Jim Kelley wrote:
There is absolutely no reason to believe that one antenna is less
responsive to charged particle noise than the other.

What about all the web references that say precipitation
static can be decreased by insulating the antenna from
the charged particles in the air?

Think about it. A charged particle hitting a bare wire
will likely transfer a charge. A charged particle hitting
an insulated wire may or may not transfer a charge depending
upon the insulation.

After all, air is an insulator. A charged particle missing
the antenna entirely is in contact with that air insulator.
--
73, Cecil http://www.qsl.net/w5dxp

"Cecil Moore" wrote in message
. com...
Jim Kelley wrote:
There is absolutely no reason to believe that one antenna is less
responsive to charged particle noise than the other.

What about all the web references that say precipitation
static can be decreased by insulating the antenna from
the charged particles in the air?

Think about it. A charged particle hitting a bare wire
will likely transfer a charge. A charged particle hitting
an insulated wire may or may not transfer a charge depending
upon the insulation.

After all, air is an insulator. A charged particle missing
the antenna entirely is in contact with that air insulator.
--
73, Cecil http://www.qsl.net/w5dxp

I once had a ladder line fed doublet.
It was disconnected at the feedthroughs because a thunderstorm was about ten
miles North.
I could pull 1 inch arcs off the feedthroughs to a grounded wire.
Made me think of Ben Franklin.

73
H.
NQ5H

H. Adam Stevens, NQ5H wrote:
"Cecil Moore" wrote in message
. com...

Jim Kelley wrote:

There is absolutely no reason to believe that one antenna is less
responsive to charged particle noise than the other.

What about all the web references that say precipitation
static can be decreased by insulating the antenna from
the charged particles in the air?

Think about it. A charged particle hitting a bare wire
will likely transfer a charge. A charged particle hitting
an insulated wire may or may not transfer a charge depending
upon the insulation.

After all, air is an insulator. A charged particle missing
the antenna entirely is in contact with that air insulator.
--
73, Cecil http://www.qsl.net/w5dxp


I once had a ladder line fed doublet.
It was disconnected at the feedthroughs because a thunderstorm was about ten
miles North.
I could pull 1 inch arcs off the feedthroughs to a grounded wire.
Made me think of Ben Franklin.

73
H.
NQ5H



A man could get killed fooling with that kind of stuff. It's a wonder
Ben lived as long as he did.
73,
Tom Donaly, KA6RUH

"Cecil Moore" wrote in message
. com...

Jim Kelley wrote:

There is absolutely no reason to believe that one antenna is less
responsive to charged particle noise than the other.


What about all the web references that say precipitation
static can be decreased by insulating the antenna from
the charged particles in the air?

I refuse to take responsibility for the things other people say. :-)

Think about it. A charged particle hitting a bare wire
will likely transfer a charge. A charged particle hitting
an insulated wire may or may not transfer a charge depending
upon the insulation.

Consider the nature of dielectric materials. I could be wrong, but I
bet if you stuck a negative oxygen ion on the outside of a jacketed
conductor, you could make the conductor inside think you had put an
electron directly on it.

After all, air is an insulator. A charged particle missing
the antenna entirely is in contact with that air insulator.

And air, which is an insulator, is also in contact with a bare wire
antenna - presumably 'insulating' it. The difference is one of
density (and dielectric constant).

I suppose if you set up a big electric or magnetic field in the proper
orientation, you could make a lot of the ions go away from an antenna.
But controlling plasmas is kinda like herding cats.

73, ac6xg

"Jim Kelley" wrote in message
...
"Cecil Moore" wrote in message
. com...

Jim Kelley wrote:

There is absolutely no reason to believe that one antenna is less
responsive to charged particle noise than the other.


What about all the web references that say precipitation
static can be decreased by insulating the antenna from
the charged particles in the air?

I refuse to take responsibility for the things other people say. :-)

Think about it. A charged particle hitting a bare wire
will likely transfer a charge. A charged particle hitting
an insulated wire may or may not transfer a charge depending
upon the insulation.

Consider the nature of dielectric materials. I could be wrong, but I bet
if you stuck a negative oxygen ion on the outside of a jacketed conductor,
you could make the conductor inside think you had put an electron directly
on it.

After all, air is an insulator. A charged particle missing
the antenna entirely is in contact with that air insulator.

And air, which is an insulator, is also in contact with a bare wire
antenna - presumably 'insulating' it. The difference is one of density
(and dielectric constant).

I suppose if you set up a big electric or magnetic field in the proper
orientation, you could make a lot of the ions go away from an antenna. But
controlling plasmas is kinda like herding cats.

73, ac6xg


My first physics job was in fusion.
Herding cats is trivial.
73
H.
NQ5H

PS I like my SteppIR.
Now THAT's broadband and insulated.

Jim Kelley wrote:
Consider the nature of dielectric materials. I could be wrong, but I
bet if you stuck a negative oxygen ion on the outside of a jacketed
conductor, you could make the conductor inside think you had put an
electron directly on it.

The question is whether the electron stays on the insulation
or migrates through it to the conductor.

The size of the charge Vs the dielectric determines how
much of the charge actually reaches the conductor. When
I went from bare wire to 600v insulation, my precipitation
static problems decreased considerably. Then when I went to
1000v insulation and a full wave loop, most of my precipitation
static problems disappeared.

