On Mon, 10 Oct 2005 11:33:48 +0000 (UTC), "Reg Edwards"
wrote:

....
At higher frequencies
there's usually enough space to erect a dipole or an inverted-L which
will perform at least as well. (Ian, you could perhaps do a useful
article on the subject.)

....

I wrote an article on the Inverted L with a remote autotuner (designed
for end-fed wires) some time ago. The configuration, it is frequency
agile, very convenient when integrated with transeiver auto-tune
controls, and works a treat. The most significant downside (like most
Marconi, Windom, Long Wire etc configs) is from an EMR safety point of
view, it has a radiator within reach of people standing on the ground.
The article is at
http://www.vk1od.net/InvertedL/InvertedL.htm .

With the experience of using such a configuration, I reckon that a
magloop with an remote autotuner designed specifically for a magloop
would be a great option for people with very little space, better than
Echolink!

Reg, if you have an expression for the loop inductance and resistance
as a function of frequency, and we could make the assumption that the
coupling coil is a broadband ideal transformer with a fixed z ratio or
otherwise characterise the transformation as a function of frequency,
I could do a software simulation of an autotuner... be an interesting
project.

BTW, the tuner values in the article above are found through
simulation of an automated L tuner, but the 3 variable binary
searching algorithm used for performance would not work for a loop.

Owen
--