Furuno FV-110GX, Operator'S Manual

Page: 50 / 188

Installation of the ADU
2-26
2.3.4 Alternative ADU cable
The allowed RF loss in the antenna cable must be maximum 20 dB RF loss @ 1950 MHz
and maximum 35 dB RF loss @ 4450 MHz. You can verify the cable attenuation margin
with the cable calibration, see
Cable calibration on page 5-11 for more details.
The DC-resistance loop of the antenna cable must be maximum 0.9 Ohm. 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.
If you want to use an alternative ADU cable make sure that the following requirements
are fulfilled:
1. Check the data sheet from the cable supplier to verify the values:
The RF- attenuation and the DC-resistance are below the maximum values specified
below:
• ADU cable RF-attenuation at 1950 MHz: Max. 20 dB including connector.
• 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: 0.9 Ohm.
2. Respect the specified minimum bending radius, see the documentation from the cable
supplier. If this is not the case, the loss in the cable will increase.
Cable Type
Thicknes
s
Absolute
maximum
length (m)
Absolute maximum
length (ft)
RG214 3/8” 50 m 160 ft
LMR-400-DB 0.405” 85 m 280 ft
LMR-600-50 1/2” 150 m 490 ft
LDF4.5-50
Andrew 5/8” 300 m 650 ft
Table 2-7: ADU cable types and maximum lengths