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Electronic Compass


Tigrin

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Hello good people,

 

I am on the search for my first "Geocaching" GPSr. I narrowed my choices down to either the eTrex Vista HCx or the eTrex Venture HC. The major difference I saw in the two devices are the electronic compass and the ability to take microSD cards, which the Vista has.

 

My questions are:

 

Do I really need the option to upgrade my memory? I only plan to add TOPO, since I already have a GPS for the car.

 

Will the Venture have a feature that will point me to the GZ and tell me how many miles/feet/etc. I am from the cache? (much like the "compass" feature in the iPhone Geocache app) This concerns me most because I am under the impression that only GPSr that has electronic compass will offer this.

 

Also, what are the advantages of an electronic compass? I don't have a problem with using a magnetic compass, but I would like to know if the implementation of the compass in the GPSr is worthwhile.

 

Any help, advice, or experiences in dealing with these features are greatly appreciated!

 

Thanks.

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No, you don't need it.

 

That said, I wouldn't own one without it. It's just too handy being able to stand still and take a bearing on a cache instead of having to keep moving to get a half accurate reading.

 

Given that all of these units with an electronic compass have issues with battery voltage, you'll either learn to perform regular calibration or consider switching to NiZn cells (I heartily recommend them) from Powergenix -- keeps the voltage profile flat until they're exhausted.

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Will the Venture have a feature that will point me to the GZ and tell me how many miles/feet/etc. I am from the cache? (much like the "compass" feature in the iPhone Geocache app) This concerns me most because I am under the impression that only GPSr that has electronic compass will offer this.

 

Just to be clear, the arrow pointing / distance to cache screen is not the same as the compass. Even the basic eTrex H (yellow) has this screen, as do all others.

 

The electronic compass is just that - an electronic compass. Some people swear that it is very useful (the argument being that when you are stood still, the GPSr can permanently tell you bearings etc, whereas otherwise the GPSr relies on you moving to know which way it is pointing) but I've never found a need for it. Perhaps heading into a cave where there would be no signal at all I can see the usefulness (ditto for heavy tree cover?)

 

Matt

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If budget was not an issue then you'll probably be happier with the Vista HCx in the long term, because if your interest in GPSr's grows, you won't out-grow the HCx as quickly. You may not think you need extra memory for maps "now" but how about a year from now??

 

But if budget is an issue then you'll probably be quite happy with the Venture Hc it's a great starter unit. No it doesn't have an electronic compass like the Vista, BUT even if it did you should still get into the habit of bringing a gold'ole mechanical compass along with you anyway. The Venture + a mechanical compass = the Vista (except for the memory thing :) ). [edit] Well actually that's not true. The Vista is capable of much more, like auto-routing your car. The Venture can't do that.

Edited by NordicMan
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I went through the same thing when buying my first caching GPSr. After much debate I decided to go with the PN-40 with the electronic compass rather than the PN-30 with out. I am glad I did. It is nice to be able stand in one position and know your direction without moving as you have to with a GPS only compass. With that said though I found my first 10-15 caches with just an app for my blackberry with just a GPS compass. So do you need no but it is just a nice added feature if you can afford it.

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Given that all of these units with an electronic compass have issues with battery voltage, you'll either learn to perform regular calibration or consider switching to NiZn cells (I heartily recommend them) from Powergenix -- keeps the voltage profile flat until they're exhausted.

not necessarily true, as i said before i use regular NiMH batteries and only had to calibrate the compass once.

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As some others have said I have found having an electronic Compass very very valuable when Geocaching. For other purposes - maybe not so much.

 

For me, being able to stop and not worry about my bearing swinging around and pointing me in the wrong direction is a great feature. Having to move to get a bearing (especially when close to ground zero) is a real pain.

 

I'll never have a GPSr without the electronic compass (have had both with and without).

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Outside of mapping ( if you compliment your handheld with a car unit you don't even need mapping) the elect. compass is the feature I like best....I also have used both types.

If you're in the thick stuff and can't move around readily its nice having the unit always pointing right at the cache....even in the open you get tired of walking around like a drunk.

Re car units if you get a Nuvi 500 you'll be completely paperless.

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Given that all of these units with an electronic compass have issues with battery voltage, you'll either learn to perform regular calibration or consider switching to NiZn cells (I heartily recommend them) from Powergenix -- keeps the voltage profile flat until they're exhausted.

not necessarily true, as i said before i use regular NiMH batteries and only had to calibrate the compass once.

I take it you're not using a Garmin? I've yet to see an eTrex, Colorado, Oregon or Dakota that didn't start to display some odd pointing behavior when the batteries started to get low.
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I take it you're not using a Garmin? I've yet to see an eTrex, Colorado, Oregon or Dakota that didn't start to display some odd pointing behavior when the batteries started to get low.

i'm using an oregon 450. the compass is off by about 30 degrees when using totally fresh batteries, but that only lasts a couple of minutes. after that the compass is perfectly fine until i get the "batteries low" warning. well, it's still fine after that, but that's when i change them. never had to recalibrate.

