Sea Tel ST94-21 Installation And Operation Manual Download

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ST94-21 C/Ku-Band TVRO

Installation

3-29

If any of these steps fail, or the ACU reports model "xx97", re-configure the PCU as described in the Setup

section of this manual. If initialization still fails, this indicates a drive or sensor problem, refer to the

Troubleshooting section.

3.16.2.

Home Flag Position

Note the approximate position of the antenna relative to the bow of the ship while it is at the home switch

position. This information will be used later to calibrate the relative position display of the antenna.

3.16.3.

BDE

Turn Power ON to the ACU. Record the power-up display, Master (ACU) Model & Software version and the
Remote (PCU) Model & Software version.

3.16.4.

Balancing the Antenna

The antenna and equipment frame are balanced at the factory however, after disassembly for shipping or

maintenance, balance adjustment may be necessary. The elevation and cross-level motors have a brake
mechanism built into them, therefore, power must be ON to release the brakes and

DishScan®

and

antenna drive must be OFF to balance the antenna. . Do NOT remove any of the drive belts. Balancing

is accomplished by adding or removing balance trim weights at strategic locations to keep the antenna from

falling forward/backward or side to side. The antenna system is not pendulous so 'balanced' is defined as the
antenna remaining at rest when left in any position.
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:

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:

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

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.

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.

When completed, the antenna will stay at any position it is pointed in for at least 5 minutes (with no

ship motion).

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.

3.16.5.

Fine Balance and Monitoring Motor Drive Torque

The DacRemP

DISPTC

graph chart provides a means for monitoring torque commands required for each

motor for diagnostic purposes and verifying antenna balance. By observing each trace, the required drive of
the antenna via the motor driver PCB may be established.

•

To view the Torque Commands, select the

graph chart.

EAR Controlled - ECCN EAR99