I am using a Spirit GT with a Geolink2 in my Goblin 700. I have never had a problem with GPS lock before with this Geolink2 and older Frsky 2.4GHz receivers.
I just upgraded to an Frsky Tandem X18RS radio with a TWMX receiver. When I use the TWMX receiver I get no GPS lock (no blue LED and GPS coordinates all set to 0 in telemetry value) on the Geolink2. I swapped in a TDMX receiver and the GPS works (steady blue LED and correct GPS coordinates).
The receivers are using FBUS to connect to the Spirit GT. The Spirit GT is on firmware version 3.7.4 and Geolink2 on version 1.4.1 (I think that is the last release).
Has this issue been seen before?
No GPS Lock on Geolink2 when using Frsky TWMX RX
This morning I disabled the telemetry in the TWMX receiver and the Geolink gets a GPS lock. If I then enable telemetry in the TWMX the GPS maintains a lock. Not a great solution.
I already reduced the telemetry power to the lowest level in the TWMX but it did not help. My guess is the long range 2.4GHx LoRA telemetry is causing this problem. Next I will try extending cables and moving the Geolink and TWMX farther apart.
I already reduced the telemetry power to the lowest level in the TWMX but it did not help. My guess is the long range 2.4GHx LoRA telemetry is causing this problem. Next I will try extending cables and moving the Geolink and TWMX farther apart.
I moved the receiver to the front bottom of the helicopter so it's now 450mm from the Geolink (previously it was about 200mm). The Geolink is out on the top of the tail boom. Lots of carbon fiber in between. This is far enough away on full power telemetry to get GPS lock.
Problem solved, hope this helps someone.
Problem solved, hope this helps someone.
Well, after mounting the TWMX in a new location and testing again there is no GPS lock. Seems the TWMX is not compatible with my Geolink 2.
I changed to a TDMX receiver which has no problem. Can't win them all!
My thanks to Spirit for making everything work as well as it does. I think the compatibility of Spirit hardware with everything else is outstanding.
I changed to a TDMX receiver which has no problem. Can't win them all!
My thanks to Spirit for making everything work as well as it does. I think the compatibility of Spirit hardware with everything else is outstanding.
We have no experience with TWMX receivers yet, but if receivers are designed well they should not cause interference for GPS because they are at a different frequencies.
In any case it is good to have telemetry receiver antennas as far from any other electronics. This should help also to servos if antennas are further away.
In any case it is good to have telemetry receiver antennas as far from any other electronics. This should help also to servos if antennas are further away.
Spirit System developer