Heading indication rotates in sector area while boat makes 390 degree rotation : C.P.

[Sivaa]

Hi all ,

With NSS7 EVO3 Simrad Chart Plotter , A 2004 Auto pilot controller & Precision 9 heading sensor and external GPS through NMEA 2000 ; the configuration was working .

Recently , it had a problem . Heading indicator doesn't align with boat's heading . Heading sensor was changed with new one . Despite different orientation, observations remained same .

With boat's heading as 359 if boat is tried to make compass calibration with a turning in starboard ; after 150 degrees , heading indicator reverses towards starting point and tends to come again towards 150 ° . Calibration could not get completed . CoG is good when compared with old chart plotter ( Only with GPS ) .

GPS performance , device list selection in auto pilot supports the configuration . What else , should I note ? Your observations and guidance can be useful in this situation . Awaiting for the same . Regards .

[Sivaa]

Based on SIMRAD help & support centre guidance - heading sensor position was changed and calibration procedure for Compass was completed . Local magnetic field strength is expected between 15 - 20 % . Installation location was with 48% .

Now , present mounted location with different positions of lumber line gives the range from 9 to 23 % of local field strength . With 15% , it is set . After a month , to be observed for variations - if any .

For references . Regards .