On Fri, 18 Sep 2009 08:51:04 +0200, Szczepan Bia?ek
wrote:

In the space of two sentences you contradict yourself. You don't get
it, do you?

"If antenna has only one source"

Thank you for confirming that in spite of quoting me, you just don't
get it.

73's
Richard Clark, KB7QHC

"Richard Clark" wrote
...
On Fri, 18 Sep 2009 08:51:04 +0200, Szczepan Bia?ek
wrote:

In the space of two sentences you contradict yourself. You don't get
it, do you?

"If antenna has only one source"

Thank you for confirming that in spite of quoting me, you just don't
get it.

You go into details.
In the Gas Analogy the monopole antena is exactly like the Kundt's tube.
See: http://en.wikipedia.org/wiki/Kundt's_tube
A dipole has the two Kundt's tubes.
S*

On Fri, 18 Sep 2009 18:33:00 +0200, Szczepan Bia?ek
wrote:

You go into details.

Yes, I do go into the details.

In the Gas Analogy the monopole antena is exactly like the Kundt's tube.

Analogy is a false arguement. In the car-seen-at-a-distance analogy,
this proves that only midgets or pygmies drive cars because we are too
big to fit into such small things seen in the distance.

73's
Richard Clark, KB7QHC

"Richard Clark" wrote
...
On Fri, 18 Sep 2009 18:33:00 +0200, Szczepan Bia?ek
wrote:

You go into details.

Yes, I do go into the details.

In the Gas Analogy the monopole antena is exactly like the Kundt's tube.

Analogy is a false arguement.

Heaviside did the Hydraulic Analogy. All is exactly the same like in the
fluids mechanics.
Next the electrons were discovered. Automatically Heaviside is a history and
the Gas Analogy is in power.


In the car-seen-at-a-distance analogy,
this proves that only midgets or pygmies drive cars because we are too
big to fit into such small things seen in the distance.

But you, radio people, are very close to waves and should be easy for you to
work out the answer for the Question:
Which Analogy is right?

I will be absent till Monday evening.
S*

On Fri, 18 Sep 2009 19:13:17 +0200, Szczepan Bia?ek
wrote:

All is exactly the same like in the fluids mechanics.

"Exactly" makes it very, very easy to show how an analogy fails:
Describe the laminar flow in terms of
the Reynolds number for
the interface between RF and a Biconical Antenna
and
the interface between RF and a thin wire Antenna.

If you do not understand
1. the terms of fluid mechanics and/or
2. cannot complete this request, then
your analogy has failed.

I won't wait for that obvious failure. This is several steps above
your pay-grade. So, you should really attempt to work on first
principles rather than rummaging in the attic for impressive artifacts
of science. The musty chestnuts you find would poison a dog.

73's
Richard Clark, KB7QHC

Richard Clark wrote:
On Fri, 18 Sep 2009 19:13:17 +0200, Szczepan Bia?ek
wrote:

All is exactly the same like in the fluids mechanics.

"Exactly" makes it very, very easy to show how an analogy fails:
Describe the laminar flow in terms of
the Reynolds number for

Hmm, I think I'd start with a very long K1FO yagi, say 50 elements.
Maybe even extend one to 100 elements to getting very fine details.
Then we look at the longitoodordinal current along the horizontal
element by element. I'll have to work on it a while though.

What are you thinking?

73's
Richard Clark, KB7QHC

tom
K0TAR

On Fri, 18 Sep 2009 18:54:25 -0500, tom wrote:

Richard Clark wrote:
On Fri, 18 Sep 2009 19:13:17 +0200, Szczepan Bia?ek
wrote:

All is exactly the same like in the fluids mechanics.

"Exactly" makes it very, very easy to show how an analogy fails:
Describe the laminar flow in terms of
the Reynolds number for

Hmm, I think I'd start with a very long K1FO yagi, say 50 elements.
Maybe even extend one to 100 elements to getting very fine details.
Then we look at the longitoodordinal current along the horizontal
element by element. I'll have to work on it a while though.

