System information

Setup 9797B-70 C-Band TXRX
5-8
Antenna B ACU would be set to:
In this example Antenna B zone 1 is caused by the stack, zone 2 is from Antenna A, zone 3 is from the mast
and zone 4 is not needed.
ZONE 1 begins (AZ LIMIT 1) at 188 degrees Relative and ends (AZ LIMIT 2) at 204 degrees Relative.
Multiply these Relative positions by 10. Enter AZ LIMIT 1 value of 1880 and AZ LIMIT 2 value of
2040. In this case the stack height only causes blockage up to an elevation of 42 degrees, so we set
EL LIMIT 12 to 0420. If the antenna is between these two AZ Limit points but the elevation is
greater than 42 degrees, the antenna will no longer be blocked.
ZONE 2 begins (AZ LIMIT 3) at 254 degrees Relative and ends (AZ LIMIT 4) at 278 degrees Relative.
Multiply these Relative positions by 10. Enter AZ LIMIT 3 value of 2540 and AZ LIMIT 4 value of
2780. In this case the Antenna B height only causes blockage up to an elevation of 12 degrees, so
we set EL LIMIT 34 to 0120. If the antenna is between these two AZ Limit points but the elevation
is greater than 12 degrees, the antenna will no longer be blocked.
ZONE 3 begins (AZ LIMIT 5) at 342 degrees Relative and ends (AZ LIMIT 6) at 348 degrees Relative.
Multiply these Relative positions by 10. Enter AZ LIMIT 5 value of 3420 and AZ LIMIT 6 value of
3480. In this case the mast height only causes blockage up to an elevation of 41 degrees, so we set
EL LIMIT 56 to 0410. If the antenna is between these two AZ Limit points but the elevation is
greater than 12 degrees, the antenna will no longer be blocked.
ZONE 4 is not needed. Enter AZ LIMIT 7 value of 0000 and AZ LIMIT 8 value of 0000. Set EL LIMIT
78 to 0000. If your ACU software includes 5 volt polarization you will not see these AZ & EL LIMIT
parameters.
EXAMPLE 3 - One blockage Zone: A ship has a
Sea Tel antenna mounted on the center line of the
ship. A mast is forward and an engine exhaust stack is
aft. In this example the Stack does NOT block the
satellite, only the mast forward does. In this example
zone 1 is caused by the mast, zone 2, 3 and 4 are not
needed:
ZONE 1 begins (AZ LIMIT 1) at 352 degrees
Relative and ends (AZ LIMIT 2) at 8 degrees
Relative. Multiply these Relative positions by
10. Enter AZ LIMIT 1 value of 3520 and AZ
LIMIT 2 value of 0080. In this case the mast
height only causes blockage up to an
elevation of 52 degrees, so we set EL LIMIT
12 to 0520. If the antenna is between these
two AZ Limit points but the elevation is
greater than 52 degrees, the antenna will no
longer be blocked.
ZONE 2 is not needed. Enter AZ LIMIT 3
value of 0000 and AZ LIMIT 4 value of
0000. Set EL LIMIT 34 to 0000.
ZONE 3 is not needed. Enter AZ LIMIT 5 value of 0000 and AZ LIMIT 6 value of 0000. Set EL LIMIT
56 to 0000.
ZONE 4 is not needed. Enter AZ LIMIT 7 value of 0000 and AZ LIMIT 8 value of 0000. Set EL LIMIT
78 to 0000. If your ACU software includes 5 volt polarization you will not see these AZ & EL LIMIT
parameters.