Specifications

Section 3 - Periodic Preventive Maintenance
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1.0 General
1.1 This section contains periodic preventive maintenance
instructions for the 4.5-Meter Transportable Earth Station
Antenna. Provided in this section are inspection and pre-
ventive maintenance procedures including cleaning, lubri-
cation and painting procedures deemed within the capabili-
ties of the average station technician. Refer to the applica-
ble vendor manuals for any repair procedures not included
in this section yet designated as capable of being per-
formed in the “field” rather than requiring specialized facili-
ties, tools and/or test equipment as well as technically
trained personnel.
1.2 An operational checkout procedure provides an ac-
curate indication of the overall earth station performance
and should be performed at monthly intervals or after ex-
tended periods of storage or long distances of travel (in
excess of 500 miles). This procedure is essentially per-
formed during the various modes of normal operation of the
earth station. In addition, the operational checkout proce-
dure should be performed after any repairs or adjustments
have been made, or whenever the earth station is suspect-
ed of degraded operation. If any discrepancy in perfor-
mance exists and the condition cannot be readily remedied
to return the earth station to a proper operating condition,
conventional troubleshooting procedures should be fol-
lowed to locate the fault. After the trouble is determined and
the repairs effected, a final operational checkout procedure
should be performed to verify that all discrepancies have
been corrected.
W
arning:
Service personnel must at all times observe all safety regu-
lations. Do not perform any maintenance task on the equip-
ment without first turning off the main power supply. Under
certain conditions, dangerous potentials may exist when the
main supply power controls are in the off position due to
charges retained by capacitors. Always discharge and
ground a circuit after removing power.
2.0 Inspection and Preventive Maintenance
2.1 The following paragraphs describe the inspection and
preventive maintenance procedures for the earth station.
These instructions include general cleaning and inspection,
the preservation of metal parts and lubrication. Periodic
replacement of assemblies or components as a preventive
measure is not required. Malfunctions of the earth station
can be traced to components, assemblies and parts through
the use of conventional troubleshooting procedures.
2.2 General Cleaning. To prevent the excessive accumula-
tion of dust and dirt as well as the removal of such contam-
inants, thoroughly clean the equipment whenever visually
inspecting the earth station components. No special clean-
ing procedures are required. However, a thorough cleaning
in accordance with the following procedures is required to
assure continued trouble-free operation.
Warning:
Use cleaning solvents outside or in a well ventilated room
with free air circulation. Avoid breathing fumes and exces-
sive skin contact with the solvents. Keep solvents away
from open flame.
A. Electrical Parts. Minor cleaning, such as the removal of
dust and loose foreign particles can be accomplished by
vacuuming, by using a soft brush or lint-free cloth or by
blowing out the dust and dirt with low pressure (5 to 25 psi),
dry compressed air. When using air to blow off the contam-
inants, either avoid or be careful when directing the air
stream on delicate parts. To remove imbedded dirt, grease
or oil from electrical parts, use a 50% solution of isopropyl
(rubbing) alcohol and apply with a soft bristle brush. It may
be necessary to brush some parts vigorously with a stiff
bristle brush to remove imbedded and hardened dirt parti-
cles. If possible, avoid excessive use of cleaning solvent on
electrical insulation. After cleaning, allow the cleaned parts
to dry for 10 to 15 minutes before placing the equipment
into operation.
B. Mechanical Parts. Clean mechanical parts by first
removing dust, dirt and other loose contaminants with a
scraper, stiff brush (bristle, or wire in the case of rust or
other corrosion) or cloth or compressed air at 25 to 40 psi.
Any accumulated imbedded dirt, corrosion, grease or oil
deposits that require further cleaning may be removed with
a bristle or wire brush and a cleaning solvent such as
trichlorethylene, or equal. Ensure that the surfaces of the
reflector alignment pins, 1/4-turn fastners with correspond-
ing spacers and adjacent rib areas remain free of dirt
buildup, cinders and any other foreign matter. After cleaninq,
allow the cleaned parts to dry completely before placing the
equipment into operation. Clean and paint aluminum, galva-
nized and plastic surfaces in accordance with the proce-
dures outlined in paragraph 3.0, Preservation of Component
Parts.
2.3 Inspection. The frequency of inspection is contingent
upon the user’s individual standards and the operational en-
vironment in which the earth station is located. However, a
visual inspection of the earth station components should be
performed at least monthly. Where there are no established
wear limits, perform a visual inspection to locate worn or
damaged parts which could cause improper functioning of
the earth station. Do not attempt to clean resolver assem-
blies or the feed motorization assembly unless they are
malfunctioning. Inspect the surface of the reflector to
ensure the surface is free of dirt, cinders or other foreign
matter. In the absence of any special inspection require-
ments, operational tests are the most effective means of
isolating parts and assemblies requiring further inspection.
Any condition noted during inspection that may preclude
continued proper operation of the earth station prior to the
next scheduled inspection should be noted. The discrepant
condition should be corrected (repaired or replaced) imme-
diately or at the conclusion of the inspection procedure.