Motorola CP150TM User Manual

CP150™/CP200
Commercial Series
Two-Way Radio Detailed Service Manual
Product Safety and RF Exposure Compliance
!
Before using this product, read the operating instructions for safe usage contained in the Product Safety and RF Exposure booklet enclosed with your radio.
C a u t i o n
ATTENTION!
This radio is restricted to occupational use only to satisfy FCC RF energy exposure requirements.
Before using this product, read the RF energy awareness information and operating instructions in the Product Safety and RF Exposure booklet enclosed with your radio (Motorola Publication part numbe r 68P81095C98) to ensure compliance with RF energy exposure limits.
For a list of Motorola-approved antennas, batteries, and other accessories, visit the following web site which lists approved accessories: http://www.motorola.com/cgiss/index.shtml.
Computer Software Copyrights
The Motorola products described in this manu al may include copyrigh ted Motorola compu ter programs stored in semiconductor memories or other media. Laws in the United States and other countries preserve for Motorola certain exclusive rights for co pyrighted computer programs, including, but not limited to, the exclusive right to copy or reproduce in any form the copyrighted computer program. Accordingly, any copyrighted Motorola computer programs contained in the Motorola products described in this manual may not be copied, reproduced, modified, reverse-engineered, or distributed in any manner without the express written permission of Motorola. Furthermore, the purchase of Motorola products shall not be deemed to grant either directly or by implication, estoppel, or otherwise, any license under the copyrights, patents or patent applications of Motorola, except for the normal non-exclusive license to use that arises by opera tion of law in the sale of a product.
Document Copyrights
No duplication or distribution of this document or any portion thereof shall take place without the express written permission of Motorola. No part of this manual may be reproduced, distributed, or transmitted in any form or by any means, electronic or mechanical, for any purpose without the express written permission of Motorola.
Disclaimer
The information in this document is carefully examined, and is believed to be entirely reliable. However, no responsibility is assumed for inaccuracies. Furthermore, Motorola reserves the right to make changes to any products herein to improve readability, function, or design. Motorola does not assume any liability arising out of the applications or use of any product or circuit described herein; nor does it cover any license under its patent rights nor the rights of others.

Table of Contents

Foreword
Product Safety and RF Exposure Compliance.......................................................................... inside cover
Computer Software Copyrights ............................................ ... ... ... .... ... ... ... ... .... ... ... ... ...............in side cover
Document Copyrights................................................................................................................ inside cover
Disclaimer..................................................................................................................................inside cover
List of Figures...........................................................................................................................................viii
List of Tables..............................................................................................................................................xi
Related Publications...................................................................................................................................xi
Chapter 1 Test Equipment, Service Aids, and Service Tools.......... 1-1
1.1 Test Equipment.............................................................................................................................. 1-1
1.2 Service Aids...................... ... ... ... .... ... ... .......................................... ... ............................................. 1-2
Chapter 2 DC Power Distribution........................................................ 2-1
i
2.1 DC Regulation and Distribution ..................................................................................................... 2-1
Chapter 3 Controller Theory of Operation.......................................... 3-1
3.1 Controller.......................................................................................................................................3-1