Edited by dfx
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It's amazing how varied the opinions are on this subject :laughing:

 

Personally I LOVE magnetic compasses in my GPSr and would never (again) buy one without one. I don't seem to need to calibrate the one in mine often at all (Garmin Vista Cx) and don't notice a serious impact in battery life whether the compass is on or off..

 

So, if you want the best of both worlds, buy a GPSr that has an electronic compass but leave it turned off, lol :laughing:

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I take it you're not using a Garmin? I've yet to see an eTrex, Colorado, Oregon or Dakota that didn't start to display some odd pointing behavior when the batteries started to get low.

i'm using an oregon 450. the compass is off by about 30 degrees when using totally fresh batteries, but that only lasts a couple of minutes. after that the compass is perfectly fine until i get the "batteries low" warning. well, it's still fine after that, but that's when i change them. never had to recalibrate.

 

You have it set to magnetic and not true? Maybe??

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Will the Venture have a feature that will point me to the GZ and tell me how many miles/feet/etc. I am from the cache? (much like the "compass" feature in the iPhone Geocache app) This concerns me most because I am under the impression that only GPSr that has electronic compass will offer this.

 

Just to be clear, the arrow pointing / distance to cache screen is not the same as the compass. Even the basic eTrex H (yellow) has this screen, as do all others.

 

The electronic compass is just that - an electronic compass. Some people swear that it is very useful (the argument being that when you are stood still, the GPSr can permanently tell you bearings etc, whereas otherwise the GPSr relies on you moving to know which way it is pointing) but I've never found a need for it. Perhaps heading into a cave where there would be no signal at all I can see the usefulness (ditto for heavy tree cover?)

 

Matt

 

Actually the compass does assist the directional arrow as the gps knows (better) which way you are facing even though you are not walking in a steady direction.

 

If you can afford it, go with the Vista. The expanded memory will allow more topos and many other options such as loading more than 1000 waypoints. If you are traveling quite a distance you'll appreciate the features much more.

Edited by BlueDeuce
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Geez... All the complaining about having to calibrate the electronic compass. Big deal. Hold it level, away from any large metal objects and spin it around twice. My 60CSx takes less than 20 seconds to do it. I can even do it "in the air" with my hands and not need to find a spot on the ground. It's always within about 5 degrees (+/- 2 or 3 deg) of my Brunton mag compass and that's plenty accurate enough for geocaching. We're not talking hundred mile treks here...

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They are battery burners..."
Evidence? mA consumption per spec sheet, meter measurement, anything?

 

I'm guessing you're thinking of the older models. 7.3 milliamps at 3V wasn't exactly what I'd call a "battery burner", and that was the old 2-axis spec when these parts were a less efficient.

 

Newer 3-axis chips draw a whopping 0.8 milliamps at 1.8V! I'm guessing the 14 seconds (or whatever it really is) that one of these would take out of a normal caching day could be afforded by even the most battery-frugal individuals.

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I've been caching for over six years and never had a GPS with a compass, or had a serious need for one.

my previous GPSr also didn't have a compass, and i didn't feel the need for one at that time either. now i do have one, and even though technically i still don't need it, it sure as heck is convenient! :laughing:

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They are battery burners..."
Evidence? mA consumption per spec sheet, meter measurement, anything?

 

I'm guessing you're thinking of the older models. 7.3 milliamps at 3V wasn't exactly what I'd call a "battery burner", and that was the old 2-axis spec when these parts were a less efficient.

 

Newer 3-axis chips draw a whopping 0.8 milliamps at 1.8V! I'm guessing the 14 seconds (or whatever it really is) that one of these would take out of a normal caching day could be afforded by even the most battery-frugal individuals.

If you are after evidence, a search on this forum for "current compass" will reveal tests that a number of us have carried out; e.g.:

 

http://forums.Groundspeak.com/GC/index.php...=176064&hl=

 

Bottom line - on most recent models, don't worry about the current drain of the compass - the back-light is the real "battery burner".

 

Hope this helps!

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I went through the same thing when buying my first caching GPSr. After much debate I decided to go with the PN-40 with the electronic compass rather than the PN-30 with out. I am glad I did. It is nice to be able stand in one position and know your direction without moving as you have to with a GPS only compass. With that said though I found my first 10-15 caches with just an app for my blackberry with just a GPS compass. So do you need no but it is just a nice added feature if you can afford it.

 

Thank you all for the vast amount of information and replies. I received more information than I had hoped for! I did what Team_Searchgeo did and decided to go up a level and ordered the PN-40 since it seem most logical, in terms of spending and features. Since it does include TOPO (on Garmin, it cost $99).

 

I hope I selected a good handheld.

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I've been caching for over six years and never had a GPS with a compass, or had a serious need for one. They are battery burners and in most cases have to be recalibrate every time the batteries are replaced.

