Richard,

OK, I will turn this right back at you. How do you know that the
countless Faraday screens remove the E-field component from
electromagnetic waves?

"Saying it does not make it so."

Yes, I understand they are used in broadcast transmission lines, and
yes, I understand they take many lightning hits.

Faraday screens are effective. How do you know that they also negate the
fundamental properties of time-varying electric and magnetic fields as
expressed by Maxwell's equations?

73,
Gene
W4SZ

Richard Harrison wrote:
Gene, W4SZ write:
"As has been said many times on this newsgroup, it is not possible to
filter out one field component or the other."

Saying it does not make it so.

Countless Faraday screens are at work removing the E-field component
from electromagnetic waves. Faraday said that the voltage in a coupled
circuit depends only on the rate of change of the magnetic flux through
the circuit. He was refering to induced voltage. It was 1831 when
Michael Faraday observed the interaction between primary and secondary
coils in what was likely the world`s first transformer. Faraday made it
himself and noted that the needle of a galvanometer connected across one
coil deflected briefly whenever he connected or disconnected a battery
across the other coil.

Gene, W4SZ wrote:
"How do you know that they also negate the fundamental properties of
time-varing electric and magnetic fields as expressed by Maxwell`s
equations?"

I did not make that claim.

Pits from the lightning strikes are evidence that the voltage gradient
is high between the coil and the Faraday screen. The second coil is
clean, not pitted.

I explained the operation of a Faraday screen earlier but was
misunderstood so I`ll quote a professional writer and consulting
engineer, B. Whitfield Griffith, Jr. who writes on page 246 of
"Radio-Electronic Transmission Fundamentals":

"It is often desirable and practical to allow one type of coupling
between circuits and eliminate the other. Figure 28-1, for instance,
shows two coils which are coupled but have a special type of shielding
between them that causes the coupling to be purely inductive and not
capacitive, This shield consists of an array of parallel wires which are
grounded at one end only. The lines of electric force from the coils
terminate on these grounded wires, so that there are no electric lines
of force passing from one coil to the other and hence no capacitive
coupling. On the other hand, since the wires do not form closed loops,
there is no circulating current in the shield and therefore nothing to
stop the penetration of the shield by the magnetic field. This type of
shield has long been known as a Faraday screen. It is important that the
capacitive coupling be eliminated in many cases, since it has the
characteristics of a high-pass filter, tending to accentuate the
harmonic content of the transmitted signal."

I never tried it, but I`d bet that someone has measured the radiated
harmonics both with and without the Faraday screens inplace. That would
prove effectiveness.

Short-circuiting the open ends of the Faraday screen wires would kill
transfer of the signal between primary and secondary of the transformer,
and the transmitter would likely complain.

Best regards, Richard Harrison, KB5WZI