Spherical radiation pattern
 

On Sep 15, 10:58*am, "christofire" wrote:
"Art Unwin" wrote in message

...
On Sep 15, 10:24 am, "christofire" wrote:

"Art Unwin" wrote in message

- - snip - -

You still did not put a stake in the ground, just walked around the
question and then walked away. One more chance before I place you in
"unsure". Where in Maxwell's equations does it refer to "particles" or
do they have no place in his views on radiation?
What is your call sign or do you prefer to remain as a unknown?

Incorrect; I gave a positive answer to the question. *My answer was based on
normal physics and identified what must, therefore, be paraphysical or
nonsense (or both). *The equations don't make any reference to particles -
as I'm sure you are aware. *As to the views of Maxwell, the person, I
daresay you can make them up to your heart's content without provable
challenge.

I don't much care what category you place me in - you already know how I
categorise people who make up their own versions of physics and expect other
to believe them ... and sadly some appear to!

My call sign, if I have one, is none of your business.

Chris

O.k. So the thread as posted in the title is now closed. On the
question on the Gauss extension this is not understood so that is also
now closed. Insults? Well they can go on for ever as this is the main
attraction for its members.

Spherical radiation pattern
 

"JIMMIE" wrote
...
On Sep 14, 1:56 pm, "christofire" wrote:
"Szczepan Bia³ek" wrote in message

...



"Richard Fry" wrote
...

- - small snip --



QUOTE
A radio antenna may be defined as the structure associated with the
region of transition between a guided wave and a free-space wave, or
vice-versa. Antennas convert electrons to photons, or vice-versa.

Regardless of antenna type, all involve the same basic principle that
radiation is produced by accelerated (or decelerated) charge. The
basic equation of radiation may be expressed simply as:

IL = Qv (A m s^-1)

where

I = time-changing current, A s^-1
L = length of current element, m
Q = charge, C
v = time change of velocity which equals the acceleration of the
charge, m s^-2

Thus, time-changing current radiates and accelerated charge radiates.

In which parts of antenna the charges acclerate?
S*

In all the parts that carry current, of course. Isn't that obvious?

Incidentally, who is A* ? ... the person who wrote:

Does one wave has many polarizations, or one antenna has many
polarizations?
Which one: transmitter or receiver? Could you teach me?
A*

Chris

Could mean that Art and S are the same person, one does seem to appear
when the other disappears.

You are right. Few mans ago I was writting that Gauss law is enough to do
antennas. Of course not this for magnetism.
Static charge produces static electric field and pulsed (in the end of the
antena) alternating field. It is radiation. For me there are ether vaves.
For Art photons or something else.
S*

Spherical radiation pattern
 

"Art Unwin" wrote in message
...
On Sep 15, 10:58 am, "christofire" wrote:
"Art Unwin" wrote in message

...
On Sep 15, 10:24 am, "christofire" wrote:

"Art Unwin" wrote in message

- - snip - -

You still did not put a stake in the ground, just walked around the
question and then walked away. One more chance before I place you in
"unsure". Where in Maxwell's equations does it refer to "particles" or
do they have no place in his views on radiation?
What is your call sign or do you prefer to remain as a unknown?

Incorrect; I gave a positive answer to the question. My answer was based
on
normal physics and identified what must, therefore, be paraphysical or
nonsense (or both). The equations don't make any reference to particles -
as I'm sure you are aware. As to the views of Maxwell, the person, I
daresay you can make them up to your heart's content without provable
challenge.

I don't much care what category you place me in - you already know how I
categorise people who make up their own versions of physics and expect
other
to believe them ... and sadly some appear to!

My call sign, if I have one, is none of your business.

Chris

O.k. So the thread as posted in the title is now closed. On the
question on the Gauss extension this is not understood so that is also
now closed. Insults? Well they can go on for ever as this is the main
attraction for its members.


What do you think gives you the power or the right to close a thread - is
this something written in the Usenet 'code of practice'? Surely, in
practice it will continue until all aspects of discussion have reached their
conclusions and more interesting threads have appeared.

Do yourself a favour Art, visit a technical library, read and try to
understand the real physics on which radio communication has been based. If
you have problems with any of the parts that are well documented then there
will be plenty of folk here who will be willing and able to illuminate,
including some with less time on their hands than myself who don't post very
often but have extensive knowledge. I think you will find it fascinating
how intelligence can be passed between two points in space without any need
for the passage of matter between them - all puns accepted!

Chris

Spherical radiation pattern
 

"joe" wrote ...

Your problem is not understanding the motion of charges in the antenna.

Sure, the derivative of a sine wave is 0 at the peak,

It is the math

but this does
not directly translate to the motion of the electrons
at specific locations in the antenna.

