ViaSat 8016, Installation And Operation Manual

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Chapter 3 - Operation
3.2.3 Signal Peaking Procedure
With the RF components functioning, perform the signal peaking procedure
as follows: (The initial setting of the elevation angle should be very nearly
correct, having been set to a horizontal reference.)
1. Jog the antenna in azimuth until the satellite signal is peaked.
2. Loosen and calibrate the azimuth angle indicator by adjusting and fixing
the pointer at the known azimuth angle of the satellite. Tighten the
screws holding the pointer and the indicator plate.
3. If fine adjustment of the elevation angle is required, jog the antenna
slightly in the elevation axis to peak on the satellite signal.
4. If required, loosen and calibrate the elevation indicator by adjusting and
fixing the pointer at the known elevation angle of the satellite. Tighten
the pointer screw.
5. Peak the feed polarization on the signal as follows:
a. Rotate feed until the signal peaks.
b. Monitor receiver C/N meter or a power meter.
c. Rotate the feed counterclockwise until the signal decreases by 1 dB.
Record the signal level. Mark a line on the feed mounting plate and a
matching line on the hub.
d. Rotate the feed clockwise until the meter has passed through the peak
and has decreased to the level recorded in step c. Make a mark on the
hub in line with the mark of the feed mounting plate.
e. Measure the distance between the marks on the hub. Calculate the
mid-point between these marks. Rotate the feed until the mark on the
feed mounting plate is aligned with the mid-point.
6. With the antenna peaked on a satellite signal, monitor the receiver C/N
meter or a power meter. Loosen the nuts which lock the studs and adjust
the subreflector spacing for maximum received signal. Use a scale to
verify that the three subreflector adjustment studs are equally spaced
from the support clamps. This will verify that the subreflector is not
skewed and consequently steering the antenna beam away from the feed.
After the maximum received signal is obtained, torque all 3/4-inch
hardware to 6 ft-lb. If further adjustment of the subreflector is required,
refer to Subreflector Adjustment procedure later in this chapter.
42S132E
3-2