3.1.1 Microprocessor Circuitry...................... ... ... .... ... .......................................... ... ... ... .... .........3-1
3.1.1.1 Memory Usage . ... .... ... ... .......................................... ... ... .... ...................................... 3-2
3.1.1.2 Control and Indicator Interface ................................................................................ 3-2
3.1.1.3 Serial Bus Control of Circuit Blocks......................................................................... 3-2
3.1.1.4 Interface to RSS Programming................................................................................ 3-3
3.1.1.5 Storage of Customer-Specific Information............................................................... 3-3
3.1.1.6 Sensing of Externally-Connected Accessories........................................................3-3
3.1.1.7 Microprocessor Power-Up, Power-Down and Reset Routine.................................. 3-3
3.1.1.8 Boot Mode Control...................................................................................................3-4
3.1.1.9 Microprocessor 7.3975 MHz Clock..........................................................................3-4
3.1.1.10 Battery Gauge..........................................................................................................3-4
3.1.2 Audio Circuitry .................................................................................................................. 3-4
3.1.2.1 Transmit and Receive Low-Level Audio Circuitry................. ... ... .... ... ...................... 3-4
3.1.2.2 Audio Power Amplifier .............................................................................................3-5
3.1.2.3 Internal Microphone Audio Voice Path .................................................................... 3-5
3.1.2.4 PTT Circuits.............................................................................................................3-6
3.1.2.5 VOX Operation ........................................................................................................3-6
3.1.2.6 Battery Charging Through Microphone Jack...........................................................3-6
3.1.2.7 Programming and Flashing Through Microphone Jack........................................... 3-6
Chapter 4 136-162 MHz VHF Theory Of Operation ............................ 4-1
4.1 Introduction....................................................................................................................................4-1
4.2 VHF Receiver ................................................................................................................................4-1
ii Table of Contents
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 P ower Control .......................... ... ... ... .... ... ... ... .... ... ... ... .......................................... ... .........4-4
4.4 VHF Frequency Generation Circuitry.............................................................................................4-4
4.4.1 F ract ional-N Synthesiz er................ ... .... ... ... ... .... ... ... ... .......................................... ... .... ... ..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 P ower Control .......................... ... ... ... .... ... ... ... .... ... ... ... .......................................... ... .........5-4
5.4 VHF Frequency Generation Circuitry.............................................................................................5-4
5.4.1 F ract ional-N Synthesiz er................ ... .... ... ... ... .... ... ... ... .......................................... ... .... ... ..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
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Table of Contents iii
Figure 7-6. VHF (136-162 MHz) Synthesizer Schematic Diagram (8486769Z02-A)..........................7-8
Figure 7-7. VHF (136-162 MHz) Voltage Controlled Oscillator Schematic
Diagram (8486769Z02-A)................................................................................................. 7-9
Figure 7-8. VHF (136-162 MHz) Transmitter and Power Control Schematic
Diagram (8486769Z02-A)...............................................................................................7-10
Figure 7-9. VHF (136-162 MHz) Controller Interconnect Schematic Diagram (8486769Z02-A)......7-11
Figure 7-10. VHF (136-162 MHz) Microprocessor Circuitry Schematic Diagram (8486769Z02-A)...7-12
Figure 7-11. VHF (136-162 MHz) Audio Circuitry Schematic Diagram (8486769Z02-A) ...................7-13
Figure 7-12. VHF (136-162 MHz) DC Regulation Schematic Diagram (8486769Z02-A) ..................7-14
Figure 7-13. VHF (136-162 MHz) Board Top Side View (8486769Z02-A) ......................................... 7-15
