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[TowerTalk] P-static vs. great balls of fire

To: "david jordan" <>, <>
Subject: [TowerTalk] P-static vs. great balls of fire
From: "Tom Rauch" <>
Reply-to: Tom Rauch <>
Date: Mon, 30 Aug 2004 15:37:45 -0400
List-post: <>
Hi Dave,

> Noise from point source such as a tower or building and
> static created when dropplets of rain or snow flakes that
are charged
> come in contact with the elements of a bare wire or beam

If the noise came from charged droplets, why would so many
people report noise as being significantly less on lower
antennas? People with stacked identical antennas report that
over and over again. Aren't charged droplets from the same
storm cloud hitting both high and low antennas in the same
time period?

Why would noise always be worse pointing a low antenna
towards a taller tower and much less when the low antenna
points away from the tall tower? After all, the same
droplets would be hitting the antennas no matter what
direction they are pointed.

> In the winter I can hear an approaching snow storm on my
160m dipole.
> Has anyone experienced a storm front in the winter
listening on a beam
> and then turned the beam away from the approaching front
and heard the
> noise floor drop?

I haven't for any whining, rapid pulsing, or hissing noise.
Over and over again, my highest identical antennas are
always much worse while the lowest antennas are much
quieter. Any antenna pointed towards the towers hears the
noise stronger (although much weaker conmpared to desired
signals than antennas on the tower) and my towers are NE of
some Beverages, and SW of others. Both groups of Beverages
are noisiest pointed at the big tower at the same time, and
both are quietest pointed away from the tall towers
regardless of storm direction.

The exception is lightning discharge noises, which also
almost immediately mute the hissing and whining when close.
Why would a lightning flash nearby instantly mute the noise
if it was charged droplets already on the way down? Why
would it rapidly build back from a low growing pitch to a
whine if the droplet flow was zero or any other steady
value?  Why doesn't the radio noise pitch follow the
acoustical noise of drops hitting a roof?

> My experience is there are several noise source scenarios.
The storm
> front which could be at a distance and approaching (not
> percepitation static),

OK. I can null the pops and crackles that make a very rough
overall sound when lightning flashes in large storms. For an
example listen to the sound file on my web page as I change
from a south west to a west to a northwest antenna while
listening to a JA.

or to this file

in the qrn-demo file, I'm changing directions every five
seconds with perfectly identical antennas. The JA file is
ten seconds on JA, and then 5 seconds each SW and W. My DX
sound file page has other examples, and when I get a chance
I'll add precipitation static demonstrations. I can easily
show lower antenna vs upper antenna.

>the combination of the local static due to
> charged rain drops or snow flakes as well as the mass of
the storm
> moving in the direction the beam is facing, and the third
being the
> local static produced by the charged rain drops and snow
flakes on the
> beam and other objects in the vicinity of the beam.

How do you know that the noise is from droplets or snow
flakes? What is the indicator of that being a cause? Why is
the intensity and pitch the same from nice little tiny
gently falling flakes and big heavy radidly moving drops?
Wouldn't you think mutiple slowly falling small flakes would
be a lower level noise like a hiss, and large drops that
could hold hundreds of times more charge and that hit almost
steady to be a noise like rain hammering on a roof? I'm not
trying to be sarcastic, but did anyone ever hear "Suzie
Snowflake" hammering on the roof? I would think the noises
would be totally different and track the ability to hold a
charge and the speed and frequency of impact, yet they are
the same sound. (I used to live in Ohio.)

> I've heard the distant noise of an approaching snow storm
and the
> distinct pops due to descrete discharges of drops of rain
on the beam
> elements.  These are very different sounding noise
sources. Once the
> approaching storm has arrived I've not been able to hear
the distinct
> discharges because the noise floor is too high to

If I stand on a building and listen to the corna hissing and
making an almost musical low pitched tone, it makes the same
sound as a receiver. It does this with or without raindrops.
When it starts is is a slow poping increasing to a growl and
finally a high pitched whine...regardless of how much the
moisture falling changes in intensity. As a matter of fact,
I hear it on my taller towers before any moisture appears.

> I've enjoyed using loop antennas in part because they
appear to me to be
> less suseptible to man-made noise, esp. when fed with
shielded twin lead
> to reduce common mode noise from long vertical runs of
single coax feds.

Why would a loop or how could a loop be more immune than a
dipole or any other antenna to propagated man-made noise

73 Tom


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