Specifications

10 MDS 4790/9790 Series I/O Guide MDS 05-3438A01, Rev. E
The RG-8A/U cable is a widely available and inexpensive feedline that
is suitable for systems with short ranges or those with short feedlines.
For longer feedlines and lower losses, Andrew HELIAX
™
semi-rigid
coaxial cable or similar products are a good choice. Table 2 shows the
length of various types of cable and the resulting degradation in signal
strength.
Mount the antenna and feedline securely to the supporting structure to
avoid damage from wind and ice loading. Follow the instructions pro-
vided by the antenna and feedline manufacturers to ensure a safe and
reliable installation.
4.0 INSTALLATION PROCEDURES
This section presents the steps necessary for installing the radio and con-
necting it to associated equipment. After completing these steps, the
radio will be ready for in-service operation.
4.1 Unpacking and Inspection
Figure 6 shows a typical radio shipment. Check the contents against the
packing list secured to the outside of the shipping box. Accessories and
spare parts kits, if any, are wrapped separately. Inspect all items for
signs of damage. Save all packing materials in case you need to ship the
radio in the future.
Table 2. Feedline Loss Chart (450 MHz)
Cable Type
3.05 Meters
(10 Feet)
15.24 Meters
(50 Feet)
30.48 Meters
(100 Feet)
152.4 Meters
(500 Feet)
RG-8A/U 0.51 dB 2.53 dB 5.07 dB 25.35 dB
1/2 in. HELIAX 0.15 dB 0.76 dB 1.51 dB 7.55 dB
7/8 in. HELIAX 0.08 dB 0.42 dB 0.83 dB 4.15 dB
1-1/4 in. HELIAX 0.06 dB 0.31 dB 0.62 dB 3.10 dB
1-5/8 in. HELIAX 0.05 dB 0.26 dB 0.52 dB 2.60 dB
Table 3. Feedline Loss Chart (960 MHz)
Cable Type
3.05 Meters
(10 Feet)
15.24 Meters
(50 Feet)
30.48 Meters
(100 Feet)
152.4 Meters
(500 Feet)
RG-8A/U 0.85 dB 4.27 dB 8.54 dB 42.70 dB
1/2 in. HELIAX 0.23 dB 1.15 dB 2.29 dB 11.45 dB
7/8 in. HELIAX 0.13 dB 0.64 dB 1.28 dB 6.40 dB
1-1/4 in. HELIAX 0.10 dB 0.48 dB 0.95 dB 4.75 dB
1-5/8 in. HELIAX 0.08 dB 0.40 dB 0.80 dB 4.00 dB