Faraday shields and radiation and misinterpretations
 

Art Unwin wrote:
Of course one can go back to the basics of mathematics way back in
Arabic times where
the mere presence of an equal sign denotes equilibrium or balance. The
equal sign is part of Maxwells equations so equilibrium is in effect.

"the mere presence of an equal sign denotes equilibrium or balance"

So sayeth the master of the physical universe - Art Unwin...

Hmmm, so if there is an equal sign, it means it's in equilibrium.

So a half wave antenna = 468/f(Mhz).

It is therefore in equilibrium.

tom
K0TAR

Faraday shields and radiation and misinterpretations
 

Art Unwin wrote:
I have gathered that you have had some experience in installing
consumer dishes and I recall you stating that dishes can only be used
in the giga hertz range, without mention that it is the size of the
antenna determines whether a dish orreflecter is pertinant or not.
Very strange!

Dishes are usable based upon their size relative to the frequency of
use. You seem not to understand that.

They work by reflecting the EM waves directed at them. The gain is set
by the area of the dish in square wavelengths, and your pretend physics
can't change that.

A DSS dish isn't even a pinpoint to reflect off of at 160m, which is
your favorite example.

A dish that provides only 3dB gain at 160m would be approximately a
kilometer in diameter. How big is your mom's garden?

tom
K0TAR

Faraday shields and radiation and misinterpretations
 

On Dec 3, 9:10*pm, tom wrote:
Art Unwin wrote:
Of course one can go back to the basics of mathematics way back in
Arabic times where
the mere presence of an equal sign denotes equilibrium or balance. The
equal sign is part of Maxwells equations so equilibrium is in effect.

"the mere presence of an equal sign denotes equilibrium or balance"

So sayeth the master of the physical universe - Art Unwin...

Hmmm, so if there is an equal sign, it means it's in equilibrium.

So a half wave antenna = 468/f(Mhz).

It is therefore in equilibrium.

tom
K0TAR

So stupid. A half wave does not have a measurement that is repeatable
therefore it is not in equilibrium. The point of repeatability is a
"period". Surely you learned that in Jnr High!

Faraday shields and radiation and misinterpretations
 

Art Unwin wrote:
So stupid. A half wave does not have a measurement that is repeatable
therefore it is not in equilibrium. The point of repeatability is a
"period". Surely you learned that in Jnr High!

Your own statement was "the mere presence of an equal sign denotes
equilibrium or balance".

I rest my case.

And stupid is as stupid does. Stupid boy.

tom
K0TAR

Faraday shields and radiation and misinterpretations
 

On Dec 3, 9:31*pm, tom wrote:
Art Unwin wrote:
I have gathered that you have had some experience in installing
consumer dishes *and I recall you stating that dishes can only be used
in the giga hertz range, without mention that it is the size of the
antenna determines whether a dish orreflecter is pertinant or not.
Very strange!

Dishes are usable based upon their size relative to the frequency of
use. *You seem not to understand that.

They work by reflecting the EM waves directed at them. *The gain is set
by the area of the dish in square wavelengths, and your pretend physics
can't change that.

A DSS dish isn't even a pinpoint to reflect off of at 160m, which is
your favorite example.

A dish that provides only 3dB gain at 160m would be approximately a
kilometer in diameter. *How big is your mom's garden?

tom
K0TAR

Again how foolish you are. There are many radiators that have
reflectors that are way below the GIGA Hz level. You are basing your
statement on laws applicable to planar forms of radiators.
Heck! There are many helix antennas in use that have reflectors that
are used in the Mega Hz range. There is absolutely no good reason why
a antenna for top band must have a reflector a kilometer in diameter
if the antenna itself replicates a point source.
I think you have shown everybody the extent of your limitations with
respect to antennas!

Faraday shields and radiation and misinterpretations
 

K7ITM wrote in news:8b542276-db03-4c3d-9658-
:

On Dec 3, 12:25*am, Lostgallifreyan wrote:

( Richard Feynman lectures)
... I don't know if he's written anything a layman can easily work
through, that doesn't come with lots of maths without which accompanying
text
doesn't help much, but if he has I'll try to read it.

