Reference
Loop
-
M/N
Loop
Assembly-Level Service
CONTENTS
REFERENCE
LOOP
-
M/N
LOOP
INTRODUCTION
...............................
B-1
Assemblies
................................................................
B-1
REFERENCE
LOOP
THEORY
OF
OPERATION
...................................
B-2
A30100
MHz Voltage
Controlled
Crystal
Oscillator
Assembly
........................
B-2
A29
Reference
Phase
Detector
Assembly
.........................................
B-2
A34
Reference
Loop
-
M/N
Loop Motherboard
....................................
B-3
A51 10
MHz
Frequency
Standard
................................................
B-3
M/N
LOOP
THEORY
OF
OPERATION
...........................................
B-4
A32
M/N
VCO
Assembly
.......................................................
B-4
A33
Output Assembly
.........................................................
B-4
A31
M/N
Phase
Detector
......................................................
B-5
Simplified
Block
Diagram
......................................................
B-7
REFERENCE LOOP
ASSEMBLY-LEVEL
TROUBLESHOOTING
.............
......
B-9
Internal
Frequency
Standard
Output
Check
.......................................
B-12
10
MHz
Reference
Output
Check
.............................................
B-13
A30J1
Output Check
.........................................................
B-13
A30J2
Output
Check
.........................................................
B-15
A30W1
Output
Check
........................................................
B-16
A29J2
Output
Check
........................................................
B-17
A29J3
Output Check
.........................................................
B-17
A29J4
Output Check
........................................................
B-18
A29J5
Output
Check
.........................................................
B-19
A51
Reference
Oscillator
.....................................................
B-20
M/N
LOOP
ASSEMBLY-LEVEL
TROUBLESHOOTING
..........................
B-21
M/N
Verification and
Low
Output
Power
Troubleshooting
...........................
B-21
M/N
Output
Frequency
Incorrect
...............................................
B-23
A33J1
Output Check
(With
Phase
Lock
Loop
Closed)
...............................
B-28
A33J1
Output
Check
(With
Phase Lock Loop Open)
................................
B-30
A33J2
Output
Check
..................................................
.....
B-32
A31TP1
Signal
Check
..................................................
....
B-34
A31TP2
Output
Check
............................................
.......
B-36
A32A1W1
Output
Check
.........
...................................
...
. B-38
A31TP1
and
A31TP2
Signal Check
. ,
.........................................
B-39
Troubleshooting
Block
Diagram
................................................
B-41
Major
Assemblies Location
Diagram
............................................
B-43
HP
8340B/41B
Table
of
Contents