Andrew 3.7-Meter Earth Station Antenna manual Preventive Maintenance

Page 81

Operate the azimuth and elevation drives as well as the feed rotation in both the plus

and minus direction from the local control/motor drive controller at least once every three months during antenna down time. Check the mechanical limit switches provided at the end points stop antenna and feed movement, and limit travel to prevent structural interference and damage. Check the mechanical limit switches for corrosion and water entry and the arm on each feed limit switch for free movement without binding. Be cer- tain both feed rotation limit switch arms are not distorted and ride centrally on the actu- ating cam to open their corresponding limit switch.

Inspect the azimuth and elevation jackscrew boots for security of attachment at both

ends, for abrasion, tears, cuts, brittleness and other damage that may expose the jackscrew to the environment (water, dust, etc.). Minor repairs can be made with RTV- 108 silicone rubber sealant.

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.

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.

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.

Check for the appearance of surface lubricants that will cause the accumulation of dirt

and grime. Clean off all excess surface lubricants with a cloth and if required, a cloth dampened not wetted with trichlorethylene, or equal.

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.

81

Preventive Maintenance

Image 81
Contents Meter ESA Table of Contents Introduction Meter Earth Station AntennaProprietary Data Information and Assistance Technical Customer Service CenterHow to Use This Manual Overview ContentGetting Started OverviewRecommended Tools Getting Started Returning Equipment Step Getting Started For Mpjk Types Only Main Reflector Assembly Enclosure Assembly Reflector-To- Mount Assembly Subreflector Feed System Overview Foundation Preparation Installation Procedures1b A-325 Tensioning For bolts over four diameters Tensioning StepMount Unpacking Assembly Using a Crane Step 4b Ground Mount Assembly Base Hardware Ground Mount Assembly Alignment with Anchor Bolts Assembly Without a Crane Step6a Manual Lift 8a Ground Mount Assembly Base Hardware 8b Ground Mount Assembly Tiller Arm Hardware Motorizable Pedestal Ground Mount Assembly Step8d Ground Mount Assembly Tiller Arm Hardware 10 Waxing Bolts Manual Pedestal Ground Mount Assembly StepStep 13 Elevation and Azimuth Struts Step 17a Azimuth Strut Assembly Front 17b Azimuth Strut Assembly Rear 20 Bracket-Support Plates Top View 21a Elevation Strut Bracket 22a Manual Actuator Assembly Manual Actuator Assembly Step23 Azimuth Pivot Bracket Assembly 25a Jack Unscrew Procedure 26 Protective Boot Attachment 28a Elevation Jack Step 29b Left Side Frame Attachment Embedded Pipe Ground Mount Assembly Step29d Elevation/Azimuth Strut Assembly Step Elevation/Azimuth Strut Assembly29f Elevation Axis Weldment Attachment 29g Azimuth Strut/Pointer Attachment 29i Fine Azimuth Adjustment Attachment 30a Domestic Pack Reflector Unpacking Step30b Export Pack 31 Reflector Seam Alignment Step Assembly32 Seam Bolt Insertions Very Important 33c Alignment Bolt Insertions 34a Mounting Ring Placement 35a Mounting and Center Rings -35b Mounting and Center Rings Alignment Test Step Enclosure Pedestal Mount Only Step 38a Enclosure Final Assembly39a Enclosure Hardware Step 43 Safety Rope Tag Lines Reflector-to-Mount Assembly Using a Crane Step44b Crane Lift Without a Crane Step 46 Reflector to Mount 48 Enclosure Bracket Alignment Step 50a Reflector to Mount Reflector-to-Mount Assembly Embedded Pipe Ground Mount Step Subreflector Step 52a Subreflector Strut Assembly53a Subreflector Assembly 53c Subreflector Assembly 54a Subreflector Attachment Subreflector Struts Embedded Pipe Ground Mount Assembly Step Subreflector Adjustment Step Step Step Feed System Operation Overview Acquiring a Satellite StepPure Noise Signal on Spectrum Analyzer Step Polarization at 45 degrees from Optimum Setting Maximizing Odd Transponders Operation Subreflector Adjustment Overview General Cleaning Electrical Parts Preventive MaintenancePreventive Maintenance Antenna Preventive Maintenance Drive System Voltage Current Checks Step Step Pedestal Mount Bearing Pad Adjustment Preventive Maintenance Jackscrews/Motors Gear Motor/Housing Fill Drain Requirements Service Lube Quantity Andrew