Mounting Of Antenna Unit For Model1933/1943 - Furuno 1833 Installation Manual

1.3

Mounting of Antenna Unit for MODEL1933/1943

1.3.1 Mounting 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.
Any obstruction will cause shadow and blind sectors.
A mast for instance, with a diameter considerably less than the width of the radiator, will
cause only a small blind sector, 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
directions is available. Thus, you should determine the angular width and relative bearing
of any shadow sectors for their influence on the radar at the first opportunity after fitting.
• If you have a radio direction finder on your boat, locate its antenna clear of the antenna
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 electrical equipment. Also avoid running the cable in
parallel with power cables.
• A magnetic compass will be affected if the antenna unit is placed too close to the antenna
unit. Observe the following compass safe distances to prevent deviation of a magnetic
compass: Standard compass, 1.00 m, Steering compass, 0.80 m.
• Do not paint the radiator aperture, to ensure proper emission of the radar waves.
• When this radar is to be installed on larger vessels, consider the following points:
• 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.
• 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 antenna unit must not be
mounted where the temperature is more than 70°C.
As shown in the figure below, the antenna unit may be installed on the bridge, on a common
mast or on the radar mast.
(a) On bridge
(b) Common mast (c) Radar mast
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