Ed Price wrote:

"Robert Baer" wrote in message
...
Ed Price wrote:

"Watson A.Name - "Watt Sun, the Dark Remover""
wrote
in message ...

"Some Guy" wrote in message
...
What a load of horse ****.

You guys are acting as if the engines and flight control surfaces of
an aircraft are intimately tied to the plane's radio receiver, and the
slightest odd or out-of-place signal that it receives is enough to
send any plane into a tail spin.

No, the laws say that you can be arrested for breaking them, and one
way
to break them is to use a FM radio while the aircraft is flying.

All this while the air travel industry is considering allowing
passengers to use their own cell phones WHILE THE PLANES ARE IN FLIGHT
by adding cell-phone relay stations to the planes and allowing any
such calls to be completed via satellite. So I guess the feeble
radiation by my FM radio (powered by 2 AAA batteries) is enough to
cause a plane to dive into the ocean, but the guy next to me putting
out 3 watts of near-microwave energy is totally safe.

You don't know what you're talking about. With the attitudes of the
air
marshals nowadays, making airliners turn around and go back to their
departure point just because a passenger is unruly, there is a high
probability that one of them is flying along on your flight, and if he
sees an earphone hanging out of your ear, you might be that unruly
passenger they arrest at the departure point. Especially with your
nasty attitude!

What about my hand-held GPS unit? Any chance me using it (during all
phases of a flight, which I do routinely) will result in a one-way
ticket to kingdom come?

Geez, what a TWERP! You can't add two and two without jumping to
conclusions! A rational conversation with you is nearly impossible.

Getting back to the original question (poor to non-existant AM
reception), I understand the idea of aperature and long wavelenths of
AM radio and the size of airplane windows - but what about the effect
of ALL the windows on a plane? Don't they create a much larger
effective apperature when you consider all of them? And since the
plane isin't grounded, isin't the exterior shell of a plane
essentially transparent to all RF (ie it's just a re-radiator) because
it's not at ground potential?

You're even dumber than I had thought. Look up Faraday Shield.
Here, try this: http://www.physlink.com/Education/AskExperts/ae176.cfm
You don't have to worry about a ground for it to work. Duh.


He's not dumber than "I" thought!

Ed
wb6wsn

"Faraday shield" to some degree is a myth.
I have seen radars inside quonset huts track a *bird* flying a few
miles away (thru the metal wall)!

You must have some strange buddies. Who in the world would set up a radar
within a metal hut? And even if they did, who would think it's a good idea
to stay inside with it if it were on?

There's nothing mythical about the Faraday shield; it works really well, so
long as there are no discontinuities (apertures) and sufficient thickness
and conductivity. Under real-world conditions, steel works pretty good, and
any thickness sufficient to support itself will yield great shielding
effectiveness. So the only real performance variable left is the holes in
the conductive surface. How many, maximum dimension, proximity of radiating
source to the shield, etc.

While I would expect a Quonset hut to really mess up the accuracy of a
radar, it likely wouldn't be a good shield, as the floor isn't metal, I
don't think the ends are metal, and the various skin panels are rather
poorly RF bonded.

Ed
wb6wsn


I do not think your objections concerning the floor or the bonding of
the panels are too relevant.
The ends are metal and not relevant either.
The radar was pointing right at the wall (no windows nearby); any
presumed leakage via remote holes that you assumed might allow the
transmitted signal to leak, but would then not be focused on the bird(s)
and the path lengths would vary.
But the reflected signal from the bird or birds would be rather weak
and could not possibly be received via the same wild path(s) to a very
directional antenna.

My point is that a Farady shield is a good attenuator, but not
"perfect" as ASSuMEd.
And it sure is not "flat" in attenuation characteristic as a function
of frequency.