info on the K9AY loop
Listening test and other observations
How to make your own K9AY
The importance of good ground
How to place wires best
of the KPAY
WA1ION version of the K9AY loop
By Mark Connelly, WA1ION
The K9AY loop antenna can provide a cardioid (heart-shaped,
single-null) pattern when one end of the antenna is connected to
ground through a variable DC resistance. This occurs because of
the interaction between electric and magnetic field pick-up patterns.
The drawing provided above are of a K9AY loop tested at sites
in Billerica, MA and East Harwich, MA during 1999.
[To get a larger version, click on the drawing above.]
The BBL-1 Broadband Loop is a scaled-down version of this
antenna. It is usually mounted on the roof of a car for seaside
DXpeditions of brief duration.
BBL-1 documentation is may be obtained in PDF format from links
found on the WA1ION DX Lab home page.
documentation [PDF document]
This antenna was first described by Gary Breed, K9AY, in
QST magazine, September 1997, with an update in the QST of May 1998.
Al Merriman, K4GLU, was the first to use this antenna for serious
medium-wave DXing. A K9AY loop accompanied Al to Newfoundland on
the very successful 1998 DXpedition.
Andy Ikin of Wellbrook Communications in the UK has also done thorough
tests on this antenna type.