I don't buy into the battery burning claim, I bought a 76CSx a couple of months ago and with a pair of Sanyo Eneloops in it I ran it one 10 hour day without being shut off and a couple of other days for at least three or four hours each time and the battery indicator went down one bar. During that time I calibrated the compass once when I first put the batteries in, and that took all of ten or fifteen seconds. Even if I would have got just the ten hour day on a set of batteries I would have been happy.

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I'm guessing the 14 seconds (or whatever it really is) that one of these would take out of a normal caching day could be afforded by even the most battery-frugal individuals.

 

Exactly...well put... So many people *want* to make up problems with using a built-in electronic compass and can't simply understand that if they don't like it? DON'T use it or buy a GPS with that feature in the first place. Instead, excuses like "inaccurate" or "battery burner" or "too hard to calibrate all the time" come up. My "old tech" 60CSx's 2 axis electronic compass doesn't use much battery at all. I've never noticed any difference and, like you said, use it sparingly. It doesn't have to be on constantly. Then again, neither does the entire GPS for real world navigation aside from geocaching games, which is what they are no matter what anyone says. Also, people seem to ack like it's so difficult to carry a spare set of rechargeable AAs or something if they're REALLY worried about "battery burning". :laughing:

 

I prefer to use a separate mag compass for my own reasons, but that doesn't mean my electronic compass is "bad" or just added crap because it's too "inaccurate" and calibrating is just soooo hard...

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You have it set to magnetic and not true? Maybe??

no i don't. how would that even make a difference in this context?

 

If you even have to ask this question then, apparently, you don't even understand the difference between true and magnetic headings, magnetic variation, etc. The difference CAN be 30 degrees off at some latitudes if you're comparing a GPS electronic compass set to TRUE readings with a separate analog magnetic compass.

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If you even have to ask this question then, apparently, you don't even understand the difference between true and magnetic headings, magnetic variation, etc. The difference CAN be 30 degrees off at some latitudes if you're comparing a GPS electronic compass set to TRUE readings with a separate analog magnetic compass.

and you apparently didn't understand the context.

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No, you don't need it.

 

That said, I wouldn't own one without it. It's just too handy being able to stand still and take a bearing on a cache instead of having to keep moving to get a half accurate reading.

 

Given that all of these units with an electronic compass have issues with battery voltage, you'll either learn to perform regular calibration or consider switching to NiZn cells (I heartily recommend them) from Powergenix -- keeps the voltage profile flat until they're exhausted.

 

Good tip. Thanks

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and you apparently didn't understand the context.

 

Yes, I did. YOU asked the question. :laughing:

no you didn't. if the problem was that the compass was set to magnetic north, it wouldn't go back to being correct after a few minutes.

Edited by dfx
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I hated the electronic compass in my 60csx. I almost returned the unit untIl someone told me how to disable it.

 

The one in my PN-40 is better. I never calibrate it, and never trust that the arrow means anything when I am standing still, but at least it never gets in the way.

Edited by sammydee
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I hated the electronic compass in my 60csx. I almost returned the unit untIl someone told me how to disable it.

 

You had to have someone else tell you how to press/hold a single button and turn (i.e. "disable") it off? :lol:

 

Even that was in the stupid next-to-nothing "instruction manual" pamphlet that came with my 60CSx...

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I have a Magellan Triton 2000, purchased from a pawnshop for about half of the retail price. It has the Sd slot color map display, camera, flashlight, compass, barometer, thermometer, headphone jack,and a metal handle that will probably work as a bottle opener in a pinch.

 

I seldom use the compass, because the calibration requires the GPSr to be placed on a leve surface with no iron or steel nearby, which rules out most of the readily available surfaces like picnic tables (nails in wooden ones, rebar in the concrete ones ) and roadways ( seldom level ). It does come in handy for the occasioins offset cache, but drains the batteries quicker so I usually keep it turned off. For most caches, the GPSr calculates the heading from the satellites accurately enough for most purposes.

 

An SD card is required for the camera, and for the topo maps, and I've found the camera to be a nice feature. The flashlight, which really drains the battery, has been useful on occasion. The barometer is not so useful to me, If I still did back country hiking, it might be. The thermometer is only accessible from a hidden diagnostics mode and not really useful.

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I seldom use the compass, because the calibration requires the GPSr to be placed on a leve surface with no iron or steel nearby, ...

that's not necessarily true, at least not for all GPSrs. i calibrated the compass on my oregon 450 hands-free while on the trail, and only once without ever recalibrating. it's perfectly accurate, up to +-5 degrees i'd say.

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I think you made the right choice if you can handle the small screen. Same size as the vista and venture. My old eyes need at least an oregon.

 

Thank you all for the vast amount of information and replies. I received more information than I had hoped for! I did what Team_Searchgeo did and decided to go up a level and ordered the PN-40 since it seem most logical, in terms of spending and features. Since it does include TOPO (on Garmin, it cost $99).

 

I hope I selected a good handheld.

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