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RainierRidgeRunner Guest
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RainierRidgeRunner
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Fri Aug 16, 2002 11:59 am
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What kind of compass should I get. I can figure out north, south, east and west. What is this declination and an azimuth?
I guess my blond roots are showing. hee-hee
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MtnGoat Member
Joined: 17 Dec 2001 Posts: 11992 | TRs | Pics Location: Lyle, WA |
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MtnGoat
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Fri Aug 16, 2002 12:10 pm
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Declination is the difference between true map north and magnetic north.
The magnetic N pole is not centered on the geographical N pole, so you must adjust your compass so that when the needle points to mag N, the compass body is offset correctly to point to map N. This adjustment is declination.
Declination changes depending on location, moving around WA it doesn't change much but if you go out of state you need to make sure you readjust it.
Diplomacy is the art of saying 'Nice doggie' until you can find a rock. - Will Rogers
Diplomacy is the art of saying 'Nice doggie' until you can find a rock. - Will Rogers
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Tom Admin
Joined: 15 Dec 2001 Posts: 17835 | TRs | Pics
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Tom
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Fri Aug 16, 2002 1:14 pm
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It's not the most polished, but this site has some basic tutorials along with some advice on buying a compass.
You may also find the following picture and link helpful:
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Backpacker Joe Blind Hiker
Joined: 16 Dec 2001 Posts: 23956 | TRs | Pics Location: Cle Elum |
Looks like Thomas said ti well. I'd get a GPS compass conbo were I you!
TB
"If destruction be our lot we must ourselves be its author and finisher. As a nation of freemen we must live through all time or die by suicide."
— Abraham Lincoln
"If destruction be our lot we must ourselves be its author and finisher. As a nation of freemen we must live through all time or die by suicide."
— Abraham Lincoln
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RainierRidgeRunner Member
Joined: 16 Aug 2002 Posts: 23 | TRs | Pics Location: Auburn,WA |
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Vine Maple Victim Member
Joined: 14 Aug 2002 Posts: 23 | TRs | Pics Location: Shoreline, WA |
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Newt Short Timer
Joined: 21 Dec 2001 Posts: 3176 | TRs | Pics Location: Down the road and around the corner |
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Newt
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Sat Aug 17, 2002 5:12 pm
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And why are the recommended compass's all 360*?
Why not a quad?
Just curious?
NN
It's pretty safe to say that if we take all of man kinds accumulated knowledge, we still don't know everything. So, I hope you understand why I don't believe you know everything. But then again, maybe you do.
It's pretty safe to say that if we take all of man kinds accumulated knowledge, we still don't know everything. So, I hope you understand why I don't believe you know everything. But then again, maybe you do.
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Vine Maple Victim Member
Joined: 14 Aug 2002 Posts: 23 | TRs | Pics Location: Shoreline, WA |
A quad as in only the four cardinal directions?
If this is your question, it's because being 5-10 (let alone even more) degrees off over the course of a couple miles will put you WAY off your destination.
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Newt Short Timer
Joined: 21 Dec 2001 Posts: 3176 | TRs | Pics Location: Down the road and around the corner |
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Newt
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Sat Aug 17, 2002 10:47 pm
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So what makes it 5-10* off compared to the 360 if the accuracy of both is the same?
NN
It's pretty safe to say that if we take all of man kinds accumulated knowledge, we still don't know everything. So, I hope you understand why I don't believe you know everything. But then again, maybe you do.
It's pretty safe to say that if we take all of man kinds accumulated knowledge, we still don't know everything. So, I hope you understand why I don't believe you know everything. But then again, maybe you do.
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Newt Short Timer
Joined: 21 Dec 2001 Posts: 3176 | TRs | Pics Location: Down the road and around the corner |
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Newt
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Mon Aug 19, 2002 8:51 am
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Hey, I'm really curious now. Did I ask somptin' that should have been really obvious and I have blindly overlooked?
I know that most everything compass related revolves around the 360, but other than that, why?
My inquiring mind needs to know.
Thanks,
NN
It's pretty safe to say that if we take all of man kinds accumulated knowledge, we still don't know everything. So, I hope you understand why I don't believe you know everything. But then again, maybe you do.
