--- In [email protected], "Paul Plack" <[EMAIL PROTECTED]>
wrote:
>
> Dick, if only that were true...
>
> Anything which changes the dielectric constant of the immediate
antenna environment detunes the antenna, conductor or not. The power
companies AVOID resonance in their transmission networks, and don't
measure SWR, so they're concerned only with the mechanical effects of
the added weight.
>
> FM and TV Broadcasters go to much trouble and expense to maintain
antenna heaters to deal with this issue. Some use ice detectors which
evaluate precip and temp on the tower, to turn on the antenna heater
automatically when conditions are favorable for ice formation.
Otherwise, ice can form so fast the heaters can't keep up, and some
broadcast stations have to shut down when SWR gets too high due to
ice.
>
> 73,
> Paul, AE4KR
Well, it is true... but it also depends on where you are!
I see that you have a 4 callsign prefix, which I think would put
you in the southern USA and east of the Misissippi River, without
looking at a map. Out here in the western edge of 7 land, and I'm
about 50 miles east of the Pacific Ocean, and 50 miles south of
Portland, we don't have the pollution (sp?) that the atmispheric
water picks up in the travel east.
Our Oregon "Bullrun Watershed" water is so pure that it's only
pollution is from the wildlife as they naturally leave droppings, but
when they ocasionally clean up that area (east of Portland) from
storm damasge, they use horses instead of mechanical equipment, and
then they put diapers on the horses!!! They don't try to diaper the
deer!! Hahahahaa!!!
In addition to having worked in Mobile Radio Communications before I
retired, I also worked in Broadcasting, and we didn't have that
trouble either place. Our only precaution was ice shields above the
studio / transmitter and other microwave parabolas to protect them
from falling ice from the antennas...
You may have heard about the weather disasters our coastal areas had
a couple of weeks ago, with bad rain and flooding, but the telemetery
charts from the Tillamook County Communications sites showed no
change of SWR that I saw. Pollution in the rain / snow makes a BIG
differance!! Pollution conducts, but naturally distilled rain and
snow water doesn't!!
However, that doesn't apply to the Los Angeles area, right on their
coast, as I've flown through such bad pollution getting into and out
of their airports that it was like flying through fog... and the
eyes burned from it!! Hahahaha!!
Best,
Dick
> ----- Original Message -----
> From: ocwarren2000
> To: [email protected]
> Sent: Tuesday, December 18, 2007 9:44 AM
> Subject: [Repeater-Builder] Re: Remote power monitoring
>
>
> --- In [email protected], Kris Kirby <kris@> wrote:
> >
> > On Sun, 16 Dec 2007, Eric Lemmon wrote:
> > > One question comes to mind: Is it really necessary that you
know
> > > exactly what the forward/reverse power readings are, or the
SWR, or
> > > are you concerned about whether the values have drifted
outside a
> > > certain tolerance? I think that I would want to hear a voice
> > > notification that power is abnormally low, or the SWR is
abnormally
> > > high, rather than the value.
> >
> > I always wondered how much a few inches of radial ice detuned
at DB-
> 224.
> > ;)
> >
>
> Well, have you noticed the ice on power poles and how it gets
> caked on and yet causes no outages, particularly on the primary
power
> towers going cross country? The only ice failures is the
breakages as
> a result of the weight, because the ice is frozen distilled water
and
> doesn't conduct. Surprised?? As such it shouldn't cause a change
in
> SWR..
>
> Check the Tillamook County, Oregon site and it shows telemetery
chart
> of such things, of Mt. Hebo and Caper Mears installations, right
on the
> Coast. Their power output will change, but not the SWR, and yet
they
> are on the West Coast of the USA at the shore of the Pacific
Ocean!!
>
> Best wishes,
>
> Dick, W7TIO
> > --
> > Kris Kirby, KE4AHR <kris@>
> > But remember, with no superpowers comes no responsibility.
> > --rly
> >
>
