[IRCA] Some help with "large" loops?

[Brian Rachford <azswdxing@xxxxxxxxx>]

I'm hoping to pick the brains of those of you who have experimented with
various "modern" loop designs.  With limited room, poor ground
conductivity, and not being able to set up something permanent, I've been a
bit discouraged by the sizes of antennas that people are using to get
nulling patterns other than a figure-eight.  However, after looking at
Bruce Conti's page on the "Super Loop" (corner-terminated, corner-fed), I
realized that this was something I could try after all.

This weekend, I threw together a "portable" 8' x 25' loop using PVC pipe
and wood for the two end supports.  I still need to do the termination and
impedance matching right, but my "close enough" beta version was promising
as far as signal strength across the BCB and noise levels, although the
quality of the backside nulling wasn't as clear (the whole point of this
experiment is to null out SoCal and/or northern Baja California).  This was
squeezed in between the house and carport, the only practical corridor I
have for something this size.  I would like the ability to have a support
20-25' high, mainly to get the loop more clear of structures.

Questions:
- How important is the shape and symmetry of the loop; e.g. wire sag,
sloping ground, differing heights of the two vertical components?
- How important is the height above ground for the bottom wire?
- Does the type of wire matter much (within reason)?
- If I want something reasonably sturdy and with the possibility of going
up to 20-25' height, am I looking at $100 or more for a suitable pair of
telescopic fiberglass poles?  I don't plan on deploying this if it's windy.

Thanks!

Brian Rachford - Prescott, AZ
azswdxing@xxxxxxxxx
http://azswdxing.wordpress.com/
_______________________________________________
IRCA mailing list
IRCA@xxxxxxxxxxxxxxxx
http://montreal.kotalampi.com/mailman/listinfo/irca

Opinions expressed in messages on this mailing list are those of the original contributors and do not necessarily reflect the opinion of the IRCA, its editors, publishing staff, or officers

For more information: http://www.ircaonline.org

To Post a message: irca@xxxxxxxxxxxxxxxx