User's Manual

AR24027 Operator’s Manual (rev A)
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4.3.2 Antenna Installation
NOTICE
The antennas for the AR24027 must be professionally installed on permanent structures for outdoor
operations. The installer is responsible for ensuring that the limits imposed by the applicable
regulatory agency (Federal Communications Commission, FCC, or CE) with regard to Maximum
Effective Isotropic Radiated Power (EIRP) and Maximum Permissible Exposure (MPE) are not
violated. These limits are described in the following sections.
The AR24027 is typically attached to a pole (with the clamp provided) with the antenna connectors
facing up. For optimum performance the radio must be mounted in close proximity to the antenna
with a cable run typically under 2 meters (6 feet). For the AR24027, AFAR Communications Inc.
provides the three antenna types listed below:
Antenna Type Gain AFAR Model Number
Omnidirectional 9 dBi ATO-2409-000
Panel 18 dBi ATD-2418-000
Dish Reflector 24 dBi ATD-2424-000
Antennas at each end of the link must be mounted such that they have the same polarization, and
directional antennas must be carefully oriented towards each other. The choice of polarization
(horizontal vs. vertical) is, in many cases, arbitrary. However, many potentially interfering signals
are polarized vertically and an excellent means of reducing their effect is to mount the system
antennas for horizontal polarization.
Of those antennas listed above, the two directional antennas can be mounted for horizontal or vertical
polarization, while the omnidirectional antenna can only be mounted for vertical polarization.
Horizontally polarized omnidirectional antennas are available upon special request.
Proper grounding of the antenna is important for lightning protection as well as to prevent electrical
noise interference from other sources. The antenna should be mounted to a mast or tower that is well
grounded to Earth. Use threaded connectors to mate to the antenna lead connectors and check that all
connectors are clean and tight. Use weatherproof connectors in all outdoor couplings. We
recommend using “rubber mastic tape” like Scotch 2228 from 3M to further weatherproof outdoor
connections.
In locations where it is warranted, install lightning protectors at the N type connectors leading to the
antennas. You may also want to install a surge arrestor/lightning protection on the Ethernet cable
where it connects to the equipment rack. The lightning protectors should be properly grounded.
Carefully follow the installation instructions provided by the manufacturer of the lightning protection
device used.