Maintenance and Troubleshooting
ST94-21 C/Ku-Band TVRO
13-22
4.
In the “Response” window
verify proper GPS position
to within 1 nautical mile
of your current position.
The Latitude & Longitude position
of the GPS will be displayed in the
following format:
“@ LAT,N,LON,E,A”
Where LAT and LON are in degrees
and minutes, LAT will be followed
by N or S (North or South), LON will
be followed by E or W (East or
West), then a status character and
finally a checksum character.
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.
13.8.
Maintenance
13.8.1.
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
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:
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
.
EAR Controlled - ECCN EAR99
Summary of Contents for ST94-21
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