On Fri, 17 Jun 2005 22:37:05 +0000 (UTC), "Reg Edwards"
wrote:
Richard, now you're plagiarising Charles Dickens.

Ah Reg,

"'t'is a far, far better thing that I do, than I have ever done"

Straight from Ronald Colman, Old Son. (who the dickens is Charles?)

73's
Richard Clark, KB7QHC

Richard Clark wrote:
On Fri, 17 Jun 2005 15:48:08 -0500, Cecil Moore
wrote:

We can demonstrate standing waves using a laser beam normal to a perfect mirror.

"We?"

Let's see, a hypothetical argument, involving
a hypothetical "We," performing
a hypothetical analysis that contains 0 places of precision, yielding
a hypothetical answer that will be
hypothetically true and
hypothetically false
hypothetically


What if there were no hypothetical arguments? ;^)

- Mike KB3EIA -

Cecil, W5DXP wrote:
"If so, where does the inductance and capacitance in free space come
from to generate that 377 ohms of characteristic impedance?"

First, impedance is a voltage to current ratio as in Ohm`s law. It can
be complex if reactance and resistance are involved, but it`s still a
voltage to current ratio. Antennas radiate power which has the units of
watts, and from the expanding radiation wavefront in free space, this
amounts to watts per square meter.

A wire one meter long placed for maximum excitation when swept by the
passing wave will have a voltage induced across it equal to the wave`s
signal strength in volts per meter.

There are no volts or amps in the wave, only the ability to generate
volts and amps in conductors.

The 377 phms of characteristic impedance is the ratio of the electric
field strength to the magnetic field strength in the wave. Its purpose
is to get the units right. The ratio of energy in the electric and
magnetic components of the wave is really one to one. It is really the
same energy swapped back and forth between the electric field and
magnetic field which physically are at a right angle and both are at
right angles to the direction of travel.

Kraus has done the math for us on page 170 of the 3rd edition of
"Antennas". His answer is 376.7 ohms, a pure resistance. This is the far
field in free space.

Best regards, Richard Harrison, KB5WZI

Richard Harrison wrote:
Cecil, W5DXP wrote:
"If so, where does the inductance and capacitance in free space come
from to generate that 377 ohms of characteristic impedance?"

First, impedance is a voltage to current ratio as in Ohm`s law.

Thanks, Richard. The question was somewhat rhetorical and was aimed at
the people who believe that EM wave energy "sloshes" around in a
transmission line between the inductance and capacitance in the
transmission line and that there is really no forward EM wave energy or
momentum traveling at the speed of light and no reflected EM wave
energy or momentum traveling at the speed of light.

So I provided a mental example of a laser beam with reflections
demonstrating standing waves in free space. Except for the wavelength,
all field conditions are similiar to an RF transmission line with
standing waves. So how does the light energy "slosh" around without the
inductance and capacitance in free space?
--
73, Cecil http://www.qsl.net/w5dxp

In article . com,
"Cecil Moore" wrote:

uctance and capacitance in the
transmission line and that there is really no forward EM wave energy or
momentum traveling at the speed of light and no reflected EM wave
energy or momentum traveling at the speed of light.

what would be the 'momentum' your referring to? is their a
knetic/stored piece i am misssing? or are you just referring to like
the flywheel effect for ex a large coil might have

ml wrote:
what would be the 'momentum' your referring to? is their a
knetic/stored piece i am misssing? or are you just referring to like
the flywheel effect for ex a large coil might have

In 1619, Kepler proposed that it was the pressure (momentum)
of sunlight that blows back a comet's tail. Maxwell, in 1873
said: "In a medium in which waves are propagated, there is a
pressure (momentum) in the direction normal to the waves ..."

From "Optics", by Hecht: "One of the most significant properties
of the electromagnetic wave is that it transports energy and
momentum." ... "Indeed, whenever we have a flow of energy, it's
reasonable to expect that there will be an associated momentum -
the two are the related time and space aspects of motion."

And, of course, energy and momentum are two things that must
necessarily be conserved. The bottom line is that if there
are any reflected waves that don't reach the source (and also
are not dissipated), they must necessarily have had their direction
of energy and momentum reversed back toward the load. Anything
else would violate the laws of physics.
--
73, Cecil http://www.qsl.net/w5dxp


----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 100,000 Newsgroups
---= East/West-Coast Server Farms - Total Privacy via Encryption =---

Wanted to thank you both for having the patients to help with so many
explanations over the past few months appreciate it

the responces you provided on this thread is rather interesting , i
understood some, but find myself not understanding 'all' and worse
still, you raised further questions and a eyebrow....

