Garmin TR-1 GOLD 906-2000-00 Benutzerhandbuch

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4. 
Set North:  You must do this, if the autopilot is connected to the GPS.
To run a GPS course requires that the autopilot compass is in agreement with the GPS’s course estimate.  You need to set 
North with the pilot in standby mode.  Do not set North except in calm sea’s and un-accelerated conditions.  You should 
be running at a reasonably high speed, it won’t hurt to be running on plane with your main engine.  With your GPS turned 
on and setup code 48 selected, press and hold the 
GPS (Select Load) button. 
If the 
Up Arrow LED illuminates, this means that your GPS connection is not sending course information to the autopilot 
correctly.  You must point your boat north and then press and release the 
Deckmount switch to set compass north.
If the 
Up Arrow LED does not illuminate, press and release the Deckmount switch to set compass north.  In this case you 
do not need to be pointing north-you only need to be going in a straight line.
Your pilot will power down after north has been set.
Rudder and Counter Rudder Gain.
Let’s assume that you pushed the Auto button when the boat was heading 45 degrees and that  after a 
few seconds your boat has been turned, by wind, to a heading of 55 degrees.  The autopilot (and you) 
know that you are trying to steer to 45 degrees and that your current heading is in error by ten degrees to 
the starboard.  How much port rudder do you suspect is the right amount to steer to bring the boat back 
to 45 degrees in a reasonable time?  Loaded question!  The amount of rudder required depends on many  
variables like hull shape, boat loading, how fast the rudder can move, boat speed through the water, and 
more.  If we had numerical values for all the variables affecting the required rudder deflection, we could 
calculate the required rudder gain and apply it with the rule:  Rudder is applied in proportion to heading 
error and the proportional constant is rudder gain. 
Since we can’t make a very good guess at what value Rudder Gain should take, we have to adopt a cut 
and try approach to finding the proper value.  Fortunately, we can provide some guidelines as to how the 
system behaves when the Rudder Gain is too large and when it is too small.
Counter rudder is rudder applied to oppose turning.  It is used to “damp” heading changes and is more 
responsive to disturbances in heading than the proportional rudder deflections caused by heading error.  
Counter Rudder is applied in proportion to the rate of turn, as measured by the gyroscope, and the 
proportionality constant is Counter Rudder Gain. We can provide some guidelines as to how the system 
behaves when the Counter Rudder Gain is too large and when it is too small.
A good way to hunt for the proper Rudder and Counter Rudder Gains is by commanding the autopilot 
to change heading and watch the heading response.  The following plot shows how a boat responds in 
heading when it is set up real well.  At time = 0 the 
Straight Right Arrow button was rapidly pressed 
and released five times, the boat heading was initially 0 degrees, in a few seconds the boat heading is 
steady on 5 degrees.  Tuning should be done with no more than a light breeze and riffles on the water.  
Tuning should be done in forward gear.