[Elecraft] OT: SGC Coupler / Small Wire Loops

Thu Mar 27 13:56:02 2003

Howdy;

   I'm a ground-floor apartment dweller.  I saw SGC at Dayton last
year selling a simple "broom-stick" loop antenna that utilized their
antenna coupler to match the coax to the antenna -- four brooms
creating an eight-foot-or-so sized cross, around which was wound
approximately 60 feet of wire.  The ends of the loop were then attached
directly to the coupler.  They were selling it as a package -- wire, some
clips and the coupler.  It looks pretty neat.

   I've been searching everywhere trying to get some more data on this
design.  I've seen and studied references to mag loops that look very
different -- solid copper, very high-Q.

   It's clear that the SGC design will get me on the air.  I'm already
on the air; I have a ground-mounted High Sierra HS1500 with a
compromise ground plane.  What's not clear is whether or not the SGC
design would be better or worse than the mag loop, or the HS1500, and
what flexibility is available.  More turns better, less turns better,
larger diameter, more or less wire, etc. etc.  I've searched for two
days on the web and cannot find anything that addresses design
considerations for this type of antenna at all.

   The key design points are that: (a) the antenna will be close to
the ground; (b) one or more turns of #14 or #16 wire on a square frame
sized anywhere from four to eight feed square; (c) I have an MFJ
transmatch unit (the 941E) that I can put directly on the loop.

   Can someone point me in the right direction?

   Appologies if this is a post asking questions that have been asked
in the past; I did find a few references to horizontal loops (tacked
around the inner walls of the apartment) in the group and read those
with interest.  But I could not find anything on this particular
design.

   Many thanks and 73,

   Martin AC6RM