Hello - The site is a good idea, because there are so many out there new to the subject that haven't found a starting point. 

Compact transmitting loops will provide as much intrigue, enjoyment, satisfation, and challenge as a person can handle. 

My feeling is that these loops are the future of small-property DX antennas for the lower bands, particularly where height restrictions apply.

1.  Those looking for "cookbook" starting points, if not solutions, will find many on the web and in the amateur literature.  Caution:  this will get you on the air, but many of these suffer from large doses of mythology, and "dry-lab" designs.  Start with the ARRL Antenna Book, 19 th edition, Chapter 5, page 10.  It only suffers a little bit!

2.  For a better understanding, read Henk's article in the ARRL Antenna Compendium, Volume 3, page 99.  This is unnecessarily pessimistic, owing to the size constraints that Henk chose to put upon himself, but it is most illuminating.

3.  For those who want to fully understand, see Antenna Theory and design, by Constantine Balanis, Harper and Row, 1982, available used at college bookstores and on the web, e.g. (ABE books).  See all of chapter 5, which is devoted to loops.  Balanis is the only author (that I've read) who makes reference to small, medium, and large loops.  What most amateurs refer to as "small" loops (to distinguish them from large ones), are actually medium in size.  (e.g. for a circular loop, one with a radius of between 1/20 wavelength and 1/2 wavelength)  When you have understood Balanis, you will be immune to nearly all of the mythology out there surrounding compact loops.

4.  I should mention that compact loops are modelable, including the effects of loop ground interaction, and that much work has been done on that subject.

5.  I now take delight in stating that for the low bands, that is 80 and 160 meters, a properly, repeat, properly implemented compact loop installation will beat the pants off a horzontal Yagi at or below one wavelength above ground, for the same budget spent.  Yes, that includes DX.  The only thing that will compete with the compact loop(and beat it, under some conditions), is a good vertical next to an ocean. 

Having said all that, whatever a person's level of expertise, go for it; build a loop, and get ready to be amazed!  There's no subsitute for hands-on experience.

Hope this info. helps those who are trying to get started.
For a chuckle on this subject, look up my call, K6HPX, on this QRZ web site, and dig my mobile antenna.  In over 40 years of mobiling, this is the most effective antenna that I've used.  It's a compact loop, of course!

Sincerely,
Ken Hirschberg, K6HPX