RadioBanter - Noise level between two ant types

Cecil Moore wrote:
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.

Only when it is AT THE FREQUENCY the receiver is tuned to.

So when you provide a DC path that does not short the antenna at radio
frequencies, it does nothing.

The only exception to this is if the charge actually causes something
to arc, but even then it is a long term buildup of charge.

This is simply a false statement.

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

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?

I haven't lived in Georgia all my life. Most of my experience with this
is actually in Ohio, but on other reflectors like TowerTalk everyone
seems to share the same common experiences.

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.

We agree there. So why are you arguing?

If it charges the antenna to the point where a dielectric fails the
sudden change will make a terrible noise and may even cause damage.
This is why no one should have a large element high in the air that
does not have a leakage path.

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.

In that case a ground on the floating side would make no difference, or
if anything make it worse. Think about it, or draw it on paper. The
charge differential (as you say above) is between the floating
particles and the earth. The greater the charge difference, the larger
the amount of charge transferred (as you said above).

If we agree on what you say above, the "millions of unsynchronized
collisions" would not impart less charge to the antenna when it is
closer to earth potential, they would impart more.

The fact is a dc path doesn't change a thing with one single exception,
the dc path prevents an antenna from building a charge in the
capaciatnce of the system, and prevents that voltage from building to
the point where some dielectric fails. Indeed that happens, and that is
why large high antennas should have a leakage path to earth.

Even on a clear calm day my 160 dipole at 300 feet, if I let the coax
dangle a few feet above earth, will knock a person for a loop when
touched. Inactive power lines, when open circuited, have to be clamped
to ground for the same reason. On a windy day the recharge rate of the
dipole is faster, and faster still in inclement weather.

When the weather is bad, there is corona off the antenna that makes a
sizzling sound that starts out as a series of slow pops and builds to
the point where it almost turns musical or tonal. If lightning flashes
even far in the distance, it immediately stops and rebuilds. The higher
the antenna and the sharper and more extended the ends, the worse the
problem is. Even when no moisture is hitting the wire.

73 Tom