Cecil Moore wrote:
wrote:

The earth is one terminal, the air and things in the air (like clouds)
have a charge difference.


But that charge difference is NOT corona unless ionization occurs.
If the charge difference doesn't reach the ionization threshold,
it's not corona, by definition.

Cecil,

I am not entering this debate one way or the other. I do have a
question, however.

How do you determine when the ionization threshold has been reached?


73,
Gene
W4SZ

wrote:
Corona comes from a charge difference between two things.

No, that's not complete. A charge difference is necessary
*but not sufficient* to cause corona. Corona comes from a charge
difference between two things that causes ionization of the air
around/between the two things. Corona, in the electrical sense
that we are using the word here, doesn't exist and cannot exist
without ionization. For this definition of the word, "corona",
my unabridged dictionary says, "7. Electrical: see corona
discharge".

In the web reference I posted yesterday, two charged spheres
arced before any corona was possible. Corona never existed
in that experiment even though arcing took place.

In every case I have looked at, and I have looked at dozens very
carefully, it has been corna off the elements. That corna (and the
resulting noise) occurs when there are particles, when there aren't,
and at a rate different than the rate of particles hitting the antenna.

Certainly white cars exist. That doesn't mean that all cars
are white.

It occurs with radomes and insulated elements and without, it occurs
with grounded elements and without.

Certainly corona exists. That doesn't mean the entire universe
is ruled by some Corona God.

It increases with increasing height, especially compared to surrounding
objects. It is worse with protruding sharp points on the elements.

For it to be defined as corona, it must ionize the air. How do
you prove that the air has indeed been ionized? At night, a
glow invariably accompanies corona ionization. Do your antennas
glow at night? Mine usually don't.

It is worse when the charge difference between earth and sky is
greatest, and less when the charge difference is less. It is terrible
when lightning is almost ready to strike. It often vanishes totally for
a brief period after a ground to cloud lightning strike.

"It" being corona, not clear-sky, dry-air, charged-particle
problems. Everyone agrees that corona exists, Tom. We just
disagree with you that corona is all that can cause a charge.
Is the 10 volt charge on a capacitor caused by corona?

Of course a book, especially a handbook, might say it is something
else. But then what they say should fit what occurs most of the time if
what they say is mostly true.

Most of the time doesn't cut it, Tom. All it takes is one
example to the contrary to prove your all-inclusive assertions
to be false. Not all cars are white just because you have never
seen a colored car.

In my experience, and I probably have much more than most people with
this after changing dozens of antennas to try to eliminate this
problem, the idea the noise comes from an element "charging" or from
particles hitting the antenna is largely incorrect.

That may be true, but the question is: Do charged particles
hitting an antenna ever cause static discharge problems. If
it has ever occurred even once in history of this planet,
your assertions are wrong. It occurred in my antenna system
multiple times while I was living in the Arizona desert. There
was not a cloud in the entire state at some of those times.

According to the web source I posted yesterday, arcing can
completely eliminate corona because the arcing occurs *before*
the corona can possibly occur. The example given was between
two spherical electrodes. The corona example involved a
pointed electrode which caused corona to occur before the
arc.

I think that idea comes from reading and believing wive's tales and
rumors, and not thinking and experimenting for oneself.

I think you should stop worshiping the Corona God, go
out to Queen Creek, AZ and perform your experiments.
Please prove that every dust particle carries a charge
identical to the charge on every antenna.

You remind me of the host of scientists who believed that
the earth was never bombarded by meteors and comets
because they couldn't see more than a handful of impact
craters.

You can run the experiment for yourself, Tom. Set up an
inverted-V dipole and discharge a capacitor at one end
between one element and a ground plane. Guaranteed, you
will hear the noise in an RF receiver when there's no
sign of corona anywhere.
--
73, Cecil http://www.qsl.net/w5dxp

Cecil Moore wrote:

For Tom^2 to be correct, every dust particle that touches
every antenna would have to carry the same identical charge
as the antenna to keep charge from transferring. I would
sure like to see them prove that assertion.

Cecil,

More fractured physics.

If every interaction between objects requires that somehow the charge is
transferred to keep things "identical", how did those nasty dust
particles get charged in the first place?

I am not arguing about antenna noise. I am questioning your misuse of
physics. There are no charge equalization laws.

73,
Gene
W4SZ

Gene Fuller wrote:
I am not entering this debate one way or the other. I do have a
question, however.

How do you determine when the ionization threshold has been reached?

Corona invariably causes a glow at night. I have witnessed
such a glow but not very often. I came across a calculation
of the ionization threshold in volts yesterday while on the
web. I don't remember the exact figure but it was in the
thousands of volts for average air conditions and varied
with the geometry of the conductor.

But the point is that, by definition, it is not corona until
ionization occurs. A wire in the air during high wind conditions
can accumulate charge from the charged particles but until it
accumulates enough charge to cause ionization of the air, it
is NOT corona, by definition.

W8JI is confusing cause and effect. The transfer of charge
from wind-driven charged particles can cause localized corona
but that's just an effect, NOT a cause. And if the antenna
wire is not allowed to reach the air ionization level,
charge may accumulate but corona will not occur.

Under thunderclouds, corona often occurs. I wouldn't try
to speculate whether rain or snow noise is caused by
charged particles or corona. But I will certainly speculate
that in a state without a cloud in the sky, a charge can
be deposited on an antenna by charged particles.
--
73, Cecil http://www.qsl.net/w5dxp

Cecil Moore wrote:

W8JI is confusing cause and effect.

