"Roy Lewallen" wrote in message
...
Mike Kaliski wrote:
Those that can get access to a copy should look at the Radio Society of
Great Britain, RadCom Magazine, December 2007 issue, Technical Topics
column by Pat Hawker G3VA. The topic? 50 Years of amateur antennas. He
covers a lot of the perennial topics of debate in this newsgroup and
provides some excellent commentary on element lengths, feedline lengths,
SWR, ATU's, modes of operation and some of the controversy. Okay, it has
probably all been covered elsewhere in books, on websites and in this
newsgroup, but there is a lot of useful information condensed into a
couple of pages. Almost a substitute fro Kraus and Terman! :-)

Mike G0ULI

Does he cover the radiation of antennas from 377 ohm "sweet spots", and
the concept of using antennas to match free space's impedance?

Roy Lewallen, W7EL

Hi Roy,

He does mention that antennas possess radiation resistance, not to be
confused with and not the same as, characteristic impedence (or feedpoint
impedence) and that the characteristic impedence will vary along an antennas
length.

As for the actual point(s) along an element at which an antenna radiates
(transfers energy to free space) with maximum efficiency, he makes no
comment.

I seriously doubt that there is anything in the article that you would
dispute.

It seems that everyone was so busy laughing on this newsgroup, that no one
has actually provided any information as to whether any detailed research
has ever been carried out as to what is going on within the radiating
elements of an antenna. There is loads of theory in the text books, but I
have yet to see any empirical measurements or results. I am aware of the
research into small loops carried out by Professor Underhill (also published
in RadCom) but it seems that even his results have been disputed.

I may have submitted the post, tongue in cheek, to stir things up a bit, but
on reflection there seems to be something of merit in the idea. I am
revisiting the appropriate chapters in Kraus and Terman to see where the
error in my logic is. In the absence of any direct evidence of
contradiction, I think it may be worth developing this idea and making a few
measurements of my own to see what the truth of the matter is. Amateur radio
is supposed to be a learning experience, right? And you can't learn without
making mistakes. After 40 years of following the diktats of professional
communications and electronic theory, I think the time is right to kick off
the traces and challenge some of the accepted authodoxies. I do know all the
conventional stuff, it just doesn't satisfy my soul.

You probably know more about antennas than anyone has a right to know Roy,
but it's a strange universe out there and it's just possible that there's a
few more things to learn yet.

Regards
Mike G0ULI