chuck wrote:
What is elusive is how the charges get changed into a
detectable signal.

Yes, there's a broad range of possible explanations.
One interesting theory is that uncharged particles
rubbing against an uncharged antenna results in a
triboelectric effect that, after contact, leaves the
antenna and particles with opposite charges. You might
call it the relativity theory of charged particles. :-)

Will you tell me again how we know that non-coronal p-static exists?

By definition, corona requires ionization of the air
which requires a certain current through the air, i.e.
at least a small arc. The question is, can p-static
exist and be heard below the corona threshold?

In 1939, another C. Moore, W9LZX, solved the corona
problem at HCJB in Quito, Ecuador by inventing the
cubical quad antenna. Describing the problem with the
Yagi beam: "Gigantic corona discharges sprang full-
blown from the tips of the driven element and directors,
standing out in mid-air and burning with a wicked hiss
and crackle. The heavy industrial aluminum tubing used
for the elements of the doomed beam glowed with the
heat of the arc and turned incandescent at the tips.
Large molten chunks of aluminum dropped to the ground
as the inexorable fire slowly consumed the antenna. The
corona discharges were so loud and so intense that they
could be seen and heard singing and burning a quarter-
mile away from the station."

So Clarence Moore invented the cubical quad to solve
the corona problem. One must admit that the cubical
quad at least reduced the corona problem by many
magnitudes during transmit. One must also admit that
the corona problem during receive is magnitudes below
the problem during transmit. At some level, the air
ceases to be ionized and corona ceases to exist, by
definition. What can we conclude by applying the
principle of antenna transmit/receive reciprocity?

Comparing the Yagi to the cubical quad is similar to
comparing a single-wire 1/2WL dipole to a full-wave loop.
The ground referenced loop with its rounded corners
certainly reduces the corona threshold level. It is
possible that the loop is quieter *because* it is below
the corona threshold and the single-wire dipole is not.
Can we hear p-static on a full-wave loop? Yes, I have
heard it on a clear-sky, low-humidity, windy day in the
Arizona desert. Did it occur without ionization of the
air? There probably were no points (pun intended) in the
system conducive to corona discharge.

Obviously a qualitative argument rather than a quantitative
one but possibly valid nonetheless based on the Quito
experience.
--
73, Cecil http://www.w5dxp.com