Series 04 Ku-Band TVRO Antenna

Setup
Series 04 Ku-Band TVRO Antenna
The ACU also provides a contact closure to ground on the SW1 terminal (J3-11) on the Terminal Mounting
Strip when the antenna is pointed within the blockage region or the system is searching, targeting or
unwrapping. The contact closure is a transistor switch with a current sinking capability of 1 Amp. This signal
can be used to control dual antenna coax switches to select IF signal connections from a second antenna
when the primary antenna is blocked.
Programming instructions:
Determine the Relative AZ limits that cause signal blockage by monitoring the REL display readings or by
graphing the expected blockage pattern. The Relative angles are with respect to the Pedestal reference,
which is normally pointed at the bow (360.0 Relative). In a dual cable-wrap antenna system, one of the
antennas may be pointed aft so its relative limits will be with respect to aft. The relative angles must be in
the range of 0 to 360 degrees (0000-3600). Convert the relative readings to limit values by multiplying by
10. Enter the beginning of the blockage region as AZ LIMIT 1 and the end of the region (clockwise direction
from AZ LIMIT 1) as AZ LIMIT 2.
EXAMPLE: A drill ship has two antennas mounted in the front of the ship with a derrick blocking the
antenna’s view to the rear. The Port antenna is mounted referenced to the bow and is blocked from 160 to
175 degrees. The Starboard antenna is mounted reference to the stern and is blocked from 355 to 375
degrees relative to the stern. (375-360=015).
The limits for the port antenna are:
The limits for the starboard antenna are:
AZ LIMIT 1 = 160 x 10 = 1600 AZ LIMIT 1 = 355 x 10 = 3550
AZ LIMIT 2 = 175 x 10 = 1750 AZ LIMIT 2 = 15 x 10 = 0150
Note: The AZ LIMITS of the starboard antenna are entered as 355 to 375 degrees. This defines a blockage
zone of 20 degrees. If the limits were entered as 015 to 355, the blockage zone would be 340 degrees.
5-2