Deni F5VJC wrote:
I have recently been plagued by rain static on a new vertical antenna,
this a 42 foot vertical fed at the base through an SG230 auto tuner,
and used on all bands. It seems I need a static bleed of some sort, a
choke or resistor. What is the best component to use in an outdoor
environment?

Take a look at page 4 of the schematic. There is already
a static bleed through 20 turns on a transformer winding
to ground plus about 40K ohms of resistance to ground. You
are already bleeding the static charge, just not fast enough
to get rid of the RF content. The problem is that the
RF content of the precipitation static is finding its
way through your receiver along with the desirable RF
signals. Question is: Is there something that discriminates
against local RF static without discriminating against
desirable RF signals?

Here's my two cents and others certainly do vehemently
disagree with me.

A single precipitation static charge transfer is at a
localized point. Desirable arriving RF waves/photons are
spread out over the entire antenna. That should make them
separable.

Folding the antenna into a loop is one way to reduce
precipitation static. Desirable arriving RF waves are
unaffected by folding as they encounter the entire antenna,
i.e. it's hard to tell the difference between the
performance of a dipole and a folded dipole.

Single charges of precipitation static, however, are
confined to one point on the antenna. If there is a discharge
path to the other side besides through the receiver, the
charge will at least partially take the shortest path of
reduced resistance. IMO, that's why folded antennas are
quieter than open-ended antennas as far as precipitation
static is concerned.

The way I reduced the problem with open-ended antennas is
to use heavily insulated wire. Bare conductors transfer
all charges. 600 volt insulation blocks charge transfer. In
my experience, 1000v insulation blocks most charge transfer.
I use something called "Quietflex" that has 1000v insulation.
Most of the precipitation static doesn't transfer to
the antenna wire while RF waves/photons flow right
through the insulation with little attenuation. I suspect
plastic encased antennas are quieter than bare antennas.

There is a wealth of information on precipitation static
on the web, a lot of it having to do with antennas on
airplanes. Folding and insulating are two ways they have
solved the problem.

Folding or insulating your vertical may or may not be
feasible. If you solve your problem, please share it with
us here.
--
73, Cecil http://www.w5dxp.com

Cecil Moore wrote:
600 volt insulation blocks charge transfer.

Lest I be nibbled to death by a flock of angry geese,
this should be, "600 volt insulation blocks *some*
charge transfer." Leaving out the word "some" was
a typo.
--
73, Cecil http://www.w5dxp.com

On Dec 9, 1:57 pm, Cecil Moore wrote:
Cecil Moore wrote:
600 volt insulation blocks charge transfer.Lest I be nibbled to death by a flock of angry geese,
this should be, "600 volt insulation blocks *some*
charge transfer." Leaving out the word "some" was
a typo.
--
73, Cecil http://www.w5dxp.com

Interesting Cecil, my vertical antenna is constucted from a 42 foot
length of coaxial cable using the outer braid as the radiator (but the
inner and outer are shorted together anyway) and this fat vertical
"wire" is suspended inside a telescopic fibre glass pole from
Spiderbeam ( not the conductive type). So, I guess my verical wire is
quite well insulated and certainly not in contact with charged rain.
We've had particularly heavy rainstorms lately in France and this is
definitely rain or rain induced static., starting and stopping in
sympathy with the rain storms very easy to identify.
73, Deni
F5VJC

Deni F5VJC wrote:
So, I guess my verical wire is
quite well insulated and certainly not in contact with charged rain.
We've had particularly heavy rainstorms lately in France and this is
definitely rain or rain induced static., starting and stopping in
sympathy with the rain storms very easy to identify.

Is anything about your antenna in contact with charged
rain? Your noise problem might have the same cause
as lightning, i.e. the global atmospheric electrical
circuit. You might be experiencing simple corona
discharge.
--
73, Cecil http://www.w5dxp.com

Cecil, can you state that if an antenna is in the house one would not
hear static?
I seem to remember that when I was at the top of a mountain in a rain
forest I put the antenna inside the car but the noise was S9 plus....
no communication could get thru
Bearing this in mind static noise was radiated to the antenna was it
not? So why cannot a droplet falling at 32 ft per sec sq not produce
radiation or if it impacts a dielectric transfer a electric charge with
curl? Isnt this lightning on a small scale? What I am getting at I
suppose
is if the antenna is protected from the environment and gets static
noise surely it is a radiaated phenomina. IR antennas have never stated
that their antenna was immune to static!


Cecil Moore wrote:
Deni F5VJC wrote:
So, I guess my verical wire is
quite well insulated and certainly not in contact with charged rain.
We've had particularly heavy rainstorms lately in France and this is
definitely rain or rain induced static., starting and stopping in
sympathy with the rain storms very easy to identify.

Is anything about your antenna in contact with charged
rain? Your noise problem might have the same cause
as lightning, i.e. the global atmospheric electrical
circuit. You might be experiencing simple corona
discharge.
--
73, Cecil http://www.w5dxp.com

art wrote:
Cecil, can you state that if an antenna is in the house one would not
hear static?

