Exalt Communications, Inc.
EX-5i Installation & Management
5000005
26
2006-05-17
as well as the potential impact to RF interference and frequency coordination if additional radio
equipment is anticipated. This is especially important if future equipment is likely to operate
within the same frequency band.
Once you have mounted, cabled and aligned the antenna, your goal will be to never require
modification, so this prior planning can be important in the path and site planning stage, and the
construction of the antenna structure.
Follow the antenna manufacturer’s instructions for mechanical mounting of the antenna. Make
sure that there will be enough room around the antenna to allow for alignment activities (moving
the antenna in vertical and horizontal arcs) and for the RF transmission line to connect to the
antenna connector unobstructed and within the specified bend radius requirements of the
transmission line.
At this point, the antenna mounts should be fully secure to the structure, the feed of the antenna
securely mounted to the antenna (if the feed is a separate assembly), and the azimuth and
elevation adjustments not completely tightened to prepare for the antenna alignment activity. It is
a good practice to connect the transmission line to the antenna connector as early in the process
as possible, so as to reduce the opportunity for debris or moisture to enter either the antenna
connector or the transmission line connector. Otherwise, a connector cover or other temporary
measures can be taken to keep the connector clear. Extra care must be taken if the antenna is
installed during inclement weather to be certain that no moisture gets inside the antenna
connector at any time.
The antenna may be aimed at this point in the general direction required for the link. Using a
compass, a reference bearing, binoculars or any other similar device, you may point the antenna
in the direction (generally) of the far-end, and slightly tighten the azimuth and elevation
adjustments enough so that the antenna maintains its general position and is safe to be left
without additional securing. See the Exalt White Paper entitled
Antenna Alignment
for more
information on the general topic of antenna alignment techniques.
4.3.2 Transmission Line from Antenna to Egress
Most installations use coaxial transmission line for the connection between the antenna and the
radio device. Coaxial transmission line may be either solid-shield or braided-shield variety.
Solid-shield cables are more resistant to external signal coupling and interference, but are
generally stiffer than braided cables. The path or site engineer(s) should be consulted to assure
that the proper materials were chosen for the installation with all factors considered. See the
Exalt White Paper entitled
Transmission Line for Exalt Indoor Radio Systems
for more
information on the general topic of transmission line.
Generally, the larger the diameter of the transmission line, the lower the loss. So for longer runs
of transmission line, larger diameter cables are highly advised. However, at every frequency,
there is a maximum diameter cable that will support the operating frequency, so be certain to
verify the specifications. This should have all been determined during the path and site planning
process.
