Hi Towertalkians,
Not long ago there appeared here some posts questioning if there was
anything that could be done about the build-up of rain static or wind static
on antennas. At the time I believe there were no posts which dealt with
alleviating the problem... with the exception of recommending that people
bothered by this phenomena investigate the feasibility of using various
cubical quad or delta loop arrangements wherein the driven elements were all
at DC ground potential... which naturally discharges any static before it
has a chance to build.
As I recall, this phenomena is also not a problem on grounded shunt fed
towers used as antennas. There were also several posts that explained there
were no outdoor antennas that were immune to a lightning strike and the
static discharge noise such a strike causes in receivers... let alone the
vaporization of said equipment with a direct hit. With all that said... I
promptly forgot about the subject until today.
As you all know the Northeast has just be hit with a fantastic snowstorm
dumping from several inches to several feet of snow on a population that is
almost chaffing at the bit to run to the sunny beaches. While the snow was
falling I happened to be listening on 20 Meters and I noticed a significant
build-up in the background static level on received signals which appeared
to increase with the ferocity of the wind driven snow.
Since I have a longstanding interest in meteorology I did some Web surfing
to see if I could come up with any research done on wind or rain induced
static precipitation on radio reception and if there really was anything
that could be done to mitigate the annoyance of the phenomena.
Wouldn't you know it! The Swiss have been plagued by this phenomena for
decades as ferocious winds whip through the Alps bringing with it snow and
horrendous amounts of static precip which renders both local and long range
communications impossible in the HF spectrum. Now the Swiss are not content
to take snow and wind lying down. The Helvetica Meteorological Society set
about researching the phenomena and investigating what if anything could be
done about it.
The results of their investigation will most likely not astound you. It was
found that a) the static WAS induced by wind friction (just as what happens
when you walk across a new carpet with leather soled shoes in the winter)
and not discharged by rain since most rain is mineral free water which
doesn't carry or dissipate static charges readily or even non-static charges
for that matter. b) that snow encrusted mountain slopes do not build static
charges as wind friction rubs against them and that likewise, skiers do not
build static charges as they careen across the slopes...... Interesting!
So, the only thing left to investigate was what was happening when those
same winds tore across metal objects like telephone wires and radio
antennas. Sure enough, what everyone knew already... was scientifically
validated... that the wind and rain caused electrostatic charges to be
induced in these metallic objects. Still the solution was baffling until
one of the researchers, a Dr. Igore Helfenschmaltz of the Bern
Meteorological Research Center chanced upon a fortuitous discovery while
doing some of his own laundry while his wife was busy having fun with the
kids on the slopes.
It seems that in the extremely dry Sahara dessert-like air of heated Swiss
homes friction induced static is also a terrible problem. Women's dresses
and skirts cling like mad to their pantyhose. Men wearing silk shirts have a
horrible time reading the daily newspapers with the paper clinging to their
sleeves blackening them with printers' ink. People get up from dinner
tables all over the country with paper napkins stuck to various garments.
It was all rather embarrassing until it all came to an abrupt end with the
introduction of a wash day product essentially similar to our Cling-Free
cloths which women (and some men) have been adding to clothes driers for
quite some time now.
Clothes come out static free and the Swiss have been happy ever since. This
phenomena struck Dr. Helfenschmaltz with the bright idea of trying the
Cling-Free anti- static wipes on his ham radio yagi antenna. He cranked down
his tilt-over tower and with a rapid application of the Swiss equivalent of
our Cling-Free product to all the exposed surface of his KT-34 beam he
quickly put the tower and beam back to their 25 meter height.
Dr. Helfenschmaltz said that he turned on his transceiver and immediately
noticed a fifteen to twenty-five decibel drop in the usual static level
which he instantly attributed to the application of the anti-static
chemicals. (I believe the responsible chemicals were silicones... but I'm
not sure on this point since it wasn't mentioned in the research and very
difficult to translate from the usual Swiss...which appears to be a polyglot
of German, French and Urdu). Gradually after several days the effect seemed
to be wearing off and so Dr. Helfenschmaltz again lowered his tower and beam
for a renewed application of the "anti-static" chemicals.
