Globalstar MCM-4M, Installation And Operation Manual

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G l o b a l s t a r M C M - 4 M I N S T A L L A T I O N
3-3
You will need to provide the following items:
1. PC Computer/LAN Components and cables – The Remote Client Terminals, hub/switch,
RJ-45 Ethernet cables.
3.2. Planning Where to Position the Components
Determine where to position the components, how the cables will be routed and that the furnished
cable lengths will be adequate.
3.2.1. Site Selection
Choosing the best mounting location on smaller platforms, where there are fewer possible locations
to choose from, is frequently a compromise. The “best” location for the antenna is the one that has
no blockage and is not in close proximity to other electronics or antennas that may interfere with the
MCM-4M or that the MCM-4M will interfere with.
Sometimes there are situations that you just can’t get around. In that case, do the best you can. At
moderate latitudes (between latitude 22 degrees and 52 degrees) there will always be two satellites
visible at any location. If an object blocking the antenna’s view of the sky is small (that is, blocks
only a small part of the sky), it should not cause an outage.
3.2.2. Single Piece Antenna
Determine the optimum mounting location, on top of the platform for the Antenna. Certain types
of antennae used with Global Positioning Satellite (GPS) receivers do not have the appropriate
band-pass filter (14.75MHz – 16.75MHz) fitted before the pre-amplifier stage. Use of this type of
antennae may cause a GPS receiver to be susceptible to interference from the MCM-4M. Where it
is found that a GPS receiver is experiencing interference from the MCM-4M, the distance between
the GPS antenna and the MCM-4M should be increased (by relocating one or both). If no suitable
alternative location can be found for either the GPS antenna or the MCM-4M, the GPS antenna
should be replaced with one that includes the appropriate band-pass filter. The MCM-4M should
be installed where:

The antenna has a clear line-of-sight view to as much of the sky above the antenna as is
practical, down to an elevation of 10 degrees above the horizon. Choose a location where
masts or other structures do not block the satellite signal from the antenna as the platform
turns.

The antenna is at least 5 feet away from other transmitting antennas (HF, VHF, GPS and
radar) that may generate signals which interfere with the Antenna, or that the Antenna may
interfere with. Although radio and radar interference is not common, the further away the
Antenna is from these other antennas, the less impact their operation could have on it.

The Antenna assembly should be rigidly mounted to the platform. If necessary, reinforce the
mounting area to assure that it does not flex due to platform motion or vibration