Please be gentle - new HAM here and love to build stuff and tinker with gear

I have a Yaesu FT-2DR and often turn it on in my shop to listen to local repeaters. I replaced the antenna with a Diamond SRH77CA but it only helps a little while inside my shop.

I want to build a J pole and found these instructions. Simple 2m

Seems easy but he uses 3/4 copper pipe. What would happen if I use 1/2 inch copper pipe instead? (I just happen to have a bunch of it laying around) and use his spacing and measurements?

My buddy (Elmer) has a SWR meter that he will bring over and help me tune everything once I have it all together.

It will be mounted on a post to the end of my shop. Can't go very high - I live in a association, but the base of the antenna will be 5 feet taller than my shop roof and about equal to my house roof located 20 feet away.

No plans for a base unit at this time (I have been told this will change ) but if this antenna works out I will build another to take to take camping when we do our yearly week at the beach.

Build it! If you have an SWR meter you’re well ahead of most.

You can also build a roll up J-Pole out of ladder line when you go portable.

J pole plans

Antenna building is my favorite part of this hobby.

It will be cheaper.

Build price or build quality? 1/2 vs 3/4

Friction fit it together and then check it for swr. That way your not doing a bunch of trimming to get to the sweet spot.
Afterwards, then you can solder it up.

in theory, the larger diameter would have a wider bandwidth. In reality, I doubt you'd notice much of a difference (my Arrow J-pole used 1/2" bar stock).

I built a few years ago using 1/2 inch. Worked fine. But the plans I used were for 1/2 inch as well.

I prefer the 2 meter Slim Jim. Made from 1/2" Copper. Take your time with the tuning, have had several that would barely bump the SWR meter. Most of mine have a shorter gap the plans below, usually about an inch.

The advantages:
Increased gain: compared to a standard J-Pole the Slim Jim has about 6dbi of gain
Wider Bandwidth: Almost 8MHz of 2:1 bandwidth (double that of the J-Pole antenna)
More RF energy aimed at the horizon: with a take-off angle of about 7 degrees for the Slim Jim, compared to 20 degrees for the J-Pole.

Plans;

http://hamuniverse.com/2metercopperslimjim.html

That looks like fun.

I made one from 1/2" copper & it worked perfectly. You could use aluminum solid rod or tube as well.

https://www.eham.net/articles/2418

LOL - that is the one I linked to in my first post. Glad to hear it worked out well using 1/2 inch

Or you’re lazy like me and buy one from N9TAX

I bought one of those for portable use and I keep it in the truck. It works well.

I wanted to build one of the N1BMX dual-banders for the home station, but when I priced the thread tap and die and materials, a Blackbird from MTC with shipping was cheaper.

I did make a ground plane for 70cm and 2m from an ARRL manual. It looked nice and worked well, but the dual-band made more sense for a permanent installation.

Sorry
i took a pic of mine since it's not up at the moment. The support pipe is 3/4" the rest is 1/2" the SO239 is soldered onto a tee, the center conductor is a piece of 12ga insulated wire fished thru a hole and soldered to the other element. I painted it black so it wouldn't stick out so bad.

You won't notice the difference in diameter in any way, just get the lengths correct.

The stub end does not have to be insulated from anything, it is electrically at zero v.  It can be grounded or not.

A J-pole is a good antenna, is pretty much omnidirectional.

The higher you mount it, the better performance you will get.  Even a difference of 5' or 10' can make a big
difference.

Remember to check continuity after soldering the coax!
John, KF5ZMD
My plans for 220 MHz antenna build

J Pole Calculator