Nera F77, Installation Manual

Page: 21 / 54

21
PLANNING
Nera F77
Continuing the Saturn tradition
Laying cables
General The coaxial cable for connection between the MCU and the
Antenna Unit should, if possible, be laid before the equipment
arrives. Make sure sufficient length of cable is ordered.
Where exposed to mechanical wear (on deck, through bulk-
heads etc.), the cable should be protected by steel pipes.
Standard procedures should otherwise be followed for cabling in
ship installations.
Special attention to existing safety regulations is required if the
cable passes through zones where there may be flammable or
explosive gases. Use suitable gasproof cable glands or bush-
ings. Be aware that the cables listed in the table below are
not
flame retardent.
Double screen 50 ohm coaxial cable must be used. The maxi-
mum length of the coaxial cable is limited by the DC and RF
loss through the cables (including pigtails):
Maximum DC loss: R loop 2.0 ohm
Maximum RF attenuation at 1.6 GHz: < 23 dB
The table below lists suitable double screened coaxial cables between MCU and ADE:
At the Antenna Unit A free end of approximately 1.5 m of the antenna cable above
the radome bottom should be provided for connection to the
coaxial connector in accordance with the installation instructions
in "
BDE - Connecting the coaxial cable to the MCU ".
At the Main The coaxial cable from the Antenna Unit should be given a
Communication Unit free end of approximately 0.5 m at the MCU location.
Nera ISDN Telephone, Choose the position for the required wall sockets and lay
Distress Alarm Unit, the cables leaving a free end of 0.5 m. Also allow a free end of
telefax or analogue 0.5 m at the Termination Box.
telephone
Antenna coaxial cable
at the MCU
“Pigtail”
QRPM911104-
1000 for
cables 4 to 5
N/female N/male
N/male
“Pigtail”
QRPM911104-
1000 for
cables 4 to 5
N/female
N/male
at the ADE
N/male
Max. length
for 23dB/2.0
Antenna cable
Bending
radius
Suitable coaxial
connectors
RG214-FRNC*108 mm 60 m
129 mm 170 m
160 mm 210 m
275 mm 380 m
Diameter
10.8 mm
12.9 mm
16.0 mm
27.5 mm
RG223 53 mm 30 m 5.3 mm
*Halogen-free/flame retardent/low smoke
105052
R906551/1
Nera
part no.
11N-50-10-4 S 10172 B-11
11N-50-7-5
11N-50-12-10
+ “pigtail”
RF 1 /
2
” 50
11N-50-23-10
+ “pigtail”
RF 7 /
8
” 50
Mounting the coaxial connector, see Appendices to
11N-50-3-54
QTZC502012