Channel Master 900 - Manual (Page 8)

ANTENNA ALIGNMENT PROCEDURE
Alignment with the satellite is obtained by setting polar-
ization, elevation and azimuth. Charts 1, 2 & 3 are 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 M6 clamp bolts (12) and turn feed clock-
wise or counterclockwise, depending on being east or
west of the satellite as shown on Chart 1. Align marks on
the horn clamp and appropriate mark on the horn scale
clamp is installed with arrow pointed toward antenna as
shown in Fig. 3.0. Keep cable groove on header in the down
position when adjusting polarization. NOTE: Single
Polarity Feed is factory assembled for vertical polar-
ity. If horizontal polarity is desired, rotate feed 90˚
(clockwise or counterclockwise).
ELEVATION
To obtain elevation value for your satellite, refer to chart 2.
Loosen bolts in curved slots of AZ/EL Housing
¹⁄₈
to
¹⁄₄
a
turn (Ref. Fig. 3.1). Turn elevation adjustment bolt clock-
wise to decrease elevation and counterclockwise to
increase elevation. Align the pointer with appropriate mark
at the desired elevation reading (Ref. Fig. 3.1). NOTE:
Degree values shown on elevation scale are Beam; that
is when the antenna face is vertical mechanical ele-
vation is 0˚, while the Beam Elevation (signal) is 22.6˚.
This will be an approximate setting. Optimum setting
achieved when fine tuning. Temporarily tighten elevation
bracket nuts.
AZIMUTH
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 the antenna
and mount, pointing it to the correct compass reading for
your location and satellite (Ref. Fig. 3.2). Slowly sweep the
antenna in azimuth until a signal is found. If the desired sig-
nal is not found, increase or decrease
elevation setting and repeat the azimuth sweep.
FINE TUNING
Use a signal strength measuring device for final adjust-
ments to obtain maximum antenna performance. Alternate
between elevation and azimuth fine tuning to reach max-
imum signal strength until no improvement can be detected.
Tighten all hardware. Torque for M8 round head, square
neck bolts is 15 N-m (11 ft-lbs).
-40 +40 0
12
ALIGNMENT
MARK
ARROW
FIG. 3.0
FEED
ASSEMBLY
FIG. 3.0 - POLARIZATION OF THE FEED
20˚
30˚
0˚
10˚
20˚
30˚
40˚
50˚
60˚
70˚
ELEVATION ADJUSTING BOLT
POINTER
PIVOT BOLT
AZ/EL
HOUSING
CLAMP
BOLT
FIG. 3.1 - SETTING ANTENNA ELEVATION
FIG. 3.2 - ROTATING ANTENNA FOR AZIMUTH