User Manual

August 6, 2003 Part 004071A revision 00b 107
Chapter 4: Installation Procedures
Before You Begin
Before you begin to install the GPS antennas:
 Select an installation location away from any objects that might obstruct
satellite visibility to 10° of the horizon. Obstructions may cause a
degradation of the GPS clock module’s performance.
 Ensure that the type and length of cabling used to connect the GPS
antenna to the GPS clock module meets your attenuation and shielding
requirements.
 To install the GPS antennas
1 Run the two coaxial cables supplied with each antenna from the NPM racks to the
intended location of the GPS antennas, such as the basestation’s roof or tower.
NOTE: Ensure that the cable remains clear of any sources of
potential interference, such as transmitting equipment or power
lines.
2 Vertically install two 1-inch-diameter pipes in a location that provides the
maximum unobstructed view of the sky.
3 Run a coaxial cable through the center of each pipe.
4 Attach a pipe adapter to the top of each pipe. Ensure that the pipe adapters are
connected tightly to the pipes by tightening the set screw. Use a 5/32-inch Allen
key to tighten the set screw.
5 Attach a GPS antenna to the end of each coaxial cable.
The GPS antennas use female TNC connectors.
6 Attach the GPS antennas to each pipe adapter.
installation.book Page 107 Wednesday, August 6, 2003 6:06 PM