9497B-21 C/Ku-Band TVRO Maintenance and Troubleshooting
7-23
The “REMOTE BALANCE” parameter (located at the end of the Remote Parameters after REMOTE TILT) of the
ACU. When enabled, Remote Balance Mode temporarily turns DishScan, Azimuth, Elevation and Cross-Level
drive OFF. This function is required when trying to balance antenna systems that have a built-in brakes on
the elevation and cross-level motors.
Assure that Antenna power is ON and that the antenna has completed initialization.
At the ACU:
1. From the ACU - REMOTE BALANCE parameter: Enable balance mode (refer to your ACU manual).
The screen should now display “REMOTE BALANCE ON”.
At the Antenna:
2. At the Antenna: Balance the antenna with the elevation near horizon (referred to as front to back
balance) by adding, or subtracting, small counter-weights.
3. Then balance Cross Level axis (referred to as left-right balance) by moving existing counter-
weights from the left to the right or from the right to the left. Always move weight from
one location on the equipment frame to the same location on the opposite side of the equipment
frame (ie from the top left of the reflector mounting frame to the top right of the reflector
mounting frame). Do NOT add counter-weight during this step.
4. Last, balance the antenna with the elevation pointed at, or near, zenith (referred to as top to bottom
balance) by moving existing counter-weights from the top to the bottom or from the
bottom to the top. Always move weight from one location on the equipment frame to the same
location on the opposite side of the equipment frame (ie from the top left of the reflector
mounting frame to the bottom left of the reflector mounting frame). Do NOT add counter-weight
during this step.
5. When completed, the antenna will stay at any position it is pointed in for at least 5 minutes (with no
ship motion).
6. Do NOT cycle antenna power to re-Initialize the antenna. Return to the ACU, which is still in
REMOTE BALANCE mode, and press ENTER to exit Remote Balance Mode. When you exit Balance
Mode the antenna will be re-initialized, which turns DishScan, Azimuth, Elevation and Cross-Level
drive ON.
7.8.2.
A REMOTE TILT calibration is required to align the level cage assembly correctly so that all sensors will be
aligned accurately to the axis they relate to. The fluid filled tilt sensor provides a two dimensional horizon
reference. The system is not able to automatically calculate the exact center value, therefore it is necessary
to perform this procedure to manually enter any offset required to make sure the PCU receives a true
reference to the horizon. The procedures below describes the process of performing this calibration from
either the ACU front panel or DacRemP diagnostic software by connecting the ACU’s RS-422 M&C Port to an
available serial port on a Laptop/Desktop computer using a standard 9 pin serial cable.
To Adjust Tilt:
Step 1 Turn Off DishScan Drive.
Using the DAC2202 ACU Front Panel
1. Go to Remote Command window by pressing and holding the two LEFT & RIGHT
arrows
:
until the EL TRIM parameter is displayed.
2. Press and release both Left & Right arrow keys again. The “SAVE NEW PARAMETERS”
window should now be displayed.
3. Press either the
ENTER key or the DOWN key until the “REMOTE DishScan
TG” parameter is displayed.
4. Press the
“RIGHT arrow to activate selection, then press the Up arrow to toggle
state to OFF. Press the
ENTER key (Note: You will see that an error code 16 is
generated when DishScan movement is off.)
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