Garmin Montana 650 Magnetic Compass

[Fox]

Maybe just a recalibration will do. I had an issue with my garmin earlier and found that FM transmitter used to play flash memories was interfering.
Contacted garmin directly and they sent me the some files for calibration.

Sent from my GT-I9505

From the setup menu, you can get into a compass calibration mode. This is straightforward, step by step instructions appear on the screen, very easy. However this does not solve the "magnetic problem" from the loudspeaker, nor would it solve any problem from your FM transmitter.
Remember also, the calibration is good in open air. When the GPS is in the car, there will most likely be a - hopefully small - deviation from
the true compass indication, due to the metallic structures of the car, possible other magnetic fields from inside the dashboard etc.
With my mount location however this error is quite small (approx. 5 to 10 degrees) which I find acceptable. When moving and the compass
going to satellite mode, it disappears.

[Fox]

I tried it today with both the marine type & the suction cup mount, & both worked fine when moving & when standing still...

I updated my unit software a couple of weeks ago, so maybe they introduced some software solution for that?!

A software update solving the problem is surprising to me. I have no clue how the software would achieve this, except
"calibrating" the compass immediately before switching over from GPS to magnetic ?????

[Rami Taha]

The i would recommend to back up your data to the computer and reset the unit to the factory settings with finger on top corner. Then restore your data.
I dont you had this problem when you bought it.

Sent from my GT-I9505

[DesertDawg]

There are a few forum threads on this.

When moving, the compass is GPS derived and when stationary via a 3 axis electronic compass. The latter is influenced by external magnetic fields.

Proof (with the help of my fridge magnet):

Abu Dhabi-20131021-00420.jpg

Abu Dhabi-20131021-00418.jpg

I have not moved the GPS, but North has changed (around 180 degrees). I can place North where I like using the magnet.

Dave

[Xof]

I have not moved the GPS, but North has changed (around 180 degrees). I can place North where I like using the magnet.

Dave

so Frankenstein can also modify the gravity field of the Earth???

[akhateeb]

I tried it today with both the marine type & the suction cup mount, & both worked fine when moving & when standing still...

I updated my unit software a couple of weeks ago, so maybe they introduced some software solution for that?!

A software update solving the problem is surprising to me. I have no clue how the software would achieve this, except
"calibrating" the compass immediately before switching over from GPS to magnetic ?????

Maybe they introduced some kind of software correction when the device is connected to the speaker mount to counter the effect of the speaker magnet.. Or maybe I was just lucky this time.. I will try it tomorrow again and see...