Telemetry problem

Hello, everyone!

I have just built a quadcopter and I have some weird stuff going on with my telemetry.

I was flying and without any aggressive movements and after a couple of minutes I lost my telemetry signal completely (signal did not even come back after I flew closer to rx, like a couple of meters).

What could be causing this kind of problem? I have turned on APM for like 20minutes just to check if telemetry is not randomly dying - it did not die.

I am using 433mhz for telemetry, 5.8ghz for video, 2.4ghz for radio.

Log screenshot:
Telemetry TX placement:

As you see my telemetry tx is mounted very close to ESC (temporarily solution), not sure if this can cause such problem.

Any thoughts?

Show your config (screenshot from 3DR Radio config tool with params).

Here you go:

  1. Update FW on both units (air unit via FTDI cable).
  2. Change NET ID to something different than default (on both units simultaneously).
  3. If you’re not limited by local regulation - change (on both units simultaneously):
  • Tx power to 20
  • Min Freq to 414000
  • Max Freq to 454000
  • of channels to 20-30

Then check.

I do not have a FTDI cable lying around, so there is no way I could update the firmware at this moment. Are there any issues with old firmware?

I will update the parameters though and I will get back to you after some testing.



so after tweaking the parameters I did a test flight and I lost my telemetry again (this time at something like 99% signal) and it did not come back until I restarted the APM. :confused:

Is this a firmware (v1.7) bug?

When I lost the signal I had solid green on UAV unit and blinking green and red on ground station.

Any thoughts?

Did the air green LED stays solid after connection was broken?


If one modem has solid green LED and other has blinking green LED - the one with solid is the real problem.
Try to upgrade FW to both units, but I suspect that air modem is damaged…

I really see no way how I could have damaged the air transceiver.

I will wait for my FTDI cable from China and see if updated firmware will help.

Also: if there’s a problem in the board not sure how to explain it working fine on the ground.

Is it possible that it interferes with noise from ESC?


I have updated the firmware to sik 1.9 (on both units) and I did a test flight - connection did not drop any more. I hope it will stay this way but for now - we can mark it as solved.


I have a [color=#FF0000]same[/color] problem. After update firmware on ground module from 1.7 to 1.9 I have a problem with identification via Mission Planner. I have a same settings (default) on air and ground modules. I try reflash by FTDI to 1.7 firmware, but helpless.
What problem?

Why you’re spamming across different threads?
First: change NET ID to something different than default.
2nd: decrease # of channels to 20-30
3rd: show your cabling (detailed photo) on air side.