GLONASS Reception Failure [Bug 83]

[GPSrChive]

There have been multiple reports by users of the GPSMAP 64 series (non 'x') and the eTrex Touch 25/35 series indicating complete failure to obtain GLONASS satellite signals. These devices all use the same MediaTek MT3332N GNSS chipset.

The Oregon 6x0, 7x0 and Rino 75x also use this GNSS chipset.

Anyone having any GLONASS reception issues with those yet?

[javawa]

My Oregon 600 can't find GLONASS satellites.

GLONASS Failure

Oregon 6x0 - v560 - No GLONASS - JaVaWa.png

[Wojtas81]

Just like another user here.

It looks like Oregon 600/650 are now GPS-only devices.

[Ziginox]

To be clear, what would indicate GLONASS is working or not? Should we just be seeing a lock on a satellite numbered 65 or higher?

If that's the case, I am not getting GLONASS reception on my Oregon 600t, running version 5.60 (patched to allow unauthed BirdsEye imagery), nor on my GPSMAP 64s (running 6.60, also patched.)

[Wojtas81]

To be clear, what would indicate GLONASS is working or not? Should we just be seeing a lock on a satellite numbered 65 or higher?

Yes, you can see this when you switch between GPS and GPS+GLONASS mode.

[GPSrChive]

To be clear, what would indicate GLONASS is working or not? Should we just be seeing a lock on a satellite numbered 65 or higher?

Please see GPSrChive > Garmin > Oregon 6x0 > Main Menu > Satellite for detailed information.

[Ziginox]

Please see GPSrChive > Garmin > Oregon 6x0 > Main Menu > Satellite for detailed information.

Thanks for the info. That page is very detailed (and I learned a bit about status for each satellite!) but I'm not seeing how to tell which satellites are GLONASS when in GPS+GLONASS mode. Could you elaborate further on it? Looks like upper row versus bottom row is not a reliable way to do it, since GPS satellites can appear on the bottom row as well.

I did some additional testing, and found that if I AutoLocate, sometimes I can get signal from an assumed GLONASS satellite (number 83), but only briefly before it falls off again.

[GPSrChive]

Please see GPSrChive > Garmin > Oregon 6x0 > Main Menu > Satellite for detailed information.

Thanks for the info. That page is very detailed (and I learned a bit about status for each satellite!) but I'm not seeing how to tell which satellites are GLONASS when in GPS+GLONASS mode. Could you elaborate further on it? Looks like upper row versus bottom row is not a reliable way to do it, since GPS satellites can appear on the bottom row as well.

Each row has enough space to display up to 12 satellite signal bars. The first row is always GPS satellites. You may also see a SBAS satellite displayed after the GPS satellites when WAAS/EGNOS is enabled. Finally, any available GLONASS signal bars will be displayed when GLONASS is enabled.

Please use the 'GPS satellite locations' link near the top of that page or see GPSrChive > GNSS for detailed satellite constellation information.