MOUNTING
1.1 Antenna Unit
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
(a) On bridge | (b) Common mast | (c) Radar mast |
Figure 1-1 Mounting methods
•No funnel, mast or derrick should be within the vertical beamwidth of the an- tenna in the bow direction, especially zero degrees ±5°, to prevent blind sec- tors and false echoes on the radar picture.
•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.
•Locate the antenna of a direction finder 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 placed too close to the antenna unit. Observe the following compass safe distances to prevent deviation of a mag- netic compass: Standard compass, 2.15 m, Steering compass, 1.60 m.
•Do not paint the radiator aperture, to ensure proper emission of the radar waves.
•The signal cable run between the antenna and the display unit is available in lengths of 15 m (standard), 20 m, and 30 m. Whatever length is used it must be unbroken; namely, no splicing allowed.
•The antenna base is made of cast aluminum. To prevent electrolytic corrosion of the antenna base, use the seal washers and
•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°C.
•Leave sufficient space around the unit for maintenance and servicing. See the antenna unit outline drawing for recommended maintenance space.