Alcatel-Lucent 9500 MXC, User Manual, Page: 315 / 916

9500 MXC User Manual
3DB 23063 ADAA - Rev 004 July 2007 Vol. III-5-15
Antenna 3, and to the secondary RACs connected to antenna 4.
8. Adjust the feedhead skew angle of the primary antenna for maximum XPD on
both primary V and H RACs. If the maximums for each are at (slightly)
different angles, adjust for a mid-point.
9. Adjust the feedhead skew angle of the secondary antenna for maximum XPD
on both secondary V and H RACs. If the maximums for each are at (slightly)
different angles, adjust for a mid-point.
10. Check the spread of XPD measurements. All four RACs should be within a 2
dB of each other, providing RAC RSLs are within 2 dB. If higher, recheck the
Tx power settings and RSLs. In some instances it may be necessary to
re-optimize feedhead alignment to achieve best balance across all RACs.
Where results are not as expected, also check for:
• Bent antenna feeds.
• Feeds not centered or not correctly supported, such as missing support wires.
• Radome or shroud damaged, or sections of the shroud missing.
• Warped or bent reflector.
• Feed frequency range. The entire Tx/Rx range (frequency boundaries of the
Tx and Rx bandwidths) must be within the antenna feed frequency range.
11. At the reference-end of the link, view the RAC performance screens for all
four RACs and adjust the feedhead skew angle of the secondary antenna for
maximum XPD on both secondary V and H RACs. If the maximums for each
are at (slightly) different angles, adjust for a mid-point. Do not adjust the
feedhead skew angle on the primary, reference antenna.
12. As for the remote end, check the spread of XPD measurements. All four
RACs should be within a 2 dB of each other.
• If higher, recheck the Tx power settings and RSLs. In some instances it may
be necessary to re-optimize feedhead alignment to achieve best balance
across all RACs
• The XPD spread between the reference and remote end RACs should also
be within 2 dB of each other.
13. Switch all transmitters to secondary and lock-on.
Ensure that as you adjust the skew angle, the physical antenna alignment does
not shift, which would make it necessary to repeat step 2. Check that antenna
mounting bolts and azimuth and elevation adjuster locks have been correctly
tightened.
The maximum points may be quite sharp, rotate the feedhead slowly to ensure
they are not missed. Data in the performance screen is updated at 1.5 second
intervals.