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Test all the batteries you plan on taking with you before setting off. You can use a simple battery meter (see Figure 11-24), available from photographic outlets and other electrical stores.
FIGURE 11-24: Battery tester
Better Antennas
If you don’t have good satellite reception, then geocaching is a no-no. Usually, when outdoors you get pretty good reception, but if you have to travel into tree-covered areas or valleys, you may find it easier if you take steps to improve the reception of your GPS receiver. There are two things you can do.
The first is to use an external antenna, like the one shown in Figure 11-25, which is designed for the Garmin GPS III, GPS III+, and GPS V.
These antennas either replace the existing antenna or connect to a separate socket. Along with the upside of better reception, there are downsides. While they are usually much better than built-in antennas when under the cover of trees or in areas where rock faces reduce the efficiency of the factory-shipped antenna, they do draw more power from the unit than the built-in antenna. This means that having additional power sources becomes vital.
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FIGURE 11-25: Lowe external antenna
Another option is to use a reradiating antenna, shown in Figure 11-26, which is a strong antenna for capturing the signal from the GPS satellites, which then retransmits it via a transmitter. The built-in antenna then picks up this amplified signal and gets a lock from that. The great thing about this is that if you geocache in a group, you can use the one reradiating antenna to work with several GPS receivers.
To use a reradiating antenna, you will need to use an external power supply (such as a 12-volt supply, or batteries, usually AA or 9-volt batteries) because it relies on this to amplify and retransmit the signal. This kind of setup is great in locations where you might otherwise not get a good satellite lock.
The drawbacks, however, are that this kind of setup is cumbersome, needs batteries, and requires a lot of cables that you need to keep under control. Again, careful use of tape and cable ties is essential.
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FIGURE 11-26: Reradiating antenna
Protecting the GPS
GPS receivers get quite a few knocks, bumps, and scrapes outdoors. They are quite robust and handle life outdoors pretty well, but you should still take a few precautions to ensure its safety. The following sections describe some steps you can take to do just that. In addition to protecting your unit from damage, you need to ensure that your GPS makes it home with you!
Protect Your GPS from Loss
“Found cache, took plastic toy, left GPS.”
This isn’t something that you read often in cache logs, but it does happen. The geocacher navigates to the cache paying close attention to the GPS unit on the way there. However, once they get to the cache, they lose interest in the GPS and put it down somewhere. They retrieve the cache, do a swap, fill in the logbook, and then replace the cache and leave — without the GPS.
It may seem unlikely but it isn’t. Unless you’re made of money, or have access to a lot of units, take steps to protect your GPS from loss. Here are some simple steps that you can take:
Tie It to Yourself
It seems simple and obvious, but this is the best way to prevent loss. Most people use a wrist lanyard, but this can become awkward. It’s far better to tie it to a convenient loop on your jacket or pants. Use strong parachute cord for this job.
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Hanging a GPS from a cord around your neck is not recommended, as it presents a grave danger to you if it snags on a branch while you are moving through undergrowth. If you want to hang a GPS around your neck, use a ball chain (such as those used with military dog tags) that will break away under pressure. However, remember that if the chain does break away, your GPS will end up on the ground!
Add Contact Details
Add your contact details to the startup screen of your unit, as shown in Figure 11-27. Many units enable you to do this. It doesn’t prevent you from losing the GPS receiver, but many people have had their units returned to them by honest geocachers because they did this. If possible, add the same information to any case in which your gear is carried.
FIGURE 11-27: Contact details on the GPS
Make It Easier to Spot
Drop your GPS receiver onto leaf-covered ground, and I’ll guarantee you that you’ll have a hard time finding it. Drop it at night and it’ll be even harder, if not impossible, to find. You have several simple options for making your unit easier to see.
One of the easiest things to do is add a piece of reflective tape to the lanyard, as shown in Figure 11-28.
Alternatively, you could replace the parachute cord lanyard with cord that contains a reflective strand within the cord, as shown in Figure 11-29.
Both of these work great. If you drop your GPS unit, all you need to do is shine your flashlight around and you are bound to find it. If you want a system that doesn’t rely on reflective tape or cord, you can add an always-on light source to your GPS by adding a Glowring, shown in Figure 11-30.
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FIGURE 11-28: Reflective tape on the lanyard
FIGURE 11-29: Reflective cord
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FIGURE 11-30: A Glowring
Glowrings are designed to be attached to key rings to make them easy to find in the dark. They work because they contain a tiny vial of radioactive tritium gas. This radioactive gas emits electrons as it decays, and these electrons strike the phosphorescent coating inside the vial, causing a faint glow of light to be emitted. These devices have a very long life span (over ten years) and require no maintenance.
Glowrings come in a variety of colors, but green is usually the brightest.
All you need to do to add a Glowring element to your GPS is get yourself one (do an Internet search, which will bring up a whole raft of suppliers) and some good glue (epoxy is best).
When you get the Glowring, take a sharp knife and carefully split the casing in half along the join, as shown in Figure 11-31.
This exposes the fragile glass vial containing the tritium. Take great care not to break this! Set it aside safely for a moment.
When you have the two halves, carefully remove the lug from one of the halves to make a flat surface.
Epoxy the plastic, along with the glass vial, to the GPS case, as shown in Figure 11-32. Don’t glue it to the screen, to the buttons, or over the antenna. Anywhere else should be fine.
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FIGURE 11-31: Splitting the outer case of the Glowring
FIGURE 11-32: Attaching the Glowring
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Leave the glue to settle and dry (consult the instructions for the adhesive) before using the GPS. Once it is hard, you can use the GPS with the new glowlight!
Protect the Screen
The screen is a vulnerable point on the GPS. There’s not much you can do to protect the screen from extremely heavy impact unless you get case designed for that purpose (such as those made by Otter; www.otterbox.com), but you can take steps to protect the screen from scuffs, scratches, and light damage. This topie is also discussed in Chapter 5, “Protecting Your GPS.”
To protect it from bumps, the trick of adding a few dots of silicone sealant to the corners really helps, as does gluing on small rubber bumpers, as shown in Figure 11-33.
If you want to protect the screen from scratches, you can always get a set of screen protectors designed for a PDA, such as the iPAQ. These screen protectors are thin, plastic sheets with a light, easily removable adhesive as a backing. You will need to cut the screen protector to the appropriate size using a pair of scissors before sticking it on because you are unlikely to find any that fit your GPS screen exactly.
A good place to keep a GPS when not in use is a belt pouch. This way, you protect it from the scratches it will inevitably pick up in pockets and from the possibility of damage if you step on it while walking.
FIGURE 11-33: Rubber bumpers add simple screen protection.
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Power Protection
A sudden jolt to the GPS receiver can cause the batteries to shift, causing it to lose power and switch off. This can be really annoying when you are on the move because you’ll have to go through the restart process again. Protect against this by adding a small bit of foam behind the battery compartment door to cushion them, as shown in Figure 11-34.
FIGURE 11-34: Pad the battery compartment to prevent power loss.
Waterproofing
The easiest way to waterproof your GPS for geocaching is to use a specially designed case for the job (see Chapter 5).
Some of the best cases come from a company called Aquapac (www.aquapac.net), which makes some superb cases for both GPS units and PDAs. They even make cases that have a special waterproof opening for cables, and stylus holders for PDAs.
Figure 11-35 shows a case designed for an iPAQ that has a waterproof outlet for cables. This is ideal for connecting the iPAQ to a GPS via a cable connection.