Antenna Alignment Procedure - Andrew 960 .96 Meter Class I Assembly Instructions Manual

ANTENNA ALIGNMENT PROCEDURE
Satellite Alignment
Alignment with the satellite is obtained by setting polarization, elevation, and azimuth. Charts are provided in this manual to determine the
values for your earth station antenna site. "6L" is the difference between the earth station antenna site longitude and the satellite longitude.
Use "6L" and your earth station latitude to obtain polarization, elevation or azimuth setting .
Polarization of Feed
Loosen feed Horn clamp bolts and turn feed clockwise or counterclockwise,
depending on being east or west of the satellite as shown on Chart 1. For coarse
setting, align marks on the horn scale. Polarization chart assumes antenna system
polarization is transmit vertical and satellite vertical Pol is perpendicular to plane
of geostationary arc. For horizontal transmit of antenna, feed must be rotated 90°
from values shown. (Starting point for polarization adjustment is 0°, as shown. Use
a signal strength measuring device for final polarization setting and tighten horn
clamp bolts to 5.4 N-m (4 ft-Ib).
Edge of Clar:'l"lP
Bracket Indicates
Degree
of
Elev<:Jtion
Azimuth - Initial Setting
Elevation Adjustment Screw
Elevation - Initial Setting
Use Chart 2 and determine your elevation setting. Loosen
elevation pivot bolts and bolts in curved slots (both sides) of
az/el housing approximately 1 complete turn. Turn elevation
adjustment bolt clockwise to decrease elevation and counter-
clockwise to increase elevation . Align the edge of the clamp
with appropriate mark on housing at the desired elevation
reading . This will be an approximate setting . Optimum
setting achieved when fine tuning .
NOTE:
Degree values shown on Elevation Scale are Beam; there
is
no need to compensate for any offset angle. (See Appendix A,
Outline Drawing). If clinometer
is
used, you must compensate for
offset angle.
Use Chart 3 and determine your azimuth setting. Values in chart must be adjusted for magnetic deviation for your location for correct
compass reading . Rotate reflector and mount pointing it to the correct compass reading. Slowly sweep the antenna in azimuth until
signal is found . If the desired signal is not found, increase or decrease elevation setting and repeat the azimuth sweep. Tighten half clamp
bolts and set screws.
Compass
• I
Rotate Antenna
~ ;;;
,/ On Ground Tube
1',- - - - - - -
--"' - :e
....
_--,
_
...
Azimuth
Example Depicts Azimuth Heading To 171·
(Azimuth
±
Magnetic Deviation)
Fine Tuning
Use Signal Tuning Device for final adjustments to obtain maximum antenna performance. Alternate between elevation and azimuth fine
tuning to reach maximum signal strength, until no improvement can be detected. Azimuth is fine tuned by loosening the (4) carriage head
bolts and swivel nut which allows adjusting the azimuth fine tune adjusting bolt for the peak signal. When fine tuning is complete, tighten
and torque all az/el hardware to
16.3
N-m
(12
ft-Ib) . Do not exceed
16.3
N-m
(12
ft-Ib). Torque Clamp Hardware to
24.4
N-m (18 ft-Ib) in
alternating sequence.
IMPORTANT: Recheck and repeat torque on four clomp bolts, in alternating sequence, until all bolts are equally torqued to 1 8 ft-Ib.
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