Model 1278K Mobile VSAT Antenna System
14
Operation and Maintenance Manual
Figure 4.2
The position should be checked per the periodic maintenance schedule in Section 6. If the cables have
drifted, manually move cables using blunt instrument on elevation drums until correct position is obtained.
At installation the Belleville springs are collapsed until no "air" is seen between the springs. You should
check this condition yearly to account for the slow settling of the cable strands. Use pliers to hold stud
and 1/4 box end wrench to tighten nut
. Be sure not to over tighten. Tighten until springs are almost
fully collapsed.
4.5 ELEVATION POSITION FEEDBACK
The elevation position feedback is produced by an electronic inclinometer and encoder mounted on output
shaft of motor. Since the AvL cable drive has no backlash, the position feedback is as accurate as the
resolution and accuracy of the clinometer and encoder. The clinometer has a resolution of 0.1 degrees
with and accuracy/linearity of 1% in the 0-45º range and monotonic in the 45-90º range. The clinometer is
rated for an outdoor environment. The encoder also provides precise feedback on units position during
operation. The limits are controlled by using inputs from the potentiometer and optical encoder together
and are set in and controlled by the TracStar Systems controller.
The clinometer mounted in the pol motor box, which provides
additional weather protection. (Fig 4.2)
4.6 ELEVATION STOW SWITCH
The elevation stow, the east elevation pivot assemblies under
the drum. (Fig 4.1) The switch is fixed to pivot wall and are
actuated by a cam profile machined into the drum side plates.
The elevation stow switch is adjusted by using needle nose
pliers and bending the limit switch lever as needed.
