TECH NOTES;

The following are technical notes contain updates for various systems and helpful diagnostic tips not contained in all manuals.

A useful diagnostic tool for systems where the drive unit is unresponsive or responding incorrectly is to;

1. Remove all five wires that connect the drive at the rear of the control unit.

2. Turn on the pilot.

3. Connect a volt meter between pins 6 and 7.

4a. Swing the course setting knob ( on 3000 systems) port or starboard of the present ships heading and observe the voltage

On the volt meter. It should be approximately equal to the supply voltage when significantly off course and should drop to zero as the knob is rotated through the present heading and then rise to supply voltage but of opposite polarity when the knob is again significantly off course to the other tack.

4b. On 4404 systems select helm mode and swing the helm knob port or starboard of the center helm position and observe the voltage on the volt meter. It should be approximately equal to the supply voltage. As the knob is rotated through the center helm position the voltage should drop to zero and then rise to supply voltage but of opposite polarity when the knob is again significantly off the center helm position but on the other tack.

Systems which fail to turn on may not have suffered a failure. In the Spectra CPU the boards are inter connected via a 26 pin connector. This connector, located on the board edge opposite where wire connections are made can become disconnected if excessive force is put on the wiring board edge. The solution is to either press down on the 26 pin connector or remove the boards and reinstall them.

On systems utilizing the C I/O computer interface card, it is recommended that this be removed if it is not connected to the external control switches and computer as this can, under some circumstances, cause a degradation in performance.

If you are having difficulty engaging the pilot you might try the following procedure.

1. Adjust the "tension lock" the knurled nut below the T handle tight enough so that the handle will stay out " latch engaged" tight enough that when you rotate the helm it does not pull the handle in, but not so tight that you can not push to disengage.

2. Sail the boat on the heading you wish to hold.

3. Set the course setting knob to a heading below the course you wish to hold and turn on the pilot.

3. Pull out the Morse handle to engage.

4. slowly rotate the course knob until the latch locks the pilot to the steering.

5. fine tune the heading using the helm knob.

6. If the Auto-trim (TM) system is on, you may have to readjust the course knob as the pilot "learns" how much lea or weather helm is required to trim out the vessel.

Note: It has been found that when sailing down wind, especially in following seas that pilot performance is optimal with the Yaw control at or near minimum and the Auto-trim ( TM) system turned off.

TUNING FOR MAXIMUM PERFORMANCE

Compass Gain - This control can be used to optimize steering performance. The most straight forward way of doing this is as follows.

Set the yaw control to minimum.

Get the vessel to it's maximum speed. This may be under engine or it could be surfing on a wave but no matter what the circumstance the optimum system performance is always adjusted at the highest vessel speed. Under these conditions quickly alter course at least ten degrees. The vessel should come to the new heading and steady up on the new heading with just one overshoot. If the pilot overshoots more than once turn the compass gain toward minimum. If the pilot is sluggish to respond, turn the compass gain toward maximum.

If the pilot subsequently fails to perform properly make sure that nothing is affecting the compass sensor. If you find the vessel is now in a condition where the speed is greater than when the control was set, repeat the procedure. If you have made a large latitude or longitude change you may have to repeat the procedure.