I’ve been working on another temporary antenna for use in my city lot during contests. You’ll recall my Moxon Beam for 15 meters that’s done such a great job on that band. I’ve been looking for something that would work on 20 and 10 meters as well, and maybe 40 meters. I came across a great write-up by Sam Moore, NX5Z, in the March 2011 QST, titled “A Four Wire Steerable V Beam for 10 through 40 meters”. That antenna requires a great deal more real estate than I have available, but I figured if I could get something pointed to Europe, I’d be doing just fine. I found a 35 foot push up steel mast on ebay and picked it up. I added a 4:1 balun from Design Baluns and the spool of 14 guage stranded wire I already had for the legs. Then I looked at how best to get the mast vertical in the most advantageous part of the yard. On Memorial Day, I found the free time to try it all out. You can see some photos nearby. After it was all up I conducted some measurements. I found that from 10 meters through 30 meters, I had a VSWR of roughly 2.5. Not the best but a level that would allow me to run coax from the 4:1 balun to my K3’s internal antenna tuner without too much loss. That saved me from running twin lead to a nearby remote antenna tuner. I also note that 40/80/160 have VSWR around 4. This means I should give some consideration to putting in place a 1:1 balun for using the antenna for the low bands, where it no doubt acts more like a low hanging dipole. That could perhaps work well for NAQP and Sweepstakes. Something to consider.
Unfortunately, once everything was in the air, I was first only able to get 65 feet of wire into play for each leg of the antenna. Then the angles of the wires came out to 60 degrees and 100 degrees. This would put center aim at roughly 80 degrees, way off the mark for Europe. If I moved the mast closer to the backyard fence, it looks like the north leg’s angle would improve to 50 degrees, which might bring Southern Europe and Northern Africa into play. On air testing revealed the directivity that I was seeking, but not sure I’m going to be happy with the aim. My thought right now is to put the Moxon on top of the push up mast, which would be a big improvement over the painter pole I’m using now. Now I need to spend some time thinking about how to get the Moxon mounted and up into the air. Stand by for more ham radio adventures!