Glonass Reception Failure [Bug 13]

[Backstreetbob]

I have recently got a 35 Touch, and it just will not connect to any Glonass satellites when GPS+ GLONASS is selected. All the Glonass Satellite numbers just flash and don't lock and only the GPS ones lock. i have synced with Express on my laptop, full factory reset, deleted the CPE and position files and re synced with express and still the same it is only locking onto GPS when they are both selected? Is anyone elses like this? Also the tracking is quite poor on it and only goes down to around 15ft accuracy.

Any suggestions ?

[GPSrChive]

Due to not-so-recent-but-still-current world events, I'm not sure anyone is enjoying favorable results from the GLONASS positioning system.

[Backstreetbob]

Due to not-so-recent-but-still-current world events, I'm not sure anyone is enjoying favorable results from the GLONASS positioning system.

Glonass works fine on my 65s and Etrex 20x..

[LostAgain]

It seems to work ok on the Montana 700 and GPSMAP 276CX, but the Montana 610's we use keep losing reception unless it's disabled, been this way for a while now.

[GPSrChive]

OK, we dug an eTrex Touch 35t out of mothballs, installed some fresh alkaline batteries, and let it rest on a window sill for a few hours. It never did find/use any GLONASS satellite signals. Best accuracy achieved with GPS + GLONASS was 13ft, while GPS Only provided 9ft.

GPS + GLONASS

eT35t GPS GLONASS 13ft.png

GPS Only

eT35t GPS Only 9ft.png

[javawa]

Here in Europe I am receiving data from four GLONASS satellites on my Oregon 700, no difference in accuracy.

[Wojtas81]

GLONASS works on every single device I have (see my signature). It gives me 6-8 additional satellites.
The only disadvantage of GLONASS is that it is single-band. Which isn't an issue on devices that have no multi-band functionality (ie. all device released before year 2020).

Having said this, AFAIK Garmin devices are GPS-centric, so they cannot establish location when no GPS signal is available. Other systems (ie. GLONASS, Galileo, Beidou) only increases stability and accuracy but cannot be used alone (at least not in Garmins).

PS. WAAS/EGNOS augmentation systems also work on every single device I have, except multi-band devices (ie. 66sr) where they are not available and not necessary.

Here in Europe I am receiving data from four GLONASS satellites on my Oregon 700, no difference in accuracy.

It is normal. You will have better accuracy when you have 5 satellites instead of 3 satellites used. But you will have not better accuracy when you have 18 satellites instead of 10 satellites used.
In other words: you cannot increase accuracy indefinitely by increasing number of satellites (and satellite systems) available.

But additional (ie. spare) satellites still improve location stability when you lose reception from some of them during your trip.

[Backstreetbob]

OK, we dug an eTrex Touch 35t out of mothballs, installed some fresh alkaline batteries, and let it rest on a window sill for a few hours. It never did find/use any GLONASS satellite signals. Best accuracy achieved with GPS + GLONASS was 13ft, while GPS Only provided 9ft.

GPS + GLONASS

eT35t GPS GLONASS 13ft.png

GPS Only

eT35t GPS Only 9ft.png

I wonder if Garmin will fix this, I doubt it though. I find the route the 35T plots has quite a bit of drifting on with it only picking up GPS and not Glonass compared to me Etrex 20x which picks up both GPS + Glonass fine, it's far more accurate.

[Backstreetbob]

Just spoke to Garmin about this issue, they will not be publishing any further software updates for this device, so it's pretty much tough luck for us owners of these. They did however offer me a 30% trade in offer where I send my Touch 35 in then they knock 30% off another device of the same kind, which isn't really an offer...