compasses that lie?

[John]

I was checking a small compass I got from china awhile back it's kept in a survival tin I made up,

the thing is the little sod is lying   for a moment I thought I was losing my mind, I always knew the sun rises in the east and sets in the west so I double checked I waited until sunset and this is what I found  

My silva the one on the left was correct and the sun set in the west however with the cheap one the opposite was true the sun set in the east LOL


Anyway it got me thinking the small one must be optimised for the southern hemisphere, best check your compasses guys  



[edit]sorry for the blurry picture my camera hates night time 
 

[nuphoria]

Yes, I to have compasses which are from China and perhaps, are still pointing that way 

[Gareth]

I remember years back, when walking with my father, getting very turned around on a cloud-bound hilltop due to a demagnetised compass*.  We bumped into a couple of other walkers who told us where we were, except that after 20 minutes we worked out they were even more lost than us.

Anyway since then I always check my compass for accuracy before going out walking.






*Not Chinese either, it was a Silva IIRC.

[Benner]

My watch Silva compass suddenly started pointing in the wrong direction one day as well.  Very odd.  The only reason I knew was because I checked it on my old marching compass (which I bloody broke when cleaning ages ago and had to modify into something else  ).  Good job I checked really.

[FredKJ]

Most of the small survival compasses are pure junk.  Nothing can replace a good liquid filled orienteering compass by the major manufacturers like Silva, Brunton or Suunto. 

[FredKJ]

Even a good compass can get the polarity screwed up.  Always check it before you go out and don't put it on dumb things like stereo speakers with powerful magnets.  Don't put them around anything that could have an electromagnetic field.  Of course in the field don't use it around metal.  Other than that a quality orienteering compass will settle quickly and always point to "magnetic" North.  It is a piece of equipment you want to "know" is working reliably.  A decent orienteering compass is not an expensive investment.  Most survival tools or kits that have a compass are pure crap. 

[Mike Micklea]

http://www.cammenga.com/cammenga-products.php?category=1

That's what I use.  Made right here in Michigan!  The knock off Lensatics can be anywhere from 3-8 degrees off when they work correctly...

[FredKJ]

Military style lensatics are typically not as good for basic outdoor orienteering.  They are usually induction damped and don't have the new features of magnetic  declination adjustment.  However if you are navigating at night the tritium illumination is better for the purpose.  Of course a good one is more than $60+.  It would be nice to see an orienteering style liquid filled with tritium. 

[Mike Micklea]

Military style lensatics are typically not as good for basic outdoor orienteering.  They are usually induction damped and don't have the new features of magnetic  declination adjustment.  However if you are navigating at night the tritium illumination is better for the purpose.  Of course a good one is more than $60+.  It would be nice to see an orienteering style liquid filled with tritium. 

I've never had problems using the Cammenga for any type of Navigation.  The Cammenga comes with instruction to adjust for declination, and if you use USGS maps it makes it even easier since they include the declination right on the map.  (assuming you have a current map, as declination changes over time)

[WhichDawg]

they had a good thread about this in BF recently, like stated always check them first, keep metal away when doing so, keep in mind ferrous metals, rocks/formations (like hematite or magnetite) and structures have metal and could effect readings, try different locations when checking.

you can't wreck them by putting magnets or electronic fields by them permanently, just temp. you need a super strong field to do that, or high-heat or a really hard sudden blow to the needle, the whole thing will break first (cheapies are poor to start with).

their will always be variations due to quality and locations, get a quality one for serious use and learn how to use your compass with a map.

and if your a man-of-steel like Def, forget it

[FredKJ]

I have used the Cammenga before, typically when I was moving at night.  Remember tritium is slightly radioactive.  Probably shouldn't keep it next to the family heirlooms.  In military applications sometimes night navigation is essential.  For most recreational outdoor activity you generally don't do that.  A decent orienteering compass can cost less than $20 and works well with a map.  I also know there is a non-tritium version of the Cammenga. 

[Mike Micklea]

I have used the Cammenga before, typically when I was moving at night.  Remember tritium is slightly radioactive.  Probably shouldn't keep it next to the family heirlooms.  In military applications sometimes night navigation is essential.  For most recreational outdoor activity you generally don't do that.  A decent orienteering compass can cost less than $20 and works well with a map.  I also know there is a non-tritium version of the Cammenga. 

Very true.  Mine is the Phosphorus Model... 

[FredKJ]

I have used the Cammenga before, typically when I was moving at night.  Remember tritium is slightly radioactive.  Probably shouldn't keep it next to the family heirlooms.  In military applications sometimes night navigation is essential.  For most recreational outdoor activity you generally don't do that.  A decent orienteering compass can cost less than $20 and works well with a map.  I also know there is a non-tritium version of the Cammenga. 

Very true.  Mine is the Phosphorus Model... 

That keeps the tadpoles swimming straight.

[FredKJ]

Supposedly tritium is only dangerous if inhaled or ingested.  Still I wouldn't EDC it in a front pocket next to important things.     The tritium capsules in a military compass glow for about 10 years.  If you buy a used one keep that in mind.  Tritium doesn't need a light to charge it.  I had a friend who recently came out of the military who discussed another problem with tritium compasses.  With modern night vision equipment opening a tritium compass can light up a whole patrol. 

[FredKJ]

http://www.cammenga.com/cammenga-products.php?category=1

That's what I use.  Made right here in Michigan!  The knock off Lensatics can be anywhere from 3-8 degrees off when they work correctly...

You're right on that.  If you prefer using a lensatic it is the only one worth getting.  Many of the knock offs are junk too.  A good compass is worth paying for.  It will last a lifetime.  I still have a Silva type 3 I bought in 1975.  It has a small bubble and is messed up some by keeping it next to some bug dope(BTW don't keep a plastic orienteering compass next to stuff like bug dope or suntan lotion.)