Hello,
I share hereunder an antenna range test comparing two antennas : one is a DIY dipole (build explained in a previous video of my youtube channel), the second one is the antenna delivered out-of-factory with the RAK wireless meshtastic kit (PCB antenna)
Hope this will encourage you to build your own dipole antenna !
EDIT : I had to reupload an updated video, replacing the one above, to this URL below. It will take more or less 2 hours from this edit to be available
Cheers
Wild… I got into Meshtastic from your videos.
I actually made the Dipole antenna you made prior to joining the forums here. This was a great video. I really appreciate your content.
One thing i struggled with (and still do) is proper antenna tuning. I picked up a Nanovna on ebay because they are really easy to come by (30$ usd) and a Calibration board (which i highly reccomend, it makes calibrations a breeze). I have used my nano vna to test resonant circuits but i really struggle understanding how to read the swr. I also have had a difficult time finding videos that explain the following concepts.
Setting up the Nano VNA for SWR and Reading the smith chart. Explaining the proper Scale to use as well as the best start and stop points for stimulus.
If you should have 3 traces or just 1 setup. I assume 3 for Log, SWR, and Smith.
Once the settings are correct. In the measurements from the Antenna, how do you know which side of the antenna to snip. I am over concerned with removing too much.
Honestly great content and thankyou for your contribution.
Thanks , it is nice you’ve got onboard watching my videos. About the use of a nano VNA, you should look at quite a few existing video tutorial on youtube. That is how I learned how to use this tool.
Abouty tuning the dipole, you always have to cut both sides so that they remain exactly at the same length! I probably forgot to explain that point in my video.
The frequency tuning works by looking at the SWR line and its value. For a given frequency, a perfectly tuned antenna at this frequency will show a SWR curve with a dip/minimum at 1.
The smith chart displays the reactance of the antenna. The reactance is composed of the resistance measured in Ohms and of the capacitance and inductance. There are also quite a lot of youtube videos to learn about how to read a Smith chart. In short, at the frequency you target, the marker on the smith chart curve should be in the middle on the horizontal line of the Smith chart. That means your antenna has a resistance of 50 Ohms and no capacitance/inductance components, which is what is wanted.
Hope this helps and does not confuse you more
cheers