HP 4280A - Page 6

Table of Contents
Model 4280A
TABLE OF CONTENTS
Section
VIII SERVICE
Title Page
8-l.
8-3.
8-5.
8-7.
8-9.
8-11.
8-13.
8-15.
8-17.
8-19.
8-25.
8-27.
8-28.
8-30.
8-33.
8-36.
8-40.
8-42.
8-45.
8-47.
8-49.
8-51.
8-53.
8-55.
8-57.
8-59.
Introduction
........... 8-l
Safety
Considerations ...... 8-1
Theory of Operation .... 8-l
Recommended Test
Equipment ........... 8-l
Troubleshooting
........ 8-l
Repair
................. 8-l
Basic Theory ...........
8-2
Connection Modes ....... 8-2
Vector-Voltage-Current
Measurement ......... 8-2
Vector Voltage Ratio
Detector ............ 8-4
Digital Control
........ 8-5
Block Diagram
Discussion .......... 8-6
Analog Measurement
Section ............. 8-6
Signal Source
.......... 8-6
Connection Mode
Switching Circuit .... 8-6
I-V Converter ..........
8-7
Vector Ratio
Detector ............ 8-9
Process Amplifier
...... 8-9
Phase Detector ......... 8-10
A-D Converter
.......... 8-10
Auto-Zero Circuit ...... 8-10
Integrator
............. 8-10
Auto-Phase Adjust
Circuit .............
8-11
Zero Cross Detector ....
8-11
Internal Bias Source
.... 8-11
Option 001 C Offset
(Al board) ..........
8-12
iv