Gary Breed, K9AY, has taken loop theory farther and describes an antenna that can be erected in almost any back yard and provides performance better than most antennas.
http://www.hard-core-dx.com/nordicdx/antenna/loop/k9ay/k9ay.html
comprises a very neat control unit which plugs into a 12v power supply.
http://www.hard-core-dx.com/nordicdx/antenna/loop/k9ay/k9ay11.html
The performance of the K9AY is miraculous. details on how to construct one yourself.
http://www.hard-core-dx.com/nordicdx/antenna/loop/k9ay/k9ay12.html
Developed in the early 1990's by American radio amateur Gary Breed.
http://www.hard-core-dx.com/nordicdx/antenna/loop/k9ay/index.html