Table of Contents vii
6881096C25-B June, 2005
8.4 UHF Frequency Generation Circuitry ............................................................................................8-4
8.4.1 Fractional-N Synthesizer ..................................................................................................8-5
8.4.2 Voltage Controlled Oscillator (VCO).................................................................................8-6
8.5 Keypad...........................................................................................................................................8-7
Chapter 9 438-470 MHz UHF Theory Of Operation............................ 9-1
9.1 Introduction....................................................................................................................................9-1
9.2 UHF Receiver ................................................................................................................................9-1
9.2.1 Receiver Front End...........................................................................................................9-1
9.2.2 Receiver Back End ...........................................................................................................9-2
9.3 UHF Transmitter............................................................................................................................9-3
9.3.1 Transmitter Power Amplifier .............................................................................................9-3
9.3.2 Antenna Switch.................................................................................................................9-3
9.3.3 Harmonic Filter .................................................................................................................9-3
9.3.4 Antenna Matching Network...............................................................................................9-4
9.3.5 Power Control...................................................................................................................9-4
9.4 UHF Frequency Generation Circuitry ............................................................................................9-4
9.4.1 Fractional-N Synthesizer ..................................................................................................9-5
9.4.2 Voltage Controlled Oscillator (VCO).................................................................................9-6
9.5 Keypad...........................................................................................................................................9-7
Chapter 10 465-495 MHz UHF Theory Of Operation.......................... 10-1
10.1 Introduction..................................................................................................................................10-1
10.2 UHF Receiver..............................................................................................................................10-1
10.2.1 Receiver Front End.........................................................................................................10-1
10.2.2 Receiver Back End .........................................................................................................10-2
10.3 UHF Transmitter..........................................................................................................................10-3
10.3.1 Transmitter Power Amplifier ...........................................................................................10-3
10.3.2 Antenna Switch...............................................................................................................10-3
10.3.3 Harmonic Filter ...............................................................................................................10-3
10.3.4 Antenna Matching Network.............................................................................................10-4
10.3.5 Power Control.................................................................................................................10-4
10.4 UHF Frequency Generation Circuitry ..........................................................................................10-4
10.4.1 Fractional-N Synthesizer ................................................................................................10-5
10.4.2 Voltage Controlled Oscillator (VCO)...............................................................................10-6
10.5 Keypad.........................................................................................................................................10-7
Chapter 11 UHF Troubleshooting Tables........................................... 11-1
11.1 Troubleshooting Table for Receiver.............................................................................................11-1
11.2 Troubleshooting Table for Synthesizer........................................................................................11-3
11.3 Troubleshooting Table for Transmitter.........................................................................................11-4
11.4 Troubleshooting Table for Board and IC Signals.........................................................................11-6
Chapter 12 UHF Schematic Diagrams, Overlays, and Parts Lists ... 12-1
12.1 Introduction..................................................................................................................................12-1
12.1.1 Notes For All Schematics and Circuit Boards.................................................................12-1
12.1.2 Six Layer Circuit Board...................................................................................................12-3
12.2 Speaker and Microphone Schematic...........................................................................................12-3
12.2.1 Speaker and Microphone Parts List................................................................................12-3