GPS receivers revisited

8:14 p.m. on October 6, 2009 (EDT)
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Hello, all!

Back in July there was a brief thread on GPS units, but it seemed to peter out. I'd like to re-open the discussion with a few specifics.

I'm OK with map and compass. But I find walking a compass course accurately enough to hit a small lake or meadow isolated behind several miles of brushy forest all too often ends in "Plan B" -- realize you've missed the lake, cuss, walk due south until you hit the road, trudge back to the car, and go somewhere else next weekend.

A friend recommends the Garmin GPSMAP 60C SX, saying that it seems to have better deep-forest reception than some newer models. I notice Trailspace reviewers like it too, but some also give Garmin's eTrex Legend and eTrex Summit HC good marks. And the unreviewed Garmin Oregon 200 sounds intriguing, as does the DeLorme Earthmate GPS PN-30.

But I don't know squat about any of them.

Philosophically I prefer a single-purpose unit, not one combined with a digital camera, a heart rate monitor, restaurant guide, or Rock Band 2. I want to navigate to specific lat-long coordinates along a route, and of course be able to back-track myself. Very detailed maps are probably not necessary, as I envision using the unit in combination with good paper maps and aerial images, but some kind of topographic map display is a must.

Is there a consensus or an undercurrent of opinion on what a GPS unit(s) are best for back-country travel?

12:50 a.m. on October 10, 2009 (EDT)
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I use the Garmin eTrex H and love it. I use it soley to confirm my position after navigation through lensatic compass, protractor, and topo map. No bells and whistles on it. I have never (knock on wood) had any "reception" problems and usually get a reliable fix within 30 seconds or so. In essence, I use it as a reminder that my land nav skills haven't disappeared since I left the military LOL.

I think it can take some sort of maps, but have never tried it.

The compass on it is a bit suspect as it only works when you are moving (like all GPS), so don't rely on it to accurately plot your course.

And, it's dirt cheap!!!

2:36 p.m. on October 10, 2009 (EDT)
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The Garmin 60 series (I suggest the 60Cx rather than the battery hog 60CSx) and the Delorme PN30 are pretty comparable (the PN40 is more comparable to the Garmin 60CSx). The Garmins have some design "features" (I consider them flaws, but Garmin insists that they are intentional) that are problematic. You might not encounter them or not be bothered. The worst is the barometric altimeter - in the Garmins that have the barometric altimeter, the displayed altitude is always the barometric altitude - you cannot choose to display only the more accurate GPS-derived altitude, although you can view it intermittently. So you have to recalibrate it frequently, just as with any barometric altimeter. The PN40 has both a barometric altimeter and a magnetic compass, but you can shut either or both off (I leave mine off virtually all the time, using the barometric altimeter as a weather-observation tool, and the magnetic compass only for geocaching when close to the cache). Or with the PN30 and 60Cx, you don't have to bother with the barometric altimeter or internal battery-hogging magnetic compass. A separate baseplate compass is more accurate and a lot easier to use than the built-in fluxgate compasses anyway, plus is not dependent on batteries

usersatch, there are a number of models of eTrex with the "H" designation ("H" means it has the high sensitivity GPS chipset). Some accept maps, including the top model which takes scanned USGS 7.5 minute quads, and some do not). You mention using a lensatic compass. Actually, a baseplate compass is far more useful and a lot easier to use than a lensatic compass. The reasons are too numerous and the discussion of why is too involved to go into here. But a clue is that the baseplate compass was designed for navigation off trail, where the lensatic compass was designed for military use when designating targets for artillery, machine guns, and mortars, not for navigation. Your statement that the compass display in a GPSR "only works when you are moving" is only partially true. Those GPSRs that have a built-in fluxgate compass (like the Garmin "S" series like the 60CSx, 70CSx, and eTrex Vista H and HCx, and the Delorme PN40, and certain Magellan models) do have a magnetic compass built-in. However, these tend to be battery-hogs and are significantly more expensive than the corresponding models which do not include the magnetic compass.

6:34 p.m. on October 10, 2009 (EDT)
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OEJ

I have taken a different approach to the GPS usage, which many do not agree with, mainly because as consumers we are directed to the fancier gadgets, especially guys. I for one do not see the need for spending 500 bucks on a high end GPS, as number one...it's just too much money, and number two...you should not be relying solely on a GPS. I am studying up on using a compass again, and will use that and a map primarily. The only time I get into trouble is when I take a wrong turn, only to find out it was a game trail. However, when I turn around I am now disoriented, as one time on the Mogollon Rim in AZ, and it was the proper use of the compass that got me out, although it took quite some time.

But with the TracBackĀ® feature on the Garmin I would just retrace my steps, and with 500 waypoints and 20 routes, or a track log of up to 10 thousand points and 10 saved tracks, that will get me back on track quickly. I can also look at the paper topo and see a landmark, and use the the Garmin as a way to check it. That is, use the altimeter to see if I am right, by comparing the topo elevation to the Fortrex reading.

The maps on these GPS units are not to scale, except the Delorme as it uses the National Geographic maps. But man...the maps for all these are so exspensive! I can download basic maps off the internet for free, and unless I am on a seriously wicked trail, I won't even have to use the map.

Nevertheless, as a photographer I am always leaving my pack somewhere, and then walking about to get pictures. The TracBack feature will be awesome for me because I can set it, and retrace my steps over and over.

Just my thoughts...

Snakey

A boa, a milksnake, and a Kingsnake...

8:50 p.m. on October 11, 2009 (EDT)
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Thanks for the responses!

I hear all of you saying that a regular magnetic compass is essential and I agree. I carry a couple and that won't change.

It sounds like the magnetic compass feature is one to do without in a GPS. And a GPS-driven altimeter is better than an electronic aneroid.

I'm puzzled by the "maps on these GPS units are not to scale" observation. I assume that any GPS that takes scanned USGS (or other) topos will display them to scale; are there other mapsets which are distorted? Which are the ones to look out for?

Bill S: Are there any big ease-of-use differences between the Garmin 60 series and the DeLorme PN-30 or PN-40, for instance in downloading and installing maps? Or in the costs of mapsets?

I'm intrigued by the description of the PN-40 displaying Google-style satellite photography, since Google Maps satellite view is one of my favorite tools for sussing out routes. Can anyone speak from experience on using this feature?

Thanks again for your help...

August 27, 2014
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