Choosing GPS receivers and software

I don't know about you, but if you share my interests in GPS receivers for hiking, biking, geocaching, and driving you may find the following interesting.

First, I need a handheld receiver for at least three of the above, so that gets rid of in-dash and other fancy systems. Those activities are can be tough on gear, so I don't want to depend on things like my iPaq. It's too delicate and if it breaks I loose much more than a GPS receiver.

Of the handhelds, Garmin makes the biggest line and I've found them much more intutive to use than Magellen receivers. Of the Garmins, there's a wide range of price and features. The more expensive models have road maps, exit services, etc., but I've concluded they aren't for me despite by interest in using GPS while driving.


Consider a good road map. Generally the bigger the better, but that's to make up for paper's problem of having everything there. Book format maps work, as long as you don't have to flip across map boundaries. Below that size, things become frustratingly small. It's hard to get a sense of the area you're passing through, you spend a lot of time looking at nearby areas, etc. That's a problem with almost any GPS receiver. While they do a great job telling you exactly where you are, I like to see all the nearby roads, and the nearest major highways too.

My iPaq's screen is too small for that, so my preference is to have a laptop computer handy. That's too bulky for a lot of stuff, so it's not ideal, perhaps the new "tablets" will be a good compromise. In practice I use my GPS II+ in familiar areas, that plus iPaq often in unfamiiar areas, and laptop sometimes on long trips.

I conclude that I don't need a GPS receiver that has maps.


Many Geocaching pages have logs that mention people's GPS receivers had trouble getting a fix under dense foliage. Some cache pages actually report a higher than normal difficulty due to the foliage. In many cases, my GPS II+ with its external quadrifiliar antenna shrugged off the foliage and worked fine, so I like that better than the more rugged "patch" antenna used in the Etrexes. On the other hand, a test at a forested site shows there was little difference betwen the two. Interestingly, it also shows the GPS III+ was more accurate than the Etrex in a open sky site. I'd like to see a study that looks at more degrees of "forested".

Garmin's external antenna is removable, and you can plug in a powered remote antenna. This is really handy in a car as the antenna has a magnetic mount. I can put it on the roof and get great reception inside the car without having to worry about the metal roof. The downside is that there is enough flex in the BNC jack and so little in the coax inside the receiver that the signal wire broke. My receiver is held together with six small screws, so I was able to repair it - several times. The most recent repair replaced the coax inside from jack to circuit board and seems to have finally done the trick.

I consider this a design flaw, I don't know if Garmin has fixed it. I was very careful to minimize lateral forces when changing antennae, however, I'm still glad to have the external antenna - and good soldering skills!

So, what makes sense to buy? Prices below are from The GPS Store. I haven't dealt with them, their prices are better than Garmin's MSRP, the most useful information is the approximate price and relative price between units.


When getting close to a geocache, I try to follow the bearing to the cache. Within 50-100 feet I watch the latitude and longitude display and manuever to getting the milli-minutes to match. One milli-minute of latitude is about 6 feet. At my latitude, a milli-minute of longitude is 4-5 feet. I prefer using UTM, but am usually too lazy to do the conversion.

What gets interesting is the preparation for finding a cache. has the detail pages and those have the coordinates. That's mostly fine at home. What I want on the road are waypoints in my GPS receiver and the HTML files on my iPaq. When I travel through an unfamiliar area and have time to stop for a cache, those are vital. Also, it's a task a passenger can do on a long trip instead of doing all the preparation at home.

If you have an account at, you can download groups of waypoints to a PC via EasyGPS, and then use it to upload to the GPS receiver. Not very convenient, but it works. Then I can use Delorme's Street Atlas or Topo programs to copy the waypoints to them.

I can readily save individual cache WWW pages via Netscape and save them where ActiveSync will get them uploaded to my iPaq.

I'm working on a Python script that will get all the cache pages for a state, create an index page, and get them all staged to be loaded into the iPaq. It will also create a waypoint file that Teletype's GPS program can understand so I can see waypoints on all the toys. I haven't quite decided how I want to automate the GPS receiver update, though.

Note that the iPaq suddenly becomes a useful device to bring geocaching. By relying mostly on the GPS receiver I can keep the iPaq protected in a pack and just pull it out to check the WWW page. However, Teletype does have something where you can scan part of a topo map and display that, and Delorme's newest Topo program can pass maps to their new Xmap Handheld program. Not that I'd ever want to become obsessed over all this....

Contact Ric Werme or return to his home page.

Last updated 2002 June 22.