Roll Up Open Stub J-Pole

thingiverse

These are spacers for building an open stub j-pole antenna. I followed these plans for the dimensions, but instead of using aluminum rods, I used wire. https://nt1k.com/open-stub-j-pole-project-completed-many-times/ The wire I used was called 10 gauge, although in my experience sizes can vary widely from manufacturers. The important thing is that the outer diameter of the wire. What I used is 5.25mm, although you could probably drill the holes out a little, or play with the horizontal infill setting to adjust them. Or just use whatever wire fits. From what I understand about antennas, thinner wire will be a reduced bandwidth. As you can see from my VNA pictures, the bandwidth on this is insane after I got it tuned, so I'm sure you could get away with slightly smaller wire. You will need 1 of the "B" pieces for the bottom. You will need 2 of the "A" pieces for the top of the middle length piece of wire, and the top of the whole antenna. This has an extra hole to attach the rope. I used 3/16" rope. The "C" pieces are the ones with only 2 holes to fill in the rest. these are for added stability. It might work without any of them, but i found 4 sufficient to keep the antenna pretty sturdy. I used a piece of 1 inch angle aluminum like the plans call for, but my holes are much smaller. i used some standoffs i had laying around to attach the wire to the bracket. They are much like the standoffs used to mount computer motherbaords but these were a little bigger, probably M4. I soldered the wire into the female side, then bolted the male side to the aluminum. lastly a panel mount SO239 plug, or antenna connection of your choice. If you have any questions feel free to ask in the comments, i usually respond within a couple days.