Topband: coax loops - the age old question...

[Rick Karlquist]

Pete Parisetti wrote:
> Hello topbanders,
>
> I would like to be the thousandth who asks the same old question - do, in
> your experience, small coax loops work?
>

I wrote an article on an improved feed system for coaxial loops
in the Sept/Oct 2009 National Contest Journal.  I should emphasize
that my contribution is to the feed system, and I don't have a
magic wand when it comes to the antenna pattern.  I posted a scan
of the article to the files section of the Yahoo Group:  "Loop Antennas".
You are correct that all the loop does is give you a null and
a corresponding receiving pattern "gain" of 1.5 dBi, same
as a short dipole.  In many cases, this provides a worthwhile
reduction in power line noise.  Another thing you can do with a loop is
locate it in an out of the way location away from noise.  Because of its
portability, this is more practical than a remote low dipole.  For
example, I have a loop at the back of my property, 1/4 mile from the road
where the power lines run.  The extra distance, along with nulling
capability, gives me a chance to overcome power line noise if it flairs
up.
Another interesting thing I do with loops is to null my own transmitter
so I can listen while transmitting and operate SO2R in 160 meter
contests.

I hope this puts into perspective what coaxial receiving loops can
and cannot do.

Rick N6RK