On Mon, 16 Feb 2009 22:22:20 -0600, Frnak McKenney
wrote:

So any non-loop antenna I can construct will necessarily be a "short
wire" or "electrically small" antenna (two useful search terms).
But how does one go about calculating the impedance of a coat hanger
or an extension cord ("short piece of wire")?

Antennas can be modeled by various NEC based programs. For example:
http://home.ict.nl/~arivoors/
http://www.eznec.com
http://www.nittany-scientific.com

Note that the common "atomic clock" gets its time from WWVB at 60KHz
(about 5000 meters) using a tiny loop antenna. Huge antennas are not
required for many application.
http://www.mas-oy.com/data/MAS_docu_AR.htm
http://www.leapsecond.com/pages/sony-wwvb/

Also, search Google for LOWFER.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Jeff,

Thanks for the reply.

On Tue, 17 Feb 2009 08:36:23 -0800, Jeff Liebermann wrote:
On Mon, 16 Feb 2009 22:22:20 -0600, Frnak McKenney
wrote:

So any non-loop antenna I can construct will necessarily be a "short
wire" or "electrically small" antenna (two useful search terms).
But how does one go about calculating the impedance of a coat hanger
or an extension cord ("short piece of wire")?

Antennas can be modeled by various NEC based programs. For example:
http://home.ict.nl/~arivoors/
http://www.eznec.com
http://www.nittany-scientific.com

Note that the common "atomic clock" gets its time from WWVB at 60KHz
(about 5000 meters) using a tiny loop antenna. Huge antennas are not
required for many application.
http://www.mas-oy.com/data/MAS_docu_AR.htm
http://www.leapsecond.com/pages/sony-wwvb/

That's what I keep reading; any caution you hear coming from me is
based on years spent in close association with Murphy. grin!

I'm a long-time devotee of the Divide'n'Conquer(tm) school of
analysis and troubleshooting. This only works well when one is
familiar with the appropriate problem-partitioning tools and has
experience using them; as it is, I'm trying to acquire the knowledge
that will let me know why things didn't work when they don't work as
expected. grin!

Also, search Google for LOWFER.

Thanks. I did see the phrase, but forgot to write it down; after
some hours searching the 'Web and reading it all seems to run
together. grin!


Frank
--
"When the government fears the people, there is liberty.
When the people fear the government, there is tyranny."
-- Thomas Jefferson
--
Frank McKenney, McKenney Associates
Richmond, Virginia / (804) 320-4887
Munged E-mail: frank uscore mckenney ayut mined spring dawt cahm (y'all)