It's pretty safe to say that if we take all of man kinds accumulated knowledge, we still don't know everything. So, I hope you understand why I don't believe you know everything. But then again, maybe you do.
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Timber Cruiser Member
Joined: 17 Dec 2001 Posts: 220 | TRs | Pics Location: Cosi |
The Silva Ranger model compass has served me well over the past 30 years. The sighting mirror is invaluable for picking out targets to navigate cross country as well as sticks out of your eye!. The accuracy outside of user ability, local attraction, solar flares and declination setting is going to be 0.5 degrees due to the graduations on the compass face. The declination is constantly changing (although only minutes/year) so you need to update for date as well as the location you are in. There is a web site where you can look up the current declination(http://www.ngdc.noaa.gov/seg/potfld/ushd.shtml ). Old topog maps may be dated to the point you will be outside of your precision needs for navigating.
As to the 360 (azimuth) or quadrant preference I would say it depends on the media you are using which is best. If you are following maps with 360 compass references and you don't want to do the math then the azimuth compass is the choice. A lot of my field work has been from point to point on plot grids, so the quadrant was easier to use.
If you are a world traveler they now have a ranger model that will cover you wherever you may roam (ie. southern hemisphere). I bought one for working in New Zealand, but don't like it as much as the NW standard.
"Logging encourages the maintenance of foilage by providing economic alternatives to development."
"Logging encourages the maintenance of foilage by providing economic alternatives to development."
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MtnGoat Member
Joined: 17 Dec 2001 Posts: 11992 | TRs | Pics Location: Lyle, WA |
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MtnGoat
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Mon Aug 19, 2002 12:12 pm
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I use a ranger as well, a good basic instrument with everything you need, really. Used it for whiteout navigation on many occasions with great results.
Also used it for quick field surveying as part of a mining exploration team, we'd lay out prospective claims with a Ranger and an inclinometer. Closed many loops of 5000' length with only a few feet of error, including one of 23,000' feet only 12 feet off. Which is something like 0.005% error, not bad for a Silva, a 'clinometer, a tape measure, slope charts, a notebook, and three geeks in the woods lugging claim posts and brush rakes around!
Competent use of any decent compass will serve you quite well.
Diplomacy is the art of saying 'Nice doggie' until you can find a rock. - Will Rogers
Diplomacy is the art of saying 'Nice doggie' until you can find a rock. - Will Rogers
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Newt Short Timer
Joined: 21 Dec 2001 Posts: 3176 | TRs | Pics Location: Down the road and around the corner |
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Newt
Short Timer
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Mon Aug 19, 2002 2:17 pm
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And I have a ranger too. Good units.
MtnGoat... not to bad for a none electronic device. I know if you keep your legs short, take a reading more often, then the error will be minimized. I also know the accuracy will depend on having the declination accurate, up to date maps, and good careful readings.
Also the quadrant makes backsights and backtracking a cinch if you are plotting the course.
It also appears that you can download the declination software to put on a PC or laptop if you so desire.
Thanks for the info,
NN
It's pretty safe to say that if we take all of man kinds accumulated knowledge, we still don't know everything. So, I hope you understand why I don't believe you know everything. But then again, maybe you do.
It's pretty safe to say that if we take all of man kinds accumulated knowledge, we still don't know everything. So, I hope you understand why I don't believe you know everything. But then again, maybe you do.
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RainierRidgeRunner Member
Joined: 16 Aug 2002 Posts: 23 | TRs | Pics Location: Auburn,WA |
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Dante Member
Joined: 16 Dec 2001 Posts: 2815 | TRs | Pics
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Dante
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Tue Aug 20, 2002 10:43 am
My $0.02
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I used to carry a Silva Ranger with a declination adjustment. FWIW I now rely primarily on a Suunto Clipper and an altimeter. It clips to the edge of your map or map case. You can adjust for declination yourself, or if you have time, mark true north lines on your map before the trip. I have not used a compass for cross country navigation (following a bearing) since I was in the Army from '83 to '86. Since then, I've only used my compass to orient my map. A properly oriented topographical map and an altimeter will tell you where you are where I usually hike.
FYI there is an illuminated version of the Ranger. I know there is one that takes batteries and I have seen references to a Tritium version online. Tritium is cool stuff--10+ years of illumination and it doesn't require batteries or an external light source to charge it up.
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