Look at the antenna current as an electron oscillating
back and forth between the ends. The position over time is described
by a function. Throughout the entire length, the electron is
changing velocity (accelerating).

Hint: the _voltage_ at the feed point may be described by a sine wave.
Your challenge is to determine how the electrons move in response
to that sine wave.

Part of understanding this is knowing the difference between what is
happing as time progresses at the different parts of the antenna.

The trick to understanding this is to carefully do and understand
the mathematics that are involved.

It is not easy to understand you. Math says that "the derivative of a sine
wave is 0 at the peak," next that it is not true and next that math is
always right.

Electrons flow free in feed line and are compressed in ends. After short
rest they come back to supply unit.
S*

Spherical radiation pattern
 

"Szczepan Bia³ek" wrote in message
...

"JIMMIE" wrote
...
On Sep 14, 1:56 pm, "christofire" wrote:
"Szczepan Bia³ek" wrote in message

...



"Richard Fry" wrote
...

- - small snip --



QUOTE
A radio antenna may be defined as the structure associated with the
region of transition between a guided wave and a free-space wave, or
vice-versa. Antennas convert electrons to photons, or vice-versa.

Regardless of antenna type, all involve the same basic principle that
radiation is produced by accelerated (or decelerated) charge. The
basic equation of radiation may be expressed simply as:

IL = Qv (A m s^-1)

where

I = time-changing current, A s^-1
L = length of current element, m
Q = charge, C
v = time change of velocity which equals the acceleration of the
charge, m s^-2

Thus, time-changing current radiates and accelerated charge radiates.

In which parts of antenna the charges acclerate?
S*

In all the parts that carry current, of course. Isn't that obvious?

Incidentally, who is A* ? ... the person who wrote:

Does one wave has many polarizations, or one antenna has many
polarizations?
Which one: transmitter or receiver? Could you teach me?
A*

Chris

Could mean that Art and S are the same person, one does seem to appear
when the other disappears.

You are right. Few mans ago I was writting that Gauss law is enough to do
antennas. Of course not this for magnetism.
Static charge produces static electric field and pulsed (in the end of the
antena) alternating field. It is radiation. For me there are ether vaves.
For Art photons or something else.
S*


Which one of Gauss's two laws?

Chris

Spherical radiation pattern
 

"Cecil Moore" wrote
...
joe wrote:
Look at the antenna current as an electron oscillating
back and forth between the ends.

At HF frequencies, the electrons move hardly at all, tending
to oscillate back and forth in place. The idea that electrons
race from end to end in an antenna is simply false.

http://c2.com/cgi/wiki?SpeedOfElectrons

"... for a copper wire of radius 1 mm carrying a steady
current of 10 Amps, the drift velocity is only about
0.024 cm/sec!"

For a 100w 10 MHz RF wave, you can divide that distance by
more than 10,000,000. Exactly how far can the electron travel
in 0.05 microsecond?

It is the photons emitted by the electrons that travel at
the speed of light in the medium. That's the fields surrounding
the antenna conductor, not the electrons in the conductor.

It is for students. Hall and others developed technics to estimate how many
electrons are free in different metals.
It is not one per atom.
S*
--
73, Cecil, IEEE, OOTC, http://www.w5dxp.com

Spherical radiation pattern
 

Art Unwin wrote:
Where in Maxwell's equations does it refer to "particles" or
do they have no place in his views on radiation?

Linear math fails at the nonlinear point. There are
lots of examples. This is just one of them.
--
73, Cecil, IEEE, OOTC, http://www.w5dxp.com

Spherical radiation pattern
 

"christofire" wrote
...

"Szczepan Bia³ek" wrote in message

At the ends are the max accelerations and the max radiation.
S*

No, you have it wrong again - the current must be zero at the ends, there
is nowhere for it to go, and there cannot be acceleration of charge is
there's no current.

Current will be when charges start their flow back to the supply. The
acceleration is close to end.

Please go away and read some books and the NEETS module to
which I provided the link.

Most of wrote that radiation is not fully known. I am trying to explain you.
S*

Spherical radiation pattern
 

Art Unwin wrote:
... it enables particles at rest ON radiators.

As far as RF is concerned, free electron particles indeed
do rest ON radiators. It's called "skin effect".
--
73, Cecil, IEEE, OOTC, http://www.w5dxp.com

Spherical radiation pattern
 

U¿ytkownik "Cecil Moore" napisa³ w wiadomo¶ci
...
Szczepan Bia³ek wrote:
At the ends are the max accelerations and the max radiation.

How can an electron accelerate at at open-circuit?
The acceleration is maximum at the current zero-
crossing with the greatest slope. That's at the
center of a 1/2WL dipole.

Accelerate and deccelerate. It is only possible with compressible electrons
(as electrn gas). It is impossible in Heavisde's hydraulic analogy.
S*