Saab R5 SUPREME AIS, Руководство по эксплуатации и установке

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R5
SUPREME - Navigation System
INSTALLATION
7000 118-301, A3 Page 26
Type Attenuation @ 1.5
GHz (dB/m)
(mm)
Weight (kg/100m)
RG 58 0.9 5 3.7
RG 400 0.6 4.95 6.3
RG 223 0.6 5.40 5.5
RG 214 0.35 10.8 18.5
RG 225 0.3 10.9 23.3
Table 8
– GPS Antenna Cables
For optimum performance of the R4 Navigation Sensor, 12 dB should remain after
subtraction of cable loss from the antenna pre-amplifier gain. Thus, a maximum of 18
dB signal loss is allowed in the antenna cable, when using the 30 dB gain MGA-2 GPS
or MGL-4 Combined GPS/Beacon antenna. Given this criteria, the following
recommended cable maximum lengths have then been calculated.
Recommended maximum cable length using standard antenna
Cable Type Max length with MGA-2 or MGL-4
RG 58 20 m
RG 400 30 m
RG 223 30 m
RG 214 51 m
RG 225 60 m
Table 9
– Recommended Maximum GPS Cable Length
Maximum cable length is calculated as:
Maximum cable length = allowed total loss / cable attenuation per meter
2.5.3 Cable Mounting
Coaxial cables should be installed in separate signal cable channels/tubes and at least
10 cm away from power supply cables. Crossing of cables should be done at right
angles (90°).
Coaxial cables should not be exposed to sharp bends, which may lead to a change of
the characteristic impedance of the cable. The minimum bending radius should be 5
times the cable's diameter.
All outdoor installed connectors should be weather proofed, e.g. with shrink tubing,
watertight seal tape or butyl rubber tape and plastic tape sealing, to protect against
water penetration into the antenna cable.