Figure 7-14. VHF (136-162 MHz) Board Bottom Side View (8486769Z02-A).................................... 7-16
VHF (136-162 MHz) Radio Parts List (8486769Z02-A)......................................................................... 7-17
Chapter 7 VHF 136-162 MHz Schematic Diagrams, Overlays, and
Parts Lists (8486769Z04-C) .............................................. 7-21
Figure 7-15. VHF (136-162 MHz) Radio Circuit Block Interconnect Diagram (8486769Z04-C).........7-21
Figure 7-16. VHF (136-162 MHz) Receiver Front End Schematic Diagram (8486769Z04-C) ...........7-22
Figure 7-17. VHF (136-162 MHz) Receiver Back End Schematic Diagram (8486769Z04-C)............7-23
Figure 7-18. VHF (136-162 MHz) Synthesizer Schematic Diagram (8486769Z04-C)........................ 7-24
Figure 7-19. VHF (136-162 MHz) Voltage Controlled Oscillator Schematic
Diagram (8486769Z04-C) .............................................................................................. 7-25
Figure 7-20. VHF (136-162 MHz) Transmitter and Power Control Schematic
Diagram (8486769Z04-C) ............................................................................................. 7-26
Figure 7-21. VHF (136-162 MHz) Controller Interconnect Schematic Diagram ( 8486769Z04-C)...... 7-27
Figure 7-22. VHF (136-162 MHz) Microprocessor Circuitry Schematic Diagram (8486769Z04-C)....7-28
Figure 7-23. VHF (136-162 MHz) Audio Circuitry Schematic Diagram (8486769Z04-C)...................7-29
Figure 7-24. VHF (136-162 MHz) DC Regulation Schematic Diagram (8486769Z04-C)................... 7-30
Figure 7-25. VHF (136-162 MHz) Board Component Side View (8486769Z04-C).............................7-31
Figure 7-26. VHF (136-162 MHz) Board Solder Side View (8486769Z04-C)..................................... 7-32
VHF (136-162 MHz) Radio Parts List (8486769Z04-C)........................... ..............................................7-33
Chapter 7 VHF (146-174 MHz) Schematic Diagrams, Overlays, and
Parts Lists (8486342Z09-A) .............................................. 7-21
Figure 7-27. VHF (146-174 MHz) Radio Circuit Block Interconnect Diagram (8486342Z09-A)......... 7-21
Figure 7-28. VHF (146-174 MHz) Receiver Front End Schematic Diagram (8486342Z09-A)............7-22
Figure 7-29. VHF (146-174 MHz) Receiver Back End Schematic Diagram (8486342Z09-A)............ 7-23
Figure 7-30. VHF (146-174 MHz) Synthesizer Schematic Diagram (8486342Z09-A)........................ 7-24
Figure 7-31. VHF (146-174 MHz) Voltage Controlled Oscillator Schematic
Diagram (8486342Z09-A)............................................................................................... 7-25
Figure 7-32. VHF (146-174 MHz) Transmitter and Power Control Schematic
Diagram (8486342Z09-A)...............................................................................................7-26
Figure 7-33. VHF (146-174 MHz) Controller Interconnect Schematic Diagram ( 8486342Z09-A)...... 7-27
Figure 7-34. VHF (146-174 MHz) Microprocessor Circuitry Schematic Diagram (8486342Z09-A)...7-28
Figure 7-35. VHF (146-174 MHz) Audio Circuitry Schematic Diagram (8486342Z09-A) ...................7-29
Figure 7-36. VHF (146-174 MHz) DC Regulation Schematic Diagram (8486342Z09-A) ..................7-30
Figure 7-37. VHF (146-174 MHz) Board Component Side View (8486342Z09-A).............................7-31
Figure 7-38. VHF (146-174 MHz) Board Solder Side View (8486342Z09-A).....................................7-32
VHF (146-174 MHz) Radio Parts List (8486342Z09-A)......................................................................... 7-33
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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 T ransmitter 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 P ower Control .......................... ... ... ... .... ... ... ... .... ... ... ... .......................................... ... .........8-4
8.4 UHF Frequency Generation Circuitry.............................................................................................8-4
8.4.1 F ract ional-N Synthesiz er................ ... .... ... ... ... .... ... ... ... .......................................... ... .... ... ..8-5
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8.4.2 Voltage Controlled Oscillator (VCO)................................................................................. 8-6
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
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
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
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vi Table of Contents
Chapter 12 UHF (403-440 MHz) Schematic Diagrams, Overlays, and
