HuntingNut
HuntingNut
   Login or Register
HomeCommunity ForumsPhoto AlbumsRegister
     
 

User Info

Welcome Anonymous


Membership:
Latest: anollmantimmy
New Today: 1
New Yesterday: 2
Overall: 12475

People Online:
Members: 0
Visitors: 86
BOT: 5
Total: 91
Who Is Where:
 Visitors:
01: Forums
02: News
03: Forums
04: News
05: Forums
06: Forums
07: Forums
08: Forums
09: News
10: Forums
11: Forums
12: Forums
13: Forums
14: Forums
15: Forums
16: Home
17: Forums
18: Forums
19: Forums
20: Forums
21: Forums
22: Forums
23: Home
24: Forums
25: Forums
26: Forums
27: Forums
28: Forums
29: Forums
30: Forums
31: Forums
32: Forums
33: Forums
34: Photo Albums
35: Forums
36: Forums
37: Photo Albums
38: Forums
39: Forums
40: Forums
41: Forums
42: Forums
43: Forums
44: Forums
45: Forums
46: Forums
47: Photo Albums
48: Forums
49: Photo Albums
50: Forums
51: Forums
52: Photo Albums
53: Photo Albums
54: Forums
55: Forums
56: Forums
57: Home
58: Forums
59: Forums
60: Forums
61: News
62: Forums
63: News
64: Forums
65: Forums
66: News
67: Forums
68: Photo Albums
69: Forums
70: Photo Albums
71: Photo Albums
72: Photo Albums
73: Photo Albums
74: Forums
75: Your Account
76: Forums
77: Forums
78: Forums
79: Forums
80: Forums
81: Forums
82: Forums
83: Forums
84: Forums
85: Forums
86: Forums
  BOT:
01: Forums
02: Forums
03: Forums
04: Photo Albums
05: Forums

Staff Online:

No staff members are online!
 

Coppermine Stats
Photo Albums
 Albums: 304
 Pictures: 2340
  · Views: 296489
  · Votes: 1302
  · Comments: 85
 

Support our Advertisers

COMPASSES
Big Game Hunting topics that dont fit other categories
Go to page Previous  1, 2, 3, 4, 5, 6  Next
Post new topic   Reply to topic   Printer Friendly Page    Forum Index » Big Game Hunting

View previous topic :: View next topic  
Author Message
FALPhil
Super Member
Super Member


Joined: Aug 18, 2007
Posts: 377
Location: Dixie

PostPosted: Sat Oct 20, 2007 3:12 pm    Post subject: Re: COMPASSES Reply with quote

Dimitri wrote:
Bushy,

Don't you also got to figure out longditidue that isn't done with the sextant as that figures lattitude ?? Confused

Dimitri

Actually, what a sextant gives you, once you do the math, is a line of position (LOP) based on spherical trigonometry. Plotted with a straightedge on a chart, it is actually a chord of a circle which represents all the places on the surface of the earth that you can measure a particular angle from the horizon (corrected for sea level) of a particular celestial body (sun, moon, star, planet). Now, if that celestial body is due north or due south, such as Local Apparant Noon (LAN), latitude can be derived. Angular altitude of the Pole Star generally translates directly to Latitude with minor corrections. Azimuth assists in refining the LOP.

When you have two LOPs that cross, you have determined your position. Depending on your plotting chart, this could be latitude and longitude, but other systems could be used. That means you have to measure the angle between the horizon and two celestial bodies. The angles must be corrected for time of day, altitude above sea level, and various and sundry factors, which are very predictable. We always shot a minimum of three LOPs for accuracy sake.

In the old days, the US Hydrographic Office used to publish volumes of lookup tables to assist in celestial navigation with a sextant. These days, if you really want to use a sextant, you can download programs into your PDA to compute everything.
Back to top
View user's profile Photo Gallery
Dimitri
Super Member
Super Member


Joined: Nov 25, 2005
Posts: 5906
Location: Southern Ontario

PostPosted: Sat Oct 20, 2007 3:29 pm    Post subject: Re: COMPASSES Reply with quote

Oh neat Phil,

I just know of John Harrison's H4 watch to calculate longitude at sea by comparing local time with Greenwich or "Zulu" time, which should have won the prize outright but he never did get it.

