User Review: DeLorme Earthmate GPS PN-40

DeLorme Earthmate GPS PN-40
Above: The current Earthmate GPS PN-40, which may differ slightly from the version reviewed.

Reviewed June 4, 2009 by Mark Goresky

Rating:
Price Paid: $245

I really like this unit. I've owned a number of portable GPS units, stating with a Garmin nautical GPS in 1991 (at 3 pounds and 2 feet long, it wasn't really a handheld); a Magellan handheld unit (since lost, so I can't tell you the precise model), a Garmin Etrex Legend, a Delorme PN-20 and now the Delorme PN-40.

Every 5 years, GPS capabilities have improved and I've been absolutely pleased with each of my purchases (less pleased with the PN-20, see my review in these pages). But I'm more than pleased with the PN-40: it is a truly amazing little gadget. Delorme has fixed the limitations of the PN-20 and has gone on to add all kinds of further improvements.

Of the various features of the PN-40, three of them especially appeal to me: (1) rapid acquisition, (2) ability to handle huge SD cards, up to 32 GB, (3) Topo maps of the whole USA plus street maps of the US and Canada.

In my back yard, which is ringed with tall trees, I did a "cold acquire" (meaning that I hadn't used the thing in about 2 weeks). Within a few seconds of turning it on, it found 6 satellites (showing red bars, indicating a signal received but not yet usable) and within 40 seconds, all the red bars had turned green and it had a 3D fix. A "hot acquire" (meaning that I turned it off, waited a few minutes, then turned it back on) took only 10 seconds, and two of the satellites had WAAS fixes as well (indicated by blue bars).

This is a huge improvement over the PN-20, and it is among the fastest receivers I have ever seen. (The PN-20 map display also became quite slow if the memory card was loaded up with maps; the PN-40 doesn't seem to suffer from this deficiency.)

TOPO-USA maps are pretty good. I currently have version 7 but ver. 8 has recently been released and I've sent in my "free update card" (good for 6 months after you buy the unit; be sure to keep the UPC code from the box) to receive them. Delorme claims TOPO-USA ver. 8 is much improved, and it is true that ver. 7 maps are a bit spotty when it comes to their coverage of hiking trails, but I've found them to be decent.

I did some hiking in various dry washes of the Anza-Borrego desert in California, and they were all indicated on the maps. (It's pretty hard to get lost in a dry wash which may only be wide enough for one person, but once you've climbed out of one wash and into another, and done that a few times, suddenly they all start to look alike, and having a GPS may be the only way you can get back to your 4x4.) With the huge memory cards, you can load the whole USA into the GPS, and throw in all of Canada too, and still have room for aerial photos and such.

Street maps: Even without loading the DVD containing "street maps of the US and Canada", the street maps in TOPO-USA are great. I've used them while driving (or rather, my navigator used them) in the car, trying to find our way to a road in central NJ. The PN-40 saved us from a number of wrong turns.

The first release of the PN-40 did not provide any maps of Canada, and so far as I know, the PN-40 still doesn't work with Street Atlas USA (why the heck not, Delorme???) but it appears that the Canada/USA street maps that are now bundled with the PN-40 are pretty much the same as Street Atlas USA, so I'm happy now. Wish list: Topo maps of Canada; street maps of Europe, please.

Other features: I only have comments on four of the many additional features of the PN-40:

--The display is bright and clear; I can read it in midday (as long as I'm wearing my reading glasses: I'm on the "wrong" side of 50 years); the colors are spectacular.

--Delorme fixed the "go to waypoint" function that I complained about in the PN-20 review; in fact they even fixed it in the PN-20, not long after I wrote my review. It is now very easy to click on a waypoint and find your way back to it using the unit.

--The PN-40 comes with "pre-cut" topo maps which makes it much easier to load them into an SD card. For the early PN-20 units, you had to run TOPO-USA on your (windows or mac) computer, select the regions you were interested in, select the range of magnifications you wanted, then click on "download" and wait, sometimes for quite a while, as the computer re-coded those map regions in a format that could be used by the PN-20. The whole process is fast and efficient with the new pre-cut maps.

--I don't really use the downloadable aerial photos, but I did test them out: Delorme has developed a remarkable overlay system that places the aerial photos exactly on top of the topo maps, much as Google Earth does. If you've ever tried to do something like this by hand you'll appreciate how clever Delorme's and Google's algorithms must be.

Disadvantages:

The first is the price. (I bought mine through Amazon which had the best price at the time. It has come down a bit since then.) It's no more expensive than similar units with similar capabilities, but it's still a serious amount of money, plus you'll want to shell out another $30 or more for a high capacity SD card. (It comes with a 1 GB SD card which for most purposes is adequate if you're willing to "cut" the maps that you are likely to need, and then to install them on the memory card. But it's much easier to get a huge memory card and then dump everything into it.)

Second disadvantage is the size and weight: it is a little bulky, and it's not because of the LCD screen. The LCD display is 3.5 cm x 4.3 cm. = 15 square cm. The glass area around the LCD display is not rectangular, but it has about 30 sq. cm. So if the whole glass area was LCD (probably technically infeasible) this would double the screen area, which would be great. With batteries, my unit weighs 7.1 oz. and it is 3.5 cm thick. For comparison, my Garmin Legend with batteries is 5.4 oz, and only 2.7 cm thick. The Garmin's screen area is 3 cm x 5.5 cm = 16.5 sq. cm., which is nearly the same size but less square. I'm sure Delorme has crammed everything into the tiniest area they can, but you'll be carrying around something that you wish was a bit smaller.

Third disadvantage is battery life: like most GPS units, this thing is hard on batteries, and (also like most gps units) it drains the batteries even when it's turned off, because it's keeping track of the time. So if you haven't used it for a few months and then you go off on a trip, be sure to start with fresh batteries (and take along a couple of spares as well).

Yes, it's true that I'm getting soft. I used to hike with topo maps and a compass, and I had a sense of accomplishment at the end of the journey. But the GPS is so darn convenient: no folding/unfolding; you don't run off the edge of the map; you don't worry about the rain getting the map wet, you don't spend an hour rummaging through your map collection, searching for the right topo maps before you leave on your hike while your hiking partners are out there waiting for you in the car with the engine running. I have friends who have sworn never to use GPS, and I completely agree with their point of view, but for me, the PN-40 is the right solution.

No, I am not paid by Delorme, nor have we ever been in contact. They didn't even ask me to remove my complaint about the PN-20 after they made the software correction. I just like this GPS and I've even gone out on a limb and recommended it to several friends, who, it seems, are still talking to me.

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