User Manual

Exalt Communications, Inc.
Exalt i-Series Installation and Management Guide
5000001 46
2007-06-25
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 Egress
Most installations use 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. Refer
to the Exalt white paper, Transmission Line for Exalt Indoor Radio Systems.
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.
In some cases, the choice of transmission line is not coaxial cable, but is instead air-
dielectric waveguide. This is an expensive solution and is generally not necessary, but
may be required for very long transmission line runs, and/or very long link distances,
and/or for systems requiring extremely high reliability.
Table 4 lists representative samples of transmission line types recommended for the Exalt
Digital Microwave Radio.
Table 4 Recommended transmission line
Manufacturer Type Description
Loss at
2.4GHz
Loss at
4.9GHz
Loss at
5.3GHz
Loss at
5.8GHz
Andrew LDF4-50 1/2-inch solid shield 3.3dB/100ft. 5.6dB/100ft. 5.7dB/100ft. 6.0dB/100ft.