Furuno 841 MARK-2 ユーザーズマニュアル
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¡ The compass safe distance should be ob-
served to prevent deviation of the magnetic
compass.
compass.
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¡ Do not paint the radome to ensure proper
emission of the radar waves.
¡ When this radar is to be installed on larger
vessels, consider the following points:
(1) The signal cable run between the antenna
and the display comes in lengths of 10
m, 15 m, 20 m and 30 m. Whatever
length is used it must be unbroken;
namely, no splicing allowed.
m, 15 m, 20 m and 30 m. Whatever
length is used it must be unbroken;
namely, no splicing allowed.
(2) Deposits and fumes from a funnel or
other exhaust vent can adversely affect
the aerial performance and hot gases
may distort the radiator portion. The an-
tenna unit must not be mounted where
the temperature is more than 70
the aerial performance and hot gases
may distort the radiator portion. The an-
tenna unit must not be mounted where
the temperature is more than 70
°
C.
Mounting
Figure 5-1 Typical antenna unit location
Unpacking the antenna unit
1. Open the antenna unit packing box carefully.
2. Unbolt the four bolts at the base of the ra-
dome to remove the radome cover.
Radome cover
Figure 5-2 Antenna unit
5. INSTALLATION
This chapter provides the procedures neces-
sary for installation. Installation mainly con-
sists of the following:
sary for installation. Installation mainly con-
sists of the following:
¡ siting and mounting the display unit and
antenna unit
¡ connection of the signal cable and the power
cable
¡ establishing the ground
¡ checking the installation, and
¡ adjustments.
5.1 Antenna Unit Installation
Siting, handling considerations
¡ The antenna unit is generally installed either
on top of the wheelhouse or on the radar mast
on a suitable platform. Locate the antenna
unit where there is a good all-round view rig-
ging intercepting the scanning beam. Any
obstruction will cause shadow and blind sec-
tors. A mast for instance, with a diameter
considerably less than the width of the
radicator, will cause only a small blind sec-
tor, but a horizontal spreader or crosstrees in
the same horizontal plane as the antenna unit
would be a much more serious obstruction;
you would need to place the antenna unit well
above or below it.
on a suitable platform. Locate the antenna
unit where there is a good all-round view rig-
ging intercepting the scanning beam. Any
obstruction will cause shadow and blind sec-
tors. A mast for instance, with a diameter
considerably less than the width of the
radicator, will cause only a small blind sec-
tor, but a horizontal spreader or crosstrees in
the same horizontal plane as the antenna unit
would be a much more serious obstruction;
you would need to place the antenna unit well
above or below it.
¡ It is rarely possible to place the antenna unit
where a completely clear view in all direc-
tion is available. Thus, you should determine
the angular width and relative bearing of any
shadow sectors for their influence on the ra-
dar at the first opportunity after fitting. (The
method of determining blind and shadow
sectors appears later in this chapter.)
tion is available. Thus, you should determine
the angular width and relative bearing of any
shadow sectors for their influence on the ra-
dar at the first opportunity after fitting. (The
method of determining blind and shadow
sectors appears later in this chapter.)
¡ If you have a radio direction finder on your
boat, local its antenna clear of the antenna
unit, to prevent interference to the direction
finder. A separation of more than two meters
is recommended.
unit, to prevent interference to the direction
finder. A separation of more than two meters
is recommended.
¡ To lessen the chance of picking up electrical
interference, avoid where possible routing
the signal cable near other onboard electri-
cal equipment. Also avoid running the cable
in parallel with power cables.
the signal cable near other onboard electri-
cal equipment. Also avoid running the cable
in parallel with power cables.