TM 9-4935-294-15/2
CHAPTER 4
REPAIR AND OVERHAUL
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Section I. PARTS, TOOLS, AND EQUIPMENT FOR FIELD AND DEPOT MAINTENANCE
included with microwave calibration test set AN/USM--
4-1. Parts
234, are authorized for maintenance personnel.
Repair parts will be procured in accordance with
calibration standards set:
Maintenance and supply
b. Common Tools and Equipment. Standard and
support, SB 9--170. Certain replacement parts such as
commonly used tools and equipment having general
fuses, lamps, and electron tubes are contained in
application are authorized for issue by tables of
combination case no. 9. A complete listing of
allowances and tables of equipment.
combination case contents is given in Appendix C of TM
9--4931--294--15/1.
4-2. Common and Special Tools and Equip-
ment
a. Special Tools. No special tools, other than those
Section II. GENERAL MAINTENANCE
be subjected to final inspection.
4-3. General
a. This chapter contains both general and specific
4-4. Handling of Disassembled Parts
maintenance instructions for repair and overhaul of the
A tray or similar receptacle should be provided for the
non--commercial electromechanical, assemblies of the
placement of major items removed in positions of proper
test set. These instructions supplement those contained
relationship for reassembly. The relative position of the
in chapter 3 of TM 9--4931--294--15/1. Refer to the
major items should be maintained until the assembly or
applicable manufacturer's handbook for instructions for
subassembly is completely assembled. This condition is
maintenance of commercial assemblies.
b. The following sections provide information and
especially important when other personnel may be
assigned to assemble the unit.
instructions for removal and installation of rack-mounted
equipment in the respective combination cases,
complete disassembly and assembly procedures for all rf
4-5. Cleaning Metal Parts
heads, removal and replacement of a typical drawer in a
General maintenance procedures involving the cleaning
combination case and disassembly and assembly of the
of metal parts are contained in TM 9-254. Individual
combination case proper.
references to this manual are not made in this chapter.
c. Restoration of the test set to a serviceable condition
may require disassembly of the assemblies and
4-6. Lubrication
subassemblies, replacement or repair of defective parts,
Lubricate the gears in the counter assemblies of the rf
and subsequent adjustments and alignment. Alignment
heads with instrument grease as specified by MIL-G-
and adjustment information for the rf heads is provided
3278A. For instructions on lubrication of commercial
by referencing the applicable calibration technical
assemblies, refer to the applicable instruction manual.
bulletins. After complete assembly, the equipment will
4-1
