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Reviews > Navigation and Map Gear > GPS > Delorme Earthmate GPS PN-40 > Test Report by Brian Tannehill


INITIAL REPORT - March 07, 2009
FIELD REPORT - May 25, 2009
LONG TERM REPORT - August 04, 2009


NAME: Brian Tannehill
EMAIL: tannehillclan (at) gmail (dot) com
AGE: 34
LOCATION: Colorado Springs, Co
HEIGHT: 5' 7" (1.70 m)
WEIGHT: 185 lb (83.90 kg)

I am fairly new to backpacking, but I have hunted/fished/camped all my life in East Texas, Colorado, and California. My kids (7, 13, 15) limit me to weekend overnight camping trips, or day hikes Geocaching. I am also an avid mountain biker. Currently I live in Colorado Springs, Co at the base of the Rocky Mountains. Pike National Forest surrounds me at 9000 – 14,110 feet (2743 m – 4301 m). Snow can happen 10 months out of the year and summer is the hottest reaching 80 deg F + (44 C+), The other months average 45 deg F (7 C).



Manufacturer: Delorme
Year of Manufacture: 2009
Manufacturer's Website: Delorme
MSRP: US$ 399.95
Listed Weight: Without batteries: 5.35 ounces (152 g); with Li-Ion rechargeable battery: 6.7 oz (190 g); with alkaline AA batteries: 7.00 oz. oz (198 g)
Measured Weight: Without batteries and SD Card 5.38 oz (154 g); With Alkaline batteries and 1 GB SD Card: 7.25 oz (204 g)

Other details from the website:

PN-40 Hardware Specifications:
IPX-7 waterproof standard, impact-resistant rubberized housing
Device dimensions: 2.43" W x 5.25" H x 1.5" D (6.17 W x 13.34 H x 3.81 cm)

A dual-core processor for lightning quick map redraws, when panning or zooming
Fast USB 2.0 data transfer to internal memory or SD card in device
Proprietary Kalman filter for enhanced GPS accuracy
Detailed onboard base map with major highways and thoroughfares worldwide, plus secondary and connector roads in the U.S.

3-axis electronic compass with included accelerometer performs when held in any position – while in motion or standing still
Sensitive barometric altimeter for reliably accurate altitude readings

Uses 2 AA batteries (included)
Optional Travel Power Kit with DeLorme-supplied rechargeable Li-Ion battery

Super high-sensitivity 32-channel Cartesio chipset by STMicroelectronics for rapid signal acquisition and ConstantLock satellite retention, even in challenging GPS environments

Acquisition Times:
Hot Start: 5-6 seconds
Warm Start:
Cold Start:
Update rate: 1/second, continuous

GPS accuracy:
Velocity: 0.05 meter/sec steady state

WAAS accuracy:

Sharp high-resolution 2.2" 65K-color Transflective TFT color display (220 x 176 pixels)

Memory & Storage
500 MB available internal Flash memory
Supports SDHC high-capacity SD-cards – up to 32 GB
Holds up to 10 tracks (10,000 points per track), 1,000 user-defined waypoints, and 50 routes

Topo USA 7.0 System Requirements
Operating Systems
Microsoft Windows Vista® Home/Basic/Home Premium/Ultimate/Business with 512 MB RAM
U.S. Version Microsoft Windows XP or 2000 (Service Pack 3 and higher): 128 MB RAM (256 MB recommended)

Intel® Pentium III 900 MHz or higher processor (1.8 GHz recommended)
1 GB of available hard-disk space
3D-capable video card with 32 MB VRAM (64 MB VRAM recommended)

My System:
I am using a Gateway T-1625, with an AMD 64 2.0 GHz processor with 1662 MB of RAM.

