22
SD Series Technical Manual
MDS 05-4846A01, Rev. H
4.4 DC Power Connection
The transceiver may be operated from any well-filtered 10 to 30 Vdc
power source. The supply must be capable of providing at least 2.5
Amperes continuously.
NOTE:
Early SD4 models supported 10.5 to 16 Vdc power, not 10 to
30 Vdc.
Always check the labeling above the power connector
to confirm the operating range for your unit.
A power connector with screw terminals is provided with each unit (see
Figure 16). Strip the wire leads to 6 mm (1/4 inch) and insert in the wire
ports, tightening securely. Be sure to observe proper polarity as shown
in Figure 16.
Invisible place holder
Figure 16. DC Power Connector (P/N 73-1194A39)
NOTE:
The radio is designed for use in negative ground systems only.
4.5 Grounding Considerations
To minimize the chance of damage to the transceiver and connected
equipment, a safety ground (NEC Class 2 compliant) is recommended
which bonds the antenna system, transceiver, power supply, and con-
nected data equipment to a
single-point
ground, keeping all ground leads
as short as possible.
Table 5. Signal Loss in Coaxial Cables (at 900 MHz)
Cable Type
10 Feet
(3 Meters)
50 Feet
(15 Meters)
100 Feet
(30.5 Meters)
200 Feet
(61 Meters)
RG-8A/U
0.85 dB
4.27 dB
8.54 dB
17.08 dB
1/2 inch HELIAX
0.23 dB
1.15 dB
2.29 dB
4.58 dB
7/8 inch HELIAX
0.13 dB
0.64 dB
1.28 dB
2.56 dB
1-1/4 inch HELIAX
0.10 dB
0.48 dB
0.95 dB
1.90 dB
1-5/8 inch HELIAX
0.08 dB
0.40 dB
0.80 dB
1.60 dB
Lead
Screws (2)
Binding
Wire Ports (2)
(Polarity: Left +, Right –)
Retaining
Screws (2)
