Meshtastic

Stock TBEAM antenna -15db SNR?

I’ve got 2 TBEAMS on a desk and I’m getting SNR as follows:

  • Medium range: 5 to 10db
  • Long: -7db
  • Very long: -20 to -15db

Firmware 1.2.45
App 1.2.31

Is this normal or is something wrong? Switching around between these modes, sometimes I get great performance, sometimes they won’t even talk next to each other.

When they first start up, everything seems to be great. But 5-6 minutes later, it’s like the radios are dead. Both boards are still blinking and the app shows fully connected via BT, but no messages are getting through. Sometimes, when messages do get through, they’re showing UserIDs from several channel changes ago. Re-flashing the firmware gets it going again, but they go silent again sometime later down the road. I’ve done this twice now.

Any tips for a non-developer on how to troubleshoot?

negative SNR is possible with LoRa if that is what you are asking. amazing, right?

for the other issues, try a newer version of the Android App:

I mean, it’s great they can work with negative SNR. But it is by design to use lower and lower signal for longer range modes? Just seems counter intuitive. These were measured with the radios right next to each other.

Will try the alpha, thanks.

Remeber that the t-beams enter sleep mode after a set amount of time, to wake them up press the user button :wink:
Also, double check your antennas, if you can measure their return loss. You may have the wrong antennas. The RF output power should remain the same for each transmission mode.
And you can also try to physically separate the t-beams, another room for example. You may end up overloading the RF input stage if they are too close to each other.

Ive discovered further issues actually. It seems every time i change the channel, it doesnt fully take effect until 2-3 reset cycles.

Changing channel name and power mode, the new settings show correctly in app and on the TTGO screens. But the radios never connect to each other, and still show the previous channel nodes instead (I changed user names as well). After pressing reset and cycling 2 or 3 times, they finally work as they should.

Am i doing something wrong or is something buggy?