The Delorme PN 40 arrived with everything that the website describes in the box:

Energizer AA batteries
Neck lanyard
1 GB SD Card
Earthmate GPS-PN 40
Topo USA 7.0 DVD Software (with complete U.S. integrated topo and street maps, plus four million places of interest)
Topo USA 7.0 Detailed Maps (Eastern, Central, West Region)
Supplementary data certificate for USGS QUAD, satellite map and NOAA chart online downloads
USB data transfer cable for PC/GPS data exchanges (8 mini-pin)
Quick start guide
Owner's manual


I have used a few of the Delorme products over the last few years. I have been lucky enough to test the Delorme LT-20 and Delorme Topo 5.0 through I am also a fairly avid user of GPS itself having used several different models to include Magellan's and Garmin's.

Fig 1 © 2009 DeLorme (

The unit is pretty much what I expected from viewing it on the website. The screen resolution is better than I expected, and the unit itself feels very rugged. I started by installing the Topo dvds provided and that went flawlessly. I took the GPS outside for an initial power up, and it acquired satellites for a 3-D fix in under 2 minutes, 1 minute 55 seconds actually. I thought that was really quick for the first time. Since then its taken anywhere from a minute or so to six seconds.

The Topo 7.0 software from Delorme installed fine on my computer. I have downloaded files from the map library through the netlink tab, to include aerial imagery, satellite imagery, and USGS quad charts. The files are various sizes, but the largest is the HI Res aerial city imagery. I can only download 150 MB at a time, and my download rate from Delorme's website has ran anywhere from 45 KB/sec to 54 KB/sec. I can also select the different files online instead of using my software. I think that is interesting, especially if I did not bring my computer with software installed and I need map data for a new location. I can go online and download it to my SD card. Very Cool!

Initially using the GPS unit and the software was tougher than I expected. I was familiar with the software, but not with transferring to the GPS unit. There are a couple of ways I can transfer files to the GPS unit. One way is through the USB data cable. The other way is through an SD Card reader. For any imagery files, it works best for me to transfer via the SD card reader. However with this method I can only transfer map files. Any routes, waypoints, or tracks cannot be transferred via the SD card reader. The GPS unit has only had one real problem so far. Less than 72 hours of receipt, the USB data cable stopped working. It would wiggle when connected to the GPS, and either disconnect or reboot the GPS unit itself. At first I wasn't sure if it was the cable, my computer or the firmware. I updated the firmware two versions ahead of what shipped to the 2.5 beta version. I also verified my USB ports worked, and also installed the software on another laptop. Everything checked out except for the data cable. I contacted customer service and they have shipped me a new replacement cable.

screen shot
Fig 2 © 2009 DeLorme ( Topo 7.0®

The screen shot in figure two, is of the Topo 7.0 software. All the tabs are still the same from a previous version of Topo 5.0. The profile picture is from a recent 2.7 mile (4.4 km) run I did behind my house. The coolest feature I have found so far is the blue line across the profile that indicates speed. I can mouse over this at any point and it shows my speed. What a great training aid. I ran the whole 2.7 miles (4.4 km) with the gps unit inside one of the pockets of my ALICE pack. Satellite lock looks very promising with this unit.


Startup and satellite acquisition of this GPS is amazingly fast. Out of the box, the first time I turned it on, it took 1 minute 55 seconds to acquire my position. If I have used it in the same day, sometimes its as fast as 6-10 seconds to acquire satellites. It even acquires satellites in most places inside my house in under 20 seconds.

I am also very pleased with the screen resolution. The colors are good, and the detail is fine for me. I can change the color scheme in the display options if I need to.

Using the imagery on the GPS unit is interesting. The unit redraws the maps very quickly. I have found that with the 1 meter aerial imagery, anything under the scale of about 120 feet becomes pixilated. To help alleviate the pixelation, in the handheld exchange options I can pick which zoom levels I want the imagery displayed.

I won't go into too much detail about the buttons on the GPS. It has the standard power, waypoint, find, page, zoom in/out, scroll and menu buttons. DeLorme's website does a great job of explaining them. I will say the buttons are not lit up. How will this effect using this unit in the dark?

