ST40 Wind Cal
The linearization and calibration procedure is in the User Calibration section of the manual. This text along with the flow diagram should get you through the wind calibration procedure. Hold in the DOWN ARROW and the DOT KEY until the display says USER CAL. You then used the DOT KEY to scroll through the calibration options until the display says TURN. Start turning is circles at about 3 knots taking about two minutes to complete. Then press the UP ARROW momentarily to enter the unit into the linearization procedure. It will sound a tone for one second and the display will change to ADJ and an indicate WIND HEADING. You should then steam into the wind and align the flasher towards the bow using the UP and DOWN arrow keys. After adjusting this angle, hold in the DOWN ARROW and DOT KEYS to exit calibration and save your changes.