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Chapter 6: Configuration and alignment Aligning antennas
Page 6-119
Aligning antennas
Use this procedure to align linked antennas (master and slave), whether integrated or
connectorized. The goal of antenna alignment is to find the center of the main beam. This is
done by adjusting the antennas while monitoring the receive signal level.
Preparation:
Ensure that the following parameters are available:
•
Location of both sites (latitude and longitude).
•
Bearing to the other end of the link for both sites.
•
Prediction of receive signal level for both ends of the link.
•
Prediction of link loss.
LINKPlanner provides all of these parameters in the form of an installation report.
If a connectorized ODU is installed at either site with two separate antennas for spatial
diversity, refer to
Aligning separate antennas for spatial diversity on page 6-120 before starting
alignment.
Note
For improved radio performance, mount the integrated ODU at 45 degrees to the
vertical; this ensures that side-lobe levels are minimized for interference transmitted or
received at zero elevation.
To achieve best results, make small incremental changes to elevation and azimuth.
Caution
The action of tightening the mounting bolts can alter antenna alignment. This can be
helpful when fine-tuning alignment, but it can also lead to misalignment. To prevent
misalignment, continue to monitor receive signal level during final tightening of the
bolts.
Procedure:
1 At each end of the link, adjust the antenna to point at the other end of the link. This should be
done with the aid of a compass.
2 Without moving the master antenna, adjust the elevation and azimuth of the slave antenna to
achieve the highest receive signal level using one of the following methods:
•
ODU installation tones on page 6-121
•
Graphical Install page on page 6-123
3 Without moving the Slave antenna, adjust the elevation and azimuth of the Master antenna to
achieve the highest receive signal level (using one of the above methods).
4 Repeat steps 2 and 3 as necessary to fine-tune the alignment to find the center of the beam.