On 15 sep, 14:01, Richard Clark wrote:
On Wed, 15 Sep 2010 06:11:41 -0700 (PDT), lu6etj
wrote:

there are not conduction currents, there not
displacement currents, there are not electrical and magnetic fields,
there are not electric charges neither electrical dipoles in soil and
water,

Hi Miguel,

There aren't? *You have problems.

just "mismatch" and "discontinuities"

*and more problems.

(do explain antenna
radiation with "mismatch")

******** Part One of Explanation ********

What about a conductive antenna is matched to an (relatively)
unconductive air (or free space for that matter)?

When your RF, conducting down the transmission line, sees the antenna,
it finds either a match and continues into the antenna, or finds a
mismatch and is reflected (yeah, some cannot accept the concept of
reflected power - so let's say that the energy does not cross the
interface except by some proportion in degree to the mismatch).

For what RF power/energy that does get into the radiating element, it
conducts down to the end of the element - and guess what? - it stops
conducting further in that direction.

Strange that this has to be said, being obvious in the first degree.

So, we have the antenna with some characteristic Z - can you put a
number to it? *We have the surrounding medium with some characteristic
Z. *They have some integral (meaning a number, integer) relationship.
Dare I call it mismatch?

When you look at the current distribution along a half wave dipole,
does it not exhibit a standing wave? *If there were not a mismatch,
where did that come from?

73's
Richard Clark, KB7QHC

Oh, yes, I quite understand, balls bounce against walls "because walls
are discontinuities" there is a "mismatch in the media" c'est finite,
that's all folks! good "explanation", why to ask more?, why to ask
"why"? (one step back, the explanation was "God").

Good night Richard (it is time for my catechism)
It is my karma... I know... my second name is Ricardo

Miguel