Here are some things to keep in mind when using the Garmin 76 GPS receiver.
- If the receiver hasn’t been used for a few weeks or more it will take longer to boot up. It needs to download a new almanac before it can get situated. Remember that Garmin receivers don’t give you access to the almanac.
- The built-in antenna is at the top of the receiver. To get a signal the antenna has to have a clear view of the sky.
- You are more likely to get a good signal if you point to the southern sky, since we are well up in the northern hemisphere.
- The GPS receiver has its own internal coordinate system. It can convert to almost any coordinate system commonly used. You can later change your data to any coordinate system you need.
- It’s best to stick to the WGS 84 datum as that is the one most commonly used with current maps. When you first use a receiver it’s best to check the datum to avoid errors of up to 200 meters!
- The receiver will work under any weather conditions. It’s not waterproof, so it should be protected in a heavy rain. Try a clear plastic bag. In below freezing conditions the batteries can lose power. Also, the LCD screen will not work as well in the cold.
Here is the data you can store on the GPS. The Garmins we use are considered recreation grade. Other brands may use different names, but they all do about the same thing.
- Waypoint — a stored location in memory. The 76 can hold up to 500. You can increase the accuracy of the waypoint by averaging while you store it. You can also give it a unique name and choose a marker.
- Route — a directed collection of waypoints that make a path. You can create a route as you save the waypoints or you can create it afterward. A route can be navigated in the original or reverse order.
- Track — the saved path made as you walk with the receiver. It is analogous to the breadcrumb trail of Hansel and Gretel. In the setup menu you can change how often and how far apart the track points are recorded. You can also save tracks as individual files. Tracks will show up on the maps screen as you work.
Each of these data types can be downloaded to mapping software. In some packages they can be composed on a computer and upload them to the GPS to use in the field.