Table Of Contents - Motorola LB3 (42.0 - 50.0MHz) Service Information

Table of Contents

Chapter 1 MODEL CHART AND TECHNICAL SPECIFICATIONS
1.0 GM360 Model Chart.............................................................................................1-1
2.0 Technical Specifications ......................................................................................1-1
Chapter 2 THEORY OF OPERATION
1.0 Introduction ..........................................................................................................2-1
2.0 Low Band Receiver.............................................................................................2-2
2.1 Receiver Front-End .......................................................................................2-2
2.2 Front-End Band-Pass Filters & Pre-Amplifier .................................................2-3
2.3 First Mixer ......................................................................................................2-3
2.4 High Intermediate Frequency (IF) and Receiver Back End ............................2-3
2.5 Low Intermediate Frequency (IF) and Receiver Back End.............................2-4
2.6 "Extender" (Noise Blanker).............................................................................2-4
3.0 Low Band Transmitter Power Amplifier (PA) 25-60 W ........................................2-5
3.1 Power Controlled Stage..................................................................................2-5
3.2 Driver Stage....................................................................................................2-5
3.3 Final Stage......................................................................................................2-6
3.4 Antenna Switch...............................................................................................2-6
3.5 Harmonic Filter ...............................................................................................2-6
3.6 Power Control.................................................................................................2-6
3.7 TX Safety Switch ............................................................................................2-6
4.0 Low Band Frequency Synthesis .........................................................................2-7
4.1 Fractional-N Synthesizer ................................................................................2-7
4.2 Voltage Controlled Oscillator (VCO) ...............................................................2-9
4.3 Synthesizer Operation ..................................................................................2-10
Chapter 3 TROUBLESHOOTING CHARTS
1.0 Troubleshooting Flow Chart for Transmitter .......................................................3-1
2.0 Troubleshooting Flow Chart for Receiver (Sheet 1 of 2)......................................3-2
2.1 Troubleshooting Flow Chart for Receiver (Sheet 2 of 2)......................................3-3
3.0 Troubleshooting Flow Chart for Synthesizer........................................................3-4
4.0 Troubleshooting Flow Chart for VCO .................................................................3-5
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