I am intrigued by this design and thinking of building one. It looks like one for 30 meters is about 33’ by 12’. For 20, 24’ x 9’. 40 meters would be a little too large, 48’ x 19’. I am interested in hearing from anybody who has one, built one or thinking about one. What kind of materials were used, for example. I have a QST article about the Black Widow beam built for 15 meters with crappie poles used for supports. I am especially interested in its feasibility for QRP operation on my deck or in a park.
There was a newer article I seen somewhere about building a 30 Meter sloper that would would be good for portable operation. DX Zone might provide the answer.
I built one for ten meters quite a few years ago using W4RNL's design, I used aluminum tubing and PVC. It worked pretty well, gain similar to a two element Yagi but with a better turning radius since it was about four feet shorter than a Yagi. I think anything lower than 20 meters is just mechanically unstable, but you can at least try. For 30 meters, bamboo and wire would probably be your best bet for one that large.
I'd like to put a moxon for 10m in my attic. I know outside is better, but I'm in an HOA so stealth is the word. I've read a lot, researched a lot, but need to get specific measurements for the space available in my attic because if possible, I'd like to be able to rotate it. MFJ has a 10m moxon, about $100 I think, if you want to go that route. Good luck, please keep us all posted. 73 de Jeff, KF5KWO
Right now, 10M doesn’t seem like it would be useful. It would be small 12 x 5. Here is the calculator that I am using - it works on my iPad http://tippete.net/cgi-bin/moxgen.pl I am looking at fiberglass products on https://mgs4u.com/?v=7516fd43adaa . I don’t think I’m ready for aluminum tubing although that may be a good choice for someone experienced. Crappie poles from Cabela’s up to 20’ https://www.cabelas.com/catalog/pro....z_btnclk=YMAL-3470532&WT.z_pg_ref=prd3143085 Just gathering data.
You’re right about 10m these days, for usre, but I’m thinking that’s the only size that will fit in my attic. Plus, the attic is only one story above the ground, so the max height above ground for the antenna would be around 15 feet or so. I know, hardly ideal. Generally, the moxon has intrigued me for a few years because of the gain and the fact that it’s smaller than a typical yagi. Thanks for including those links as well! I’m juggling antenna projects, and considering a portable 20m antenna for beach ops, and hopefully getting my stealth 80m wire loop put up starting today.
I've built Moxons, including two for 6 meters. They're reasonably small on that band. Spreaders are fibreglass, elements are wire. They work as well as a 2-element Yagi but have somewhat smaller turning radius and wind loading. In an attic: If you can rotate it, great. If you can't rotate it, this would not be helpful. A loop running the interior perimeter of an attic might be better and with a good tuner cover more bands.
I agree, a loop fed with balanced line into a good tuner would probably give him more options than just ten meters. What kind of rig are you running? I have a good reason for asking.
I found out bamboo is cheap. Will it hold up? It could be good for testing designs. I figure about 70-75 feet is needed for a 30 meter antenna and it looks like the cost might be $50-75.