What are you thinking?

I am thinking that Stefan by lacking a demonstration of this
employment of his own chosen metaphor displays a vacuum in two subject
areas. As it stands, he stumbles through the nuances of RF. Instead,
he is trying to extrapolate them through a second subject, where, of
course, he tumbles over the nuances of fluidics.

The best we can expect is for him to haul a book to the nearest Xerox
and lean on the copy button to produce a snow job. The deepest
impression he will get of that intellectual experience is a paper cut.

73's
Richard Clark, KB7QHC

"Richard Clark" wrote
...

I won't wait for that obvious failure. This is several steps above
your pay-grade. So, you should really attempt to work on first
principles rather than rummaging in the attic for impressive artifacts
of science.

And what should do Richard Harrison who wrote: "At the open circuited ends
of a resonant antenna there is almost double
the forward voltage but zero total current due to cancellation of the
dorward and reflected currents at the open circuit. At the open circuit
in the wire, all the energy in the wave is transferred to the electric
field. "
S*

"Szczepan Bia³ek" wrote in message
...

"Richard Clark" wrote
...

I won't wait for that obvious failure. This is several steps above
your pay-grade. So, you should really attempt to work on first
principles rather than rummaging in the attic for impressive artifacts
of science.

And what should do Richard Harrison who wrote: "At the open circuited ends
of a resonant antenna there is almost double
the forward voltage but zero total current due to cancellation of the
dorward and reflected currents at the open circuit. At the open circuit
in the wire, all the energy in the wave is transferred to the electric
field. "
S*


What Richard wrote is correct, if written in a slightly provocative manner
(deliberately?). But he wasn't stating that the electric field 'At the
open-circuited ends of a resonant antenna' passes energy into a radiated
radio wave. The energy that makes it that far (i.e. isn't radiated on
account of current in the element) is stored temporarily in an
'electrostatic' field which is one of several 'reactive' or 'induction'
field components that surround a dipole antenna and decay with distance much
faster than the radiation field components (i.e. those that make up a radio
wave). As I've noted before, the term 'electrostatic' should not be
interpreted literally as an unchanging field - it is used to differentiate
between the reactive components and the radiation components of electric
field - if this offends you, just call it a 'reactive' component of electric
field. This stored energy is passed back into the antenna during the
following RF quarter cycle.

And guess what ... one of the reactive field components is longitudinal!

.... but it isn't part of a radio wave - both parts of a radio wave, the
magnetic field and the attendant electric field, are directed transverse to
the direction of propagation, but now I'm repeating myself from a week or
more ago. Power cannot be abstracted from the reactive fields, including
the longitudinal one; they affect the imaginary part of the terminal
impedance of the antenna.

Of course, I expect you will contradict all this but I still recommend that
you read a proper account of the fields around a dipole rather than making
up your own version. Since you appear to have a phobia of libraries, you
could buy a second-hand copy of Kraus, Antennas for only $15 online:
http://www.abebooks.com/servlet/Sear...nnas&x=55&y=10
and there are many, many other sources.

Failing that, you could always search the web for a bootleg copy, or one of
the MIT Radiation Laboratory series of books. I don't condone bootlegging
but someone in another newsgroup recently gave a link to a collection of
illegal copies and, in the hope of ending these ridiculous arguments, I'll
pass on what he wrote:
http://cer.ucsd.edu/~james/notes/MIT...diation%20Lab/

Chris

On Mon, 21 Sep 2009 18:53:15 +0200, Szczepan Bia?ek
wrote:

And what should do Richard Harrison who wrote

Which has absolutely nothing to do with the failure of your swampy
metaphor - EXCEPT to demonstrate its stagnation into a cesspool by
being completely ignored by you.

It's amusing to see you wading out there tho'. ;-)

73's
Richard Clark, KB7QHC