[TowerTalk] Modeling the Moxon

[Jeff AC0C]

Dave,

If you are reusing the telrex elements for part of this you will want to put 
your build into a mech anal program like Yagi Mechanical or similar and 
check out the wind survivability.  The 40m 3-element Telrex for example 
comes out to show a failure at around 53 mph and that's assuming they are 
using 6061 which is not at all a known fact.  I'm reusing a 40m telrex boom 
and 20m Telrex aluminum for a 17m beam and the numbers come out pretty good 
there - assuming 6061.  Wind is a big problem here - it may or may not be on 
your end.

Good luck.

73/jeff/ac0c
www.ac0c.com
alpha-charlie-zero-charlie

-----Original Message----- 
From: Dave Sublette
Sent: Thursday, July 27, 2017 7:28 AM
To: Central KY CW/DX Operators ; Bill via TowerTalk
Subject: [TowerTalk] Modeling the Moxon

I have spent a fair amount of time reading a few of the Moxon construction 
articles about the modified Moxon for 40 meters.  I have a spare 6 element 
20 meter Telrex monobander for 20 meters in my barn.  Doing some scratching 
on paper, it looks like I could build two, two element Moxons for 40 using 
the material in that yagi.  I would need to buy the tubing necessary to 
build the Tee sections on the end.

Since all of the element diameters and taper schedules would be different, I 
should model it.  I have the Antenna Model Software package.  I haven’t used 
it much.  I haven’t modeled antennas in over 15 years. I used to use K6STI 
software when I did and I loved it.  Some of the articles I have read say 
good things about the Antenna Model program.  I am wondering if that would 
be good enough to use on the Moxon.

Now I know the Moxon doesn’t model well. The W6NL version is the standard 
and the best advice is to build it like that.  But I have all this beautiful 
aluminum that I don’t want to waste.  Plus, the 3 1/2 inch boom on the T-rex 
is really stout enough to handle this antenna.  At least one article says 
they wish they had used a larger boom diameter.

I suppose a good plan would be to model the W6NL and then my version on the 
same software and adjust my version until the results matched those obtained 
with the W6NL.  The question is ..  Is the Antenna Model package adequate 
for the job?

A really good answer would be that someone has already modeled the W6NL on 
Antenna Model and would share the file with me.  :-)

Thanks,

Dave, K4TO
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