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On Sun, 25 Jul 2010 10:56:16 -0700 (PDT), K1TTT
wrote:

and i suppose you have a coherer in your receiver also?

Is this in the same sense of coherence as to Art's babble of
equilibrium?

73's
Richard Clark, KB7QHC

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Uzytkownik "Richard Clark" napisal w wiadomosci
...
On Sun, 25 Jul 2010 10:56:16 -0700 (PDT), K1TTT
wrote:

and i suppose you have a coherer in your receiver also?

Is this in the same sense of coherence as to Art's babble of
equilibrium?

In Art's equilibrium and Michael's "truds" are more sense than in yours
"magnetic whirls".
All radio history apply to the longitudinal electric waves (Tesla waves) in
wires and in the space.

Lodge made the long wire antennas (see Fig 2):
http://www.antiquewireless.org/otb/lodge1102.htm

The sparks are rather harmfull for transmitting. The better is a field
emission of electrons ("truds" or the "time dependent Gauss law").

You are an expert.
Does antenna radiate if it is coated with the thick good insulation?
S*

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"K1TTT" wrote
...

and i suppose you have a coherer in your receiver also?

Unfortunatly the coherer do not work nowdays. To much electric waves in the
rare plasma.

But the Lodge's "electrical radiation" ("time dependent Gauss Law") works.
"Lodge then added a postscript to his own paper acknowledging Hertz's work
in an extremely positive way. He concluded the postscript by saying: "The
whole subject of electrical radiation seems working itself out splendidly".
S*

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tom wrote:
On 7/23/2010 4:23 PM, Jim Lux wrote:

If the ball is wet, especially with distinct droplets, then you can get
corona forming much earlier. The electrostatic forces tend to make the
droplets fly off.


Non-rhetorical question(s).

I must be missing something then. Why don't I see corona on the tips of
leaves at the tops of my trees? Trees are pretty conductive when
hundreds of kilovolts are involved.

In the clear air field (the 100V/meter sort of thing), you're not going
to see corona, because the voltages aren't high enough.

In thunderstorm type fields, you would see corona, if you look closely.
There's an interesting paper (which I can't find right now, but I'll
look) where someone measured the current from a field of wheat.

Not all breakdown will produce visible corona.

If you have a resistive thing (i.e. a tree), covered with sharp points,
then the object tends to adopt the overall voltage profile surrounding
it, so there's not much net difference in voltage between the
leaf/needle and the surrounding, so the field isn't locally high, so
there isn't any breakdown.



Or my antenna masts for that matter, 'cause they are grounded, too.

You probably DO have corona breakdown, it's just not noticeable. It's
kind of a challenge to measure microamp currents in a 100 foot tower.
And if that milliamp or microamp is spread over a large area (i.e. your
tower isn't a smooth machined surface with only the one point having
small radius of curvature) then it would be less noticeable.

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On Mon, 26 Jul 2010 10:26:52 +0200, "Szczepan Bialek"
wrote:

Does antenna radiate if it is coated with the thick good insulation?

Radiate what?

73's
Richard Clark, KB7QHC

Grounding for Gable end bracket & mast.
 

Szczepan Bialek wrote:
"tom" wrote
t...
On 7/23/2010 4:23 PM, Jim Lux wrote:
If the ball is wet, especially with distinct droplets, then you can get
corona forming much earlier. The electrostatic forces tend to make the
droplets fly off.

Non-rhetorical question(s).

I must be missing something then. Why don't I see corona on the tips of
leaves at the tops of my trees? Trees are pretty conductive when hundreds
of kilovolts are involved.

You have missed that: "Physically, St. Elmo's fire is a bright blue or
violet glow, appearing like fire in some circumstances, from tall, sharply
pointed structures such as lightning rods, masts, spires and chimneys, and
on aircraft wings. St. Elmo's fire can also appear on leaves, grass, and
even at the tips of cattle horns.[3] Often accompanying the glow is a
distinct hissing or buzzing sound."



St. Elmo's fire and corona discharge are distinctly different, although
St. Elmo's is often described as corona, it actually isn't.

Yes, corona in high fields does sound like hissing or buzzing. Anyone
who has been on a high mountain in a thunderstorm has probably
experienced this, and even more exciting is when you get corona
discharge off your hair standing on end.

St Elmo's is a bit different. It has a distinctly different appearance:
a sort of bluish glow that extends some distance surrounding the object,
as opposed to corona, which seems to be "stuck" to the surface. And then
a high field streamer discharge is still different. If you've seen both,
it's noticeably different, but hard to describe.

As best can be determined, St Elmo's arises when the surface of an
object is wet and in a field. The water sprays off the surface (much
like is done in electrospraying), and the droplets carry charge away.
Several different things then happen: 1) The charge causes the droplet
to break apart into smaller droplets from electrostatic forces; 2) the
field at the surface of the droplet is now too high and the air
breaksdown at the surface of the droplet, discharging it, and 3) the
droplet starts to shrink from evaporation, getting smaller, so the field
at the surface grows, etc.

So St. Elmos is not really corona off the object, but corona/breakdown
on the droplets being electrosprayed off the surface.

It is possible to generate St. Elmo's in the lab on the surface of an
object with fairly large radius of curvature (i.e. that would NOT be
subject to surface corona) in a moderate field. If someone wants to try
an experiment, put a wet cork or dowel of wood in a shallow tray or
puddle of water with a large flat electrode suspended over it to create
the overall field. A field of 10kV/cm will work quite nicely. I used
two baking pans separated by cut down styrofoam cups driven by a small
modular HV supply (50kV@ a few mA) driven by a variac. Make sure you
have a resistor in series with your HV supply, because occasionally
you'll get a flashover, and you want to limit the current.

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"Richard Clark" wrote
...
On Mon, 26 Jul 2010 10:26:52 +0200, "Szczepan Bialek"
wrote:

Does antenna radiate if it is coated with the thick good insulation?

Radiate what?

What is better: bare metal or insulated metal?
S*

Grounding for Gable end bracket & mast.
 

Szczepan Bialek wrote:

"Richard Clark" wrote
...
On Mon, 26 Jul 2010 10:26:52 +0200, "Szczepan Bialek"
wrote:

Does antenna radiate if it is coated with the thick good insulation?

Radiate what?

What is better: bare metal or insulated metal?
S*

For what?

Insulated antennas work just fine.



--
Jim Pennino

Remove .spam.sux to reply.

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On Mon, 26 Jul 2010 19:26:04 +0200, "Szczepan Bialek"
wrote:

Radiate what?

What is better: bare metal or insulated metal?

To radiate what?

73's
Richard Clark, KB7QHC

Grounding for Gable end bracket & mast.
 

On 7/25/2010 12:14 PM, Szczepan Bialek wrote:
wrote
. net...
On 7/24/2010 2:43 AM, Szczepan Bialek wrote:

Your ground wire is broken. Check it.

Your brain is broken, check it.

Have you ever seen the glow: "In addition, the scientist was able to
demonstrate that standing waves existed along the wires. In a darkened room,
he observed a visible glow along the wires at one-half wavelength intervals
corresponding to the voltage peaks. He also performed a number of other
experiments concerning the characteristics of discharging Leyden jars during
that spring and summer of 1888."
From: http://www.antiquewireless.org/otb/lodge1102.htm
S*



Yup broken. Stuck in "post Google search results" mode. Definitely not
Bing.

tom
K0TAR