Furuno FMD-811 - Manual (Page 44)

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4.9 Sweep Timing
This adjustment ensures proper radar pic-
ture, especially on short ranges. The radar
measures the time required for a transmit-
ted 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 pic-
ture center. The range of objects will also
be incorrectly shown.
(1) Correct (2) Target pushed
inward
(3) Target pushed
outward
Figure 4-9 Examples of improper and
correct sweep timings
1) Transmit the radar on the shortest range
and adjust the sensitivity and STC.
2) Visually select a straight echo (harbor
wall, straight pier).
3) Display the Installation Setup 2 menu
and select Adjust Sweep Timing.
5) While looking at the target selected at
step 2, press cursor pad at the 9 o’clock
or 3 o’clock position to straighten the tar-
get.
6) Press the [ENT] key.
4.10 Closing the Installation
Menus
Press the [MENU] key and turn off the
power.
4.11 Signal Cable Connection
1. Connect the signal cable to DJ-1 on the
rear panel of the display unit.
Rubber cover
DJ Connector
Boot-band
Cable
Display unit DJ-1
2. Cover the connector with the rubber
cover. The projection on the connector
base is inserted into the groove on the
rubber cover.
Display unit
Rubber cover
Grasp Grasp
Groove
3. Put the boot-band as shown below, and
tighten it.
Display Unit
Boot-band