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Recently I held a GPS navigation seminar at a Cabalas’ store in Oregon. At one point during the seminar one man described the inaccuracy of his GPS and asked what he could do about it. He was frustrated that on several occasions while returning to camp the GPS compass arrow (while in the “Find,” “Where to” mode) was providing unreliable information. He’d arrive in camp and the receiver would direct him in a new direction and distance.

As he related his story, I noticed that several other attendees nodded in agreement that they too had the same problem. I asked the fellow if he had ever calibrated the electronic compass. “Yes, when I first got the GPS,” was his reply.

I explained that the electronic compass should be calibrated after EVERY battery change. That’s right, every time you replace those batteries, the electronic compass needs calibration.

Most of the top of the line GPS receivers come with an electronic compass. The electronic compass moves and operates seemingly like a traditional magnetic compass. This is different than the original compass page on older units like the Magellan 315, Garmin 12, Yellow eTrek (the $100 model) and early DeLorme receivers. These units will provide compass information but you must move to get accurate information. Movement updates position and heading data.

Here is an example of how to calibrate the electronic compass of the Garmin Map60CSx.

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  1. First select “compass page.”  You should see this screen.
  2. While on the compass page press the “menu” button one time; push and release.

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  1. Look for “Calibrate Compass.”
  2. On this menu page rocker down and select “calibrate” compass.  Follow the screen directions.

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Follow the manufactures owner’s manual instructions about the use of an electronic compass.  Keeping the receiver level is important in some models.

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I recommend verifying the GPS receiver’s direction information with a quality magnetic compass such as the Silva Ranger (515CL) or the Suunto M3 before going further.

Don’t forget to adjust the magnetic compass for declination.

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