Parts Lists (8486635Z03-O).............................................. 12-5
Figure 12-3. UHF (403-440 MHz) Radio Circuit Block Diagram (8486635Z03-O)..............................12-5
Figure 12-4. UHF (403-440 MHz) Receiver Front End Schematic Diagram (8486635Z03-O) ...........12-6
Figure 12-5. UHF (403-440 MHz) Receiver Back End Schematic Diagram (8486635Z03-O)............12-7
Figure 12-6. UHF (403-440 MHz) Synthesizer Schematic Diagram (8486635Z03-O) .......................12-8
Figure 12-7. UHF (403-440 MHz) Voltage Controlled Oscillator Schematic
Diagram (8486635Z03-O) ..............................................................................................12-9
Figure 12-8. UHF (403-44 0 MH z) Trans mit te r an d Pow er Cont ro l Sche m atic
Diagram (8486635Z03-O) ....................................... ... .... ... ... ... ... .... ... ... ... .....................12-10
Figure 12-9. UHF (403-440 MHz) Controller Interconnect Schematic Diagram (8486635Z03-O)....12-11
Figure 12-10. UHF (403-440 MHz) Microprocessor Circuitry Schematic Diagram (8486635Z03-O) 12-12
Figure 12-11. UHF (403-440MHz) Audio Circuitry Schematic Diagram (8486635Z03-O)..................12-13
Figure 12-12. UHF (403-440 MHz) DC Regulation Schematic Diagram (8486635Z03-O).................12-14
Figure 12-13. UHF (403-440 MHz) Board Component Side View (8486635Z03-O) ..........................12-15
Figure 12-14. UHF (403-440 MHz) Board Solder Side View (8486635Z03-O)...................................12-16
UHF (403-440 MHz) Radio Parts List (8486635Z03-O) ......................................................................12-17
Chapter 12 UHF (438-470 MHz) Schematic Diagrams, Overlays, and
Parts Lists (8486348Z09-A) ............................................ 12-21
Figure 12-15. UHF (438-470 MHz) Radio Circuit Block Diagram (8486348Z09-A)............................12-21
Figure 12-16. UHF (438-470 MHz) Receiver Front End Schematic Diagram (8486348Z09-A)..........12-22
Figure 12-17. UHF (438-470 MHz) Receiver Back End Schematic Diagram (8486348Z09-A)..........12-23
Figure 12-18. UHF (438-470 MHz) Synthesizer Schematic Diagram (8486348Z09-A)......................12-24
Figure 12-19. UHF (438-470 MHz) Voltage Controlled Oscillator Schematic
Diagram (8486348Z09-A).............................................................................................12-25
Figure 12-20. UHF (438-470 MHz) Transmitter and Power Control Schematic
Diagram (8486348Z09-A)..................................... ... ... .... ... ... ... .....................................12-26
Figure 12-21. UHF (438-470 MHz) Controller Interconnect Schematic Diagram (8486348Z09-A)....12-27
Figure 12-22. UHF (438-470 MHz) Microprocessor Circuitry Schematic Diagram (8486348Z09-A) .12-28
Figure 12-23. UHF (438-470 MHz) Audio Circuitry Schematic Diagram (8486348Z09-A) .................12-29
Figure 12-24. UHF (438-470 MHz) DC Regulation Schematic Diagram (8486348Z09-A) .................12-30
Figure 12-25. UHF (438-470 MHz) Board Component Side View (8486348Z09-A)...........................12-31
Figure 12-26. UHF (438-470 MHz) Board Solder Side View (8486348Z09-A)...................................12-32
UHF (438-470 MHz) Radio Parts List (8486348Z09-A).......................................................................12-33
Chapter 12 UHF (438-470 MHz) Schematic Diagrams, Overlays, and
Parts Lists (8486348Z13-C) ............................................ 12-37
Figure 12-27. UHF (438-470 MHz) Radio Circuit Block Diagram (8486348Z13-C)............................12-37
Figure 12-28. UHF (438-470 MHz) Receiver Front End Schematic Diagram (8486348Z13-C) ........ .12-38
Figure 12-29. UHF (438-470 MHz) Receiver Back End Schematic Diagram (8486348Z13-C)..........12-39
Figure 12-30. UHF (438-470 MHz) Synthesizer Schematic Diagram (8486348Z13-C)......................12-40
Figure 12-31. UHF (438-470 MHz) Voltage Controlled Oscillator Schematic
Diagram (8486348Z13-C).............................................................................................12-41
Figure 12-32. UHF (438-470 MHz) Transmitter and Power Control Schematic
Diagram (8486348Z13-C)........................... ............................................. .... .................12-42
Figure 12-33. UHF (438-470 MHz) Controller Interconnect Schematic Diagram (8486348Z13-C)....12-43
Figure 12-34. UHF (438-470 MHz) Microprocessor Circuitry Schematic Diagram (8486348Z13-C).12-44
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Figure 12-35. UHF (438-470 MHz) Audio Circuitry Schematic Diagram (8486348Z13-C).................12-45
Figure 12-36. UHF (438-470 MHz) DC Regulation Schematic Diagram (8486348Z13-C).................12-46
