User Manual

SRU Installation
SRU Installation Manual
17286-1000 Rev. B 03/14/01
1-2
1.2 SRU Alignment
This chapter contains information about SRU alignment.
1.2.1
1.2.11.2.1
1.2.1 Preparation and Overview of Procedure
Preparation and Overview of ProcedurePreparation and Overview of Procedure
Preparation and Overview of Procedure
It is recommended that a person be present at both the SRU and the associated BRU for
this antenna alignment procedure. It is also advisable to have some form of communication
between the two sites, such as cell phones, two-way radios or telephones. Mirrors or strobe
lights (for flashing the path) are recommended for situations in which the antenna locations
are not readily visible from one another, as a result of distance or atmospheric conditions. It
is absolutely essential that there are no obstructions present in the path of the beam.
The objective of this procedure is to aim the main lobe of the SRU antenna precisely in the
direction of the associated BRU. This is accomplished by performing a rough visual
alignment first; then further alignment is performed while monitoring the Receive Signal
Level at the Subscriber Radio Unit with a voltmeter. The alignment process consists of
adjusting the direction of the SRU until the received signal level is maximized.
Do not confuse the alignment directions (horizontal, vertical - that is, azimuth, elevation)
with the polarization of the antenna feed assembly. Antenna polarization should be
established prior to installation. Verify that the polarization of the SRU matches the
polarization of the BRU.
Connect a Voltmeter to ensure that the SRU is getting power. A reading of zero means that
there is a problem with the SRU, SAS, or cable (or voltmeter). A reading of +4.0 Volts
indicates it is likely that the SAS is not admitting and is presently scanning through the
channels of the channel plan as it attempts to admit. Or that the SAS cannot admit because
Figure 1-1Antenna Pattern