AutoHelm ST 2000 Plus - Comcast.net

Chapter 6: Adjusting Tiller Pilot Settings 65Calibration Level 9: magnetic variationUse Calibration Level 9 to input the level of magnetic variationpresent at the boat’s current position.• -ve variation = west• +ve variation = eastThe tiller pilot transmits this value onto the SeaTalk bus, so it can bepicked up by other SeaTalk instruments.Calibration Level 10: heading error correctionUse Calibration Level 10 to switch on Northerly or Southerly headingerror correction:• 0 = Off• 1 = Northern Hemisphere, 2 = Southern HemisphereYou might notice that the autopilot tends to be a little less stable onNortherly headings in the higher latitudes of the Northern hemisphere(or Southerly headings in the Southern hemisphere).This is caused by the increasing angle of dip of the earth’s magneticfield at higher latitudes, which has the effect of amplifying rudderresponse on Northerly (Southerly) headings. This error affects allmagnetic compasses and gets worse further away from the equator.With heading error correction switched on, the tiller pilot cancompensate for this error by automatically adjusting the autopilotgain (depending on heading). This will provide precise coursekeeping on all headings.6 Adjusting Tiller Pilot SettingsNorthNorthwithoutcompensationwithcompensationD3263-2