Motorola EP450 Service Manual page 122

6
Fractional-N Synthesizer .......................................................................................10-5
Voltage Controlled Oscillator (VCO)......................................................................10-6
Keypad ........................................................................................................................10-7
UHF 490-527 MHz Theory Of Operation .......................................................................... 11-1
Introduction ................................................................................................................. 11-1
UHF Receiver.............................................................................................................. 11-1
Receiver Front End ............................................................................................... 11-1
Receiver Back End................................................................................................ 11-2
UHF Transmitter.......................................................................................................... 11-3
Transmitter Power Amplifier .................................................................................. 11-3
Antenna Switch ..................................................................................................... 11-3
Harmonic Filter ...................................................................................................... 11-3
Antenna Matching Network ................................................................................... 11-4
Power Control........................................................................................................ 11-4
UHF Frequency Generation Circuitry.......................................................................... 11-4
Fractional-N Synthesizer ....................................................................................... 11-5
Voltage Controlled Oscillator (VCO)...................................................................... 11-6
Keypad ........................................................................................................................ 11-7
UHF Troubleshooting Tables.............................................................................................12-1
Troubleshooting Table for Receiver.............................................................................12-1
Troubleshooting Table for Synthesizer ........................................................................12-3
Troubleshooting Table for Transmitter.........................................................................12-4
Troubleshooting Table for Board and IC Signals.........................................................12-6
V
VHF Schematic Diagrams, Overlays, and Parts Lists ........................................................7-1
Introduction ...................................................................................................................7-1
Notes For All Schematics and Circuit Boards .........................................................7-1
Six Layer Circuit Board............................................................................................7-3
Speaker and Microphone Schematic ............................................................................7-3
Speaker and Microphone Parts List ........................................................................7-3
VHF 136-162 MHz Theory Of Operation.............................................................................4-1
Introduction ...................................................................................................................4-1
VHF Receiver................................................................................................................4-1
Receiver Front-End .................................................................................................4-1
Receiver Back-End..................................................................................................4-2
VHF Transmitter ............................................................................................................4-3
Transmit Power Amplifier ........................................................................................4-3
Antenna Switch .......................................................................................................4-3
Harmonic Filter ........................................................................................................4-3
Antenna Matching Network .....................................................................................4-4
Power Control..........................................................................................................4-4
VHF Frequency Generation Circuitry ............................................................................4-4
Fractional-N Synthesizer .........................................................................................4-5
Voltage Controlled Oscillator (VCO)........................................................................4-6
Keypad ..........................................................................................................................4-7
VHF 146-174 MHz Theory Of Operation.............................................................................5-1
Introduction ...................................................................................................................5-1
VHF Receiver................................................................................................................5-1
June, 2005
INDEX:
HKLN4216C