Calibrate ETrex

Walks For Awareness · Post by **Walks For Awareness** » 11 June 09 12:52 am

G'day,

I have had a Garmin E Trex for about 6 years but it has not been correctly callibrated since a trek in the Vic Alps wilderness zone in '04. I generally don't use the GPS when trekking, map and compass usually suffice but recently I went geocaching with my sister and we discovered the ETrex was up to 500m out. Batteries were fresh, sats were locked on, datam correct but calibration out.

How can I fix this without sending it back to the USA?

My brother mentioned calibration can be messed up if I put the batteries in backwards, which I do when trekking to avoid accidental power-up.

Could this be the problem and is it permanent?

Cheers

Walks For Awareness · Post by **Walks For Awareness** » 11 June 09 12:59 am

G'day, I have had a Garmin E Trex for about 6 years but it has not been correctly callibrated since a trek in the Vic Alps wilderness zone in '04. I generally don't use the GPS when trekking, map and compass usually suffice but recently I went geocaching with my sister and we discovered the ETrex was up to 500m out. Batteries were fresh, sats were locked on, datam correct but calibration out.

How can I fix this without sending it back to the USA?

My brother mentioned calibration can be messed up if I put the batteries in backwards, which I do when trekking to avoid accidental power-up.

Could this be the problem and is it permanent?

Cheers

PS Also posted at software index

Papa Bear_Left · Post by **Papa Bear_Left** » 11 June 09 1:11 am

Seems strange... GPSrs use mathematical calculations, not analogue stuff that needs calibrating.

Try resetting it to factory defaults and entering your location, date, etc. again.

Post by **CraigRat** » 11 June 09 1:23 am

Umm, feel free to correct me, but you cant calibrate these unit's position as far as I'm aware.

What are you using as your reference to determine how it is out by 500m? A fixed point of known lat/lon or a waypoint in the unit?

Did you set the Datum BEFORE entering waypoints, or after? If it was after you MUST remove them and add them again, as the ones in the unit get 'corrected' to the old datum and remain out by whatever the old error was!
This is one of the most common mistakes made with these units.

Also, if you leave it on and in view of the birds for around 10 minutes it should update its almanacs etc that it uses to determine your position.

You could try kicking it in the guts with a hard reset (see here: http://www.worldcat.org/wcpa/servlet/DC ... cerpt=true)

Udderchaos · Post by **Udderchaos** » 11 June 09 8:05 am

calibration? not sure if there is such a thing for a gps without a compass

it sounds like map datum to me. make sure its set on WSG84. thats much more likely....

failing that i would be installing the latest firmware and see what happens (assuming you have a pc cable for it)

Im pretty sure putting batteries in the wrong way wont have the results you speak of. if it didnt toast it completly you normally get away with it

covert · Post by **covert** » 11 June 09 10:05 am

tell use the model number. might be able to help you more.

covert · Post by **covert** » 11 June 09 10:14 am

please only post a topic once in the forum.

Map Monkey · Post by **Map Monkey** » 11 June 09 12:11 pm

Happy to answer here.

It may help to mention which version of an Etrex you are using, together with information on what mapsets, if any, are on the GPSr.

Are we talking about altitude by any chance, where the particular GPSr will use barometric calibration for accuracy?

The "Lock on Road" feature may affect some users interpretation of the real issue as your position on the displayed map may be misleading....500m is a large discrepency though.

I hope that helps.

mm

Geof · Post by **Geof** » 11 June 09 12:34 pm

Just put new batteries in it and leave it in one place turned on out side for 15 minutes with a clear view of the sky.

Craigrat wrote:Did you set the Datum BEFORE entering waypoints, or after? If it was after you MUST remove them and add them again, as the ones in the unit get 'corrected' to the old datum and remain out by whatever the old error was!
This is one of the most common mistakes made with these units.

^^Very important!^^

Height calibration is not that important for geocaching.

Rigger64 · Post by **Rigger64** » 02 July 09 7:26 pm

I Have a Garmin eTrex Vista. That is having problem with the newest firmware Version. apparently After speaking with Garmin Aus it appers there is a problem in that i appers that the almnac seam to disaper if it losses sat lock.
we have a couple of these units @ work as well but one is running Ver3.70 & the unit i em using has Ver3.80 is there any way of getting the unit to rolback to Ver3.70 as the other unit that is running 3.70 works very well & mine is running like a wet week?

Regards:
Rigger64

Rigger64 · Post by **Rigger64** » 02 July 09 7:51 pm

If your using an eTrex Vista Don't download the latest firmware Version Being Version 3.80 it has a big glich in it.

Rigger64 · Post by **Rigger64** » 04 July 09 1:45 pm

Rigger64 wrote:I Have a Garmin eTrex Vista. That is having problem with the newest firmware Version. apparently After speaking with Garmin Aus it appers there is a problem in that i appers that the almnac seam to disaper if it losses sat lock.
we have a couple of these units @ work as well but one is running Ver3.70 & the unit i em using has Ver3.80 is there any way of getting the unit to rolback to Ver3.70 as the other unit that is running 3.70 works very well & mine is running like a wet week?

Regards:
Rigger64

RE: My last post i have managed to roll back my GPSr.
i found a website that is of very much use to all of us. For Garmin & maggelan as well.
Here is the link if you want to have a look.

http://gpsinformation.net/

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