10
MDS 4710/9710 Technical Manual
MDS 05-3305A01, Rev. E
2.4 Power Connection
The transceiver is compatible with any well-filtered 10.5 to 16 Vdc
power source. The power supply should be capable of providing at least
2.5 A of continuous current.
The red wire on the power cable is the positive lead; the black is nega-
tive.
NOTE:
The radio is designed for use only in negative ground systems.
2.5 Safety/Earth Ground
To minimize the chances of damage to the transceiver and connected
equipment, a good safety ground is recommended which bonds the
antenna system, the radio transceiver, power supply, and connected data
equipment to a single-point ground. Normally, the transceiver is ade-
quately grounded if the GE MDS mounting brackets are used to secure
the radio to a well-grounded metal surface.
If the transceiver is not mounted to a grounded surface, connect a safety
ground to the transceiver case. A ground can be connected to one of the
four screws on the bottom of the transceiver. Do not use any of the four
screws that hold together the upper and lower parts of the transceiver
case.
Connect all rack equipment and associated hardware grounds to the
building’s ground system for the primary power. The objective is to
create a single-point ground system, keeping all grounds leads as short
as possible.
To prevent damage, provide a good ground connection for the equip-
ment connected to the
INTERFACE
connector.
Finally, use lightning protectors where the antenna transmission lines
enter the building. Bond them to the tower ground, if it is nearby.
Table 5. Length vs. Loss in Coaxial Cables at 960 MHz
Cable Type
10 Feet
(3.05 Meters)
50 Feet
(15.24 Meters)
100 Feet
(30.48 Meters)
500 Feet
(152.4 Me-
ters)
RG-8A/U
0.85 dB
4.27 dB
8.54 dB
42.70 dB
1/2 inch HELIAX
0.23 dB
1.15 dB
2.29 dB
11.45 dB
7/8 inch HELIAX
0.13 dB
0.64 dB
1.28 dB
6.40 dB
1-1/4 inch HELIAX
0.10 dB
0.48 dB
0.95 dB
4.75 dB
1-5/8 inch HELIAX
0.08 dB
0.40 dB
0.80 dB
4.00 dB
