Hi Tim,

"Tim Shoppa" wrote in message
...
On Mar 22, 9:24 pm, "Joel Koltner"
wrote:
I think his method, especially for physically compact antennas and
feed systems which tend to have very low radiation resistance at HF
frequencies, is a great check on theoretical calculations. There has
to be a meeting point between mathematical models/NEC and reality and
he is working at one such point.

Agreed -- the controversy comes into play in that he ends up computing
electrically-small loop antennas as being upwards of 70-90% efficient, when
everyone "knows" that such antennas are typically 10% efficient. He even
goes after Chu/Wheeler/McLean/etc. in suggesting that the fundamental limits
for the Q of an ESA are orders of magnitude off (slide 47), and that's pretty
sacrosanct terriority (see, e.g., www.slyusar.kiev.ua/Slyusar_077.pdf -- even
the Ruskies buy into the traditional results :-) ).

Hence, while I don't really have the background to know precisely how much of
what Underhill promotes is true or not, it's definitely intriguing to me, and
I'm looking around for various rebuttals by those more skilled in the art than
I am.

One link I found: http://qcwa70.org/truth%20and%20untruth.pdf (but this was
written before the PowerPoint presentation I originally linked to).

---Joel