The worst case of precipitation static seems to be for
airplane antennas. Insulation is the recommended cure
although folding is also mentioned. Please do a web
search for "precipitation static" and see for yourself.

http://www.atis.org/tg2k/_precipitation_static.html
--
73, Cecil http://www.qsl.net/w5dxp

Cecil Moore wrote:
Jim Kelley wrote:

Consider the nature of dielectric materials. I could be wrong, but I
bet if you stuck a negative oxygen ion on the outside of a jacketed
conductor, you could make the conductor inside think you had put an
electron directly on it.


The question is whether the electron stays on the insulation
or migrates through it to the conductor.

Actually, the question is whether or not one can hear the resulting
noise.

The size of the charge Vs the dielectric determines how
much of the charge actually reaches the conductor.

Perhaps you mean the amount of charge Vs. the dielectric determine the
voltage.

When
I went from bare wire to 600v insulation, my precipitation
static problems decreased considerably. Then when I went to
1000v insulation and a full wave loop, most of my precipitation
static problems disappeared.

I see your point. The poorer the dielectric and the greater it's
thickness, the lower the induced voltage. There should be some
effect, yes. What'd you use, 20 meters of CRT anode wire or spark
plug wire? :-) The point with which Tom seemed to take issue was the
implication that an antenna with low DC resistance would have lower
precipitation static noise. I also disagree with that notion.

The worst case of precipitation static seems to be for
airplane antennas. Insulation is the recommended cure
although folding is also mentioned. Please do a web
search for "precipitation static" and see for yourself.

http://www.atis.org/tg2k/_precipitation_static.html

I'm glad we agree on the definitions. In one of your previous
references I noted the term precipitation static used (incorrectly) to
describe the noise associated with static discharge. This is a
distinction I attempted to point out in my earlier post.
Precipitation, among other things, can cause charge to accumulate on
objects which are insulated from ground. This accumulation can
continue to increase until breakdown occurs, causing a spark and a
noise which is big enough to knock down the receiver AGC for a few
seconds (or worse). Precipitation static is the noise which is
apparent when a relatively high flux of ions impinges upon an antenna.
Low DC impedance antennas won't accumulate large amounts of charge
or generate a static discharge, but they are nevertheless sensitive to
the static noise just as any other antenna would be. In other words,
you and Tom W8JI are both right - you just don't know why. ;-)

Did you see the article in Harper's magazine on W6AM? Pretty neat.
Even that article mentioned precipitation static.

73, ac6xg

Jim Kelley wrote:
Cecil Moore wrote:
The size of the charge Vs the dielectric determines how
much of the charge actually reaches the conductor.

Perhaps you mean the amount of charge Vs. the dielectric determine the
voltage.

size = amount = magnitude = amplitude. It is hard to visualize
how a charge could make it to the conductor without the migration
of a quantum particle.

The point with which Tom seemed to take issue was the implication
that an antenna with low DC resistance would have lower precipitation
static noise. I also disagree with that notion.

Both of you misunderstood the definition of "noise" that I was
using. With the feedline completely disconnected from the
transceiver, arcing occurred and that aural noise woke me up at
night. It was aural noise from the arcing caused by precipitation
static charge tansfer that woke me up and a low DC resistance
eliminated it.

Precipitation
static is the noise which is apparent when a relatively high flux of
ions impinges upon an antenna. Low DC impedance antennas won't
accumulate large amounts of charge or generate a static discharge, but
they are nevertheless sensitive to the static noise just as any other
antenna would be. In other words, you and Tom W8JI are both right - you
just don't know why. ;-)

When a charge hits a closed loop, there are two paths it can take
to equalize the charge around the loop. Only one of those paths
is through the receiver and that is a higher impedance path than
the other path. When a single-wire dipole needs to equalize the
charges between the dipole elements, there is only one path available
- through the receiver which often has a capacitor in series and thus
blocks DC charge equalization. This is, of course, not the only reason
that a loop is quieter than a single-wire dipole but is simply one of
the reasons.

Incidentally, "Quietflex" antenna wire, with its 1000v insulation
reduced the problem to an acceptable level in the Arizona desert.
I still use that wire for my dipoles.
--
73, Cecil http://www.qsl.net/w5dxp

H. Adam Stevens, NQ5H wrote:
I once had a ladder line fed doublet.
It was disconnected at the feedthroughs because a thunderstorm was about ten
miles North.
I could pull 1 inch arcs off the feedthroughs to a grounded wire.
Made me think of Ben Franklin.

For sure, a gradient is established by thunderstorms
resulting in all sorts of electrical and magnetic
phenomena. But the particular type of noise I am
talking about is precipitation static caused by
charged particles hitting a bare wire dipole when
one element of the dipole is floating. In particular,
this type of noise can occur in the Arizona desert
when there is not a cloud in the sky. Here is how
"precipitation static" is defined:

http://www.atis.org/tg2k/_precipitation_static.html

"ATIS is a United States based body that is committed to
rapidly developing and promoting technical and operations
standards for the communications and related information
technologies industry worldwide using a pragmatic, flexible
and open approach. ATIS is accredited by the American National
Standards Institute (ANSI)."
--
73, Cecil http://www.qsl.net/w5dxp