I couldn't possibly cover every detail about this software program in this report so here is a list of basically what I can do on this Topo software:

Map Display
Handheld Export

I will only touch on a few things at this time. The one tab I use the most is of course the handheld export. This allows me to send the data from the software to the GPS unit.

Fig 3 © 2009 DeLorme ( Topo 7.0®

In the options tab, I can choose which maps I want to send to the GPS unit. This is a big plus, as most of the files take up a lot of room. The HI Res imagery takes up almost 1 GB by itself.

Also in the netlink tab is the Delorme Map Library. This library is a yearly subscription based library that contains USGS 1:24K topo map, 1 meter color aerial imagery, 1 meter black and white imagery, nautical charts (too bad I'm land locked in Colorado), Sat 10 (10 meter satellite imagery), and Hi resolution city data. I still say for me that 10 meter satellite imagery is useless but will try it out none the less. I would like to know if I can download other imagery and import it into the software/GPS?

Fig 4

The second coolest feature I have found with this GPS is the Geocaching feature. Through, I can send the caches directly to this unit. No more 3rd party software to mess with. The upgraded firm ware version allows details about the caches to show up, and according to Delorme's blog will even let me mark them found in my GPS. I do have some work to do though, Fig 4 shows 230 geocaches within 5 miles (8 km) of my house.

The one big question with GPS units is battery life. So far I have only used Energizer alkaline batteries. I used the ones provided until they died, and then I switched to some Energizer industrials. In my last trip back from Las Vegas, Nevada, I turned the GPS on and left it on until the batteries ran out. I used it on the trip information page, with the backlight set to 45 seconds. I got 5 hours and 56 minutes of battery life. This is the largest drawback with this unit. In about two weeks worth of time and pretty continual use I have changed the batteries 3 times already. DeLorme says the internal clock is powered by the batteries while the unit is off. I do not like this feature.

The battery meter has four bars to represent battery life. The battery status ranges from four solid green bars, three solid green bars, two yellow bars, and one red bar. I have noticed twice so far that if I hit the two yellow bar mark, turn the GPS off overnight, it will be dead the next morning. I'm attributing this to the internal clock being powered while the unit is off, and will look for this through out the test. In the instruction manual, it suggest using the backlight at 15 seconds, removing the batteries for long storage periods (what's considered long? The manual says more than a month), setting the GPS to power saving mode, disabling GPS while indoors (who would use it indoors anyway?) or using batteries with a higher attributing rating (such as Duracell Ultras, Energizer E2's, etc.) There is a huge discussion on the DeLorme forum about battery life. Other users seem to get anywhere from 5-12 hours depending on batteries and usage.

Another surprise with this unit is how long it takes to build and transfer maps. After I download the maps from DeLorme's web site (which takes upwards of 45 minutes for certain resolutions). I have to create a map, save it, and then send it to the unit. Creating the maps with the Hi Res aerial imagery takes somewhere around an hour to an hour and a half on my computer. Transferring map packages is best done through the SD card reader, but it still takes what seems like forever. I have not timed this but I think its in the ball park of 5-8 minutes to transfer to the SD card.


So far this GPS is one of the coolest units I have seen. There is still a bit of a learning curve for me involved with it. Its simple things that I know how to do, just not sure where they are in the abundance of menus on both the GPS unit and the software.

Getting comfortable using the software and transferring maps still takes time. Not just because I am slow but the map building done by the software is slow.

This concludes my Initial Report. My Field Report is posted below. Thanks to and DeLorme for allowing me to participate in this test.



So far I've used this GPS on two day hikes, and two runs, along with numerous car trips to a few local fishing holes. I've also used it on a 2 day drive back from Las Vegas to Colorado Springs, Colorado. Altitudes ranged from 6600 ft (2012 m) to a little over 7000 ft (2134 m). Distance ranged from 1.5 miles (2.4 km) to a little over 4 miles (6.4 km).


