COBHAM Sea Tel 9711-56 IMA C Band, Руководство по установке

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Sea Tel 9711-56 IMA Optimizing Cross-Pol Isolation
15-1
EAR Controlled - ECCN EAR99
15. Optimizing Cross-Pol Isolation
Now that all of the other setup items have been checked and changed as necessary, it is time to contact the NOC to
arrange for cross-pol isolation testing and whatever other commissioning the NOC asks for. Read this procedure
thoroughly before you are asked to begin. Assure that you are on the correct satellite and have RX network lock. (the
NOC may have you adjust TX Frequency and/or modem TX level prior to beginning cross-pol isolation). At the
appointed time follow the steps below for the cross-pol isolation testing.
15.1. Optimizing Cross-Pol Isolation
1. Access the Tools - Position Antenna
screen.
NOTE: You will use Skew to optimize
polarization because it drives the feed
immediately (Linear Offset is slower, longer term
drive).
2. Record the value in the Skew field in the
upper section of the screen. If this
satellite has a known Skew, it will be
entered in the satellite configuration
displayed here. If this satellite is not
skewed this field will be 0.0.
3. While talking to the technician at the
NOC make adjustments to the Skew
value to adjust polarity of the feed
under his/her direction (minus values are
accepted – type a minus sign before the
number value). It is best to adjust in one
degree increments to get close to best
isolation and then half degree steps and
then tenths as needed. Click “Submit”
after each numeric change is typed in.
4. Record the DIFFERENCE in Skew value
which was required to achieve optimum
cross-pol isolation.
5. Set Skew back to the value recorded in
step 2.