Model 1278K Mobile VSAT Antenna System
11
Operation and Maintenance Manual
Figure 3.2
3.4 AZIMUTH
AvL CABLE DRIVE
The patented azimuth AvL cable drive produces a drive
system with zero backlash high stiffness, no wear, no
lubrication, and maximum reliability. The system
consists of three 5/64 7x19 stainless steel aircraft
control cables reverse wrapped twice around the
grooved capstan (Figure 3.2) and once around the
drum, with solid connections on one end and high force
Belleville springs on the other end. One cable has the
capacity to withstand a 80mph wind load. The
additional cables are used to provided increased
stiffness and drive redundancy.
If a cable becomes
damaged during usage, cut off cable and continue
to use positioner. Replace cable when time
permits at your maintenance facility.
The cables are sized to last the life of the
positioner. No replacement from wear is expected. The springs package at one end will
automatically compensate for any elongation of the cable.
Cable position should be checked as per periodic maintenance schedule in Section 7. If cables have
drifted, manually move cables using blunt instrument on azimuth drum until correct position is obtained.
(Figure 3.2)
At installation, the Belleville springs are collapsed until no “air” is seen
between the springs. (Figure 3.3) You should check this condition yearly
to account for the slow settling of the cable strands. Use 3/8 box-end
wrench to tighten the nut. Be sure not to over tighten.
Figure 3.3