[TowerTalk] Rain static

[Tom Rauch]

 > > That would be consistent with charged drops (or
snowflakes
> > or dust
> > > particles) that hit the "thing" and steadily deposit
> > charge.  The voltage
> > > builds up, and periodically discharges.
> >
> > It would be consistent with the entire earth charging at
a
> > different potential than clouds as the earth collects
many
> > more water, snow, or dust particles than the antenna
that is
> > connected somehow to earth.
> >
>
> again, note that precipitation is not even required.  The
electric field
> near the earth increases enough to cause corona discharge
from antennas just
> due to the presence of a charged cloud above you.

Which once again is consistent with how the system behaves
in real life. I often have the noise appear when it is not
actually raining here yet. Same thing with hissing guy wire
points or other from other protrusions on large towers (like
500 foot towers).

Of course this doesn't exclude other proposed causes like a
tiny noise generated when a water droplet connects to the
antenna conductor, it just fits what happens in the real
world much better.

So we see this thread repeats over again the same
observations from multiple sources:

1.) Noise can occur without anything hitting the antenna
2.) Grounded antennas still have the noise
3.) Noise level or pitch does not often appear correlate
with rate of droplet contact, but noise level commonly is
reported to track with height of antenna being used
4.) The same "stuff" hitting a low antenna and a high
antenna does not produce the same noise level
5.) The pitch is the same on all antenna in a close cluster,
level changes are the same, but levels are not the same with
higher antennas being more problematic for noise level
6.) If I insulate an entire antenna except for a single
sharp conductive point that protrudes (PhelpsDodge Super
Stationmaster antenna for example) it still has the same
noise problems as a bare antenna (like folded dipoles), and
the problem stays regardless of being "dc grounded" or not.
7.) If I get near the worse antenna when this is happening,
I can hear an acoustical noise that matches the pitch of RF
noise. Corona does that.

This is why I don't consider the "droplet making a noise
discharge when it hits the antenna element" theory a primary
effect, if it is any effect at all.

73 Tom