User's Manual

Exalt Installation and Management Guide
ExtendAir (TDD) Series Digital Microwave Radios
28 203591-010
2012-09-04
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 the antenna is mounted, cabled, and aligned, your goal is to never require modification. This
prior planning is important in the path and site planning stages and in construction of the antenna
structure.
Follow the antenna manufacturer’s instructions for mechanical mounting of the antenna. Ensure that
there is enough room around the antenna 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 in preparation of 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, to
reduce the opportunity for debris or moisture to enter either the antenna connector or the transmission
line connector. Use a connector cover or other temporary measures to ensure that the connector is kept
clear. Take extra care if the antenna is installed during inclement weather to ensure that no moisture
gets inside the antenna connector at any time.
Now the antenna can be aimed in the general direction required for the link. Use a compass, a
reference bearing, binoculars or any other similar device to point the antenna in the direction
(generally) of the far end radio, and then slightly tighten the azimuth and elevation adjustments so that
the antenna maintains its general position and is safe to be left without additional securing. Refer to the
Exalt white paper, Antenna Alignment, for more information on antenna alignment techniques.
Transmission Line from Antenna to Radio (rc models)
Most installations use a very short length of coaxial transmission line for the connection between the
antenna and the radio device. Coaxial transmission line can either have a solid or braided shield. Solid-
shield cables are more resistant to external signal coupling and interference, but are generally stiffer
than braided cables. Consult the path or site engineer(s) to ensure that the proper materials are chosen
for the installation and that all factors were considered.
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 supports the operating frequency. Verify the specifications. This should
is determined in the path and site planning process.
Table 4 lists representative samples of transmission line types recommended for the Exalt Digital
Microwave Radio.