Open Stub J-Pole Project – Completed (Many times)
by NT1K on Jan.03, 2011, under Projects, Uncategorized
I’ve constructed a 144/440 Dual band Open Stub J-Pole Antenna.
Assembled Open Stub J-Pole
I saw the plans for this on the internet (link to plans) by Allen Lowe (N0IMW). Since I had a Metal Fabrication backround I thought this would be an easy build.
Plans for Dual Band J-Pole 1
Plans for Dual Band J-Pole 2
I also created a PDF and JPEG Version which you can download if you like.
I did some minor changes from the above. Instead of using nuts I used pressed “PEM” nut on the underside and used thread protecting vinyl caps on the tips
Aluminum J-Pole Base 2nd View
Here are some SWR Shots. I don’t have state of the art equipment so this will do for now
Testing the SWR on 440Mhz
Testing the SWR on 146Mhz
It was a really fun and quick build. Plus it works okay. It’s no Diamond X510. What else do you expect for around $20 in parts? I love it.
If for whatever reason you can not build this. It is manufactured by the designer of this antenna and has them for sale on his website for a reasonable price. So check out ARROWANTENNAS.COM for the OSJ and other quality crafted antennas.
EDIT (5/2/11): I’ve Also built a “Adjustable” version of the Open Stub ( OSJ ) J-Pole as seen HERE.
EDIT (10/20/2011): Someone let me use a MFJ Antenna analyzer so here is a reading from the VHF side of the Antenna.
@ 145.98Mhz I got a reading of 1.0SWR with a 51ohm impedance. The antenna was resting on a wooden chair so I am not sure what the value would be when fully installed but I don’t think it would change that much since it doesn’t need grounding.
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OSJ-Pole – Adjustable « N1BMX
April 21st, 2011 on 16:33[...] was the correct spacing but the SWR was horrible So I used a extra bracket from one of the many Dual Band OSJ-Poles I’ve built. It worked out pretty [...]
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OCF Dipole antenna question - The RadioReference.com Forums
May 7th, 2013 on 11:30[...] has the parts. Emergency Amateur Radio Club – Hawaii – Homebrew Projects here is another one http://nt1k.com/blog/2011/open-stub-…ed-many-times/ __________________ Don't confuse my personality with my attitude. My personality is who I am. My [...]
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March 21st, 2011 on 04:49
Wonderful build was able to hit many repeaters with it attached to a pole stuck in a sleave in my front yard. Can’t wait until I get it up on the roof.
Thanks
September 22nd, 2012 on 05:16
thanks for the antenna plans and your contributions.
March 24th, 2013 on 04:46
Wonderful work!
Thanks.
73 from Spain,Europe