Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

   Home   Help Search  
Pages: [1]   Go Down
  Print  
Author Topic: Moxon Antenna?  (Read 2296 times)
KC9KEP
Member

Posts: 208


WWW

Ignore
« on: August 28, 2009, 06:41:48 PM »

Has anyone built the Moxon antenna that was recently
featured in ARRL/QST magazine?

It's rather rectangluar with about a 6' radius swing
for 10m if I recall.

It looks interesting, but I was wondering if anyone
had built such an antenna.

73

KC9KEP
Logged
N3OX
Member

Posts: 8853


WWW

Ignore
« Reply #1 on: August 28, 2009, 07:41:38 PM »

I've got two Moxons, one for 6m:

http://www.n3ox.net/projects/sixmoxon

and one for 20m, with some add-on circuitry for 17m:

http://www.n3ox.net/projects/2017moxon

Bunch of other builders here:

http://www.moxonantennaproject.com

I built mine very carefully, trying to get the measurements really close and both of them worked right away with low SWR and good F/B ratio.

I don't quite get 30dB F/B on the 6m one in actual measurements, but I get a healthy 22dB or so:

http://n3ox.net/files/mox_compare.jpg

The measured pattern is a bit ripply because of tropospheric variation on the ham who was acting as my signal source, and something took a big bite out of my pattern that I don't quite understand. ;-)  

But it's workin...


73
Dan
Logged

73,
Dan
http://www.n3ox.net

Monkey/silicon cyborg, beeping at rocks since 1995.
KE4DRN
Member

Posts: 3714




Ignore
« Reply #2 on: August 28, 2009, 07:57:18 PM »

Hi,

I also have a few, 2m, 6m and 20m

direct fed with 50ohm coax, no matching needed.

73 james
Logged
N2RRA
Member

Posts: 646


WWW

Ignore
« Reply #3 on: August 30, 2009, 05:02:10 PM »

Here Here!

I built many of these Moxons and I Love them!

Built them for 2m, 6m, 10m, 40m and built a tri-band 10,15 and 20 meter. Their easy, inexpensive, and have the best Front-to-back performance than all yagi\'s and log periodic. If you consider expense think about how munch you can save by buying a 500 ft. spool of 12-14 awg. wire from home depot and save yourself hundreds of dollars. Weight savings is a huge factor when worrying about structural support and strain on your rotor. Less wind load is a big factor.

Depending on the band they do have limitations like number of elements per band, but they offer a space savings way of getting on the air and obtaining the same forward gain. Generally tri-band yagis comprise of a 2el per band like a 6el tribander. Same amount of forward gain but better front-to-back plus all of the above.

Big major advantage is broad band width without sacrificing forward gain or front-to-back gain unlike yagis.

Think about practicality building a Moxon as supposed to buying a full sized tri-band yagi or mono-band beam and it should make some sense. Yes! you can stack other antennas above it like yagis and not worry.

The whole point of this hobby is too experiment and see for yourself the difference between each of them. Step back and look at your hard work mysteriously out performing other antennas by working Japan, Yemen, Australia and say "it was possible to work them because I built that antenna". Build it and take pride when you tell that DX station the reason you have a 5/9+ 30 over signal is due to your home brew yagi, quad, loop, delta loop, G5RV or of course better yet MOXON.

73\'s!
Logged
KC9KEP
Member

Posts: 208


WWW

Ignore
« Reply #4 on: September 01, 2009, 10:55:42 AM »

One more Moxon antenna question ..

It appears that these antennas are relatively
light.

Do you suppose that one could use a conventional
television type tripod, mast and rotator with the antenna?

thx!

73

KC9KEP
Logged
WB6BYU
Member

Posts: 13038




Ignore
« Reply #5 on: September 01, 2009, 10:57:03 AM »

It depends - are you building the antenna for 2m or 80m?
Logged
KE7ORS
Member

Posts: 73




Ignore
« Reply #6 on: September 05, 2009, 08:49:31 AM »

I built one for 20 meters a month or so ago and love it. It is mounted at about 30 feet above the ground and rotated with a Radio Shack TV antenna rotator. Not expensive. I am very impressed with the performance so far. It has been getting into just about everywhere I point it except for Africa. Hopefully that will improve as the solar cycle advances.

Go for it. It is a cheap antenna and works very well.

73
Tracy KE7ORS
Logged
KC9KEP
Member

Posts: 208


WWW

Ignore
« Reply #7 on: September 10, 2009, 07:20:01 AM »

Thanks all!

I would probably be building a Moxon for 20 meters.

An 80 meter version would be quite large (about 102 feet!)

Now, can anyone tell me if it would be feasable
to use a 20 meter Moxon antenna for 10 meters as well?

Thanks again!

73

KC9KEP
Logged
KE4DRN
Member

Posts: 3714




Ignore
« Reply #8 on: September 10, 2009, 05:21:30 PM »

Hi Tom,

please join www.cebik.com
you'll need a free login and password,
it keeps out the mass downloaders.

The late Dr. Cebik, W4RNL, has a wealth
of information on Moxon designs, nesting them,
as well as many other antenna designs along
with NEC plots.

Enjoy your Moxon !

73 james
Logged
N3OX
Member

Posts: 8853


WWW

Ignore
« Reply #9 on: September 12, 2009, 03:52:01 PM »

"Now, can anyone tell me if it would be feasable
to use a 20 meter Moxon antenna for 10 meters as well? "

Hm... not directly, and I don't think even indirectly.

You can make it work pretty well on 20/17/15 with switched-in capacitors in the reflector and switched matching networks at the feedpoint...  I checked that in EZNEC when I was designing the one I use now.

I don't remember if I tried to get it to work on 12 and 10, but it gets more difficult the more different the frequency is from the natural design frequency.

You could probably successfully build a 10m Moxon on the same spreaders you use for the 20m Moxon (if you do the spider type) and just use a coax relay or maybe even parallel the feedlines.

Another option would be to build a 20m Moxon on a boom and then build a 10m yagi on the same boom... you could probably use "open sleeve" coupling (where you just put the 10m driven element really close to the 20m one)  and just build a driver-reflector type 10m yagi on the 20m Moxon's boom.

73
Dan
Logged

73,
Dan
http://www.n3ox.net

Monkey/silicon cyborg, beeping at rocks since 1995.
KE4DRN
Member

Posts: 3714




Ignore
« Reply #10 on: September 14, 2009, 07:25:09 PM »

hi,

www.cebik.com has several articles on
stacking or nesting the Moxon,
some mulitband designs as well.

have fun with the Moxon !

73 james
Logged
Pages: [1]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!