An enclosure for a Jpole antenna, I made mine for 869mhz, but have included the Fusion 360 files if you wish to resize the top section to accomodate differnt lengths.
For mine the copper I had was about 1.4mm diamater, it came from twin and earth cable.
SMA male connector came from a SMA male to IPX pigtail.
Use a calculator to get in the right ballpark:
https://www.omnicalculator.com/physics/j-pole-antenna
Some rough instructions
- Cut a secton of copper wire and use something to bend around, so that there is about 4mm gap.
- Give your self a few extra CM for each length, so you can tune with.
- Snip the SMA male with about a 1-2 cm
- Feed through the bottom section
- Strip to expose the shielding and core, solder the core to the long section and the sheilding to the short section, about 8mm from the bottom.
- use a bit of hot glue around the joint and glue on the mid section of the tube
- Check it out with the SWR meter and trim. Make sure to take your measurements with the top section on.
- when trimming, I was taking about 2.5mm of the long section for every 1mm I took of the short section.
- When she resonates, glue the last section on
Some important notes
- I found that once I put the top cover on, it shifted the resonant frequency lower significantly. Meaning I had to “Over trim” the antenna, but this corrected after adding the top piece of the enclosure.
- I have provided the measurements of mine, however this could differnt depending on the material, colour etc.
- I used Creality Clear PETG.
Tags
The author marked this model as their own original creation.