Motorola CP150 Service Manual page 4

ii
4.2.1 Receiver Front-End........................................................................................................... 4-1
4.2.2 Receiver Back-End ........................................................................................................... 4-2
4.3 VHF Transmitter............................................................................................................................. 4-3
4.3.1 Transmit Power Amplifier .................................................................................................. 4-3
4.3.2 Antenna Switch ................................................................................................................. 4-3
4.3.3 Harmonic Filter.................................................................................................................. 4-3
4.3.4 Antenna Matching Network............................................................................................... 4-4
4.3.5 Power Control ................................................................................................................... 4-4
4.4 VHF Frequency Generation Circuitry............................................................................................. 4-4
4.4.1 Fractional-N Synthesizer................................................................................................... 4-5
4.4.2 Voltage Controlled Oscillator (VCO) ................................................................................. 4-6
Chapter 5 146-174 MHz VHF Theory Of Operation ............................ 5-1
5.1 Introduction .................................................................................................................................... 5-1
5.2 VHF Receiver................................................................................................................................. 5-1
5.2.1 Receiver Front-End........................................................................................................... 5-1
5.2.2 Receiver Back-End ........................................................................................................... 5-2
5.3 VHF Transmitter............................................................................................................................. 5-3
5.3.1 Transmit Power Amplifier .................................................................................................. 5-3
5.3.2 Antenna Switch ................................................................................................................. 5-3
5.3.3 Harmonic Filter.................................................................................................................. 5-3
5.3.4 Antenna Matching Network............................................................................................... 5-4
5.3.5 Power Control ................................................................................................................... 5-4
5.4 VHF Frequency Generation Circuitry............................................................................................. 5-4
5.4.1 Fractional-N Synthesizer................................................................................................... 5-5
5.4.2 Voltage Controlled Oscillator (VCO) ................................................................................. 5-6
Chapter 6 VHF Troubleshooting Tables ............................................. 6-1
6.1 Troubleshooting Table for Receiver............................................................................................... 6-1
6.2 Troubleshooting Table for Synthesizer .......................................................................................... 6-3
6.3 Troubleshooting Table for Transmitter........................................................................................... 6-4
6.4 Troubleshooting Table for Board and IC Signals ........................................................................... 6-7
Chapter 7 VHF Schematic Diagrams, Overlays, and Parts Lists...... 7-1
7.1 Introduction .................................................................................................................................... 7-1
7.1.1 Notes For All Schematics and Circuit Boards ................................................................... 7-1
7.1.2 Six Layer Circuit Board ..................................................................................................... 7-3
7.2 Speaker and Microphone Schematic ............................................................................................. 7-3
7.2.1 Speaker and Microphone Parts List.................................................................................. 7-3
Chapter 7 VHF (136-162 MHz) Schematic Diagrams, Overlays, and
Parts Lists (8486769Z02-A) .............................................. 7-5
Figure 7-3. VHF (136-162 MHz) Radio Circuit Block Interconnect Diagram (8486769Z02-A) ........... 7-5
Figure 7-4. VHF (136-162 MHz) Receiver Front End Schematic Diagram (8486769Z02-A).............. 7-6
Figure 7-5. VHF (136-162 MHz) Receiver Back End Schematic Diagram (8486769Z02-A) .............. 7-7
June, 2005
Table of Contents
6880309N62-C