Good day all, on this thread I will post all my 433mhz antenna builds and readings, here you can see my first 4 attempts to make a 433mhz antenna initial I realized they were pretty big using my Nano VNA I was able to come up with a folded dipole that was almost 50% shorter than my last 3 builds I have also attached the VNA readings.
I will be using these on relays when I make them.
Feel free to ask question I am also open to suggestions
My next step will be to permanently connect the feeder lines and encase the setup
I basically stumbled upon this design, #4 was way too complicated to be reliably repeated it was maxing out form factor (PVC pipe diameter), so I was cutting off some of the folds a U shaped fold fell.
Took up the fallen fold changed the orientation of the clips, loaded the longest piece of waste copper I had as a resonator, used the fold as “radial(s)”(see pic to understand), I also used it to dial the the ohms in, it turned out to be a joy to tune, plus it was perfect for the inside of a P
That’s fantastic! I’ve got a VNA as well and been testing the antennas that I have for my various LoRa projects, mesh and tracking systems. The only antenna I found that was actually in 900mhz range was my ipx slim antenna. Seems to be just the antenna, but I wonder if the supporting spring housing on the outside may be a ground plane or part of the antenna itself. Being you can see the antenna in the center of the spiral wound spring.
All other rubber ducky’s were below 868mhz or 2.4 GHz and so on. surprisingly, still made contact from 8km away. Imagine if it was properly tuned. Lol
I’d like to make one like yours in 915mhz range just haven’t gotten around to it yet.
After doing a ton or reseaech, I realized I needed to make my own antanna if I was ever going to get any antenna that would be at the correct frequency, I tried numerous types/ designs in the end the Sleeved dipole and Jpole seem to fit to bill for my applicantion, the coils while the might be small don’t have much range, as someone once told me, nothing beats having more meat in the air.
Feel free to ask me anything will be more than happy to share.
Thanks for the time I appreciate it, I have 3 prototypes so far, did’nt post the last one as I wasn’t finished tuning it, so far I have a Hatted Dipole, a Sleeved Dipole and the j pole is what I am working on now after tuning will post when tuning is complete.
From what I have seen, the Math is not perfect but it gets you very near to where you should be, the Nano VNA is a good investment especially if you are making antennas
surprisingly, still made contact from 8km away. Imagine if it was properly tuned. Lol