Figure 12-37. UHF (438-470 MHz) Board Component Side View (8486348Z13-C) ..........................12-47
Figure 12-38. UHF (438-470 MHz) Board Solder Side View (8486348Z13-C)................................... 12-48
UHF (438-470 MHz) Radio Parts List (8486348Z13-C) .......................................... ... .... ... ... ... ... .... ... .. 12-49
Chapter 12 UHF (465-495 MHz) Schematic Diagrams, Overlays, and
Parts Lists (8486634Z02-O)............................................ 12-53
Figure 12-39. UHF (465-495 MHz) Radio Circuit Block Diagram (8486634Z02-O) ............ ... ... .... ... .. 12-53
Figure 12-40. UHF (465-495 MHz) Receiver Front End Schematic Diagram (8486634Z02-O).........12-54
Figure 12-41. UHF (465-495 MHz) Receiver Back End Schematic Diagram (8486634Z02-O) .........12-55
Figure 12-42. UHF (465-495 MHz) Synthesizer Schematic Diagram (8486634Z02-O) ..................... 12-56
Figure 12-43. UHF (465-495 MHz) Voltage Controlled Oscillator Schematic
Diagram (8486634Z02-O)............................................................................................ 12-57
Figure 12-44. UHF (465-495 MHz) Transmitter and Power Control Schematic
Diagram (8486634Z02-O)............................................................................................12-58
Figure 12-45. UHF (465-495 MHz) Controller Interconnect Schematic Diagram (8486634Z02-O)....12-59
Figure 12-46. UHF (465-495 MHz) Microprocessor Circuitry Schematic Diagr am (8486634Z02-O) 12-60
Figure 12-47. UHF (465-495 MHz) Audio Circuitry Schematic Diagram (8486634Z02-O)................. 12-61
Figure 12-48. UHF (465-495 MHz) DC Regulation Schematic Diagram (8486634Z02-O)................. 12-62
Figure 12-49. UHF (465-495 MHz) Board Component Side View (8486634Z02-O) ..........................12-63
Figure 12-50. UHF (465-495 MHz) Board Solder Side View (8486634Z02-O) .................................. 12-64
UHF (465-495 MHz) Radio Parts List (8486634Z02-O)................ .... ... ... ... ... .... ... ... ... .... ... ... ... ... .... ... .. 12-65
6880309N62-C June, 2005
viii Table of Contents
List of Figures
Figure 1-1. Programming/Test Cable...................... ... ... ... .... ... ... ... .... ... ... ... ... ......................................1-4
Figure 1-2. Wiring of the Connectors..................................................................................................1-4
Figure 2-1. DC Power Distribution Block Diagram..............................................................................2-1
Figure 4-1. VHF Receiver Block Diagram...........................................................................................4-1
Figure 4-2. VHF Transmitter Block Diagram.......................................................................................4-3
Figure 4-3. VHF Frequency Generation Unit Block Diagram..............................................................4-5
Figure 4-4. VHF Synthesizer Block Diagram ......................................................................................4-6
Figure 4-5. VHF VCO Block Diagram.............. ... .... ... ... ... .... ... ... ... .... ... ... ... ... .... ... ... ............................4-7
Figure 5-1. VHF Receiver Block Diagram...........................................................................................5-1
Figure 5-2. VHF Transmitter Block Diagram.......................................................................................5-3
Figure 5-3. VHF Frequency Generation Unit Block Diagram..............................................................5-5
Figure 5-4. VHF Synthesizer Block Diagram ......................................................................................5-6
Figure 5-5. VHF VCO Block Diagram.............. ... .... ... ... ... .... ... ... ... .... ... ... ... ... .... ... ... ............................5-7
Figure 7-1. Six-Layer Circuit Board: Copper Steps in Layer Sequence..............................................7-3
Figure 7-2. Speaker and Microphone Schematic................................................................................7-3
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
Figure 7-6. VHF (136-162 MHz) Synthesizer Schematic Diagram (8486769Z02-A)..........................7-8
Figure 7-7. VHF (136-162 MHz) Voltage Controlled Oscillator Schematic
Diagram (8486769Z02-A).................................................................................................7-9
Figure 7-8. VHF (136-162 MHz) Transmitter and Power Control Schematic
Diagram (8486769Z02-A)..................................... ... ... .... ... ... ... .......................................7-10
Figure 7-9. VHF (136-162 MHz) Controller Interconnect Schematic Diagram (8486769Z02-A)......7-11
