
69
SAILOR FleetBroadBand
Training Manual
3
Check the data sheet available from your local cable supplier that
both the RF attenuation and the DC resistance are kept within the
maximum specified levels:
Antenna cable specification
Maximum value
RF attenuation @ 1.6 GHz
20 dB
Modem attenuation @ 54 MHz
4 dB
Modem attenuation @ 36 MHz
3 dB
DC resistance (Looped)
1 Ω
Figure 3-8: SAILOR FleetBroadband antenna cable specification
Also ensure that the specified minimum bending radius of the
antenna cable is respected. If this is not the case, the loss in the
cable will increase.
3.3.3 Obstruction
Place the antenna with a free line of sight towards the satellite in
all directions to make sure that there is maximum reception of the
satellite signal. Do not place the antenna close to large objects
that may block the signal.
The antennas are rotating 360º in azimuth and down to -25º
elevation for the SAILOR 500 FleetBroadband and down to -60º
elevation for the SAILOR 250 /150 FleetBroadband, when pitching
and rolling, to allow the continuous pointing towards the satellite in
heavy sea states.
The amount of degradation of the signal depends on the size of
the obstruction and the distance from the antenna. As a rule of
thumb, any obstruction that subtends an angle of less than 3º at
the antenna is not seen as an obstruction and has limited effect.
The table below provides a guideline for obstruction sizes and
maximum distance to the object, which will cause only limited
degradation, as the angle will be less than 3º.
Distance to obstruction
Width of obstruction
3 m
16 cm
5 m
26 cm
10 m
52 cm
20 m
104 cm
Figure 3-9: SAILOR FleetBroadband maximum obstruction
3.3.4 Interference
The antenna must be mounted as far away as possible from
the ship’s radar and high power radio transmitters (including
other Inmarsat based systems), because they may compromise
the antenna performance. RF emission from radars might
actually damage the antenna. The RF emission from SAILOR
FleetBroadband antennas itself may also interfere with other radio
systems. Especially other Inmarsat systems and GPS receivers
with poor frequency discrimination are vulnerable to the radiation
generated by the SAILOR FleetBroadband antennas.
NOTE!
Check the instruction from the
cable supplier.
Содержание Sailor 250 FleetBroadband
Страница 1: ...FleetBroadband Installation Training manual Commissioning and On Board repair ...
Страница 2: ......
Страница 4: ......
Страница 9: ...Inmarsat Network ...
Страница 10: ......
Страница 34: ...24 1 Chapter 1 Inmarsat Network Figure 1 34 Return direction connection bearers ...
Страница 36: ......
Страница 37: ...Product Presentation ...
Страница 38: ......
Страница 70: ......
Страница 71: ...Installation ...
Страница 72: ......
Страница 107: ...97 SAILOR FleetBroadBand Training Manual 3 ...
Страница 108: ......
Страница 109: ...Interfaces ...
Страница 110: ......
Страница 132: ......
Страница 133: ...Repair ...
Страница 134: ......
Страница 165: ...155 SAILOR FleetBroadBand Training Manual 5 Figure 5 59 ...
Страница 174: ...164 Chapter 5 Troubleshooting 5 Example Terminal LED steady green Antenna LED steady green Figure 5 77 Figure 5 78 ...
Страница 178: ...168 Chapter 5 Troubleshooting 5 Example GPS module defective Figure 5 86 Figure 5 87 Figure 5 88 Figure 5 89 ...
Страница 186: ......
Страница 187: ...Removal Replacement ...
Страница 188: ......
Страница 217: ...207 SAILOR FleetBroadBand Training Manual 6 ...
Страница 218: ......
Страница 219: ...Software Upload ...
Страница 220: ......
Страница 221: ...211 SAILOR FleetBroadBand Training Manual 7 Figure 7 1 ...
Страница 230: ......
Страница 231: ...System Test ...
Страница 232: ......
Страница 236: ......
Страница 237: ...Abbreviation ...
Страница 238: ......
Страница 242: ......
Страница 243: ...R R of EXP 727Antenna ...
Страница 244: ......
Страница 255: ...245 SAILOR FleetBroadBand Training Manual 10 ...
Страница 256: ......
Страница 257: ...R R of EXP 325Antenna ...
Страница 269: ......
Страница 270: ...TT 100 MSO 030207 www cobham com satcom ...