Art Unwin wrote:
Ceci
If the surface of a conductor is completely covered by precharged
particles
and is aprouched by a changing electrical field would it not it be
opposed by the
electric field pre placed on the surface?

The charged particles (electrons) are the carriers of the
RF wave. The negative charge of the electrons seems to matter
little in the generation and sustaining of RF EM photonic waves
since photons are generally assumed to possess neutral charge.
However:

From PhysicsWeb News: "A physicist in the US has analyzed radio waves
from distant galaxies to obtain a new upper bound on the electrical
charge of the photon. Brett Altschul of Indiana University has found
that the charge is no more than 10^-46 times the charge of the electron
— assuming the existence of photons with positive and negative charges.
This is 13 orders of magnitude better than the previous direct bound on
the charge of a particle that we normally assume to be neutral".
--
73, Cecil http://www.w5dxp.com