A Wire Moxon for 10m

[Crawdad]

Sometime in the near future (God willing of course) I'll be relocating to a home with room for something other than a wire Inverted V. So I have decided to homebrew a wire Moxon for the SSB sub-band of 10 meters. Having never had/used a directional antenna before I wanted something lightweight and relatively simple to make. I have read as much as I could find on the Moxon (there's quite a bit out there) and initially planned on using tubing for the elements but decided on wire for the first one I put together. My time is limited so this work-in-progress may take a few weeks to complete, but Cycle 25 is just showing signs of firing up here so I'm not in a giant rush. Hopefully what I post here may help someone else out if they're thinking along the lines of a beam with decent gain and a very good front-to-back ratio without a second mortgage. This antenna would also be easy to design and build for 11 meters.

I'm using a few parts of the design found at www.kg4jjh.com/moxbeam.html. It's a nice website with lots of good info on homebrewing this antenna and I thank KG4JJH for sharing all that info.
The antenna will look similar to this when complete:


I started By using MoxGen to calculate the element lengths and spacing. MoxGen can easily be downloaded to your computer at: https://www.ac6la.com/moxgen1.html



Next I used EZNEC Demo to model the antenna. I settled on 21 feet Above Ground Level.


Here's the spreader hub designed and used by KG4JJH. Again, thanks to him for sharing.
Took about 30 minutes to lay out, cut and drill this from a 7-1/2" piece of treated 2x4.

Then I test fitted the 1/2" OD fiberglass spreader tubes.


That's all I could get done in the limited time I had that day, so that's all for now. Any advice from builders/users of this type antenna will be most appreciated.
I'll post as I go along if anyone's interested. If not, post STOP to end this thread.

73

 

[S&W357]

Great info Rick! Please keep us updated and the thread rolling.

 

[Crawdad]

Ok, it's been 7 months since I started this thread, life happens, and my QTH hasn't changed. And the proposed 10m Moxon has morphed into an actual 6m Moxon. The basic design I chose hasn't changed however, just a few minor things. The principle is exactly the same.

The hub is cut from a piece of 1" thick plastic cutting board. The spreaders are a 1/4" OD fiberglass tube slid inside a 1/2" OD.


The element end spacers/insulators were chopped out of a small plastic washtub. A Budwig dipole feedpoint on the driven element.

Just a temp mount today for some testing.


So far so good. Seems to work well, have made a few decent distance contacts on it. It's solid but very lightweight, would be simple to use portable on a push-up.

73

 

[S&W357]

Awesome work Rick!

 

[Crawdad]

If anyone's interested here's the initial numbers on the 6m Moxon in its temporary mounting:


I plan on tuning closer to resonance once the antenna is in its final position and mount.
As I suspected MoxGen calculates long (good idea), so I entered 50.3 aiming for 50.125. It's still a bit long, but I think won't require excessive trimming. Of course YMMV.

73

 

[Crawdad]

Awesome work Rick!

Thanks Ralph! Here's hoping your monsoon will end and you can get yours up in the air where it belongs.

73

 

[Crawdad]

Here's the final analyzer run on the 6m Moxon after some trimming, tuning and re-postioning:

I was aiming for resonance near 50.145, looks like I may have trimmed once too often. But I can live with those numbers just fine.
It's working well for stateside contacts, several at 1k miles+. We'll see how it does for real DX if/when 6m really opens up.

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