autohelm 6000

il faut refaire la calibration du compas, mais comment, c'est une autre histoire...
Un extrait de la notice (en anglais, désolé)
Automatic compass deviation correction
The ST6000 Plus will correct the fluxgate compass for most deviating
magnetic fields. Compass errors due to deviating magnetic fields can
be up to 45°, depending on your vessel type. The correction procedure
reduces these to a few degrees, so it is essential to perform the
procedure as the first item in your initial sea trial.
CAUTION:
Failure to carry out the deviation correction may result in
impaired autopilot performance on some compass headings.
To allow the system to determine the deviation and calculate any
correction required, you must turn your vessel in slow circles. This
procedure must be carried out in calm conditions and preferably in flat
water.
To perform the deviation correction:
1. Make sure that the autopilot is in Standby mode .
2. Press and hold the standby key for 2 seconds to display the User
Setup entry page.
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If CAL LOCK is displayed, you need to turn off the lock feature
contained in Dealer Setup (see Chapter 5).
3. Press the disp key to move on to the Swing Compass page.
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64 ST6000 Plus Autopilot Control Unit Owner,s Handbook
4. Press the +1 or -1 key to change the setting from OFF to YES. The
Turn Boat page is then displayed.
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5. Keeping the boat speed below 2 knots, turn the vessel in slow
circles. It should take at least 3 minutes to complete 360°.
6. Keep turning your boat until the unit beeps and the Deviation
screen is displayed.
This shows the maximum deviation detected, and indicates that
compass correction has been completed successfully.
Note: If the deviation value exceeds 15°, you should consider moving
the fluxgate compass to a better location.
7. Press the disp key to move on to the Heading Alignment page.
Chapter 7: Post Installation Procedures 65
8. Use the +1 and -1 keys, or the +10 and -10 keys, to increase or
decrease the displayed heading, until it agrees with the ship?s
steering compass or a known transit bearing.
9. Press and hold standby for 2 seconds to exit calibration and save
the new settings.
Note: Setup options are always saved on exit.
Further heading alignment adjustment
You should always check the compass alignment after swinging the
compass. However, once the initial deviation correction procedure has
been performed, you can make adjustments to the alignment as often as
you wish, without swinging the compass again.
Although the compass deviation correction procedure removes most of
the alignment error, you will probably be left with small errors (of the
order of a few degrees) that will vary depending on the heading.
Ideally, you should check the heading reading against a number of
known headings, plot a deviation curve, and determine the heading
alignment value that will give the lowest average alignment error. This
value can then be entered on the Heading Alignment screen, as
described above.
If the average heading error is more than 5°, you should perform the
compass deviation correction procedure again.

Bon courage!