NorthStar Navigation Multi-Function Unit M84 - Manual (Page 79)

Northstar M121/M84 Installation and Operation Manual 78
Heading line
The heading line is a white line that extends
from your boat to the edge of the radar
window.
Show the heading line.
Hide the heading line.
19-4-1 Setup > Radar > Installation
Note: This option is shown only when the radar
is enabled (see Section 18-3)
1 Press MENU twice to display the Setup
menu, then select Radar.
2 Select Installation:
Park position
If your radar has an open array and you
take it out of enabled mode, the open array
continues to rotate for a short distance before
it finally stops. The stop position is known as
the park position. You can adjust the angle of
the parking position so that the open array
will always stop at your preferred position; for
example, facing the bow.
1 Select Park position then enter the angle of
the new park position.
Note: You may need to try a few different park
positions to find the correct one. The strength
of the wind will also affect the park position.
Zero bearing
Use the zero bearing alignment to rotate the
radar image, one degree at a time, so that a
known object dead ahead is directly under the
boat’s heading marker.
This means that the radar image is aligned
with the displayed chart and the compass.
An accurate bearing alignment is particularly
important when the radar image is overlaid
onto the chart.
Adjust this on a chart window with the radar
overlay on.
1 Select Zero bearing then use the arrow keys
to enter the new bearing angle.
Zero range
The zero range is also known as the radar range
offset and as the trigger delay.
If your radar window shows a blank, black circle
around the centre or a solid circle of color at
the centre, you need to adjust the zero range
setting until this circle disappears or almost
disappears. Ideally, the radar sweep should start
at your boat (a radar range of zero).
To adjust the zero range setting:
1 Position your boat about 45 to 90 m (50
to 100 yards) away from and parallel to a
straight-walled jetty or similar feature.
2 Adjust the gain setting if necessary, so that a
reasonably good image of the jetty echo is
displayed on the radar window. At this stage,
the jetty echo may appear to be bent.
3 Select Zero range then use the arrow keys to
adjust the zero range setting until the jetty
echo appears as a straight line on the radar
window.
Antenna height
The Installation Manual for your Northstar radar
explains how to find the optimum height for
your radar scanner (antenna).
Select Antenna height then enter the height of
the antenna above sea level.