Harris DX 25U, Техническое руководство

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Section V
Maintenance/Alignments
5.1
Introduction
This section provides general system preventive maintenance
information, board replacement and alignment procedures and a
transmitter frequency change procedure.
5.2
Maintenance
The importance of keeping station performance records cannot
be overemphasized. Separate logbooks should be maintained for
operation and maintenance. These records can provide data for
predicting potential problem areas and analyzing equipment
malfunctions.
5.2.1
Maintenance Logbook
The maintenance logbook should contain a complete description
of all maintenance activities required to keep the equipment in
operational status.
The following is a list of maintenance information to be recorded
and analyzed to provide a data base for a failure reporting system:
DISCREPANCY
Describe the nature of the malfunction including all observ-
able symptoms and performance characteristics.
TIME/DATE
Time of day and date discrepancy occurred.
CORRECTIVE ACTION
Describe the repair procedure used to correct the mal-
function.
DEFECTIVE PART(S)
List all parts and components replaced or repaired and
include the following details:
a. TIME IN USE
b. PART NUMBER
c. SCHEMATIC NUMBER
d. ASSEMBLY NUMBER
e. REFERENCE DESIGNATOR
SYSTEM ELAPSED TIME
Total time on equipment
NAME OF REPAIRMAN
Person who actually made the repair
STATION ENGINEER
Indicates Chief Engineer noted and approved the repair of
the equipment
5.2.2
Preventive Maintenance
Preventive maintenance is a systematic series of operations per-
formed periodically on equipment and consists of six operations:
inspecting, feeling, tightening, cleaning, adjusting, and painting.
•
INSPECT. Inspection is the most important preventive main-
tenance operation because it determines the necessity for the
others. Become thoroughly acquainted with normal operating
conditions in order to readily recognize and identify abnormal
conditions. Inspect for the following:
1. Overheating, which is indicated by discoloration, bulg-
ing of parts, and peculiar odors.
2. Oxidation.
3. Dirt, corrosion, rust, mildew, and fungus growth.
•
FEEL. By checking for overheating, lack of proper venti-
lation or other defects can be detected and corrected before
serious trouble occurs. Become familiar with operating
temperatures in order to recognize deviations from the
normal range.
•
TIGHTEN. Tighten loose screws, bolts, and nuts. Do not
overtighten.
•
CLEAN. Clean parts only when inspection shows that clean-
ing is required and only use approved cleaning solvent.
•
ADJUST. Make adjustments only when inspection shows
that they are necessary to maintain normal operation.
•
PAINT. Paint surfaces with the original type of paint (using
prime coat if necessary) whenever inspection shows rust or
broken paint film.
5.2.3
Maintenance Of Components
The following paragraphs provide information necessary for the
maintenance of components.
5.2.3.1 Transistors and Integrated Circuits
Preventive maintenance of transistors and integrated circuits is
accomplished by performing the following steps:
CAUTION
USE CARE TO AVOID THE BUILDUP OF STATIC ELECTRICITY
WHEN WORKING AROUND INTEGRATED CIRCUITS.
a. Inspect the surrounding area for dirt. Accumulations could
form leakage paths.
b. Use compressed dry air to remove dust from the area.
WARNING
ALWAYS WEAR SAFETY GOGGLES WHEN USING COM-
PRESSED AIR.
c. Examine all transistors for loose connections or corrosion.
Tighten the transistor mounting hardware to no more than
5 inch-pounds. Overtightening the transistor hardware will
cause the insulators to short. Torque specification for tran-
sistor mounting hardware is 5 inch-pounds.
5.2.3.2
Capacitors
Preventive maintenance of capacitors is accomplished by per-
forming the following steps:
a. Examine all capacitor terminals for loose connections or
corrosion.
b. Ensure that component mountings are tight. Do not over-
tighten capacitor mounting straps as excessive pressure
could cause internal shorting of the capacitors.
c. Examine the body of each capacitor for swelling, discol-
oration, or other evidence of breakdown.
Rev. Z1: 06-02-00 Additional info to ECN 46105 888-2297-002 5-1
WARNING: Disconnect primary power prior to servicing.