Figure 7-10. VHF (136-162 MHz) Microprocessor Circuitry Schematic Diagram (8486769Z02-A)...7-12
Figure 7-11. VHF (136-162 MHz) Audio Circuitry Schematic Diagram (8486769Z02-A) ......... ... .... ...7-13
Figure 7-12. VHF (136-162 MHz) DC Regulation Schematic Diagram (8486769Z02-A) ...................7-14
Figure 7-13. VHF (136-162 MHz) Board Top Side View (8486769Z02-A) .........................................7-15
Figure 7-14. VHF (136-162 MHz) Board Bottom Side View (8486769Z02-A) ....................................7-16
Figure 7-15. VHF (136-162 MHz) Radio Circuit Block Interconnect Diagram (8486769Z04-C) .........7-21
Figure 7-16. VHF (136-162 MHz) Receiver Front End Schematic Diagram (8486769Z04-C)............7-22
Figure 7-17. VHF (136-162 MHz) Receiver Back End Schematic Diagram (8486769Z04-C)............7-23
Figure 7-18. VHF (136-162 MHz) Synthesizer Schematic Diagram (8486769Z04-C)........................7-24
Figure 7-19. VHF (136-162 MHz) Voltage Controlled Oscillator Schematic
Diagram (8486769Z04-C)...............................................................................................7-25
Figure 7-20. VHF (136-162 MHz) Transmitter and Power Control Schematic
Diagram (8486769Z04-C)........................... ............................................. .... ...................7-26
Figure 7-21. VHF (136-162 MHz) Controller Interconnect Schematic Diagram (8486769Z04-C)......7-27
Figure 7-22. VHF (136-162 MHz) Microprocessor Circuitry Schematic Diagram (8486769Z04-C)....7-28
Figure 7-23. VHF (136-162 MHz) Audio Circuitry Schematic Diagram (8486769Z04-C) ...................7-29
Figure 7-24. VHF (136-162 MHz) DC Regulation Schematic Diagram (8486769Z04-C) ...................7-30
Figure 7-25. VHF (136-162 MHz) Board Component Side View (8486769Z04-C).............................7-31
Figure 7-26. VHF (136-162 MHz) Board Solder Side View (8486769Z04-C).....................................7-32
Figure 7-27. VHF (146-174 MHz) Radio Circuit Block Interconnect Diagram (8486342Z09-A) .........7-21
Figure 7-28. VHF (146-174 MHz) Receiver Front End Schematic Diagram (8486342Z09-A)............7-22
Figure 7-29. VHF (146-174 MHz) Receiver Back End Schematic Diagram (8486342Z09-A) ............7-23
Figure 7-30. VHF (146-174 MHz) Synthesizer Schematic Diagram (8486342Z09-A)........................7-24
Figure 7-31. VHF (146-174 MHz) Voltage Controlled Oscillator Schematic
Diagram (8486342Z09-A)...............................................................................................7-25
Figure 7-32. VHF (146-174 MHz) Transmitter and Power Control Schematic
Diagram (8486342Z09-A)..................................... ... ... .... ... ... ... .......................................7-26
June, 2005 6880309N62-C
Table of Contents ix
Figure 7-33. VHF (146-174 MHz) Controller Interconnect Schematic Diagram ( 8486342Z09-A)...... 7-27
Figure 7-34. VHF (146-174 MHz) Microprocessor Circuitry Schematic Diagram (8486342Z09-A)...7-28
Figure 7-35. VHF (146-174 MHz) Audio Circuitry Schematic Diagram (8486342Z09-A) ...................7-29
Figure 7-36. VHF (146-174 MHz) DC Regulation Schematic Diagram (8486342Z09-A) ...................7-30
Figure 7-37. VHF (146-174 MHz) Board Component Side View (8486342Z09-A).............................7-31
Figure 7-38. VHF (146-174 MHz) Board Solder Side View (8486342Z09-A).....................................7-32
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
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
Figure 8-1. UHF Receiver Block Diagram .......................................................................................... 8-1
Figure 8-2. UHF Transmitter Block Diagram ...................................................................................... 8-3
Figure 8-3. UHF Frequency Generation Unit Block Diagram ............................................................. 8-5
Figure 8-4. UHF Synthesizer Block Diagram...................................................................................... 8-6
Figure 8-5. UHF VCO Block Diagram................................................................................................. 8-7
Figure 9-1. UHF Receiver Block Diagram .......................................................................................... 9-1
Figure 9-2. UHF Transmitter Block Diagram ...................................................................................... 9-3
Figure 9-3. UHF Frequency Generation Unit Block Diagram ............................................................. 9-5
Figure 9-4. UHF Synthesizer Block Diagram...................................................................................... 9-6
