Thales VesseLINK Certus 200, Руководство пользователя, Страница: 27 / 131

2-7
User Manual PN 84469 Rev L
Antenna Unit
The Above Deck Unit (ADU) or Antenna is a standalone unit that connects to the BDU through
a single coaxial cable. DC power, RF transmit and receive signals, control data and GPS data are
communicated between the ADU and BDU using this single coaxial cable.
Figure 2-8 Above Deck Unit (ADU) / Antenna For Certus 350 and Certus 200 Systems
RF COAXIAL CABLE INSTALLATION CONSIDERATIONS
Good quality RF coaxial cable is recommended. Several considerations must be taken into
account concerning the cable when installing a VesseLINK system. These include:

RF Cable loss - The VesseLINK system is designed to operate with an RF cable loss of
10 dB or less in the L-band frequency of operation (1616-1626 MHz). Thales accessory
cables listed below have been selected to meet this criteria.
DC losses due to cable resistance (inner conductor and shield) - The VesseLINK
system is designed to work with a maximum total RF cable ohmic resistance of 1.10
Ohms round-trip (inner conductor and shield). Thales accessory cables listed below meet
this criteria.

Cable length - The maximum cable length that the VesseLINK can operate with is 50
meters due to the delay requirements of the system. The maximum Thales cable length
accessory cable is 50 meters in length.
Table 2-2 Coaxial Cable List
Cable TDSI Part Number
25 meters LMR-300 FR 855023-082
50 meters LMR-400 FR 855033-164
NOTE
The cables are Fire Rated (FR) providing resistance to fire and
continued operation in the presence of fire, improving safety when
being used.