Oregon 400t Compass

[+Xantos10]

I have only been using my Oregon 400t for about a month but I am not very satisfied with some of the features. I find that the compas has a hard time determing the correct direction to North which causes the line drawn to my cache to keep moving. Sometimes the North arrow is pointing to the east and sometimes to the west. It seems to jump around alot. Is this a known issue or is it something specific to my unit. I like the paperless feature of the GPSr but I would really like to see the direction to the cache settle down; especially when you get close to the cache. Anyone else having this issue and do you know a soloution?

[+twolpert]

Lots of threads out there about this. This is not a compass problem. It's an artifact of multi-path reception. In short, multi-path causes abrupt shifts in your reported position. These shifts can be quite large -- up to 30 to 50 feet. Near the cache, these shifts can put your reported position on different sides of GZ from moment to moment. This causes the "pointer" to swing abruptly. Remember that the pointer is really a relative bearing from your current (reported) location to the next waypoint. When standing still or moving slowly, it also incorporates the direction you are facing.

 

Note, however, that this only affects the "pointer to next". It should not affect the reported direction of true (or magnetic) north, which is an entirely different thing. If you are observing large swings in the direction of north, you may have other issues. (There is a secondary effect of multi-path which can also cause this kind of issue. But I don't have enough experience with the Oregon to know whether or not it's prone to that problem. Most units are not.)

 

That said, calibrate early and often

[+g-o-cashers]

The first thing you should do is disable the electronic compass in the unit. Setup>Heading>Compass>Off and try it.

 

If the problem still persists it's what twolpert said. The problem is not the compass it is an erratic heading caused by "bounce" in high sensitivity receivers when you get very close to your destination. Certain versions of Oregon firmware make this worse. Beta 3.13 is a little better than 3.10 and some of the earlier 2.8x and 2.9x beta releases.

 

If turning the compass off fixes the issue it may be that you 1) don't have the compass calibrated or 2) aren't holding the unit flat when you slow down (the compass turns on below 1mph).

 

The compass issues just amplify the multi-path problem so shutting the compass off will usually make the problem a little better but not completely eliminate it.

 

My suggestion to avoid the first issue is use the map page to navigate with your track log enabled. That way you can locate the cache by aligning your direction of approach with the tracklog rather than relying on the GPS heading to find the cache.

[+Xantos10]

I have tried turning the compass off. When I do, both my direction arrow and path to the cache freezes up. You can rotate the GPSr and everything on the screen rotates with the unit. I had a 60CSx (someone stole it a few weeks ago) and never saw this issue with it. But I have to deal with what I have and that is an Oregon.

[+g-o-cashers]

That is an issue with the Oregon right now. The heading freezes are related to the GPS receiver performance at slow speeds under tree cover. Have you tried beta 3.13 yet? There is an issue with beta 3.13 that causes the unit to shut off, particularly in automotive mode if you use Custom POIs. If you don't use that combination it might be worth a shot to see if 3.13 works a little better.

[+Xantos10]

I thought about loading 3.13 but did not know how stable it was. I never use automotive mode so if that is one part of the recipe for it to crash, then I should be ok.