RadioBanter - View Single Post

June 11th 06, 11:50 PM posted to rec.radio.amateur.antenna

wrote:
I don't have a lifetime to spend picking nits with Cecil, but I do
resent his immediate implications I haven't looked at the closely for a
long time.

Do you think the people who report the problems that you haven't
experienced and don't understand resent your assertion that they
believe in magic? The actual magical thinking is asserting that
charged particles don't transfer part of their charge to bare
wire antennas.

In my experience the vast majority of noise people complain about is
caused by corona from the element or something in the immediate area of
the element.

That may be true but we are not discussing corona noise. Exactly
where do I go wrong in the following explanation?

1. A highly charged particle encountering one element of a bare
copper wire dipole will transfer approximately half its charge
to the wire.

2. A charge unbalance between the two elements of a dipole will
cause a differential current to flow in a link coupled system.

3. The differential current may be detected by an RF receiver.

Now I'm sure there will be some cases where people disagree with this,
but anyone who can A-B-C test antennas will find that other than a pop
or arc across a dielectric from antennas that accumulate enough charge
to exceed charge leakage the only thing that really matters is how
"pointed" the antenna is and how exposed the points are to the air
around the antenna.

This is simply a false statement. Many desert hams, like
myself in the 1990's, have experienced another kind of noise.
I've never experienced it from snow, but I can understand
how it could happen with snow falling through dry air. The
snow phenomenon has been reported here on this newsgroup.

All that crud hitting the antenna isn't significantly different in
potential than the air around the element, it just has a lower
impedance.

Absolutely false! Charged dust particles are a fact of life
in the Arizona desert. There is often not enough moisture in
the air to discharge them. Your limited experience is showing.
How often does the relative humidity get down to 10% with
high winds and dust in Georgia?

As a matter of fact, it is rather silly to claim the particles
discharging make noise and then at the same time claim that a DC path
somehow reduces or eliminates that noise.

I didn't claim it "reduces or eliminates that noise". I claimed
it eliminates arcing which is certainly a type of noise.

The CLOSER the antenna would
be allowed to float to the potential of the particles the LESS change
in potential would occur. Pulling the element to earth would make each
tiny discharge worse and make more noise, not less.

My problem was that 1/2 of the antenna was at DC ground potential
and the other half was floating which is typical of a store-bought
G5RV. That seems to cause the worst case of arcing. But it is simple
physics to realize that each particle acts independently. The charge
transfer from each particle causes a tiny differential current between
the two elements of the antenna. Millions of unsynchronized collisions
per second certainly would produce differential RF noise.

A link-coupled balanced dipole system would probably never arc but
there would be a differential noise pulse through the receiver as
described in the graphic in my other posting.
--
73, Cecil http://www.qsl.net/w5dxp