This unit has performed great. I noted in the initial report that I had a problem with the USB data cable. Customer service promptly sent one out. However, the new one is a bit different. In Figures 5,6,7 I show how it connects. The new data cable is a two piece design. One piece is the USB cable, and the other piece connects to the GPS. With the old one piece cable I would connect and disconnect the data cable to the back of the GPS each time I wanted to hook it up. With the new two piece, I connect the dongle to the back of the GPS and leave it. Then when I want to connect the GPS to the computer, I simply plug in the USB cable.
new data cable
Fig 5

Fig 5 shows the new piece that fits in the back of the GPS.
data cable
Fig 6

Fig 6 shows how I use the GPS. There is no worry about the piece falling out as it is a tight fit.
data cabe connected
Fig 7

Fig 7 shows all the pieces connected.

I've hiked with the GPS unit both hanging from my neck and in a pocket. I was a little worried hanging it from my neck. When I hike I notice the unit bounces from side to side. I thought the buttons would get mashed from it bouncing around while I walked. This is not the case though and I have not had any problems with this. I have also not had any problems with it residing in any pocket. The unit keeps excellent lock in a pocket while underneath thick canopy. This is one of the better features of the GPS unit.

I've downloaded lots of imagery and maps from Delorme's website. So far my favorite is the 1 m color aerial imagery.

Here is a list of the imagery available. The one piece of imagery I do not use are the NOAA Charts. They are kind of hard to use being landlocked in Colorado. They are more for coastal areas.
USGS 1:24K Quad Maps are scanned raster maps made from the original USGS topographic maps and were acquired between 1995-1998.
SAT-10 Maps are 10-meter resolution natural color satellite imagery and was acquired in 2001.
DeLorme Color DOQQs consists of 1-meter color imagery and was acquired in 2005.
USGS DOQQ Maps are 1-meter resolution Black-and-White (grayscale) aerial imagery and was acquired between 1992 - 2003.
High Resolution City imagery consists of high resolution (approximately 1 foot) color orthoimagery and was acquired in 2002. (About 50 geographic areas available for this.)

I can download the imagery from inside the Topo 7.0 software via the netlink tab. Each section I click for download contains 3 square kilometers of data (this does not change no matter what type of imagery I select). There are over 300 sections I can download for my city alone. Needless to say I have not downloaded them all, and they could take a while. I've downloaded about 85 sections alone just for the 1 meter color aerial imagery. This equates to a box that measures about 12 miles (19 km) east to west and 10 miles (16 km) north to south. I have to do this for each type of imagery that I want. Each 3 square km of imagery is different sizes though, and this leads to different download times.

The Hi res city imagery is the largest at 19.5 MB per section. The next is 1 meter color imagery at 1.04 MB per section. The 1 meter black and white imagery comes in at .54 MB per section. The USGS quads are .08 MB per section and the 10 meter satellite imagery is .03 MB per section.

In my initial report I noted I updated the firmware two versions to 2.5 beta. Now I notice that the regular edition of 2.5 is out. I will download it and report on it for the LTR portion of my test. I just find it odd that another version is ready within 2 months of me using this GPS. I went years without upgrading firmware in my old GPS and this one adds some functionality for geocaching, which should be cool.

One thing I have not figured out with the Topo 7.0 computer software, is how to make it start up in my area of the US. Every time it starts, it goes to somewhere in New Hampshire. I've even gone in and changed settings, telling it my coordinates, but still no joy.

On the GPS itself I can show the different imagery layers from the TOPO 7.0 display through all layers of the downloadable imagery. I can also specify at what zoom levels on the GPS what imagery I want to see. Another cool feature is an overlay function called hybrid map. This overlays topographic lines and trails and such over the imagery. Sometimes though in steeper sections of mountains it can be a bit cluttering.

