3-4
16. Choose HEADING DATA and then press the EDIT soft key.
HEADING DATA
▲
¡
MAGNETIC
¤
TRUE
▼
17. Choose the appropriate heading data format and then press the ENTER soft key. Select
MAGNETIC when connecting with a magnetic compass, or select TRUE when
connecting with a gyrocompass.
18. Choose ANTENNA ROTATION and then press the EDIT soft key.
ANTENNA ROTATION
▲
¡
ROTATE
¤
STOP
▼
19. Choose ROTATE and then press the ENTER soft key. This lets you perform the various
radar adjustments which follow.
20. Choose RADAR OPTIMIZATION and then press the EDIT soft key.
RADAR OPTIMIZATION
▲
¡
ON
¤
OFF
▼
21. Choose ON and then press the ENTER soft key. Then, the radar’s video and tuning are
automatically adjusted.
22. After optimization has been completed, choose TIMING ADJUST and then press the
EDIT soft key.
TIMING ADJUST
▲
¡
ON
¤
OFF
▼
This adjustment ensures proper radar performance, especially on short ranges. The
radar measures the time required for a transmitted echo to travel to the target and return
to the source. The received echo appears on the display based on this time. Thus, at
the instant the transmitter is fired, the sweep should start from the center of the display
(sometimes called sweep origin.)
A trigger pulse generated in the display unit goes to the antenna unit through the signal
cable to trigger the transmitter (magnetron). The time taken by the signal to travel up to
the antenna unit varies, depending largely on the length of signal cable. During this
period the display unit should wait before starting the sweep. When the display unit is
not adjusted correctly, the echoes from a straight local object (for example, a harbor wall
or straight pier) will not appear with straight edges – namely, they will be seen as
“pushed out” or “pulled in” near the picture center. The range of objects will also be
incorrectly shown.
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