Redline Communications RDL-3000 Series Instruction sheet

RDL-3000 Installation Guidelines
70-00159-01-05 Proprietary Redline Communications © 2011 Page 54 of 66 October 18, 2011
4.1 GPS Antenna Installation
The GPS antenna is installed with a standard antenna thread-mounted to an L-shaped
bracket. The bracket can be strap-clamped to a roof mast or bolted to a flat surface.
Use an LMR-195 (or equivalent) coaxial cable to connect from the GPS antenna to the
RDL-3000 GPS antenna port. The GPS antenna can be connected using up to 46 m
(~150 ft) of high quality antenna cable.
Figure 47 - Sync - Collocated RDL-3000 Units
4.1.1 Choosing the GPS Antenna Location
It is important to conduct a site survey before installing the GPS antenna. A poorly
installed or badly located GPS antenna may not maintain accurate timing -- resulting in
increased interference in the wireless network that may result in service outages.
Prior to installing the GPS equipment, it is recommended to use a small handheld GPS
device to perform a survey for three to six hours. Check readings at regular intervals to
confirm that a minimum of three satellites, each having signal levels above 36 dB (post
correlation signal to noise (CNo)), are visible at all times.
To provide the best coverage, a GPS antenna should be installed at the highest point
available at the site. If the GPS antenna is mounted on the same tower as the sector
controller, the antenna must be located above the RDL-3000 wireless antenna.

RDL-3000 Installation Guidelines
70-00159-01-05 Proprietary Redline Communications © 2011 Page 55 of 66 October 18, 2011
The GPS antenna must have a clear view to approximately ten degrees of the horizon in
all directions. Surrounding obstacles such as trees, buildings, etc should not exceed a
20 degree elevation angle. Blockage due to buildings, mountains, etc. should be less
than 50% of the sky.
RF Interference
To avoid the influence of reflected waves, the antenna must not be installed less than 2
m (~6.5 ft) away from metallic objects having dimensions greater than 0.2 m (~8 in).
Grounded metal structures may block or reduce the signal from a satellite.
To minimize susceptibility to radio interference, the GPS antenna should generally be
located at least 1 m (~3.25 ft) away from antenna systems for any another high
frequency system (e.g., microwave, GSM, CDMA, 3G). Avoid mounting the GPS
antenna within the main beamwidth of any active (radiating) antenna system.
4.1.2 GPS Antenna Kit
The Redline GPS antenna kit is designed to accommodate most installations. This kit
includes the following items:
GPS Antenna
6 m (19.5 ft) LMR-195 50 ohm antenna cable with TNC / M connectors.
Mounting Hardware
Figure 48 - Sync - GPS Antenna Installation Kit