Preventive Maintenance - Andrew 4.9-Meter ESA Operating And Maintenance

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Visually inspect the feed window for dirt and the feed, feed supports, feed window,
and reflector for distortion, foreign object damage and environmental deterioration due
to ice and snow, dust, rain, hail, and high winds, etc. which may cause electrical compo-
nent and/or structural deformation.
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Check the cable attachment to the resolvers and to the LNA or LNB's and enclosure
mount interface for security, the cable rouging for secure hanger attachment and the
cable insulation for cuts, cracking, abrasion, and other deterioration. Check the LNA or
LNB's and the resolvers for a secure mechanical attachment. Ensure proper torquing of
polarization drive gear box setscrews and appropriate tensioning of corresponding drive
chain assembly, if applicable.
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Check (if applicable) that the drain holes in the bottom of the enclosure are not
obstructed and there is no evidence of water accumulation. Check the enclosure doors
for proper closure and that the door seals are intact, not torn, abraided or otherwise
damaged. Check that all other seals are intact and if not, use a coating of RTV-108 (sili-
cone rubber sealant) to seal any exposed electrical fitting, bolt hold, or other possible
water entry to electrical components in order to maintain a weatherproof condition. If the
enclosure is provided with a vent fan, check for free operation of the fan blade. The fan
bearings are permanently lubricated; any binding, abnormal noise or vibration necessi-
tates replacement of he fan assembly. Check and replace the fan filter element if it
appears dirty or obstructed with dust.
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Visually inspect all mechanical parts for freedom of operation with no misalignment,
binding or interference. Check all cabling for sufficient slack to prevent cable strain as
well as adequate restraint to prevent abrasion or chaffing during antenna and feed
movement.
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Check security of antenna mounting and interconnecting assembly hardware. Be cer-
tain all electrical grounding connections (including cross-axis grounding straps) are
intact and secure, not corroded or broken. Thoroughly clean any noticeable corroded
portions of grounding cables, unplated portion of universal terminals and corresponding
mounting surfaces using a wire brush. Replace rather than tighten any loose A325
structural hardware. The hardware distorts at initial installation and once loosened will
not maintain the required high strength friction connection. All other assembly and instal-
lation hardware should be tightened to its original torqued condition. When installing
new structural hardware, do not use a wrench with a lever arm longer than two feet.
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Examine painted aluminum and galvanized surfaces and touch-up where required.
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Preventive Maintenance