There seems to be no end to it. Every QST is loaded with "new" Windom antennas that have lumped inductance and capacitance and various voltage and current baluns and are "guaranteed to work all bands from DC to daylight." It really bothers me that so many young, or at least young to Amateur Radio, hams are getting fleeced by unscrupulous dealers who charge tons of money for a piece of wire.
Here's the real story. The Windom antenna has been around forever it seems. My first inkling of it was from a 1936 article about an OCF (off-center fed) antenna that was simply a wire that was fed by another wire. I don't know who first tried this method but it was named for General Loren G. Windom (W8GZ) who died in 1988. "Windy," as he was known, was a much-decorated hero of WW-II. And after the war he was a technical contributor to QST. He and Don Wallace (W6AM) shared the honor of working more postwar DXCC countries than anyone else (366) and Windy earned 5 band DXCC #3.
There is nothing magic about the Windom antenna. Instead of you paying a lot of money for wire here is a diagram of an OCF from an early issue of Ham Radio magazine. This one doesn't require anything but a couple of trees to support it. It's good for 80, 40, 20 and 10 meters WITHOUT an antenna tuner and with a tuner you could likely work all bands. It does require a 4/1 balun but you can make one of those yourself for less than 40 bucks and if you have some wire and a piece of left-over 300 ohm TV twin lead you are in business.
This, of course, is a very old example of a Windom and there are more mordern articles and descriptions of OCFs in ARRL antenna books and their annual handbooks. There are no special precautions associated with Windom antennas 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. Use any handy trees to support it.
Incidentally, you'll notice that in this sketch the balun is connected to the "transmitter" with 75ohm coax You may not know it, but the center feed point of a normal half-wave antenna is closer to 75 ohms than the usual 50 ohm coax that most hams use. But there are so many other variables associated with antennas that the difference is negligible. (There are many articles and descriptions of modern OCF antennas on the Internet and in ARRL handbooks and antenna books.) I hope that I have dispelled at least some of the myths associated with the Windom antenna, and I hope you won't be duped into paying a lot of money for something so simple. Antennas are "mysterious" to new hams, and there are many dealers out there just waiting to take advantage of you. Like most wire antennas, the Windom is easy to do-it-yourself and it will work but it is not any better than a normal half-wave antenna and it is just as long so it's not a space saver. A half-wave for 80 meters fed with no-loss window line and an antenna tuner will let you work all bands.
One more note: There is a company that will sell you a 270 foot, 8 band, OCF for $403.00 (plus shipping). If you have enough space for that, may I suggest 273' of #12 wire from the "Wireman" for $77. Form it into a loop or triangle and feed it with 600 ohm window-line through any popular antenna tuner and work ALL HF bands for less than a hundred bucks. The fallacy of power "being lost" in a tuner is BS, unless you have a lousy tuner. Any simple T-match antenna tuner with decent size components will do, and any RF that is reflected down the line, goes right back up to the antenna, so you don't lose anything. If you have 400 bucks to throw away, that's up to you. But, there is a better (and cheaper) way.
Should you have any questions or comments about this antenna send me an email at firstname.lastname@example.org.