System information

Maintenance and Troubleshooting 9497B-20 Ku-Band TVRO
7-14
Furuno default value is in Japan at
34.4N 135.2E
(@3444,N,13521,E,,_).
After acquiring a good fix at Sea
Tel the string is
@3800,N,12202,W,A^
for our 38N 122W Latitude and
Longitude position.
The status character tells you the
status of the GPS.
“,” (Comma) = GPS has NOT
acquired a proper fix,
“N” = GPS fix is NOT valid
“A” = GPS has acquired a valid fix.
7.4. Maintenance
7.4.1. 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 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 antenna should be balanced within one ounce at
the typical trim weight location of 10 inches from the axis of rotation.
1. Turn Antenna power breaker ON
2. To turn OFF antenna drive (AZ, EL & CL) follow the Pedestal Control Unit Configuration procedure in
this chapter to set the PCU configuration to (N0000) but do NOT save.
3. Balance the antenna elevation axis with the elevation near horizon (referred to as front to back
balance) by adding, or subtracting, small counter-weights.
4. Then balance Cross Level axis (referred to as left-right balance) by moving existing counter-
weights. Do NOT add counter-weight during this step.
5. Last, balance the Elevation Axis with the antenna pointed at zenith (referred to as top to bottom
balance) by moving existing counter-weights. Do NOT add counter-weight during this step.
6. When completed, the antenna will stay at any position it is pointed in for at least 5 minutes (with
little, to no, ship motion).
7. Turn antenna power OFF, and then back ON, to re-Initialize the antenna. This will also turn antenna
drive (AZ, EL & CL) back ON.
7.4.2. To Adjust Tilt:
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.
Step 1 Turn Off DishScan Drive.
Using the DAC2202 ACU Front Panel
: