Ross 4500DR-104-07, User Manual, Page: 134 / 161

134 • GPS Option SRG-4500 User Guide (v7.0)
Recommended Cables
Table 16.1 summarizes the cable types if you do not purchase one of our GPS options that include the necessary
cables.
Cable, Antenna, and Amplifier Combinations
Table 16.2 summarizes the recommended cabling specifications. Refer also to Figure 16.5 and Figure 16.7 .
Installing the GPS Antenna
The GPS antenna must be mounted in an outdoor location, and be positioned such that it has an uninterrupted view
of the sky, i.e. with as much of the hemisphere of sky above it in plain view.
With the GPS Option enabled, the SRG-4500 provides a 5 volt DC voltage that is impressed upon the RF signal
line. The current is internally limited to 50mA. The Ross supplied antenna and line amplifier (optional equipment)
require less than 30mA combined.
To install the GPS antenna
1. Remove the nut and washer from beneath the antenna cap.
Figure 16.1 Antenna Cap — Location of Nut and Washer
Table 16.1 Recommended Cables
Cable Signal Attenuation
Outer
Diameter
DC
Resistance
Bending
Radius
Operating
Temperature
RG58 Black PVC
or LBC/LMR195
0.66dB/m @ 1.6GHz 5mm 0.05ohms/m 25mm -40 to +80°C
LBC/LMR400
Black polyethylene 0.18dB/m @ 1.6GHz
10.25mm 0.01ohms/m 50mm -40 to +80°C
Warning
— The cable supplied with the GPS-4500-8M and GPS-4500-35M is type LMR195FR or
equivalent. In the GPS-4500-100M and GPS-4500-200M include the same cable as found in the
GPS-4500-8M plus 100M (or 200M) of LMR400FR. These cables are not a plenum rated. Before
installation, verify that the supplied cable(s) meet the local regulatory requirements for your facility.
Table 16.2 Possible Combinations
Antenna Cable Amplifier
Extension
Cable
Overall Gain
at RF Input
Expected DC
Volts at
Antenna
GPS-4500-8M +28dB 8m of RG58 none none +22.72dB 4.99
GPS-4500-35M +28dB 35m of RG58 none none +4.9dB 4.97
GPS-4500-100M +28dB 8m of RG58 none 100m of 4.72dB 4.97
GPS-4500-200M +28dB 8m of RG58 +28dB 200m of 14.72dB 4.93
Cap
Nut
Cable
Washer