Dimitri

_________________
A thousand hills, but no birds in flight, ten thousand paths, with no people's tracks. A lonely boat, a straw-hatted old man, fishing alone in the cold river snow.
Back to top
View user's profile Visit poster's website Photo Gallery
Bushmaster
Super Member
Super Member


Joined: Jun 12, 2005
Posts: 10302
Location: Ava, Missouri

PostPosted: Sat Oct 20, 2007 3:50 pm    Post subject: Re: COMPASSES Reply with quote

Thanks FALPhil...Saved me a lot of remembering not to mention, a lot of typing. I haven't used a sextant for so many years I doubt that I could do it anymore...

Come on Big D...Yer fallin' behind here...(2721/2744)

_________________
I have one nerve left and yer standin' on it...

DEMOCRACY Two wolves and one sheep voting on what to have for lunch...
LIBERTY A well armed sheep contesting the outcome of the vote...
Back to top
View user's profile
Dimitri
Super Member
Super Member


Joined: Nov 25, 2005
Posts: 5906
Location: Southern Ontario

PostPosted: Sat Oct 20, 2007 3:54 pm    Post subject: Re: COMPASSES Reply with quote

Sorry Bushy, come November your going to have even a bigger lead on me as I'm going to be gone for the 2nd week of November and unless I find a way to get Internet access on my little trip I'm going to fall back even farther. Laughing

Dimitri

_________________
A thousand hills, but no birds in flight, ten thousand paths, with no people's tracks. A lonely boat, a straw-hatted old man, fishing alone in the cold river snow.
Back to top
View user's profile Visit poster's website Photo Gallery
watchmaker
Member
Member


Joined: Jun 29, 2007
Posts: 98
Location: New York

PostPosted: Sat Oct 20, 2007 9:32 pm    Post subject: Re: COMPASSES Reply with quote

Nobody is pulling any legs, the compass needle is adjusted for any of the 5 zones of dip in the world, a compass bought in Australia will stick to the card in Canada, because the balancing of the needle was done for zone 5 and Canada is zone one.

This post of mine will explain what dip is.

COMPASS DIP

This will be of interest only to the people that travel to locations around the world, and are in need of using a compass to get their bearings.
I first encountered compass dip, many years ago, in a trip to Bariloche, Argentina. I was there to fly-fish for trout in the Nahuel Huapi Lake and climb the Cerros Tronador, Catedral and Lopez.
I took my regular base plate compass, which I had used extensively in North America, and I found there that the needle was sticking to the card providing false readings.
I was baffled until my guide explained that most climbers from the states had compasses that stick and that I needed a compass with the needle balanced for the area. In my compass, the pull from the forces of the magnetic north made the south end of the needle dip and stick to the card.
I found later that when compasses are made, they are balanced for the zone that they are going to be sold, and that the manufacturers have indentified 5 zones of dip.

MAP OF THE FIVE ZONES





Compasses sold in North America are adjusted for the zone one, and where I was in Argentina was considered zone four. Compasses sold over there by the sporting good stores where adjusted for that zone.
If you have opportunity to travel to Australia, you will be in zone five and the dip of the needle will be even more pronounced.

ENTER THE GLOBAL NEEDLE

Suunto has come out with a couple of traveler’s compasses with a global needle. Brunton has at least one in their line and maybe other manufacturers are doing the same.
This is a needle that is optimized to be use in all places (that is why they are called Global compasses). Brunton is making the 8096 AR (a racing compass) with the global needle, and it makes sense as the runners don’t have to stop and level the compass perfectly to take readings as the global needle can work with even a 20 degree tilt.

