This is an easy to erect, cheap, and versatile antenna which you can use on all bands from 80 through 10 meters. It must be fed with open wire feeders and must use a matching unit (antenna tuner) between the feed line and your transceiver.
You may use 450 ohm "window line" or 600 ohm open-wire feeders or you could do as the "old timers" did and make your own feed line out of plastic spreaders and number 12 or 14 twisted copper wire. (REAL old-timers used dowels that were boiled in linseed oil to waterproof them.<
There are no special precautions associated with this antenna other than the usual - keep it away from power lines and do not orient it so that it might fall on power lines in a storm. The sketch above is a little deceptive - the loop appears to be a "diamond shape" but it is actually a horizontal square. Use any handy trees to support it and try to keep it as square as possible because its efficiency will be determined by the amount of area it encompasses. Of course, if you cannot make it square it can be in a triangle shape. (Mine is more of a "273 foot rectangle" than a square.) Just be aware that as the amount of "enclosed" area of the antenna decreases the more it will take on the characteristics of an ordinary dipole.
In an ideal world this antenna will be most efficient if it is matched to the transceiver using a balanced antenna tuner. But I have used it with a commercial balanced tuner and with one that uses a 4/1 balun for feeding open wire and both tuners do a nice job of matching.
When using the 80 meter (3.5 Mhz) version on higher bands the loop appears to show more gain in all directions. Another advantage of getting it as high as possible (it will function as low as 30ft above ground) is that at greater heights the "take off" angle seems to flatten out very close to that of a vertical and it becomes a good omni-directional DX antenna. I know for sure that the loop on 20 meters way outperforms my DX Engineering 4BTVvertical, which has about 50 radials and was more difficult to erect than the loop.
Another facet of this antenna is that the two ends of the feed line may be connected to each other and it may be used on 160 meters where the loop acts like a "top hat" capacitance. Of course, in this case you must have an antenna matching unit that will tune 160 meters.
Should you have any questions about this antenna send me an email at firstname.lastname@example.org.