Neptune 13458-000, Руководство по установке и обслуживанию

Страница: 121 / 150

l
The feed line should not be attached to the antenna while it is
being hoisted up the tower or other supporting structure. The
feed line should be attached after the antenna is in place.
l
The antenna connector must not be damaged during
installation. There have been reports of damage to the
antenna's N connector where the center pin has become bent
and shorts out the antenna system.
Feed Line Overview
The feed line is a significant contributor to both good and poor
system performance. A properly installed feed line is critical to
optimal system performance. Testing the antenna while it is on
the ground can ensure the system works properly. It is best to
install the connectors with the proper tools and a trained installer.
With the proper tools and jigs, installing coaxial (coax)
connectors takes only a few minutes each. Not using the proper
tools as recommended by the manufacturer could potentially
cause problems, either immediately or after several years of
seemingly proper operation.
Coaxial Cable Lengths for the Gateway
Table 31 provides part numbers of acceptable coax cables.
Length Part Number
40 ft. or < Times Microwave Part Number: LMR-400-UF or LMR-400
100 ft. or < Andrew Part Number: LD54-50A
> 100 ft. Andrew Part Number: AVA5-50 or AVA5-50FX
Table 31 – Acceptable Coax Cables
You can order coax cable assemblies already terminated as
accessories from Neptune or purchased from companies such as
Tessco Technologies, Talley Communications, and Hutton
Communications. Each end must be terminated with an N-male
type connector. However, the larger 7/8-inch diameter coaxial
cable, such as Andrew AVA5-50, uses a 7-16 DIN female
connector on each end. Jumpers provide downsizing for the last 6
feet of the installation, allowing a more flexible and manageable
connection. The jumpers are preassembled with the appropriate
connectors at each end: a 7-16 DIN male on one end and an
N-male on the other. See Table 32 on the next page.
R900 Gateway Installation and Maintenance Guide 103
Appendix C RF Antenna and Coax Installation