Quick post to show this off. I needed a 70 cm antenna for packet radio (maybe more on that later), and didn’t want to fiddle with a Yagi or a ground plane.
Found this design for a 433 MHz Moxon: https://www.printables.com/model/88507-moxon-antenna-frame-lrs-433mhz. Since my target frequency is 430 MHz, I scaled this up (in PrusaSlicer) just a bit: 104% front-back and 103% side-side, according to the calculator at http://w4.vp9kf.com/moxon_design.htm. It’s printed in PLA with 10% fill, and obviously could be more robust if I filled it more.
Using 14 gauge bare copper wire, it was a little rough getting the wire lengths right. I ended up matching the length for the reflector wire, but reduced the length of the driven elements to keep a 5 mm gap between the ends of the wires. I soldered a bit of RG-316 onto the driven elements and used a simple screw-terminal BNC connector on the end of the coax.
The nanoVNA says the SWR is below 2:1, and I didn’t check beyond that.
I have more notes if anyone is interested; in the interest of keeping things simple, here is a photo.
Photo of a vertical 430 MHz Moxon antenna, with copper wires zip-tied on to a 3D-printed frame. The coax comes through the middle and attaches to a split driven element on the right.