Climbers can benefit from a global needle as they have more latitude to take a reading from a peak that is too close, as sometimes bearings have to be taken using the imaginary center line of a mountain instead of a peak when using the regular compasses, as the tilt upward will ground the regular needle. With the global needle the chances that you can still use the peak for your target are increased if the angle is less than 20 degrees.

So we should welcome the development of the Global needle and hope that more choices will be made available in the different models of compasses.
All the best
Watchmaker
Back to top
View user's profile
FALPhil
Super Member
Super Member


Joined: Aug 18, 2007
Posts: 377
Location: Dixie

PostPosted: Sun Oct 21, 2007 11:57 am    Post subject: Re: COMPASSES Reply with quote

Bushmaster wrote:
Thanks FALPhil...Saved me a lot of remembering not to mention, a lot of typing. I haven't used a sextant for so many years I doubt that I could do it anymore...

I'll tell ya, Bushy, with a sextant, a good automatic wrist chronometer, and H.O. No. 9, I would feel comfortable navigating around the world. I loved it. I'd probably still be doing it if Jimmy Carter had never been elected. The U.S. Merchant Marine went down the tubes on his watch. Mad
Back to top
View user's profile Photo Gallery
twofifty
Member
Member


Joined: Feb 07, 2007
Posts: 158
Location: BC Rockies

PostPosted: Sun Oct 21, 2007 6:02 pm    Post subject: Re: COMPASSES Reply with quote

Thanks for your research Watchmaker.
Back to top
View user's profile
sniper
Super Member
Super Member


Joined: Aug 18, 2005
Posts: 735
Location: Utah

PostPosted: Wed Oct 24, 2007 5:33 pm    Post subject: Re: COMPASSES Reply with quote

Dimitri wrote:
Vince,

With me if something has batteries they will fail when I need them even if they are new! Murphy really hates me when it comes to batteries,
Dimitri

Yeah that, Dimitri! Just one more thing to fail.

When I lived in Eurpoe in the early 60s, the Swiss army hd a compass that was really neat! About the size of a matchbox, and it slid in and out of an attached cover. a'la matchbox. I always wanted one, but they were really expensive, and my old Silva seems good enough to get confused by. Very Happy
Back to top
View user's profile
Dimitri
Super Member
Super Member


Joined: Nov 25, 2005
Posts: 5906
Location: Southern Ontario

PostPosted: Wed Oct 24, 2007 5:55 pm    Post subject: Re: COMPASSES Reply with quote

Sniper,

Check this out:

www.thecompassstore.com/51dp65.html



Its a "Global" compass too!. Smile

Dimitri

_________________
A thousand hills, but no birds in flight, ten thousand paths, with no people's tracks. A lonely boat, a straw-hatted old man, fishing alone in the cold river snow.
Back to top
View user's profile Visit poster's website Photo Gallery
twofifty
Member
Member


Joined: Feb 07, 2007
Posts: 158
Location: BC Rockies

PostPosted: Thu Oct 25, 2007 6:55 pm    Post subject: Re: COMPASSES Reply with quote

A Swiss company, Recta, makes a 'matchbox' compass almost identical to this Suunto you found, with the option of having degrees, radians, or mills; one model is 'global'. Had a chance to handle one indoors at a trade show and liked the quality.

See www2.recta.ch/FMPro?-d...ge=e&-find

What I did not like so much is the small size of the graduation (degree) marks on the bezel, which made it harder to read for my eyes. I also found that the open compass is quite short which makes it harder to get map bearings, compared to the long baseplate found on the Type 15 Sylva or similarly built Suunto.
Back to top
View user's profile
Dimitri
Super Member
Super Member


Joined: Nov 25, 2005
Posts: 5906
Location: Southern Ontario

PostPosted: Thu Oct 25, 2007 7:00 pm    Post subject: Re: COMPASSES Reply with quote

Twofifty,

I think ether Suunto or Recta out source the manufacture to another or simply both have the rights to make it the same for one reason or another (perhaps a common goverment contract ?? Confused ), if you look carefully there the same compass and the companies both list it as model "DP 65". Smile