I think one of the key things that made his physics lectures popular
is that they were delivered without a whole lot of math. You could
get into that if you wanted, but you could also get a lot out of just
listening to the _ideas_.

If you drop me an email, perhaps I can send you a bit more about this
particular lecture...

Cheers,
Tom


Thankyou, I'll go for that. I've also been given two books by Marcus Chown,
who I found has a knack of conveying things clearly at some depth.
Entertaining too. My email is (slightly obfuscated) z dot crow at BTinternet
dot com for as long as I still use their service. (Contract runs out fairly
soon so even though they're ok I'm looking at alternatives.. :)

Faraday shields and radiation and misinterpretations
 

On Dec 3, 9:57*pm, tom wrote:
Art Unwin wrote:
So stupid. A half wave does not have a measurement that is repeatable
therefore it is not in equilibrium. The point of repeatability is a
"period". Surely you learned that in Jnr High!

Your own statement was "the mere presence of an equal sign denotes
equilibrium or balance".

I rest my case.

And stupid is as stupid does. *Stupid boy.

tom
K0TAR

That's correct. The equal sign denotes the presence of balance. Making
up an equation that is not in balance is not corrected by the addition
of an equal sign. Starting with fraud in mind never can later be
corrected other than the continuance of fraud. Seems like your efforts
in persuading others of your expertise is not working out as you
thought.Just the opposite.

Faraday shields and radiation and misinterpretations
 

On Thu, 03 Dec 2009 14:13:57 -0800, Richard Clark
wrote:

On Thu, 03 Dec 2009 16:51:05 -0500, Registered User
wrote:

- good stuff from RC snipped -

Either way I've learned as current varies the fields it produces will
vary. If the fields vary they're not static. Too simplistic? What am I
missing?

Static comes in two flavors. One means "not moving." The other means
high potential (which can be "not moving" AND, ironically, "moving").
Such is the legacy of electrostatic potential covering DC to Gamma.

I was wondering about the latter as a possibility but couldn't find
the proper words. My interpretation is although the individual fields
may vary the total potential of the fields is constant. Is this
correct?

The difference between rods, number of rods, thickness of rods, and
mesh all speak to bandwidth. 2, 3, or 4 rods will not be remarkable.
16 rods will closely approximate a cone of sheet metal (as would a
grid of similar spacing). The same can be said of the
rod/rods/mesh/sheet in the upper section approximating a solid disk.

IIUC the current flows around the cone of a discone regardless of
solid, sheet or mesh construction. This appears to be contrary to the
quote above where current flows around each individual hole in the
mesh.

Well, language can be a barrier here when you say "around the cone."

I should have said the current flows around the cone parallel to its
base.

- more snippage -

I appreciate the clarifications and the links. It all helps to better
my knowledge and understanding of these topics. Thank you

Faraday shields and radiation and misinterpretations
 

Art Unwin wrote:

Again how foolish you are. There are many radiators that have
reflectors that are way below the GIGA Hz level. You are basing your
statement on laws applicable to planar forms of radiators.
Heck! There are many helix antennas in use that have reflectors that
are used in the Mega Hz range. There is absolutely no good reason why
a antenna for top band must have a reflector a kilometer in diameter
if the antenna itself replicates a point source.
I think you have shown everybody the extent of your limitations with
respect to antennas!

A typical helical antenna would be in the "mega" hertz range would be
for 435 MHz. The planar reflector for that antenna is 70cm, or 1
wavelength. Which would lead one to conclude that a planar reflector
for top band would be about 160m.

And now Art will make up more new physics for his response.

tom
K0TAR

Faraday shields and radiation and misinterpretations
 

Art Unwin wrote:

Again how foolish you are. There are many radiators that have
reflectors that are way below the GIGA Hz level. You are basing your
statement on laws applicable to planar forms of radiators.
Heck! There are many helix antennas in use that have reflectors that
are used in the Mega Hz range. There is absolutely no good reason why
a antenna for top band must have a reflector a kilometer in diameter
if the antenna itself replicates a point source.
I think you have shown everybody the extent of your limitations with
respect to antennas!

And you just might want to look up the definition of "axial mode".

tom
K0TAR