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-   -   Rain Static ? (https://www.radiobanter.com/antenna/111179-rain-static.html)

Deni F5VJC December 9th 06 06:20 AM

Rain Static ?
 
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?
I thought the auto ATU would in itself provide a static bleed path,
but apparently not.

Any thoughts, how have you solved this?

73, Deni

F5VJC


Dave December 9th 06 11:32 AM

Rain Static ?
 
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?
I thought the auto ATU would in itself provide a static bleed path,
but apparently not.

Any thoughts, how have you solved this?

73, Deni

F5VJC

Are you sure it's rain static?

Most all verticals have higher noise levels than horizontal antennas. Reason, as
it is reported, is that man made noise is vertically polarized.


Cecil Moore December 9th 06 12:52 PM

Rain Static ?
 
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 December 9th 06 12:57 PM

Rain Static ?
 
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

Deni F5VJC December 9th 06 02:11 PM

Rain Static ?
 


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


John Smith December 9th 06 03:27 PM

Rain Static ?
 
Dave wrote:
...

Most all verticals have higher noise levels than horizontal antennas.
Reason, as it is reported, is that man made noise is vertically polarized.


Dave:

Frankly, I think that the statement, "most man made noise is vertical
polarized" is a myth. How many power lines do you see running
vertically? How many extension cords do you see running vertically?
How many phone lines do you see running vertically? Etc, etc.

I think this needs looked at in a new light. Now most 160m antennas are
easier to construct for horizontal operation--perhaps this is where the
myth got started?

Regards,
JS

John Smith December 9th 06 03:45 PM

Rain Static ?
 
Deni F5VJC wrote:
...
Any thoughts, how have you solved this?

73, Deni

F5VJC


Deni:

Perhaps a very high resistance hooked to the radiator and gnd would be
the quick, cheap fix?

Regards,
JS

Cecil Moore December 9th 06 04:14 PM

Rain Static ?
 
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 Moore December 9th 06 04:16 PM

Rain Static ?
 
John Smith wrote:
How many power lines do you see running vertically?


How many ground wires do you see running vertically
from power pole capacitors and transformers? :-)
--
73, Cecil http://www.w5dxp.com

Cecil Moore December 9th 06 04:17 PM

Rain Static ?
 
John Smith wrote:
Perhaps a very high resistance hooked to the radiator and gnd would be
the quick, cheap fix?


Perhaps not. Such is already provided inside the SG-230.
--
73, Cecil http://www.w5dxp.com


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