Garmin Geko 201

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Intrigued by Garmin's Geko 201 Personal Navigator®? It's smaller than an eTrex and dwarfed by its big brother, a GPSMAP 76S (below).

First, the Geko is a serious GPS receiver. It features WAAS differential correction; memory for 500 waypoints, twenty routes, a whopping 10,000 track points and ten saved tracks; and it connects to external power or to your PC for data transfer with an optional cable. It floats. The array of five buttons is easy to use. The screen is small (about a third of the screen dimensions of the GPSMAP 76), but it's not hard to read. Menu choices allow configuration of the data screens to your liking. The back is rubberized, and so you can lay it on your dashboard and not have it slide around. Using only two AAA batteries, the unit is light as well as small enough to fit in a shirt pocket (but the limited power supply may be an issue for some as explained below).

The Geko also has four built-in GPS games, a novelty to emphasize that GPS can be fun. Interestingly, the Geko games are similar to serious field data collection methods that use GPS to follow pre-designed waypoint grids.

The Geko doesn't show base maps but is adept at recording points and lines. If you want a GPS unit primarily for hiking or recording locations, the absence of base maps isn't that significant. Fact is that the base maps in many GPS units don't provide enough detail (unless you can download more features from a CD) to be of much use at a close-in scale. If you wish to see highway maps when you are traveling, the Geko easily connects to a PDA or laptop computer to display your location in inexpensive navigation programs or projected on aerial photos. (Check out Vito Smart Map, or Delorme XMap Handheld Pro, inexpensive Pocket PC programs that turn the Geko into a sophisticated mapping receiver.)

The Geko utilizes a built-in "patch" antenna (a square plate inside the unit, located under the lizard logo). It works best in a horizontal orientation (the top edge of the unit pointed to the horizon). That way the antenna can look up to the sky. The Geko provides remarkable GPS satellite reception while held naturally in your hand or laid on your car's dashboard. The Geko is more comfortable to hold than the larger GPS 76 series (which uses a quad-helix antenna that works best in a vertical position with the unit's top edge pointed at the sky).

As an experiment, I took both the GPSMAP 76 and the Geko 201 (one in my left hand, the other in my right) on a hike through a forest. The tree leaves weren't out yet (mid-March in Wisconsin), but the timber on the test site is large and the terrain hilly. I wanted to see if the Geko could hold a track in a wooded situation.

The tracks of the two units appear to the right. The GPSMAP 76S track is the wide purple line, while the Geko track is yellow. I started out with WAAS turned on for both units; but since the differential correction signal was lost as soon as I stepped into the woods, I turned it off on the Geko to preserve battery power.

My surprise back home when I downloaded the tracks into OziExplorer was how similarly the two units performed. As shown on the right, the tracks lay directly on top of each other. The Geko experienced a small spike and break in the track near waypoint 059, but overall had no problem holding a signal. I also walked through a dense pine plantation. Although the signal strength dropped for both units, neither had any problem maintaining a position in this test. (Results, of course, could be less favorable under heavy summer foliage, less attention to holding the unit properly or other factors.)

On the highway, the Geko actually recorded a better track than the GPSMAP 76S. The reason was that both units were laying flat on the dash. The Geko works better in that orientation (although the GPS 76 will accept an external antenna if needed whereas a Geko cannot).

Garmin claims that two AAA alkaline batteries can last up to twelve hours (on battery saver mode). For economy, however, I use NiMH rechargeable batteries. I know that NiMH power cells don't last as long as alkaline in GPS units, but the duration of my 600 mAh batteries was far shorter than I expected ― only 40 minutes set on standard mode in 32° F March weather. At 60° F (~16° C) the Geko ran just two hours in standard mode. It operated five and a half hours in battery saver mode with NiMH batteries on the warm dashboard of my car. [Note: Manufactures are  constantly improving the mAh rating of their cells. 800 mAh AAA cells are now available, which should provide better performance than I've listed here.]


Since the Geko has a port for an external power supply, an extra $29 cable will let you plug it into a 12-volt cigarette lighter receptacle. If you are away from your car for a long time, as on a camping trip, you can use the Geko and power cable with a portable 12-volt battery pack (relatively inexpensive at $30-$50).

For a much lighter external power source, online retailer CycoActive offers a 3-volt C-cell power kit for Geko 201 and eTrex GPS units. It is practical to carry in a GPS case or on a belt (or under your coat in the winter). The C-cell pack is said to last three times longer than AA batteries in an eTrex, and probably longer still in a Geko. You can wire the cable so the battery powers the Geko and the Geko sends GPS data to a PDA or PC. Check out the wiring diagram for a Garmin 17N (p. 9) if you want to know how to attach GPS wires from a CycoActive cable to a DB9 serial connector and a battery. A circuit continuity probe ($2) will help you tell which wire is which. (My battery box, which doesn't come with the kit, is a traveler's plastic soap box.)

I've found that the watertight Geko serves as an external GPS antenna for a navigation program that I use on my iPAQ Pocket PC (Vito Navigator). I've mounted the Geko on a 2.5' wooden pole attached to a backpack. Using a PC interface cable with 12-volt cigarette lighter adapter or the C-cell setup described above, the Geko draws power from a battery in the backpack and sends spatial data to the iPAQ.

With the Geko used as an external GPS antenna, I can use the iPAQ for both forest inventory collection and real-time mapping without juggling both a GPS unit and the iPAQ data recorder. Another advantage to putting the Geko on the pole is that I no longer need to worry about keeping it oriented for good signal reception. The horizontal mount on the pole is optimal and hands-free.

The "Geko on a pole" approach (about $200 including the GPS, cables and an external battery) works like commercial GPS antenna/backpack setups that cost considerably more. As shown in the photo, the construction is simple. The Geko attaches to a plastic switch plate with a screw (meant for a bicycle handlebar mount) and a rubber band. Hot glue and another screw attach the plate to the pole. Remove the screw and the rubber band to use the Geko solo.



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