Yesterday a friend of mine and I made a road trip across California, into Nevada and back into California. He had his Garmin Map 76CSx and I had my 76Cx. His unit only had the base map, while mine was loaded with MapSource Topo USA and City Navigator v7. Because of a very busy workload my friend had not had time to work with his unit. And I had not experience with the electronic compass or altimeter. You might have called the day a gps training day for him and I.
The 76CSx gives the user the option of using the electronic compass or the gps compass. The electronic compass was not initially functional on his unit because he had installed fresh NiMH batteries in it before leaving. He had been running alkaline batteries in his unit. We went into Setup and changed the battery type to NiMH. But once we got into my pickup I pulled out my 12v power adapter for that fits his unit and we plugged it into vehicle power source. This powers the gps, and does not recharge the batteries.
Both of us selected a location a city (town) in Nevada that we were headed for and the pointer of My Compass page pointed in the direction we were going to travel. His electronic compass did not show a pointer. The users of Garmin CSx units have the choice of selecting the electronic compass or selecting the gps compass (satellite). The advantage of using other Garmin gps units gave me a clue on how to resolve the problem. On the compass page hit the menu button and it provides a number of options. Select the Calibrate Compass option. It then takes you through the process, hold the compass level and slowly turn the compass. It will tell (on screen) you if you are turning it to fast, to slow, or just right. You will then receive a message Calibration Successful or Calibration Failed. It took less then five minutes and two tries and I got the message Calibration Successful.
The Compass Pointer appeared and we were in good shape. In fact I like the electronic compass because it will change when you are moving slow. Back in the Blue Garmin Legend days I had to be moving about two miles and hour. With my 76Cx I must be moving about one mile an hour to get the pointer to move. One of my early objections to electronic compasses was that they were a big power drain on the gps. But newer units with improved chips have reduced power consumption and I no longer see it as an issue with the Garmin CSx models. The difference in early models had the Electronic Compass and Altimeter units using an extra thirty percent battery power.
We stopped at a mountain summit with an elevation marker. I have verified the elevation on topographic maps. I expected my 76Cx not to be on the money; in fact it was fifty-eight feet short of the correct elevation. The 76CSx was showing a different elevation but it was also incorrect. The next step was to calibrate the Altimeter. The unit gives you two ways to calibrate it, one if you know the elevation, and the other if you do not know the elevation. We first tried it using the unknown elevation option. It was not close; in my mind close is a few feet plus or minus. I then tried the known elevation option and almost fifty feet off. I just checked a manual and it tells me that using the known elevation well increase the accuracy of the unit. Otherwise there is no claim to exact accuracy. So if you are out flying in you small plane and it clouds up do not depend on this altimeter to clear a mountaintop.
A note on using Satellite elevation, if you are receiving a group of satellites that are closely clustered your accuracy will not be as great as when you are receiving data from the same number of satellites widely scattered in space. Garmin says that satellite elevation can be off as much as four hundred feet.
Another friend, who would take advantage of the altimeter in his job, has become frustrated with the one in his 60CSx and depends other resources.
When you add a function to a gps the user needs to read the manual, and practice with it.
Aside from the Electronic Compass and the Altimeter, the two gps units provided us with other critical information. My friend riding in the passenger seat was watching the Map Screen on the both units as we crossed the Stateline into Nevada. The position arrow on his Base Map, and on my City Navigator Map showed our position in relationship to the State line. We had lunch over in Nevada and then returned to California by way of old pioneer roads, and logging roads. Again the gps units showed our location in relationship to the State line. Mr. Coyote was safe from me in Nevada, with my rifle in a locked case, and the ammunition store in the camper shell. But once we had crossed back into California Mr. Coyote became a legal item of interest. When we had left the pavement I had switched from the City Navigator map to the topo map in my gps.
In California many hunting Zone Boundaries are Main Haul logging roads, State Highways, and Interstate Freeways. Using the published boundary information from the Fish & Game, Forest Service and BLM maps, and MapSource Topo software on my gps my comfort level is up in regards to these boundaries. In one area I have added Google Earth Maps, with key waypoints to keep me of trouble.
The scary issue is that State lines do not follow roads; so depending on where I am hunting I can be in California, Oregon, or Nevada. The position arrow on my gps will help identify my location in relationship to the Stateline. Gps units are common in the rural law enforcement community.