On the GPS itself I can display the maps at different zoom levels. I can also change the how the GPS displays the zoom levels. One display is a standard scale bar. It shows a certain length of bar, and gives a scale above it as to how many feet it is. Kind of like a scale on a map. Another way I can display the zoom is through a ratio. Basically just like my maps, it will tell me what resolution level I am at. 1:6K, 1:24K, etc. The third option is an actual zooom level. I equate these to the zoom levels within TOPO 7.0 it shows the same type of level, like level 10, 11, 12.


So far I realy like this gps. Its very easy to transfer geocaches to the unit with the send to gps function. My favorite aerial imagery is the 1 meter color resolution. Since the data cable has been replaced I have not had any problems with the gps like I did before. It acquires satellites faster than any unit I have used and it holds lock very well.

This concludes my field report.



Over the course of four months, I have used this GPS in many different environments. Anything from day hiking, to geocaching, 4 wheeler riding, camping trips, fishing, and driving across country. Temperatures have ranged anywhere from around 45 F (7 C) to around 90 F (32 C), elevations have ranged from 7000 ft (2134 m) to 12,000 ft (3658 m).


Over 4 months of testing and I have upgraded the firmware twice now. I updated to the latest version of 2.5. The Delorme forum was a great help though as the listed exactly how to upgrade and what problems I would encounter. The directions according to the forums were " Upon the first reboot after the update, all you will see is Sat #120. Allow the device to acquire a 3-D Fix. This might take a little longer than usual, as it is downloading GPS data from scratch. Once you have a 3-D fix, reboot. You should now see a normal constellation, with 138 instead of 120."

It looks like now there is a version 2.6 out. I have not noticed a reason to upgrade though at this time.

The note from the forums worked exactly like it says it would. It also reset some preferences, but it did not delete any of my geocaches/waypoints, which made me very happy. It was great to have information like this to walk me through the procedure.

I noted in the previous reports that the new firmware supported geocaching. All I have to do is click the "Send to GPS" tab on the geocaching web page. It is totally paperless, no more third party software to manage caches with, no more carrying my PDA along with a GPS, I just have one thing with all the information I need to find the cache. While I am out in the field, the new firmware gives me the option to log the geocaches out in the field, and has an option to navigate to the next closest cache. When I get home, I can connect to the geocache site, and upload any field notes and found status. I found it painfully slow to type in all my field notes while in the field. Then I found that I could edit the field notes on the computer before uploading to the website. Now I just add the note TFTC Thanks for the Cache, and then edit my notes before posting to the geocaching website.

This GPS is the most accurate GPS I have seen! On a lot of my caches the GPS said I was within 1 foot (.3 M) of the cache, and I was literally right on top of it. I've never been that close to a cache before with a GPS.

The one thing I am not happy with is battery life. The longest time I got out of the unit was right at 6 hours. I know a lot of people that hike longer than that, and I like to have the GPS track me while hiking so I can download the track when I get back to the computer. One of the problems I did have though was with in the battery compartment. There are springs that hold the batteries in place and connect to the positive and negative end of the batteries. I noticed one time while changing batteries, that I had flattened the springs and the batteries were not making contact with the metal to provide power to the unit. I had to pull the spring back out so it made contact again.

The PN 40 holds lock really well. I have had it hold lock while packed numerous pockets, under trees, in rock canyons, and even inside my house. I am very impressed with the antenna in this unit. My favorite map to use is the 1 meter color imagery. I have used the Sat 10 Imagery, and found that to be better suited for a large area like Los Angeles, Ca when I was driving out there.


This is one of the coolest GPS units I have ever used. It is feature packed and very easy to use!

In the end the things I really liked are:
Geocaching feature
Multiple Maps/imagery
GPS lock

Things I do not like are:
Battery Life
Battery Life
Battery Life

This concludes my reports on the Delorme PN 40. Thanks to Delorme and Backpackgeartest for allowing me to participate in this test.

This report was created with the Report Writer Version 1.5 Copyright 2009. All rights reserved.

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