Motorola 6864115B62-C Detailed Service Manual page 259

Table of Contents
Chapter 1 MODEL CHART AND TECHNICAL SPECIFICATIONS
1.0 GM140/GM160 Model Chart................................................................................1-1
2.0 GM340/GM360/GM380 Model Chart ...................................................................1-2
3.0 GM640/GM660/GM1280 Model Chart .................................................................1-3
4.0 Technical Specifications ......................................................................................1-4
Chapter 2 THEORY OF OPERATION
1.0 Introduction ..........................................................................................................2-1
2.0 UHF (403-470MHz) Receiver .............................................................................2-1
2.1 Receiver Front-End .......................................................................................2-1
2.2 Front-End Band-Pass Filters & Pre-Amplifier .................................................2-2
2.3 First Mixer and High Intermediate Frequency (IF)..........................................2-2
2.4 Low Intermediate Frequency (IF) and Receiver Back End.............................2-2
3.0 UHF (403-470MHz) Transmitter Power Amplifier (PA) 25 W ..............................2-3
3.1 First Power Controlled Stage..........................................................................2-4
3.2 Power Controlled Driver Stage .......................................................................2-4
3.3 Final Stage......................................................................................................2-4
3.4 Directional Coupler .........................................................................................2-5
3.5 Antenna Switch...............................................................................................2-5
3.6 Harmonic Filter ...............................................................................................2-5
3.7 Power Control.................................................................................................2-5
4.0 UHF (403-470MHz) Frequency Synthesis ..........................................................2-6
4.1 Reference Oscillator .......................................................................................2-6
4.2 Fractional-N Synthesizer ................................................................................2-6
4.3 Voltage Controlled Oscillator (VCO) ...............................................................2-7
4.4 Synthesizer Operation ....................................................................................2-8
5.0 UHF (403-470MHz) Transmitter Power Amplifier (PA) 45 W ..............................2-9
5.1 Power Controlled Stage................................................................................2-10
5.2 Pre-Driver Stage ...........................................................................................2-10
5.3 Driver Stage..................................................................................................2-10
5.4 Final Stage....................................................................................................2-11
5.5 Directional Coupler .......................................................................................2-11
5.6 Antenna Switch.............................................................................................2-11
5.7 Harmonic Filter .............................................................................................2-11
5.8 Power Control...............................................................................................2-11
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