Strange Readings

[+ADKcachers]

The last few times out, under varying levels of tree cover, severe to none, my receiver will lead me to a point, then suggest that I look some 100 to 300 feet off in a different direction.

 

Other times, after zeroing in, it will indicate that I'm 30 feet away and send me in a circle or 2 back to the original point.

 

I use nimh batts, should I go with the alkaline?

[+strikeforce1]

Batteries shouln't be a problem, I use recharagables with no problem. When heading to a waypoint, swithc screens and see what sat locks you have and accuracy. There are times with heavy tree coverage, you loose some sat's and accuracy. In open fields, you should get good readings for the mose part. If you are running a newer GPSr, you need to be moving, to get the pointer to respond properly. Also, as you approach the area, .004 away, walk slower for better accuracy. The 30 ft away is reasonable for hunting, at that point start looking for likely spots for the cache or micro. Sf1

Edited June 16, 2004 by strikeforce1

[mortonfox]

If "power saving" mode is enabled, turn it off. Also, once you're about 50-100 feet from ground zero, let the GPS sit there for a while to get a consistent reading and then use a compass to close in on the cache.

[+mattt]

What brand/model are you using?

 

Different models have some problems with estimating etc.

 

I use a Magellan Meridian Green - It estimates my position - so when I slow down, it assumes I am farther than I really am - this creates a "slingshot effect" - I get to ground zero and then It slowly tells me that I am past the spot.

 

to overcome this - I stop at 50 to 75 feet out and let my GPSr settle down.

[+ZackJones]

Also, once you're about 50-100 feet from ground zero, let the GPS sit there for a while to get a consistent reading and then use a compass to close in on the cache.

Would you please explain to me how you use a compass to find a cache once you get close to it. I've seen this mentioned a few times here on the forum, but no one has actually explained how to do it and why.

 

Thanks in advance for your or any other replies.

 

Zack

[+cmpalmer]

Would you please explain to me how you use a compass to find a cache once you get close to it. I've seen this mentioned a few times here on the forum, but no one has actually explained how to do it and why.

 

Thanks in advance for your or any other replies.

When you are about 1.5 to 2 times as far from the cache as your accuracy, set your GPSr on the ground and let it "settle".

 

For example, if it is showing 20' accuracy, get at least 30'-40' away. Actually, the farther the better, but if it is too far away, it doesn't help you much since you might not have line of sight to the cache area. A little sketching will help you understand that the farther away you are, the more accurate the bearing should be.

 

Try to pick a spot in a clearing if the actual cache area is under heavy tree canopy.

 

Set your GPS to show you the bearing to the waypoint/cache.

 

Turn the dial of your compass to that bearing on the outer ring, then hold the compass perpendicular to your body and turn your *body* until the compass arrow lines up with north (0 degrees).

 

You are now facing the cache. If you sight along the front of the compass and imagine a line, that line should pass very close to the cache. The distance shown on your GPSr tells you how far to go. Learning your stride length will allow you to estimate how far you need to walk.

 

If this doesn't help you find it, try again from a different direction (say 90 degrees away from the first position). If you do it right, the imaginary line from your first position should cross the imaginary line from your second position right on top of the cache.

Edited June 16, 2004 by cmpalmer

[+ZackJones]

cmpalmer: Thanks for the very informative reply. A quick question or two if I may.

 

When the GPS is set to show the bearing is NE or SW, etc sufficient or should it be showing the degrees? My guess is degrees would be more accurate?

 

I believe I understand the rest of your explanation. I'm going to set up a test cache out in the back yard and give it a try.

 

Zack

[+Rogue_monkey]

degrees is what you want it to show if you are going to use a compass. make sure your gpsr is set to magnetic for the north reference or the readings from your gpsr and compass will be off. the difference in degrees will depend on where you live. where i am the difference is 10 degrees may not seem a lot but it is after a bit of travelling

[+The Jester]

if you're going to use a compass, you might as well get a good one that allows you to adjust for declination. Then set the GPSr to true north. This is nice in town or the drive to a cache, as most road systems are set on the true north grid. It can 'interesting' if the GPSr says due north but the road seems to go NE/NW! Just make sure to re-adjust the declination when you are in a new area.

 

My favorite way to use a compass while searching for a cache is to tie it to stout cord and just fling it into the bushes. When I hear a 'ting' I just follow the cord to the ammo box! With practice you can even judge how full the box is before opening it just by the tone of the 'ting'!

[+Rogue_monkey]

if you're going to use a compass, you might as well get a good one that allows you to adjust for declination. Then set the GPSr to true north. This is nice in town or the drive to a cache, as most road systems are set on the true north grid. It can 'interesting' if the GPSr says due north but the road seems to go NE/NW! Just make sure to re-adjust the declination when you are in a new area.

 

My favorite way to use a compass while searching for a cache is to tie it to stout cord and just fling it into the bushes. When I hear a 'ting' I just follow the cord to the ammo box! With practice you can even judge how full the box is before opening it just by the tone of the 'ting'!

if you set the gpsr to true north you will have to add the declination to the bearing number you get before you dial it into the compass. or like i said you be off by a few degrees.

[+cmpalmer]

I usually leave my GPS set to magnetic north as I rarely use it in conjunction with printed maps. If my math is right, a 10 degree difference at 100' comes out to 17 feet in whichever direction it is off.

[+The Jester]

if you set the gpsr to true north you will have to add the declination to the bearing number you get before you dial it into the compass. or like i said you be off by a few degrees.

Or like I said:

get a good one that allows you to adjust for declination.  Then set the GPSr to true north.

 

I have a couple and both allow me to enter the declination offset (21-22 degrees at home) and then all bearings to and from the compass are in true degrees. No adding or subtracting or remembering East/West.

[+Rogue_monkey]

ok jester i see what your saying now, we where both refering to a good compass with the ability to change declination, but we differed in which north to use and now that i think about it more yes both ways will work. true to magnetic and magnetic to magnetic.

 

right so yes your way will work and so will mine, i should have thought about your way a little more first. thanks for making me think, i like a challange every once and a while

[Cholo]

off in a different direction.

 

Could this be the business bonanza of the future.....GPSr repair? Think of the possibilities! Think of the business cards and signs! "Joe's Geo Repair and Yellow Jeep Detailing", "Let us tweak your unit", "Garmins r Us", "Etrex Tex the Right to Bury Ammo Boxes". Yes, the possibilities are endless, and ........aaaaaaggggghhhhh

[Wanderingson]

You may need to get you one of these:

 

[+ADKcachers]

What brand/model are you using?

Thanks folks, all helpful answers. It's a Magellan Sportrak.