now i must go once again to 'the books'

something about this and keep forgetting the name , when a light is
shined thru a splitter the 2 "" beams still have a relationship to each
other

then i think quantum things but even if i expertly understood all
these parts, would I have the answers??

seems even w/o a through understanding these things are predictable, so
why hasn't anyone built a radio that works on this ? seems it would go
faster and further I dunno (referring to the particles that always are
opposite once split)(if we could use force to flip one, and the other
fliped regardless of distance, than 0/1 streams can be read no?


hey people thought people like einstein were nutz too and he was smart

m



In article ,
Cecil Moore wrote:

ml wrote:
what would be the 'momentum' your referring to? is their a
knetic/stored piece i am misssing? or are you just referring to like
the flywheel effect for ex a large coil might have

In 1619, Kepler proposed that it was the pressure (momentum)
of sunlight that blows back a comet's tail. Maxwell, in 1873
said: "In a medium in which waves are propagated, there is a
pressure (momentum) in the direction normal to the waves ..."

From "Optics", by Hecht: "One of the most significant properties
of the electromagnetic wave is that it transports energy and
momentum." ... "Indeed, whenever we have a flow of energy, it's
reasonable to expect that there will be an associated momentum -
the two are the related time and space aspects of motion."

And, of course, energy and momentum are two things that must
necessarily be conserved. The bottom line is that if there
are any reflected waves that don't reach the source (and also
are not dissipated), they must necessarily have had their direction
of energy and momentum reversed back toward the load. Anything
else would violate the laws of physics.

Look at the title of this thread. Why slosh?

Transmission lines are used to convey energy, and at high frequencies
they serve as resonant circuits, measuring devices, and impedance
matching sections.

Viltage and current at any point on a transmission line is expressed as
the sum of the voltages and currents of two waves, one traveking forward
toward the load (the incident wave) and one reflected from the load (the
reflected or reverse wave).

The reflected wave consists of energy from the wave traveling toward the
load which is rejected by the load becausse the voltage to current ratio
does not fit the only voltage to current ratio the load can accept, its
impedance, perhaps a complex value.

All energy in the wave traveling toward the load and all energy
traveling away from the load (the opposite travel direction) must
conform to the absolute value of the line`s characteristic impedance
(Zo).

Phase of the reflected current traveling back toward the generator is
given a negative sign because the reflected wave is traveling in the
reverse direction from the forward wave which travels toward the load.
(See page 86 in the 1955 edition of Terman.

Phase of the reflected current traveling toward the generator is
everywhere proportional but out of phase with reflected voltage. The
reflected voltage to current ratio is: -Zo.

Actual voltage across the load is the sum of the incident and reflected
voltages. Actual current through the load is the sum of the incident and
reflected currents. The vector ratio of load voltage to load current
must equal the load impedance which may be a complex value.

The vector ratio of incident voltage to treflected voltage at the load
is called the reflection coefficient of the load. It may be obtained
from forward and reverse powers at the load. I have a special slide rule
given me by the Bird wattmeter people to convert wattmeter forward and
reverse indications into a reflection coefficient or an SWR.

The transmission line and its load completely control the volts and amps
everywhere in the system driven by a certain generator. There are no
renegade volts and amps sloshing around. The idea is preposterous.

Best regards, Richard Harrison, KB5WZI

In article ,
(Richard Harrison) wrote:


A wire one meter long placed for maximum excitation when swept by the
passing wave will have a voltage induced across it equal to the wave`s
signal strength in volts per meter.

There are no volts or amps in the wave, only the ability to generate
volts and amps in conductors.

so if in my transmision thier is of course volts, and waves


if the waves have the ability to generate it, how can their be no volts
or amps in the wave? what force has it how did it get seperated from
the 'volts'

is it making volts from the pure wave energy which in turn moves the
electrons?

so therefore that means when i measure volts in my coax, it's because
the waves produced it my moveing the copper's electrons?

ml wrote:
(Richard Harrison) wrote:
There are no volts or amps in the wave, only the ability to generate
volts and amps in conductors.

if the waves have the ability to generate it, how can their be no volts
or amps in the wave? what force has it how did it get seperated from
the 'volts'

I think maybe what Richard is trying to say is that the wave
actually consists of an E-field and an H-field. The E-field
results in volts and the H-field results in amps. The charged
particles responsible for the voltage and current cannot move
at the speed of light.

Probably a more modern way of saying the same thing is that
RF waves are photonic energy, moving at the speed of light.
The photons are the fields and the fields are the photons.
Electrons cannot move at the speed of light. Photons generated
by excited electrons are what move at the speed of light.
--
73, Cecil http://www.qsl.net/w5dxp


----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 100,000 Newsgroups
---= East/West-Coast Server Farms - Total Privacy via Encryption =---