Motorola GP344 - Theory of Operation

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Table of Contents
Chapter 1 THEORY OF OPERATION
1.0 Introduction ..........................................................................................................1-1
2.0 Transmitter...........................................................................................................1-1
2.1 General ..........................................................................................................1-1
3.0 Receiver...............................................................................................................1-3
3.1 Receiver Front-End ........................................................................................1-3
3.2 Receiver Back-End.........................................................................................1-4
3.3 Automatic Gain Control Circuit .......................................................................1-5
4.0 Frequency Generation Circuitry...........................................................................1-6
4.1 Synthesizer.....................................................................................................1-6
4.2 Voltage Controlled Oscillator (VCO)...............................................................1-8
Chapter 2 TROUBLESHOOTING CHARTS
1.0 Introduction ..........................................................................................................2-1
Troubleshooting Chart for Receiver (Sheet 1 of 2) ..............................................2-2
Troubleshooting Chart for Receiver (Sheet 2 of 2) ..............................................2-3
Troubleshooting Chart for Transmitter ................................................................2-4
Troubleshooting Chart for Synthesizer ...............................................................2-5
Troubleshooting Chart for VCO ..........................................................................2-6
Troubleshooting Chart for Controller....................................................................2-7
Chapter 3 UHF PCB/SCHEMATICS/PARTS LISTS
1.0 Notes For All Schematics and Circuit Board........................................................3-1
2.0 Allocation of Schematics and Circuit Boards .......................................................3-2
2.1 UHF2 (450-527MHz) ......................................................................................3-2
3.0 UHF2 PCB, Schematic Diagrams and Radio Parts List (RF Board)....................3-5
3.1 8404102G03/G04/G05/G07/G08....................................................................3-5
3.2 8416243H04.................................................................................................3-23
3.3 8471475L01..................................................................................................3-37
3.4 8485641Z02 .................................................................................................3-51