NEC DTU-70 Instruction Manual page 23

SECTION. 5 MAINTENANCE
5-1 General .................................................................................................................... 5-1
5-2 How to Stop Operation ........................................................................................... 5-2
5-3 Transmitter Operation Log ..................................................................................... 5-5
5-4 Monthly Maintenance Services .............................................................................. 5-5
5-5 Annual Maintenance Services ................................................................................ 5-6
5-5-1 Transmitter Station ........................................................................................... 5-6
5-5-2 Transmitter ........................................................................................................ 5-7
5-5-3 Check of Soldering.............................................................................................. 5-8
5-5-4 Check Items for Exciter .................................................................................... 5-9
5-5-5 Check Items for Coaxial System ....................................................................... 5-9
5-6 Probable Causes of Troubles .................................................................................. 5-10
5-6-1 Inability Starting ............................................................................................... 5-10
5-6-2 Output Lowering ............................................................................................... 5-10
5-6-3 C/N Lowering ................................................................................................... 5-10
5-6-4 Detection of Reflection Power .......................................................................... 5-11
5-7 Replaceable Parts and Replacement Periods .......................................................... 5-11
5-8 Troubleshooting ...................................................................................................... 5-13
5-8-1 Fault Indications ................................................................................................ 5-13
5-9 Replacement procedure of units ............................................................................... 5-15
5-9-1 Replacement procedure of power amplifier ...................................................... 5-15
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GWP-G22996