5-7
Maintenance
54-0144 Rev. C
5. Remove the Molex connector from J11 on the
CPU board
– Fig. 5-5.
6. Remove the 4 locking nuts and flat washers and
take unit off of the bracket.
7. Replacement is the reverse of this procedure.
Antenna Gyro Calibration
1. Connect a PC to the communications port as
described in
Section 4.4, “Computer Diagnostics.”
2. Type
HALT<cr>
while the system is performing
the limit switch initialization routine. The
system will complete the initialization function
by finding the azimuth and elevation switch
limits and then go to the home position.
3. Type
DEBUGON<cr>
to enter Debug Mode.
4. Type
EL,300<cr>
.
5. Place the digital level on the top of the antenna
gyro housing. Measure and record the Antenna
Gyro Angle using the digital level.
6. Type
=CALUP,XX.X<cr>
, where
XX.X
is the
digital level reading obtained in Step 5.
7. Type
TRKANG<cr>
and observe the following
message on the PC screen:
AZ xxx.xx
EL yy.yy
8. Verify that the elevation (yy.yy) is within 0.5
˚
of
the value entered in Step 6 + 15
˚
(e.g., the digital
level reading was 12
˚
; the elevation value should
be in the range of 26.5
˚
-27.5
˚
).
9. Type
=CALAZ<cr>
. Verify that the Antenna
Gyro Azimuth scale factor is between -0.00090
and -0.00110.
10. Type
=CALEL<cr>
. Verify that the Antenna
Gyro Elevation scale factor is between 0.00090
and 0.00110.
11. Type
ZAP
to restart/reinitialize the system.