K4QKY's initial impressions resulted in comparing the MOXON antenna with his 160 meter ladder line fed tuned horizontal loop at 65 feet. Click here for additional details about Don's 160 meter loop antenna including dimensions, height and radiation plots. The loop antenna is up at nearly twice the height of the MOXON. Furthermore, being several wave lengths long on 17 meters, the loop usually outperformed the MOXON during testing. Here is a sampling of testing results
"Since I put up the MOXON in place of the folded x-beam, stations that remember the signal from the x- beam are telling me the moxon is by far the better antenna. I have seen on the average of 2 to 3 s units improvement. I added the garden stake to support the center of the reflector, great idea. My coax is fed thru 1/2 in pvc pipe to the feed point and wire wrapped. I will be putting a balun on because I am slightly getting into the TV. I was doing some work on the computer late the other night about midnight and kept hearing faint voices and whistles at 18.140. I had the moxon pointed SW and put out a QRZ. V73B, Buzz came back to me and gave me a 5-9. It may be magic but I am hearing a lot more with this moxon. Last night I called KH6BB, working from the USS Missouri in Pearl Harbor. Ned said my signal was extremely strong compared to other stations he had been working. I just finished a QSO with Frank in California, K6KS. He mentioned several times about my signal. He even told me he could hear me without an antenna hooked up. I must be in a good location for the angle of take off. One thing I have seen, signals from Tasmania are not as strong as the x-beam. I will observe a little longer. Bad news is, my center support is drooping from the weight of the poles. I got a bad piece of plywood from the wire spool end. I am now looking for a 18 in diameter fiberglass hub. don't know if I want to use the 18 in diameter aluminum plate I had made up. My goal is on a 50' pushup, stacked MOXONs, 20m at 30ft and the 17m at 40ft. By the way, I can't see whereby lifting the sag in the reflector helped. If so by very little. Really enjoy this and everyone I talk to is very interested. This project is growing!"
KD6WD "John", having gone thru thousands of feet of wire building antennas since becoming a ham, offered the following comments 09/11/03:
John has been comparing the Moxon to his 2 element cubical quad. The top of the quad is at 50 feet with the Moxon on a pushup pole at 20-22 feet. The Moxon is being fed with RG58 and the Quad with RG 213. Although signals varied, the Cubical quad heard the stations by almost a full S unit better in some cases. What was surprising was that in many cases there was only 1/4 to 1/2 S unit difference on receive. In about 7% of the cases there was absolutely no difference in the received signal level. The further away the DX station was, the less difference there was in received signal level. The signal reports returned either were identical or 1/2 s unit better on the Quad.
John doesn't plan on giving up his quad. Besides, the quad has six bands on it and works very well. John is planning another Moxon... this time for 40 meters on a longer mast from his 36 foot tower. Since the 17 meter Moxon works well at 20 feet, John feels that a 40 meter wire version should work well at 45 or 50 feet.
Thanks to Allen Baker, KG4JJH, who wrote an article for the May, 2003 issue of QST magazine entitled The Black Widow--A Portable 15 Meter Beam..., John elected to use fiberglass crappie poles for this project. John feels that this was the right decision as it helped get rid of the dacron rope support structure that were used with his earlier pvc sprinkler pipe prototype. Use of these poles also dropped the weight to less than six pounds, reduced the total wind area to 2 1/2 feet, and allowed use of an economical rotor ($69.95 new or $25.00-used). Since the MOXON works so well at 20 feet, the mast can be a single 1 1/4 inch 20 ft 6061-t6 aluminum schedule 40 pipe properly guyed. Even on mornings with very heavy wind gusts, the crappie poles kept the wire on the MOXON tight even though the RS pushup mast flexed about 6 or 8 inches.
John lives in Florida.
KF4EFH "Kevin" is testing his MOXON at 30 feet against his A-99 vertical antenna . Kevin says that receive seems to be 3-7 db increase over the Solarcon vertical A-99 http://www.universal-radio.com/catalog/hamants/1001.html . One Station that he could not hear at all on the vertical was 5-7 on the Moxon. Reports from several European stations placed the Moxon at least 3+ db over the vertical including Slovenia "S59PC", Beirut Lebanon "OD5NH", Hungary "HA5OG", Bulgaria "LZ2KV" and U.K "G2BKZ".
K6SGH "Steve" is testing his MOXON at 40 feet suspended beneath a tree. After using the antenna for a week, he reports that he continues to be impressed with it's overall performance. "For such a small antenna, two simple wires, it is really amazing." Steve says that he was listening to one of the other project participants "Ron" talk to a ham in California. During the conversation, he rotated his MOXON 360 degrees noting the front to back and side rejection to be equally amazing at least 30db. There was one point, off the back corners, where the rejection was even greater.
Steve tested the antenna with K4QKY "Don" on 17 meters. Don and Steve both believe that front to back rejection on 17 meters is still good. Signals were up and down but Steve believes that the 17 meter element is working as well it did when it was a monobander.
More testing will follow including separately feeding each element.
K6VYX "Martin" is testing his MOXON (with bamboo spreaders) from a push-up mast. Martin reports that he loves his MOXON and has worked Poland with his 100 watt rig and got a signal report of 57 to 59. Martin is testing his MOXON against a Gap vertical and routinely notes the MOXON to be 5 to 6 S units better than his vertical! Marin will be soon be replacing his bamboo spreaders with fiberglass Crappie fishing poles that all of the other project participants are using.
N0KHQ "John" has been testing his Coaxial MOXON on a daily basis comparing it against his Sterba Curtain as a reference. He feels that this is a somewhat unfair test but the Sterba is the only other antenna that he has. The Sterba and the Moxon (at 30') seem to compare equally on receive.....the jury is still out on transmit.
The Moxon front to back appears to be good. Because John is feeding the front element and rear element 270 Degrees out of phase, he believes the gain of the antenna to be somewhere around 8db (not to be confused with dbi). All testing is being done with 100 watts output.
As we move into the winter months more accurate testing will be done and performance updates will be added to this page as they become available.
A Coaxial Moxon is soon to be published on the Hamuniverse.Com website, but will not include the phasing or feeding as discussed here.
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