Antenna Alignment Procedure - Andrew Type 183 Assembly Instructions Manual

ANTENNA ALIGNMENT PROCEDURE

Satellite Alignment
Alignment with the satellite is obtained by setting polarization, elevation, and azimuth. Charts are provided on page 11, 12
and 13 to determine the values for your earth station antenna site. "∆L" is the difference between the earth station antenna site
longitude and the satellite longitude. Use "∆L" 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 counter clockwise, depending on being east or west
of the satellite as shown in Polarization Chart on page
11. Align marks on the horn clamp and appropriate
mark 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˚).
Rib
Loosen
Pivot Bolt
Clinometer
Clamp
Bolt
Elevation Alignment
Use Elevation Chart on page 12 and determine
your elevation setting. Using a clinometer, adjust
the elevation by turning the elevation screw
Loosen
Elevation adjusting nuts until the desired elevation is
Bolt
obtained.
Note: Degree values shown on the clinometer
Elevation
Adjustment are mechanical. When the reflector face is
Screw
vertical, mechanical elevation is 90˚ or axis
is 0˚, while the beam elevation (signal) axis
is 22.62˚. Therefore, as the reflector is tilted,
remember to compensate for the 22.62˚ offset
Trunnion
angle to get the correct beam elevation. (See
Appendix A, Outline Drawing, Page 18). This is
an approximate setting. Optimum setting will be
achieved during the fine tuning.
Elevation
Hex Nuts
9
Horn
Scale
Alignment
Mark