I was looking for a new antenna to try this weekend. I will be in the NAQP CW Contest and there will be many stations active across the US, Canada, and hopefully some DX. I have been thinking about a Loop antenna for some time. My main use for it initially will be as an NVIS antenna for VA/MD/DC/PA contacts. So I am going to build a 40 meter full-wavelength horizontal loop. I am only going to put it up about 15 feet high and see how it acts for nearby stations. After some testing, I may move it up to 30 or 40 feet and try it for longer-range work.
There are many articles on the Web. Here is one that had much useful information for a 40 meter horizontal loop: 40 meter Horiz Loop
Reading about the loop. it is recommended that you feed it in a corner and use 450 ohm open ladder line. To use it on multiple Bands, it appears that the losses could be significant and I really would want to use a remote tuner an/or ladder Line. But for just 40 meters, my models suggest that the SWR could be < 3:1 across the Band. If so, I could feed it with coax. Since I have a disconnected coax feedline lying outside, I am going to give that a try.
I am going to start with 4 legs, each about 34′ long. I am going to connect one end to my feedline using a short jumper wire and a wire nut. That will allow me to adjust the length and see if I can get the SWR curve into a reasonable place. I will post an update after I see if/how this works. My guess is that I will want to go to ladder line or the remote tuner later.