Dimitri

_________________
A thousand hills, but no birds in flight, ten thousand paths, with no people's tracks. A lonely boat, a straw-hatted old man, fishing alone in the cold river snow.
Back to top
View user's profile Visit poster's website Photo Gallery
sniper
Super Member
Super Member


Joined: Aug 18, 2005
Posts: 735
Location: Utah

PostPosted: Fri Oct 26, 2007 6:22 pm    Post subject: Re: COMPASSES Reply with quote

Thanks, Dimitri. I had no idea thery were still making those things. Smile
Back to top
View user's profile
watchmaker
Member
Member


Joined: Jun 29, 2007
Posts: 98
Location: New York

PostPosted: Thu Nov 01, 2007 4:30 pm    Post subject: Re: COMPASSES Reply with quote

SILVA RANGER 515 CL COMPASS

A mirror sighting compass that I use when I want the field reading to be as accurate as possible. The mirror can be tilted 45 degrees to observe the needle for proper positioning on the gate at the same time that a bearing is taken with the sight.

With scales of 1:24,000, 1:25,000, and 1:50,000 , the Silva Ranger 515 CL sighting compass makes plotting easy no matter which type of topographic map you're using.

Other versatile compass features include a 0-360 degree bezel with 2 degree increments, clinometer, 1/20-inch scale, millimeter rules, silicone feet for map gripping, adjustable declination, sighting mirror with vee notch, and lanyard with adjustable slider.

Dimensions: 4" x 2-1/2"
Overall Weight: 2.3 oz.



Price of the compass is about $60 USD it is one of the top notch compasses for map work.

Suunto also have a similar model, and Silva an others also have smaller mirror compasses without declination scale or clinometers



Best
Watchmaker
Back to top
View user's profile
Elvis
Super Member
Super Member


Joined: Jul 27, 2008
Posts: 7025
Location: south island New Zealand

PostPosted: Fri Aug 29, 2008 1:39 am    Post subject: Re: COMPASSES Reply with quote

Heres my 5cents worth. Ive always carried a silva brand compass when hunting and find the best thing is to set the "wobbly" before leaving camp/vechile so if I plan to hunt in a say mainly westerly way then my compass will be pointing east when its time to come back later. to do this you need a backstop feature eg a road \river.to catch you on return heading then you only have to options up or down stream etc. My good wife bought me a garmin etrex gps this year ands its great. I went to the other end of country to hunt this year .set the hut as waypoint and never felt even slightly challenged as to how to get back. was even better to put in clearings in bush crossings that deer were using and wallows. when going back into the area days later ask gps where they were and slow down when getting close. great tool.

_________________
You shot it You pluck it !
Them who eats the most duck eats the most feathers!
Back to top
View user's profile
whittling
Super Member
Super Member


Joined: Apr 21, 2008
Posts: 586
Location: Texas (home state is Mass)

PostPosted: Fri Aug 29, 2008 5:44 am    Post subject: Re: COMPASSES Reply with quote

I use just a map .. print one off the internet ... use a Map to find where I am...
OK ..survival experts HERE are the facts ..Moss grow THICKEST on the north side of trees That are out of the sun ... the top of tallest pine trees point south or southwest usually ...

_________________
Molon labe!
Service, honor and courage, without these a warrior is nothing.
Back to top
View user's profile Send e-mail Photo Gallery
Display posts from previous:   
Post new topic   Reply to topic   Printer Friendly Page    Forum Index » Big Game Hunting
Page 5 of 6
All times are GMT - 7 Hours
Go to page Previous  1, 2, 3, 4, 5, 6  Next



Jump to:  


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum


Advertisements
 


Valid CSS! Valid HTML 4.01!
Click to check if this page is realy HTML 4.01 compliant for speed :)

All logos and trademarks in this site are property of HuntingNut.com.
The comments are property of their posters, all the rest © 2011 by HuntingNut.com
Interactive software released under GNU GPL, Code Credits, Privacy Policy

.: Upgraded to DragonFly 9.2 by Dizfunkshunal :.