TRAK MODEL 9200 MODULAR FREQUENCY/TIME SYSTEM
TM4400013
REV.
D
1-1
CHAPTER 1
INTRODUCTION
1-1 GENERAL
This manual contains the description, installation, operation, and maintenance instructions for the Model 9200
Digital Distribution Unit (DDU). It is intended to provide electronics personnel with the information necessary to
operate and to maintain it to the lowest replaceable unit, LRU, or assembly level.
1-2
LEVEL of COVERAGE
This manual provides coverage to the LRU only. No schematic or logic diagrams of replaceable assemblies are
provided. Unlike instruments in use a few decades ago, where it was possible to troubleshoot to the logic gate
level, the Model 9200 uses modern technology consisting of CPU’s, gate arrays, and imbedded software.
Packaging is largely surface-mount technology. Only factory-trained technicians with a high level of training can
perform maintenance below the LRU level. Most LRU’s have an MTBF in excess of ten years, so frequent
replacements are usually not required.
1-3
ORGANIZATION of MANUAL
The body of this manual describes operation of the basic Model 9200 and its most common plug-in modules.
