Etrex20 magnetic variation setting

[+ecanderson]

Just triple checking, but when you change the declination manually, you won't see any difference unless you also tell the handheld to use magnetic vs. true north on the display.

 

The topic here is eTrex 20, but what unit are you using where you're not seeing any difference? I looked back, but I don't see that you've said (apart from your Suunto) which Garmin model you currently own.

[Forkeye]

I have the 62sc and Etrex 30. So for this test I will use the Etrex 30, and by the way the 62sc gives different results, but still not expected ones either. In the heading setting I select user ,enter declination ,select done and return to the compass page. I just don't see the expected changes when I check back at the compass page heading. My correct declination for where I live is 16 deg. east. So lets say I set my Suunto compass declination to 45 deg. east just for a test, (I know its the wrong declination for where I live), line up the compass needle with the inner dial arrow and take note of where the N on the outer ring of the dial points. Its way off to the west of true north by 24 deg., and so where true north should be reads 24 deg. So 24+16=40 deg.

OK so now back to the gps and set the user declination to 40 deg. east and then go back to the compass page and the N on the outer compass ring is pointing east of where true north should be by interestingly approx.16 degrees, so now I change the user value to 60 deg. east and still the N points to ALMOST the same direction ,but not by a difference of 20 deg.

Is the N on the outer ring of the gps compass ring not supposed to point to north? If yes the why does it not point to the same direction as my Suunto does when the declinations are set the same and when I change my user gps declination by a large value the N barely changes position ,but yet does not point north either. I also calibrated the compass every time I changed declination. This puzzles me, but as I stated earlier I always use the true setting anyway so it is correct with my real Suunto compass. What do you mean by telling the hand held to use the user setting, if I select user, does that not tell it to use that setting? I know I am slightly off topic ,sorry for that, but I thought declination was part of this topic.

Edited January 11, 2014 by Forkeye

[+ecanderson]

Have to ask again, Forkeye (see 1st sentence, prior post). After you have set the declination, the ONLY way you will see any difference based upon that is if you go into the settings and tell your unit you want to see magnetic north on the compass, not true north. From what you've said above, I'm still not sure that this was the case during your experiments. All a declination adjustment does (manual or automatic) is offset the position of the compass pointer by x degrees when you specifically tell the unit to show you a magnetic heading. We've got to be 100% certain of this before anything else is going to make any sense.

[Forkeye]

I go into settings, then heading , then north reference, set it to user, enter the value I want, click done at the bottom and reverse the sequence, push quit, to go back to the compass page. should I do the above procedure again I will see my selected value still when I get to that page again. Compass is set to auto so when standing still it should be good to go . Is there another setting to turn on some place? Not that I am aware of, because if I use magnetic setting it works ok, as well as true setting, its just the user setting that doesn't work here. Also when you select a display box and a field to show should it be heading or bearing, there is no choice of true or magnetic, obviously its going to display the reference you have previously picked. If there is another setting to adjust I am not aware of it. One more thing ,when I look at the compass page, in one of my field boxes which shows heading on the top of the compass page, it shows a little M in the bottom right corner of the box, showing the unit value for the display, not a U, but ok maybe that's to be expected, it shows T when set to true and G when set to grid and M when set to magnetic. I no longer have my 76csx, but if I remember the user never seemed to work on it either, that unit used to display the magnetic and grid values it used, so at least you could quickly see if they were close to correct. My above post was for the Etrex 30, now for the 62sc, it will show the N on the compass ring being about 5 deg. east of north no matter what value I enter into the user value , and again the heading box shows this value and a small m in the bottom of the field box. I do not believe the user entered feature works because if it did the N on the compass ring should point the same direction as my Suunto compass does, it works ok for the magnetic setting.

Edited January 12, 2014 by Forkeye

[Fangamon]

I just found out today that all Garmins have an updatable internal world map for calculating MV.

[+ecanderson]

Absent any new firmware updates for a considerable time (e.g., old 60 series), how is the table ever updated?