:56 GMT, Gary S. Idontwantspam@net wrote:
Think of how easily the antenna length could be adjusted.


Hi Gary,

I have four high accuracy laboratory thermometers one of which is 6"
from this keyboard (ambient 18.4° C) with a range of -1° to 51° C over
a length of roughly 16 inches. I've built precision heaters and
designed using TEMs; nothing is easy about controlling heat.

- It's a stupid idea -

73's
Richard Clark, KB7QHC
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Old April 13th 04, 01:46 AM
Richard Clark
 
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On Mon, 12 Apr 2004 21:47:52 GMT, "Henry Kolesnik"
wrote:
Several
dentists and a PhD metallurgist all said that the metal mercury is not toxic
and is not absorbed but the salts of it are.


Hi Henry,

You may as well had said several fools - especially the metallurgist
passing as a toxicologist. The Dental practice is one of the single
highest pollution hot spots of industry and acids in saliva are known
to leach Mercury.

There is NO MINIMUM EXPOSURE LEVEL to Mercury. No matter how little,
it has some debilitating effect that is measurable.

73's
Richard Clark, KB7QHC


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Old April 13th 04, 02:41 AM
 
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Cecil Moore wrote:

No troll, just a wild hair. I got to thinking of using mercury as the
conducting medium for an RF antenna switch and then wondered if mercury
could replace the upper part of a whip where there is low current and
high voltage. The mercury changing length in a thermometer triggered
these unthinkable thoughts. Imagine changing the current through a
resistor in order to tune an antenna by varying the mercury level.
--
73, Cecil, W5DXP


Had the same wild hair once.

One problem is that changing the length through temperature requires a
thin column of mercury in a stiff container; probably not ideal for
an antenna.

I came up with a bunch of other practical issues that I'm sure will all get
posted here in time.

The best use of mercury in antennas is to go down to the creek and
gather gold with it. Sell the gold and buy an antenna.

--
Jim Pennino

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Old April 13th 04, 02:46 AM
Richard Clark
 
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On Mon, 12 Apr 2004 21:47:52 GMT, "Henry Kolesnik"
wrote:

When I was a dumb kid in the 50s we used to go into the garbage of those
hard of hearing and get their discarded hearing aid batteries to salvage the
mercury.


Hi Henry,

Another point of toxicity. Because the nuclear "Boomers" contained a
closed loop environmental system, ALL such batteries were banned from
the boat irrespective of their need in ANY equipment. We had to make
do with substitutes and jury rig our own holders or means to provide a
voltage for key equipment that would work fine on surface craft.

73's
Richard Clark, KB7QHC
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Old April 13th 04, 02:52 AM
 
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Richard Clark wrote:
On Mon, 12 Apr 2004 21:47:52 GMT, "Henry Kolesnik"
wrote:
Several
dentists and a PhD metallurgist all said that the metal mercury is not toxic
and is not absorbed but the salts of it are.


Hi Henry,


You may as well had said several fools - especially the metallurgist
passing as a toxicologist. The Dental practice is one of the single
highest pollution hot spots of industry and acids in saliva are known
to leach Mercury.


There is NO MINIMUM EXPOSURE LEVEL to Mercury. No matter how little,
it has some debilitating effect that is measurable.


73's
Richard Clark, KB7QHC


Utter nonsense.

Ever hear "The poison is in the dose"?

There is some amount of every element in your body, including mercury,
plutonium, arsenic and anything else you care to name.

--
Jim Pennino

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Old April 13th 04, 03:03 AM
 
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Richard Clark wrote:
On Mon, 12 Apr 2004 21:47:52 GMT, "Henry Kolesnik"
wrote:


When I was a dumb kid in the 50s we used to go into the garbage of those
hard of hearing and get their discarded hearing aid batteries to salvage the
mercury.


Hi Henry,


Another point of toxicity. Because the nuclear "Boomers" contained a
closed loop environmental system, ALL such batteries were banned from
the boat irrespective of their need in ANY equipment. We had to make
do with substitutes and jury rig our own holders or means to provide a
voltage for key equipment that would work fine on surface craft.


73's
Richard Clark, KB7QHC


The key here is "closed environment", which means crap accumulates.

A lot of things are banned on subs because it is easier to ban them than
it is to monitor them for for safe levels and then clean the whole damn
sub when a level gets too high.

None of this means you should get your panties in a wad because there is
a mercury wetted relay in the house.

--
Jim Pennino

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