Figure 9-5. UHF VCO Block Diagram................................................................................................. 9-7
Figure 10-1. UHF Receiver Block Diagram ........................................................................................10-1
Figure 10-2. UHF Transmitter Block Diagram .................................................................................... 10-3
Figure 10-3. UHF Frequency Generation Unit Block Diagram ...........................................................10-5
Figure 10-4. UHF Synthesizer Block Diagram....................................................................................10-6
Figure 10-5. UHF VCO Block Diagram...............................................................................................10-7
Figure 12-1. Six-Layer Circuit Board: Copper Steps in Layer Sequence ........................................... 12-3
Figure 12-2. Speaker and Microphone Schematic .............................................................................12-3
Figure 12-3. UHF (403-440 MHz) Radio Circuit Block Diagram (8486635Z03-O) ......... ...... ... .... ... ... . 12-5
Figure 12-4. UHF (403-440 MHz) Receiver Front End Schematic Diagram (8486635Z03-O)........... 12-6
Figure 12-5. UHF (403-440 MHz) Receiver Back End Schematic Diagram (8486635Z03-O) ...........12-7
6880309N62-C June, 2005
x Table of Contents
Figure 12-6. UHF (403-440 MHz) Synthesizer Schematic Diagram (8486635Z03-O) .......................12-8
Figure 12-7. UHF (403-440 MHz) Voltage Controlled Oscillator Schematic
Diagram (8486635Z03-O) ..............................................................................................12-9
Figure 12-8. UHF (403-44 0 MH z) Trans mit te r an d Pow er Cont ro l Sche m atic
Diagram (8486635Z03-O) ....................................... ... .... ... ... ... ... .... ... ... ... .....................12-10
Figure 12-9. UHF (403-440 MHz) Controller Interconnect Schematic Diagram (8486635Z03-O)....12-11
Figure 12-10. UHF (403-440 MHz) Microprocessor Circuitry Schematic Diagram (8486635Z03-O) 12-12
Figure 12-11. UHF (403-440MHz) Audio Circuitry Schematic Diagram (8486635Z03-O)..................12-13
Figure 12-12. UHF (403-440 MHz) DC Regulation Schematic Diagram (8486635Z03-O).................12-14
Figure 12-13. UHF (403-440 MHz) Board Component Side View (8486635Z03-O) ..........................12-15
Figure 12-14. UHF (403-440 MHz) Board Solder Side View (8486635Z03-O)...................................12-16
Figure 12-15. UHF (438-470 MHz) Radio Circuit Block Diagram (8486348Z09-A)............................12-21
Figure 12-16. UHF (438-470 MHz) Receiver Front End Schematic Diagram (8486348Z09-A)..........12-22
Figure 12-17. UHF (438-470 MHz) Receiver Back End Schematic Diagram (8486348Z09-A)..........12-23
Figure 12-18. UHF (438-470 MHz) Synthesizer Schematic Diagram (8486348Z09-A)......................12-24
Figure 12-19. UHF (438-470 MHz) Voltage Controlled Oscillator Schematic
Diagram (8486348Z09-A).............................................................................................12-25
Figure 12-20. UHF (438-470 MHz) Transmitter and Power Control Schematic
Diagram (8486348Z09-A)..................................... ... ... .... ... ... ... .....................................12-26
Figure 12-21. UHF (438-470 MHz) Controller Interconnect Schematic Diagram (8486348Z09-A)....12-27
Figure 12-22. UHF (438-470 MHz) Microprocessor Circuitry Schematic Diagram (8486348Z09-A) .12-28
Figure 12-23. UHF (438-470 MHz) Audio Circuitry Schematic Diagram (8486348Z09-A) .................12-29
Figure 12-24. UHF (438-470 MHz) DC Regulation Schematic Diagram (8486348Z09-A) .................12-30
Figure 12-25. UHF (438-470 MHz) Board Component Side View (8486348Z09-A)...........................12-31
Figure 12-26. UHF (438-470 MHz) Board Solder Side View (8486348Z09-A)...................................12-32
Figure 12-27. UHF (438-470 MHz) Radio Circuit Block Diagram (8486348Z13-C)............................12-37
Figure 12-28. UHF (438-470 MHz) Receiver Front End Schematic Diagram (8486348Z13-C) ........ .12-38
Figure 12-29. UHF (438-470 MHz) Receiver Back End Schematic Diagram (8486348Z13-C)..........12-39
Figure 12-30. UHF (438-470 MHz) Synthesizer Schematic Diagram (8486348Z13-C)......................12-40
Figure 12-31. UHF (438-470 MHz) Voltage Controlled Oscillator Schematic
Diagram (8486348Z13-C).............................................................................................12-41
Figure 12-32. UHF (438-470 MHz) Transmitter and Power Control Schematic
Diagram (8486348Z13-C)........................... ............................................. .... .................12-42
