F6ARC - FG/F6ARC - FM/F6ARC, please QSLs via bureau or direct with a SAE and 1 US dollar (EU), 2 US dollars (Outside EU) or one valid IRC, to: FE11DX, STEPHANE LAIGNEAU 1 RESIDENCE FRANCOIS FOREAU 28110 LUCE - FRANCE
"God gave us two ears and one mouth, so we ought to listen twice as much as we speak" ~Irish Proverb~
Five Band HF Beam covering from 20 to 10 meters
Moxon Rectangle on 20m, Reflector-Radiator Yagi on 17m, 15m and 12m, Radiator-Director Yagi on 10m.
The forward gain of a Moxon Rectangle is almost the same as a full-size two-element Yagi. So why choose the Moxon version rather than its "big sister"? Because this design offers certain advantages:
I have been using this antenna since May 2013. Bear in mind that only two elements are active on each band, therefore it can't compete with multi-element monobanders. Although tests were carried out without another antenna as reference, I have made enough tests to rate its performance. I live out in the country, but soil quality is rather poor (sandy). The antenna is less than 14 meters (45.9 ft) above the ground. However, the least I can say is that the results are well beyond my expectations.
Sept 4, 2015: two elements (reflector-driver combination) operating on 18 MHz have been added to the original model (DXBeam, DXB20151210-8mx).
In conclusion, I would say that this multiband beam is a good compromise for those who have antenna restrictions. The only potential issue (and only for those lacking sufficient mechanical knowledge) is the bending of the corner sections. Perhaps that's the price to pay for getting optimal performance from such a small antenna.
"If the Moxon Rectangle didn't exist, you'd have to invent it."
View looking West/Southwest
My tower sits on the highpoint of the property from which the ground slopes down in all directions (for at least 200 meters straight out from the tower base) except those between Northeast and Southeast. The picture above shows a profile of the terrain when beaming LP to Australia. Despite its low height, my two element Moxon seems to perform surprisingly well on 20m. Ian, VK3MO, carried out an analysis of my long path takeoff from what I believed was a “less than perfect” HF ground (see chart below – HFTA software) .
Here's what Ian wrote to me: “The plot shows just how beneficial your ground slope is in enhancing your long path signal. I have done 3 plots for comparison. Firstly the plot for your ground slope, secondly the plot if your antenna was over flat ground and the same height and finally your antenna at a height of 150 feet over flat ground. The result shows your ground slope provides a better result than a 150 ft high tower”.
A higher antenna does not necessarily mean better results!
6701113 Last modified: 2015-09-10 12:00:34, 9875 bytes
You must be logged in to file a report on this page
Book Totals: 663 qso's 624 confirmed Get a free logbook at QRZ.COM