Service manual

iv Table of Contents
June, 2005 6880309N62-C
Chapter 7 VHF (146-174 MHz) Schematic Diagrams, Overlays, and
Parts Lists (8486342Z13-C) .............................................. 7-37
Figure 7-39. VHF (146-174 MHz) Radio Circuit Block Interconnect Diagram (8486342Z13-C) .........7-37
Figure 7-40. VHF (146-174 MHz) Receiver Front End Schematic Diagram (8486342Z13-C)............7-38
Figure 7-41. VHF (146-174 MHz) Receiver Back End Schematic Diagram (8486342Z13-C) ............7-39
Figure 7-42. VHF (146-174 MHz) Synthesizer Schematic Diagram (8486342Z13-C)........................ 7-40
Figure 7-43. VHF (146-174 MHz) Voltage Controlled Oscillator Schematic
Diagram (8486342Z13-C)...............................................................................................7-41
Figure 7-44. VHF (146-174 MHz) Transmitter and Power Control Schematic
Diagram (8486342Z13-C)...............................................................................................7-42
Figure 7-45. VHF (146-174 MHz) Controller Interconnect Schematic Diagram (8486342Z13-C) ......7-43
Figure 7-46. VHF (146-174 MHz) Microprocessor Circuitry Schematic Diagram (8486342Z13-C)...7-44
Figure 7-47. VHF (146-174 MHz) Audio Circuitry Schematic Diagram (8486342Z13-C) ...................7-45
Figure 7-48. VHF (146-174 MHz) DC Regulation Schematic Diagram (8486342Z13-C) ..................7-46
Figure 7-49. VHF (146-174 MHz) Board Component Side View (8486342Z13-C).............................7-47
Figure 7-50. VHF (146-174 MHz) Board Solder Side View (8486342Z13-C) .....................................7-48
VHF (146-174 MHz) Radio Parts List (8486342Z13-C) ........................................................................7-49
Chapter 7 VHF 146-174 MHz Schematic Diagrams, Overlays, and
Parts Lists (8486769Z04-C) .............................................. 7-53
Figure 7-52. VHF (146-174 MHz) Radio Circuit Block Interconnect Diagram (8486769Z04-C) .........7-53
Figure 7-53. VHF (146-174 MHz) Receiver Front End Schematic Diagram (8486769Z04-C)............7-54
Figure 7-54. VHF (146-174 MHz) Receiver Back End Schematic Diagram (8486769Z04-C) ............7-55
Figure 7-55. VHF (146-174 MHz) Synthesizer Schematic Diagram (8486769Z04-C)........................ 7-56
Figure 7-56. VHF (146-174 MHz) Voltage Controlled Oscillator Schematic
Diagram (8486769Z04-C)...............................................................................................7-57
Figure 7-57. VHF (146-174 MHz) Transmitter and Power Control Schematic
Diagram (8486769Z04-C)..............................................................................................7-58
Figure 7-58. VHF (146-174 MHz) Controller Interconnect Schematic Diagram (8486769Z04-C) ......7-59
Figure 7-59. VHF (146-174 MHz) Microprocessor Circuitry Schematic Diagram (8486769Z04-C)...7-60
Figure 7-60. VHF (146-174 MHz) Audio Circuitry Schematic Diagram (8486769Z04-C) ...................7-61
Figure 7-61. VHF (146-174 MHz) DC Regulation Schematic Diagram (8486769Z04-C) ...................7-62
Figure 7-62. VHF (146-174 MHz) Board Component Side View (8486769Z04-C).............................7-63
Figure 7-63. VHF (146-174 MHz) Board Solder Side View (8486769Z04-C) .....................................7-64
VHF (146-174 MHz) Radio Parts List (8486769Z04-C).........................................................................7-65
Chapter 8 403-440 MHz UHF Theory Of Operation ............................ 8-1
8.1 Introduction .................................................................................................................................... 8-1
8.2 UHF Receiver ................................................................................................................................8-1
8.2.1 Receiver Front End...........................................................................................................8-1
8.2.2 Receiver Back End ...........................................................................................................8-2
8.3 UHF Transmitter ............................................................................................................................8-3
8.3.1 Transmitter Power Amplifier..............................................................................................8-3
8.3.2 Antenna Switch................................................................................................................. 8-3
8.3.3 Harmonic Filter..................................................................................................................8-3
8.3.4 Antenna Matching Network...............................................................................................8-4
8.3.5 Power Control ...................................................................................................................8-4
8.4 UHF Frequency Generation Circuitry.............................................................................................8-4
8.4.1 Fractional-N Synthesizer...................................................................................................8-5