Topics

2 m Jpole antenna build #antennas

Jon KF6LMD
 
Edited

Last year at the CFF event Talia (KM6UMY) and myself were lucky enough to be stationed with Richard (WA6RWS). He gave us some ideas on how we could setup our mobile ham shack and suggested we try building a Jpole antenna. It took us most of a year to get around to building one, but we finally took the time this last week to make it happen. We made a lot of mistakes I'm sure, but we had a fun time with the build. 

For the plans we used a combination of the 2 meter J antenna uploaded by Dennis (WU6X), and some ideas from the hamuniverse site: http://www.hamuniverse.com/jpole.html for the antenna build
and http://www.hamuniverse.com/kl7jrvertsupport.html for the antenna base. The mast is just a single 10 foot piece of chain link fence top rail, which inserts into the base. Richard may recognize the New England Red painted 2x6 board that is part of the base, as that's a piece of his old house! We thought it was a fitting tribute since he gave us so many ideas for this project. 

Our goal was to have everything operational by the club check in on 6/20, we had the mast deployed and turned on our radio at 7:32, so just barely made it!

Here's some pics of the process:


73
Jon KF6LMD

Dennis - WU6X
 
Edited

Fantastic ... You can adjust the SWR by sliding the feedpoint up/down.

73,
Dennis, WU6X


From: sfarc@w6ek.groups.io <sfarc@w6ek.groups.io> on behalf of Jon KF6LMD <jonpthomasson@...>
Sent: Friday, June 21, 2019 10:58 AM
To: sfarc@w6ek.groups.io
Subject: [from W6EK Groups.io] 2 m Jpole antenna build #antennas
 
Last year at the CFF event Talia (KM6UMY) and myself were lucky enough to be stationed with Richard (WA6RWS). He gave us some ideas on how we could setup our mobile ham shack and suggested we try building a Jpole antenna. It took us most of a year to get around to building one, but we finally took the time this last week to make it happen. We made a lot of mistakes I'm sure, but we had a fun time with the build. 

For the plans we used a combination of the 2 meter J antenna uploaded by Dennis (WU6X), and some ideas from the hamuniverse site: http://www.hamuniverse.com/jpole.html for the antenna build
and http://www.hamuniverse.com/kl7jrvertsupport.html for the antenna base. The mast is just a single 10 foot piece of chain link fence top rail, which inserts into the base. Richard may recognize the New England Red painted 2x6 board that is part of the base, as that's a piece of his old house! We thought it was a fitting tribute since he gave us so many ideas for this project. 

Our goal was to have everything operational by the club check in on 6/20, we had the mast deployed and turned on our radio at 7:32, so just barely made it!

Here's some pics of the process:


73
Jon KF6LMD

--
Dennis - WU6X

Clyde Campbell
 

Good Work. I have two J poles on my roof. one for 2 Meters and the other is for my UHF  441MHz ALLSTAR node.
and you did come in load and clear on the net
73
 Clyde AB4CC

Jon KF6LMD
 

Thanks Clyde, Greg, and Dennis. It's good to know these antennas will last the test of time. The SWR right now is at 1.4/1.5. I guess that's not too bad, I may try to fiddle with it more later on. Greg, I hadn't thought of using it for satellites, i'll have to give that a try  at some point! 

Maybe we'll see some of you at field day this afternoon!

73 - Jon

Dennis - WU6X
 

I had mine up for over 30 years I think. 

Dennis
530-305-0180
iPhone Mobile

On Jun 22, 2019, at 9:48 AM, Jon KF6LMD <jonpthomasson@...> wrote:

Thanks Clyde, Greg, and Dennis. It's good to know these antennas will last the test of time. The SWR right now is at 1.4/1.5. I guess that's not too bad, I may try to fiddle with it more later on. Greg, I hadn't thought of using it for satellites, i'll have to give that a try  at some point! 

Maybe we'll see some of you at field day this afternoon!

73 - Jon

--
Dennis - WU6X

Richard
 

That is a good looking antenna. hi hi
Thanks for sharing.  
You had a great signal into the repeater on the Thursday night net.

Richard WA6RWS

Greg D
 

Hi Jon,

Yes on the satellite antenna, but note that the downlink side was to my shortwave receiver, and that satellite (RS-10) was known as the "Easy Sat" because of how sensitive its receiver was, and how easy the 10 meter downlink was to hear.

As we discussed at Field Day, the simple "Ground Plane" antenna built from a SO-238 connector and 5 pieces of 18 1/5" copper wire is also usable as a satellite antenna.  Easy to build, though not as durable as the copper pipe variety.

Another possibility for an easy satellite antenna, and one with a bit of gain for hearing the current crop of smaller satellites, could be to build a "Tape Measure Yagi" out of some PVC and a bit of old measuring tape.  There are several similar designs, some using the steel tape, some using 10 gauge copper wire.  Some random examples from the Web:

https://www.jpole-antenna.com/2017/02/07/build-it-2-meter-tape-measure-yagi-beam-antenna/
http://www.fredspinner.com/W0FMS/CheapYagi/vjbcy.html

Antennas are great, low cost ways to experiment in the hobby.

Enjoy!

Greg  KO6TH



Jon KF6LMD wrote:

Thanks Clyde, Greg, and Dennis. It's good to know these antennas will last the test of time. The SWR right now is at 1.4/1.5. I guess that's not too bad, I may try to fiddle with it more later on. Greg, I hadn't thought of using it for satellites, i'll have to give that a try  at some point! 

Maybe we'll see some of you at field day this afternoon!

73 - Jon

Jon KF6LMD
 

Thanks for the links to the tape measure yagi. We may try that one and the ground plane at some point. We really appreciated you talking to us about your antenna's at field day. I did think of a question today about the copper antennas. Do you need to coat them with something if they're going to be exposed to the elements?  I know copper can turn green if it's left outside, but I'm not sure if that somehow damages its electrical characteristics as an antenna. The other thing I was thinking I'd need to do would be to put some sealant around the exposed coax at the feedpoint. 

Greg D
 

Hi Jon,

I didn't bother with the copper, and don't recall reading anything suggesting it was important to protect.  Sealing the coax, yes, very important to keep water out of there!

One last comment was that I had a LOT of trouble getting my J-pole to resonance.  Measured the SWR, adjusted things so it was good.  Then moved the antenna, and the SWR was all wonky again.  I believe this is because I didn't have an effective coil of wire at the feed point to decouple the feed line.  So, if you see things get strange, look to more turns or putting some clamp-on ferrite chokes there.

Greg  KO6TH


Jon KF6LMD wrote:

Thanks for the links to the tape measure yagi. We may try that one and the ground plane at some point. We really appreciated you talking to us about your antenna's at field day. I did think of a question today about the copper antennas. Do you need to coat them with something if they're going to be exposed to the elements?  I know copper can turn green if it's left outside, but I'm not sure if that somehow damages its electrical characteristics as an antenna. The other thing I was thinking I'd need to do would be to put some sealant around the exposed coax at the feedpoint.