I can state that if an antenna is in a closed house one
would not hear *precipitation static* which by definition,
involves charged particles. Here's the definition.

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

But there are lots of other kinds of static. I just heard
on The Discovery Channel that a certain percentage of the
static we hear is left over from the Big Bang that happened
some 12.5 billion years ago. There's lots of static here
in East Texas, mostly from lightning and old power line
equipment. I have never noticed precipitation static in TX
or in CA. But it was overwhelming in the Arizona desert.
--
73, Cecil http://www.w5dxp.com

Cept the Big Bang wasn't...
Looking back in time by looking out into the universe is only partially
correct (yes those photons may have traveled 12 billion light years to
get here, that does not make them the beginning of the universe, it
only makes them as far as we can see at this point in our technology
....
There is a force pushing mega amounts of matter (clusters of galaxies)
apart in spite of the local gravitational well that by BBT has to be
pulling them back together - a force that was absolutely NOT predicted
by the BBT nor can be accomodated by it without adding some constants
here, removing some there, changing the value of this and tweaking that
- and those frantic tweaks again and again are not as a result of
calm, cool, theoretical considerations, but because the *^&$#)@!
universe is not cooperating!...
As a scientific explanation the BBT resembles The House that Topsy
Built, only more rickety...
And then there is the little complication that there is NOW energy
contained in every cubic inch of empty space, and E = MC^2, and -oops-
the total weight of the universe has changed 'again', the Hubble
constant rolls off into the weeds 'again' ...
"Bring me the big erasor, we've got some constants to modify 'again',
Earl."

denny / k8do

"Cecil Moore" wrote in message
t...
art wrote:
Cecil, can you state that if an antenna is in the house one would not
hear static?

I can state that if an antenna is in a closed house one
would not hear *precipitation static* which by definition,
involves charged particles. Here's the definition.

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

But there are lots of other kinds of static. I just heard
on The Discovery Channel that a certain percentage of the
static we hear is left over from the Big Bang that happened
some 12.5 billion years ago. There's lots of static here
in East Texas, mostly from lightning and old power line
equipment. I have never noticed precipitation static in TX
or in CA. But it was overwhelming in the Arizona desert.
--
73, Cecil http://www.w5dxp.com

IMO there seems to be a corellation between how dry the air is before the
rain starts and how much static is generated.

"Cecil Moore" wrote in message
t...

snip

I just heard
on The Discovery Channel that a certain percentage of the
static we hear is left over from the Big Bang that happened
some 12.5 billion years ago.

Yes and no. There certainly is something termed galactic noise and most of
it has apparently been ricocheting around the cosmos all this time. It was
first discovered by Bell Labs scientists using a supercooled microwave
amplifier whose noise was higher than expected. They covered the feedhorn
and lo! ... The noise dropped!

http://www.amsat.org/amsat/archive/a.../msg00336.html retells
part of the story.

There's no way any of us will be affected by galactic background, however,
We'd need a system noise temperature better than 3K (That's 3 Kelvin, not
3,000) to detect it. The best consumer LNA's are way noisier. BTW, some
parts of the sky are "hotter" than this background level; if we use a low
noise TVRO dish system, we could detect a few star clusters. Of course the
sun and the moon can be detected.

Cecil Moore wrote:

The way I reduced the problem with open-ended antennas is
to use heavily insulated wire. Bare conductors transfer
all charges. 600 volt insulation blocks charge transfer. In
my experience, 1000v insulation blocks most charge transfer.

Your radio doesn't actually hear clear down to DC, does it? :-)

The effect is heard as a result of the charge striking the antenna,
thus changing the charge on the antenna. As you know, for a given
capacitance, a 600 volt dielectric couples charge just as well as a
1000 volt dielectric. In such a case the 'pop' is capacitively
coupled broadband noise. But whether the antenna is insulated or not,
looped or not, the static noise is due to a rapid (albeit small)
change in charge on the antenna being coupled by some means into the
receiver.

I use something called "Quietflex" that has 1000v insulation.
Most of the precipitation static doesn't transfer to
the antenna wire while RF waves/photons flow right
through the insulation with little attenuation. I suspect
plastic encased antennas are quieter than bare antennas.

Maybe. It would make sense that the amount of static noise coupled
from the environment would be proportional to the coupling
capacitance. Knowing that charge tends to gather on a surface, the
thicker the 'dielectric', the lower the capacitance. A small series
capacitor in most circuits would tend to differentiate an impulse,
producing a signal which is proportional to the slope of the impulse.
With larger values of capacitance the coupled signals tend to follow
the input. So although it's not likely that insulation would reduce
the number of noise 'events', it is possible that it would narrow the
resulting broadband power spectrum. This could be helpful, as long as
it narrows it in the part of the spectrum you happen to be using. ;-)

73, ac6xg