GE MLSH041, Maintenance Manual

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TABLE OF CONTENTS
LBI-38438A 3
1 DESCRIPTION ........................................................................................................................................4
2 INITIAL ADJUSTMENT........................................................................................................................4
2.1 TRANSMITTER ADJUSTMENT...............................................................................................4
2.2 RECEIVER ADJUSTMENT .......................................................................................................4
2.3 RE-INSTALLATION ..................................................................................................................4
3 MAINTENANCE .....................................................................................................................................5
3.1 PREVENTIVE MAINTENANCE...............................................................................................5
3.1.1
Connections ...................................................................................................................5
3.1.2 Electrical System ...........................................................................................................5
3.1.3 Mechanical Inspection ...................................................................................................5
3.1.4 Antenna..........................................................................................................................5
3.1.5 Alignment ......................................................................................................................5
3.1.6 Frequency Check ...........................................................................................................5
3.1.7 Disassembly...................................................................................................................5
3.2 PA TRANSISTOR REPLACEMENT .........................................................................................6
3.3 CHIP COMPONENT REPLACEMENT.....................................................................................7
3.3.1
To Remove Chip Components.......................................................................................7
3.3.2 To Replace Chip Components .......................................................................................7
4 DISASSEMBLY PROCEDURE .............................................................................................................8
4.1 TO REMOVE THE SYSTEM CONTROL/SYNTHESIZER BOARD.......................................8
4.2 TO REMOVE THE TRANSMITTER RECEIVER BOARD......................................................8
4.3 TO REMOVE THE FRONT PANEL/CONTROL UNIT............................................................8
5 ALIGNMENT AND TROUBLESHOOTING PROCEDURES ...........................................................11
5.1 SYNTHESIZER...........................................................................................................................11
5.1.1
Test Equipment Required ..............................................................................................11
5.1.2 TX VCO & RX VCO Alignment...................................................................................12
5.1.3 Transmitter Frequency Adjustment ...............................................................................13
5.1.4 Receiver Frequency Adjustment....................................................................................13
5.1.5 Modulation Level Adjustment .......................................................................................13
5.1.6 Audio Check ..................................................................................................................14
5.1.7 Audio Output Level Adjustment Procedure...................................................................15
5.2 TRANSMITTER..........................................................................................................................16
5.2.1
General Description of Adjustment ...............................................................................16
5.2.2 Measuring Instruments ..................................................................................................16
5.2.3 Adjustment System ........................................................................................................17
5.2.4 Transmitter Adjustment Procedure ................................................................................17
5.3 RECEIVER ..................................................................................................................................20
5.3.1
Receiver Alignment .......................................................................................................20
5.3.2 Alignment Procedure .....................................................................................................21
5.3.3 Fixed Squelch Adjustment.............................................................................................21
5.3.4 Receiver Test Procedures...............................................................................................22
5.3.5 Test Procedure ...............................................................................................................22