TM 11-5820-801-30
CHAPTER 3
DIRECT SUPPORT MAINTENANCE INSTRUCTIONS
Section I. GENERAL
assemblies (3A2 through 3A12) are described in
3-1. Introduction
a. Direct Support Maintenance Requirements. Direct
illustrated in paragraph 3-12.
support personnel shall isolate faults in Amplifier,
Parametric AM-6602/MSC-46(V) (in dual channel
3-2. Unit 1 Voltage and Resistance Measurements
installation) to a replaceable module or part in Units 1, 2
a. Introduction. Faults in Unit I can be isolated to a
and 3 and shall remove and replace the faulty item. In
replaceable part or subassembly by the use of system
Unit 1, faulty parts shall be removed and replaced except
monitors and a multimeter to measure voltages and
for circuit card assembly 1A1 (Temperature Monitor) and
resistances. The diagnostic troubleshooting chart (para
Klystron Power Supply I PS I, which shall be removed
and replaced as subassemblies. In Unit 2, Modules 2A1,
The chart requires that some voltage checks be made in
2A2, 2A3, and 2A4 shall be removed and replaced, if
addition to those provided by the system monitors. When
faulty. In Unit 3, faulty parts of 3A1 shall be removed and
a fault is apparently located, either a voltage check or a
replaced; all other Unit 3 subassemblies-3A2, 3A3, 3A4,
resistance check of the suspected part will confirm its
3A5, 3A6, 3A7, 3A8, 3A9, 3A10, 3A11, 3A12-shall be
operability. Always check the part to ensure that it is
removed and replaced as necessary. In addition, an
faulty before removal. Voltage checks are made with all
apparent fault in AM-6602/MSC-46(V) may be isolated to
cables connected (to J1, J2, J3) and the POWER switch
a fault in Unit 4 or to a fault in primary power input.
and circuit breakers (REFRIG, PARAMP, MAIN) set to
Correction of these two types of faults is not discussed in
ON; that is, with normal operating power. Resistance
this manual.
checks are made with all cables removed (from J1, J2,
b. Outline of CHAPTER 3 Material Voltage and
J3) and Klystron Power Supply connector P1
resistance measurements for Unit I are given in
disconnected.
b. Parts Identification. Unit I parts layout is shown in
4 and 3-5, respectively. Fault isolation to a replaceable
voltage-resistance checking are the five E1 resistors (RI,
module or part is described in paragraph 3-6. A
R2, R3, R8, R9) connected to tie points E1-1 through E1-
diagnostic chart is provided as the principal aid in
10, on terminal board E1, the vacuum gage circuit for M2
troubleshooting. Gain and bandwidth RF test procedures
connected to tie points E1-16 through E1-22, circuit card
are described in paragraph 3-7. RF tests of waveguide
assembly Al including socket connector labeled j4 (fig. 2-
assemblies are given in paragraph 3-8. Pump frequency
17), and circuit breakers CBI and CB2. The system
and power RF tests are given in paragraph 3-9. Main
monitors (meters M1, M2, M3, M4, MS, switches S2, S3,
power failure troubleshooting is discussed in paragraph
panel lamps DSI, DS2, test points J5, J6) are used to
check the remainder of the circuit.
2A3, 2A4, subassembly IPSI and Unit 3 waveguide
3-1