Again the static noise level dropped so significantly that for the first
time he was able to hear weak stations that were previously totally
inaudible. While he had solved the problem of the wind and snow and rain
static induced charges he had not solved how to keep the chemicals applied
to his beam since they always wore off within a few days.
Helfenschmaltz soon realized that the ultimate solution to the entire
problem was also aesthetically unpalatable but he forced himself to try it.
For the third time he lowered his crank-down-tilt-over tower and this time
he affixed the Cling-Free-like applicator cloths every ten centimeters along
the length of each element of his KT-34 beam with a good vinyl electrical
tape- probably Scotch 33+ since the Scotch 88 is difficult to import into
Switzerland. He also affixed the cloths the same distance apart across the
boom and down the mast being careful to not put tension on the final tape
wrap to prevent flagging. Then he cranked the works into the air and when
everything was securely locked in place... did the unthinkable. He climbed
the tower and taped the Cling-Free anti-static cloths every ten centimeters
down its entire length.
(When asked why he didn't do this when the tower was near the ground.... he
simply replied... "I forgot.")
As you can imagine the dozens upon dozens of boxes of anti-static wipes
taped to every surface of his tower and beam must have looked like a rare
sight indeed flapping in the normally quiet Swiss landscape. But he didn't
care! He said. He had had it with wind induced static precipitation and he
simply had to do somehtning about it. It was all in the name of research
anyway. Back in the shack he was overcome with joy as he tuned the length
and breadth of the HF bands which were now as static free as he had ever
heard while a fierce wind with driving snow pummeled his antenna and tower.
It wasn't a pretty or for that matter "quiet" sight.... all those cloths
flapping in the breeze, but with each flap a new application of anti-static
chemicals provided static-free reception for months and months and months.
And in the spring when the birds returned to the verdant valleys of the
Swiss Alps, Dr. Helfenschmaltz (who prefers to be called Igore by his
friends [pronounced Eye-gore] reports he hasn't sighted a single avian
perching on his beam. And so Towertalkians... peace is at hand in the war
on wind and rain induced static precipitation as well as unwanted avian
encroachment. Birds simply will have nothing to do with any structure that
smells like a clothes drier and is as slippery as a newly laundered load.
And a final bit of triumph in all this research can now be reported. As the
wind wildly whips the anti-static cloths to incessantly flog the aluminum
and galvanized steel of Dr. Helfenschmaltz' antenna.... he noticed a not so
subtle polishing effect on all the affected metal surfaces which caused
everything to sparkle and glint in the bright sunlight of the Swiss countryside.
Dr. Helfenschmaltz is being considered for a Nobel Prize in Meteorology (or
Laundry Science) and is currently seeking a patent for his antenna polishing
process. I just knew you all wanted to know these pertinent research results
so that you too can soon validate the Helfenschmaltz' research....as it was
reported on this memorable date in glorious Swiss history... April 1, 1997
[©1997 Roger Elowitz, K2JAS "Glorious Swiss Ingenuity"]
73 de Roger, K2JAS (Yes! Him Again!....ol' "Jolly And Smiley")
PS. Here's some meteorological trivia you may also have a need to know.....
a) I am not sure how clouds get formed. But the clouds know how to do
it, and that is the important thing.
b) Clouds just keep circling the earth around and around. And around.
There is not much else to do.
c) Water vapor gets together in a cloud. When it is big enough to be
called a drop, it does just that. (This is simple but clever.)
d) Humidity is the experience of looking for air and finding water.
e) We keep track of the humidity in the air so we won't drown when we
breathe.
f) Rain is often known as soft water, oppositely known as hail.
g) Rain is saved up in cloud banks.
Happy 1st of April ...All. Hope you weren't too "annoyed" to laugh.
--
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