COBHAM SAILOR 900, Руководство по установке

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Installation of the ADU
98-150471-A02 Chapter 3: Installation 3-23
Installation
3.3.4 Alternative ADU cable
The allowed RF loss in the antenna cable is determined by the attenuators of the PSM and
VIM modules. The electronic design guarantees that minimum 20 dB RF loss @ 1700 MHz
in the antenna cable will work, but typically an RF loss of about 25 dB will be within the
limits of the cable calibration. You can verify the cable attenuation margin with the cable
calibration. See
Cable calibration on page 6-11 for more details.
The DC-resistance loop of the antenna cable must be maximum 0.7 Ohm at 55°C. This is to
ensure the power requirements from ACU to the antenna and to ensure the performance of
the system. Preferably choose one of the cable types listed in the table below.
Check the data sheet from the cable supplier that both the RF- attenuation and the DC-
resistance are kept within the maximum specified values:
• ADU cable RF-attenuation at 4450 MHz: max. 35 dB including connector.
• ADU cable modem-attenuation at 10 MHz: Max. 2 dB
ADU cable modem-attenuation at 36 and 54 MHz: Max. 4 dB
• ADU cable loop DC-resistance max: 0.7 Ohm.
Also ensure that the specified minimum bending radius is respected. If this is not the case,
the loss in the cable will increase. Check the documentation from the cable supplier.
Cable Type Absolute maximum length (m) Absolute maximum length (ft)
RG223-D 25 m 82 ft
RG214/U 50 m 164 ft
S 07272B-05 70 m 230 ft
LMR-600-50 105 m 344 ft
LDF4.5-50 Andrew 290 m 951 ft
Table 3-7: ADU cable types and maximum lengths
SAILOR900HP.book Page 23 Monday, July 18, 2016 12:44 PM