Installation manual

6009-33 Installation Manual Site Survey
2-6
2.8.1.
The first concern about 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 not required to be from a UPS
(same one that supplies power to the below decks equipment), but it is recommended.
Antenna Power Cable
2.8.3.
If your system includes a marine air conditioner, 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
2.8.4.
The AC power for the ACU and other below decks equipment is not required to be from a UPS (same one that
supplies power to the ADE), but it is recommended.
ACU Power Cable/outlet
2.8.5.
Use good quality shielded cable (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
2.9. Grounding
All metal parts of the ADE shall be grounded to bare metal at the mounting pedestal. Grounding straps from the base
of the ADE to a dedicated lug on the mounting pedestal are preferred, but grounding may also be accomplished by
exposing bare metal under all mounting bolts prior to final tightening. Preservation of the bare metal should be done
to prevent loss of ground.
Grounding should be ensured throughout the entire mounting to the hull. While it is presumed the deckhouse is
permanently bonded and grounded to the hull, in cases where the deckhouse and hull are of different materials a
check of an independent ground bonding strap should be made. Masts should be confirmed to be grounded to the
deckhouse or hull.