I started this thread to contain only test results and links for various antennas for all Meshtastic Devices.
Nice, I just got my NanoVNA today and did some testing myself. All 4" antenna’s I’ve got with my T-Beams were supposed to have 915mhz antenna’s, yet they’re at around 778-880mhz. Really all over the place sadly. Also tested another set 7" meant for my telemetry radios for drones, those came out at around 997mhz.
Clearly the small 4" antenna’s work because I’ve been able to link 2 units between a 5 mile distance and a third unit down below to catch the msg.
I’m curious what type of results could be expected from a fine tuned antenna.
Thoughts on that?
I had the same problems with the short antennas (tuneds to 868 MHZ) that came with my TTGOs. The one medium length one i have is locked away in one of my 3d printed cases so i haven’t had a chance to test it yet. I think i will only be buying antennas from digikey for these in the future.
I have gotten a Nano VNA and tested my 915 MHz antennas. Here are the results for others:
Lilygo T-Beam stock Quarter wave, I found it needs a finger on base for ground plane and low VSWR
VSWR of 1.5 at 906.8 MHz. Without finger on base, VSWR is over 3 and highly variable.
Lilygo T-Echo stock antenna: VSWR was about 4.5 from 900 to 930 MHz. I could not get the VSWR lower.
Unbranded 5.4 dBi 915M Indoor Dipole from 5.4dBi Indoor Antenna For US915Mhz Helium Hotspot Miner Helium Hotspot Antennas | eBay
Best VSWR 1.2 at 916 MHz, and VSWR of 1.3 at 906.9 MHz
Ziisor 915M 5 dBi antenna from 915 MHz LoRa Antenna with RP or SMA Male 915MHz for Meshtastic LoRaWan Aerial | eBay
Best VSWR of 1.3 at 921 MHz, and VSWR of 1.6 at 906.9 MHz. This appears to be a sleeve dipole design.
Ziisor Indoor magnetic mount 915H 6 dBi with a 1 meter cable This needs to be attached to metal ground plane for proper operation. I got it from Indoor LoRa Antenna 915 MHz Long Range Aerial for 923 MHz RP SMA Male Low SWR | eBay
Best VSWR 1.3 at 900 MHz, and VSWR 1.4 at 906.9 MHz. This appears to be a collinear dipole design.
I hope this is a help to others.