Sea Tel 6012-71 C-BAND, Installation Manual

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6012-71 Installation Manual Site Survey
2-6
2.8.1.
The first concern with the coaxial cables installed between the ADE & BDE is length. This length is used to
determine the loss of the various possible coax, Heliax or fiber-optic cables that might be used. You should
always provide the lowest loss cables to provide the strongest signal level into the satellite modem.
ADE/BDE Coaxial Cables
Signal cable shall be continuous from the connection within the ADE radome, through the structure of the
ship to the BDE. Splices, adapters or dummy connections will degrade the signal level and are discouraged.
Be careful of sharp bends that kink and damage the cable. Use a proper tubing bender for Heliax bends.
Penetrations in watertight bulkheads are very expensive, single cable, welded penetrations that must be
pressure tested.
Always use good quality connectors that are designed to fit properly on the cables you are using. Poor
quality connectors have higher loss, can allow noise into the cable, are easily damaged or fail prematurely.
In as much as is possible, don’t lay the coaxes on power cables. Try to have some separation from Inmarsat &
GPS cables that are also passing L-band frequencies or radar cables that may inject pulse repetition noise –as
error bits - into your cables.
2.8.2.
Be cautious of length of the run, for voltage loss issues, and assure that the gauge of the wires is adequate for
the current that is expected to be drawn (plus margin). Antenna power is recommended (but not required) to
be from a UPS, generally the same one that supplies power to the below decks equipment.
Antenna Power Cable
Power cables shall comply with the provisions of IEC 60092-350 and -351 as practical. Power cables may be
routed through the same conduit as the signal cable from the junction box to the base of the ADE. Power
cables shall pass through separate radome penetrations from the signal cable.
The power cable shall be continuous from the UPS (or closest circuit breaker) to the ADE connections within
the radome. The power circuits shall be arranged so that ‘active,’ ‘common’ and ‘neutral’ (ground) legs are all
made or broken simultaneously. All circuit legs shall be carried in the same cable jacket.
2.8.3.
If your system includes a marine air conditioner (available with the 81 inch radome ONLY), run an AC power
cable to it from a breaker, preferably from a different phase of the electrical system than supplies power to
the ADE & BDE. Be EXTREMELY cautious of length of the run for voltage loss and gauge of the wires for the
current that is expected to be drawn.
Air Conditioner Power Cable
Power cable shall comply with the provisions of IEC 60092-350 and -351 in so far as practical. Power cables
may be routed through the same conduit as the signal cable from the junction box to the base of the ADE.
Power cables shall pass through separate radome penetrations from the signal cable.
The power cable shall be continuous from the closest circuit breaker to the ADE connections within the
radome. The power circuits shall be arranged so that ‘active,’ ‘common’ and ‘neutral’ (ground) legs are all
made or broken simultaneously. All circuit legs shall be carried in the same cable jacket.
2.8.4.
The AC power for the ACU and the ADE is not required to be from a UPS (same one that supplies power to
the ADE), but it is recommended.
ACU Power Cable/Outlet
Power cable shall comply with the provisions of IEC 60092-350 and -351 in so far as practicable.
2.8.5.
Use good quality shielded cables (twisted pairs, individually foil wrapped, outer foil with braid overall is best).
You only need 2-wire for NMEA signal, 4-wire for Step-By-Step and 5-wire for Synchro … always use shielded
cable. Be cautious of length and gauge of the run for voltage loss issues.
Gyro Compass Cable