Digital Repeater Line
DSP85 Series
WESTELL.COM
© 2016 Westell Technologies
14 June 2016 Doc. No. 960-1666-MNL rJ
1.877.844.4274
Page 20 of 77
2.3
Important Installation Notes
Inadequate isolation between the outside and inside antennas may cause regenerative feedback in the system. This
feedback can cause the amplifier to emit a continuous signal at maximum amplitude and, in some cases, interfere
with normal operation of the cell site. It is important to consider the layout and placement of the system carefully.
Refer to the Preface Safety Guidelines and Important Safety Information for proper antenna selection and
installation.
DANGER!
To avoid serious injury or death and repeater damage, do not install donor or server
antennas near overhead power lines or high power components. Allow enough
distance so that, if antennas fall, they will not contact those components.
WARNING!
Close proximity to the donor or server antennas with the repeater in operation may
expose the user or installer to RF fields that exceed FCC limits for human exposure.
CAUTION
Amplifier or handset damage may occur if a handset is connected directly to the
repeater or to the coax that leads to the repeater.
2.4
Installation Guidelines
2.4.1
Donor Antenna
Accurately determine the azimuth to the donor cell site.
Obtain the donor site information and approval from the service provider/carrier.
Ensure that the radiation path to the donor cell site is as unobstructed as possible.
Mount the donor antenna at or toward the edge of the roof, in the direction of the donor site. Try
to avoid having the RF signal from the donor pass above the location(s) of the service antennas.
Normally, service antennas are located behind and below the donor antenna (as viewed from above).
This approach will help avoid interference and feedback to and from the service antennas.
Normally, mounting the donor antenna higher will allow a less obstructed path to the donor site.
However, in high traffic metro areas avoid mounting the donor antenna any higher than necessary
as the quality of the donor signal may start to become less stable and it is more likely to encounter
adjacent channel interference.
When possible, shield the donor antenna’s rear by locating it so that HVAC units and/or penthouse
structures are behind the antenna, relative to the donor cell site location.
Ground system components in accordance with NEC 810-15, 21 as required.
