20-30 Loops 
Assembly-Level Service 
CONTENTS 
INTRODUCTION 
.............................................................. 
C-1 
Assemblies 
.................................................................. 
C-1 
OVERALL 
THEORY 
OF 
OPERATION 
............................................ 
C-2 
In 
CW/Manual Mode 
.......................................................... 
C-2 
In 
Swept 
Modes 
............................................................. 
C-2 
20-30 
Loop Characteristics 
..................................................... 
C-3 
PLL2 
Theory 
of Operation 
......................................................C-3 
PLL3 
Theory 
of 
Operation 
..................................................... 
C-6 
PLL1 
Theory 
of Operation 
...................................................... 
C-7 
Simplified 
Block 
Diagram 
...................................................... 
C-9 
20-30 
LOOPS 
ASSEMBLY-LEVEL 
TROUBLESHOOTING 
......................... 
C-11 
Troubleshooting 
Phase 
Lock 
Loop 
2 
.............................................C-11 
Troubleshooting 
Phase 
Lock 
Loop 
3 
............................................ 
C-13 
Troubleshooting 
Phase 
Lock 
Loop 
1 
............................................ 
C-14 
Verify 
the 
N1 
Divider 
........................................................ 
C-15 
Troubleshooting 
Block 
Diagram 
................................................ 
C-17 
Major 
Assemblies 
Location 
.................................................... 
C-19 
REPLACEABLE 
PARTS 
...................................................... 
C-20 
HP 
8340B/41B 
Table 
of 
Contents 
i/ii