On Mon, 08 Mar 2004 17:09:08 GMT, "aunwin"
wrote:

Art, KB9MZ wrote:
"It does not mean that a radiating antenna which is in the parallel
configuration will have a high impedance."

Parallel configuration can mean several things. I will take it to mean
the antenna shares some of the characteristics of a parallel resonant
circuit.

Does not lead to:

You CAN have a low resistance of 1 ohm or you CAN have one 1000 ohms

Parallel resonant circuits exhibit a high impedance, there are no
other interpretations.

( Yes I spoke also to the professor of Log
periodic fame as well, very interesting person)
"Broadband Logarithmically Periodic Antenna Structures," 1957 IRE
National Convention Record, Part 1.
Dwight E. Isbell, U.S. Patent No. 3,210,767 teaches:
"...directivity... was better than 9db over isotropic."
"Advantageously, however, the antennas of the invention need
no adjusting for their performance over a wide band width
compared to the parasitic types...."
"The longest dipole element should be approximately
0.47 wavelength long."

It is difficult to mis-interpret this patent as it is only 5 pages
long with two of those pages as illustrations, and the last page is
less than half full of text. We may note many design issues that Art
has taken umbrage of having been pointed out repeatedly
1.) half wave, full size dipoles (series resonant structures);
2.) wide bandwidth as an advantage;
3.) comparison to standards, in this case isotropic;
4.) no loads or components adding to complexity (no adjustments);
5.) Dwight Isbell learned his craft from books and instructors who
wrote those ( -gasp!- ) books (he was a graduate student
with R. H. DuHamel);
6.) Such information as we have about his design are found in
( -gasp!- ) books;
7.) furthermore, Mr. Isbell has never exhibited Netourette's
Syndrome in these messages posted here.

73's
Richard Clark, KB7QHC