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Built a Moxon today

rixdafix

561 Missouri Mobile (WDX561)
Dec 19, 2022
111
291
73
East Central Missouri
Used 14awg wire from an old extension cord, hub and insulators are cut from a couple of old campground signs. Spreaders are from a previous 1/4 wave ground plane project.

I cut a section of female acme threaded paint roller handle to use as a nut for the center of the hub. The top post (supports spreader guys) and extension pole mast thread into either end.

I modeled it at 27.2mhz, measured a million times and cut the wires once. Assembles in about 10 minutes, zipties are just right so everything slides together.

Maiden voyage tomorrow on the box stock McKinley wind gusts permitting.

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The antenna works better than I imagined. There's a photo of it deployed on the reclaim 16lsb thread. SWR was 1.2 on channel 1 through 5 and 1.0 on 6 through 40. That was according to the SWR function on the McKinley.

It was a great lesson on the importance of antenna height also. At 16 feet and lower, it didn't really offer the rear rejection I hoped for but once I extended the pole to it's max 18 feet the antenna came alive.

Now that I know the wire portion works I'll probably build a lighter frame work. Anyway just wanted to post a follow up and some results.

Peace
 
I set the Moxon up on our deck yesterday and tried it out with my old Tram and Gemtronics radios. I powered them from a 12v battery, not optimal but functional. While I did make a few contacts, I noticed random static.

Should I run a temporary earth ground to any of the components such as mast or coax shield when using portable antennas? I noticed on a couple of occasions after adjusting mast height I would get a very slight static discharge when first touching the radio.

I know next to nothing about reactance, impedance, and such. Should I incorporate a balun and how do I know if I need one?

SWR wasn't as good as when I have the mast resting on the ground. I could only raise the mast to about 15 feet above deck because of wind but deck is also 10 feet above ground below.

Thanks in advance for any insight!

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