.....and Cecil is confusing himself.

Cecil Moore wrote:
Gene Fuller wrote:
I am not entering this debate one way or the other. I do have a
question, however.

How do you determine when the ionization threshold has been reached?

Corona invariably causes a glow at night. I have witnessed
such a glow but not very often. I came across a calculation
of the ionization threshold in volts yesterday while on the
web. I don't remember the exact figure but it was in the
thousands of volts for average air conditions and varied
with the geometry of the conductor.

How many systems have you looked at Cecil where you were right next to
the antenna while this was going on?

More than I have or many times less?

My bet is many times less. Probably none.

I'd bet you never were on a 300 foot or taller tower or on the roof of
a building, and I'd also bet you never had multiple antennas of various
tyoes to compare.

I'd wager all your data comes from what you picture in your mind.

73 Tom

Cecil,

First things first.

Ionization threshold has nothing to do with "voltage". It has everything
to do with field strength. This topic has been studied extensively for
centuries. Don't believe everything you find on the web, especially if
it requires "glow-in-the-dark" or "thousands of volts" as a determinant
for ionization.

73,
Gene
W4SZ

Cecil Moore wrote:
Gene Fuller wrote:

I am not entering this debate one way or the other. I do have a
question, however.

How do you determine when the ionization threshold has been reached?


Corona invariably causes a glow at night. I have witnessed
such a glow but not very often. I came across a calculation
of the ionization threshold in volts yesterday while on the
web. I don't remember the exact figure but it was in the
thousands of volts for average air conditions and varied
with the geometry of the conductor.

But the point is that, by definition, it is not corona until
ionization occurs. A wire in the air during high wind conditions
can accumulate charge from the charged particles but until it
accumulates enough charge to cause ionization of the air, it
is NOT corona, by definition.

W8JI is confusing cause and effect. The transfer of charge
from wind-driven charged particles can cause localized corona
but that's just an effect, NOT a cause. And if the antenna
wire is not allowed to reach the air ionization level,
charge may accumulate but corona will not occur.

Under thunderclouds, corona often occurs. I wouldn't try
to speculate whether rain or snow noise is caused by
charged particles or corona. But I will certainly speculate
that in a state without a cloud in the sky, a charge can
be deposited on an antenna by charged particles.

wrote:
Cecil Moore wrote:
W8JI is confusing cause and effect.

....and Cecil is confusing himself.

Charged dust particles can *cause* corona but they
don't necessarily cause corona. If the air is not
ionized, corona is impossible.
--
73, Cecil, http://www.qsl.net/w5dxp

wrote:
How many systems have you looked at Cecil where you were right next to
the antenna while this was going on?

I don't know exactly how many. All it takes to prove
you wrong is a single one. If you simply admit that
at one time in the history of man, a charge accumulated
on an antenna without the presence of corona, I will
be satisfied. When you assert that 100% of all charged
up antennas is caused by corona, it doesn't matter
if you are right 99.99% of the time. Logically, you
are 100% wrong if 0.01% of charged up antennas do not
involve corona.

When there is not a cloud over the entire state of
Arizona, charged up antennas in the dry, dusty,
windy Arizona desert are not caused by corona.

More than I have or many times less?

I multiply 6 times 7 once and get 42.
You multiply 6 times 7 ten times and get 56. Do
you really think you are right? The laws of physics
are not supposed to be the results of how many
flawed experiments are run.

Charged particles can exist in the absence of corona.
Like the cave men did, rub some amber against some
wool and then touch it to your dipole. That pop
you hear is NOT corona.

When a charged particle touches a reference bare
antenna wire, it transfers part of its charge to
the antenna. You have already agreed with that.
The rest is simple physics.

Exactly how do you prove that all charged up antennas
are causing ionization? What instrument did you use
to measure all that ionization?
--
73, Cecil, http://www.qsl.net/w5dxp

Cecil Moore wrote:
Reg Edwards wrote:

There was no precipitation unless it was plant pollen in the air. I
don't suffer from hay fever or asthma.


Some 19th century doctors scoffed at the idea that there
could be germs so small that they could see them. :-)
Dust particles come in all sizes. Run some clear air
through a HEPA (High Efficiency Particulate Air) filter
and see what you get.

There are always particles in the air. Sometimes they
carry a charge. Air itself, is made up of particles.
Quantum Electrodynamics tells us that charge transfer is
impossible without particles.

For Tom^2 to be correct, every dust particle that touches
every antenna would have to carry the same identical charge
as the antenna to keep charge from transferring. I would
sure like to see them prove that assertion.

Cecil, if you're too chicken to do the experiment, just say so,
I'll understand. Also, quit misrepresenting my ideas. That's an
old Oakie debating trick that won't fly on this newsgroup. The first
thing you have to prove is that a charged particle striking your antenna
makes an audible noise in your receiver. Just because a charged particle
strikes your antenna doesn't mean you can hear it. I have an idea.
Borrow a big, old, awkward Texas kid from one of your neighbors.
Wash his head and blow dry his hair to get all the moisture out.
Now, have him stand out at your vertical and run a comb through
his hair. After the comb is charged, have him touch it to the antenna
while you listen to your radio inside the shack. See if you can hear
an audible click whenever the comb discharges into the antenna. If you
can hear something, it at least means that charged particles can make
a noise. If you can't,you have to rethink your position.
I know you go all gun shy and hysterical whenever someone mentions you
do an experiment, but it wouldn't kill you to try _something_ in order
to prove your point. You might learn something, too.
73,
Tom Donaly, KA6RUH