RadioBanter - View Single Post

June 12th 06, 11:52 PM posted to rec.radio.amateur.antenna

"Cecil Moore" wrote in message
news

wrote:
You can a call me a liar if you like, but it doesn't change the facts.

Being ignorant doesn't make you a liar. The fact is that
many hams have experienced charged particle noise. Your
denial of such doesn't change the known facts.

The meaning of most of your posting escapes me so I will
just summarize my position.

When I lived in the Arizona, clear-sky wind-driven charged
dust particles transferred lots of energy to my bare-wire
G5RV. It caused arcing whether the outside braid was grounded
or not. It only happened when the wind was blowing and
the humidity was very low.

I'm not sure what your point of disagreement is so help
me out.

Youze guyz are arguing about two cases of "arcing" and going off on
tangents.

First case is as Cecil has experienced and 'splained, is the static
electricity charge buildup and corresponding noise/discharge on conducting
"things" due to charged particles - aka rubbing the glass rod with furry
animal coat. The part (antenna) gets charge from the "rubbing" by the
particles, air, whatever...., builds up voltage and is looking for discharge
across anything that provides jumping points for the voltage accumulated.
This is the case of clear Arizona skies, with no clouds in sight, just wind
doing it's "thing". W8JI might not believe it, but it IS the fact.

Second case is, as it was hotly discussed on Contest and other reflectors,
and first mentioned by VE3BMV, W0UN, W4ZV and others, in conjunction with
lightning and protection against it - is the static electricity charge
buildup due to the clouds "rubbing" in the air and creating huge static
charge between the clouds and the earth ground and objects "residing" on
ground and connected to it. There the highest , mostly grounded, objects get
"first crack" at the "touching" the voltage gradient generated by the static
electricity buildup. If there is a sharp object, it will start "acting" by
generating corona and "peacefully" discharging the potential. If it can't
keep up with rate of "peaceful" charge, it will invite lightning strike. The
corona can be visible at the times, or it doesn't have to be.
Then we get cases when the high antenna is the highest object and will be
the "discharger" and the noisiest one. That appears to discharge the charge
from the area (space) in the vicinity of the high (object) antenna -
umbrella. You can look at it as a capacitor plate, collecting charge from
the space around it. Lower antennas get benefit of discharged space and are
quiet. This is especially noticeable with stacked antennas. The top one
would be typically 20/9 noise - hash, the lower one would be dead quiet.
The same then applies when you have higher object than antenna in question,
that antenna could be quiet, but when (beam) is aimed at the higher object
(the static discharger) it can receive noise, but at much lower strength.

This umbrella effect seems also work as a lightning prevention by
discharging the space in the vicinity of the structure and preventing
critical buildup of voltage causing creating of leader and inviting
lightning strike (99.9%). I and others have noticed practical elimination of
lightning strikes to our installation when sporting tall, grounded towers
with large antennas (capacitor plates). They seem to bleed the deadly
potential from the air "sandwich" between the sky (clouds) and ground and
objects under the "umbrella" and making lightning look at pointy grounded
objects before and after our "ugly" antennas and discharge their deadly
megawatts there.
So large antennas on tall towers - GOOD to repell lightning. Pointy, sharp
objects - BAAAAD, they attract lightning. So, one can protect his QTH and
radio junk by either inviting lightning to strike the lightning arresters
and hopefully conduct them to ground, or better, repelling it by the Antenna
Umbrella - the biggest mother antenna (capacitor plate) on the tallest
possible and well grounded tower (no protruding VHF vertical pointy junk
above) you can put up.

Scientwists might not find this believable, but those with big towers and
large grounded antennas noticed remarkable absence of direct lightning
strikes vs. when previously sporting pointy verticals or towers without
antennas on the top.
When I had my TH6 at 60 ft. and above it, way up 2m Ringo Ranger on a mast,
I got visited by direct lightning trice within 2 years. When put up Big
Bertha with 60 ft boom Razors, never again over 10 years. Not very
statistically scientific, but very noticeable. Same experienced by W0UN,
W0ZV and others.

Soooo, the judge's verdict is: Cecil is right, W8JI is partially right, jury
to judge by the above 'splanation of this humble servant. :-)

I hope this clears some static static.

--
Yuri Blanarovich, K3BU, VE3BMV