Well, there are several types of loop antennas, so
perhaps you can describe your intended application and
we can provide more specific help.
The most common "loop antennas" would be a full-wave
loop (about 8 1/2' on a side - two or more can be
combined to form a cubical quad beam) or a small loop
(perhaps 6" in diameter) used for direction-finding.
Other varieties of loop antennas:
- 3/2 and 2 wave loops (usually installed in a vertical
plane and give added gain over a full wave loop.)
- large horizontal loops (often a full-wave loop for
40 or 80m, which will make it over 100' around) will
allow operation on multiple bands.
- small transmitting loops (perhaps 2' in diameter) can
allow operation in a limited space.
- the DDRR antenna looks like a 3' diameter loop placed
6" to a foot over a conducting surface. Variations can
be used as low profile mobile antennas.
- the Moxon beam looks like a loop, but really has
openings on the sides. A Hex beam, "Cobbweb" antenna,
and similar designs also fit in this category.
- a "loopstick" is a coil wound on a ferrite rod - good
for receiving, but not efficient for transmitting.
- the Sterba curtain, axial mode helix, folded unipole,
"Wonderbar" antenna, and many others could be included
in the general heading of "loops", depending on your
An excellent resource for antenna designs is W4RNL's
site at www.cebik.com
His series of articles called
"An-Ten-Tenas" are specific for 10 meters.