Kongsberg Seapath 320, Installation Manual, Page: 45 / 152

Installation Manual
M300-62/rev.2 29
Note
If the Antenna Bracket supplied by Kongsberg Seatex is not used, it is
important that the antennas are rigidly mounted so that the distance
between the antennas does not change due to vibrations or accidental
dislocation.
The antenna baseline length is recommended in the range 2.5 to 4.0 metres, but 1 to 5
metres can be used. Maximum heading accuracy is achieved at 4.0 metres baseline.
The maximum length for each of the antenna coaxial cables is 100 metres for the
cable type normally delivered with the system (1/2" Superflex). If longer cables are
needed, a low noise signal amplifier (LNA) should be fitted.
3.2.2 MRU 5
For the MRU, consider the following:
The unit is designed for installation in an indoor environment and for operation
within the temperature range.
The unit is to be mounted close to the user equipment of which it is supposed to
measure the motion. This is to avoid errors in alignment with the user equipment and
to eliminate errors due to ship hull torsion.
If the system is not allocated to measure motion of a particular user equipment,
mount the MRU as close to the Navigation Reference Point (NRP) as possible. This
to ensure best roll and pitch measurements. If it is not possible to mount the MRU
close to NRP, try to mount it along the longitudinal axis of the ship and as close to
the NRP as possible. Avoid mounting the MRU high up or out to the side of the ship.
Be aware of:
Vibrations Direct mounting onto the main hull structure is preferable.
Note
The worst mounting positions are thin walls that may come in resonance
with vibrations driven by machinery, propellers, pumps or motors. Avoid
mounting the MRU close to hydraulic pumps and valves where there are
high frequency vibrations.
Temperature changes For safe mounting of the MRU, place the unit in a location
where the temperature is low and where changes in temperature
are slow. A location directly on the hull far away from the heat
of the machinery, heaters and air conditioning systems is
preferable.
Corrosion problems Place the MRU in a location where no direct splashing seawater
is present.