Figure 12-33. UHF (438-470 MHz) Controller Interconnect Schematic Diagram (8486348Z13-C)....12-43
Figure 12-34. UHF (438-470 MHz) Microprocessor Circuitry Schematic Diagram (8486348Z13-C).12-44
Figure 12-35. UHF (438-470 MHz) Audio Circuitry Schematic Diagram (8486348Z13-C).................12-45
Figure 12-36. UHF (438-470 MHz) DC Regulation Schematic Diagram (8486348Z13-C).................12-46
Figure 12-37. UHF (438-470 MHz) Board Component Side View (8486348Z13-C)...........................12-47
Figure 12-38. UHF (438-470 MHz) Board Solder Side View (8486348Z13-C)...................................12-48
Figure 12-39. UHF (465-495 MHz) Radio Circuit Block Diagram (8486634Z02-O)............................12-53
Figure 12-40. UHF (465-495 MHz) Receiver Front End Schematic Diagram (8486634Z02-O) .........12-54
Figure 12-41. UHF (465-495 MHz) Receiver Back End Schematic Diagram (8486634Z02-O)..........12-55
Figure 12-42. UHF (465-495 MHz) Synthesizer Schematic Diagram (8486634Z02-O) .....................12-56
Figure 12-43. UHF (465-495 MHz) Voltage Controlled Oscillator Schematic
Diagram (8486634Z02-O) ............................................................................................12-57
Figure 12-44. UHF (465-495 MHz) Transmitter and Power Control Schematic
Diagram (8486634Z02-O) ....................................... ... .... ... ... ... ... .... ... ... ... .....................12-58
Figure 12-45. UHF (465-495 MHz) Controller Interconnect Schematic Diagram (8486634Z02-O)....12-59
Figure 12-46. UHF (465-495 MHz) Microprocessor Circuitry Schematic Diagram (8486634Z02-O) 12-60
Figure 12-47. UHF (465-495 MHz) Audio Circuitry Schematic Diagram (8486634Z02-O).................12-61
Figure 12-48. UHF (465-495 MHz) DC Regulation Schematic Diagram (8486634Z02-O).................12-62
Figure 12-49. UHF (465-495 MHz) Board Component Side View (8486634Z02-O) ..........................12-63
Figure 12-50. UHF (465-495 MHz) Board Solder Side View (8486634Z02-O)...................................12-64
June, 2005 6880309N62-C
Table of Contents xi
List of Tables
Table 1-1. Recommended Test Equipment.......................................................................................1-1
Table 1-2. Service Aids ..................................................................................................................... 1-2
Table 1-3. Recommended Service Tools.......................................................................................... 1-2
Table 2-1. Voltage Regulators........................................................................................................... 2-2
Table 3-1. Radio Memory Requirements........................................................................................... 3-1
Table 3-2. SPI Bus Signal Definitions................................................................................................ 3-2
Table 6-1. Troubleshooting Table for Receiver................................................................................. 6-1
Table 6-2. Troubleshooting Table for Synthesizer............................................................................. 6-3
Table 6-3. Troubleshooting Table for Transmitter............................................................................. 6-4
Table 6-4. Troubleshooting Table for Board and IC Signals ............................................................. 6-7
Table 11-1. Troubleshooting Table for Receiver............................................................................... 11-1
Table 11-2. Troubleshooting Table for Synthesizer...........................................................................11-3
Table 11-3. Troubleshooting Table for Transmitter........................................................................... 11-4
Table 11-4. Troubleshooting Table for Board and IC Signals ........................................................... 11-6
Related Publications
CP150/CP200 Basic Service Manual .............................................................................................6880309N61
CP150/CP200 User Guide..............................................................................................................6880309N60
6880309N62-C June, 2005
xii Table of Contents
June, 2005 6880309N62-C
Chapter 1 Test Equipment, Service Aids, and
Service Tools

1.1 Test Equipment

Table 1-1 lists test equipment required to service the CP150/CP200 Radios.
Table 1-1. Recommended Test Equipment
Motorola Part No. Description Characteristics Application
R2600 series System analyzer This item will substitute for
items with an asterisk (*)
*R1074A Fluke 87 digital multi-
meter
Fluke 85 RF probe 500 MHz, 30 VAC max Use with Fluke 87 digital multi-
*R1377A AC voltmeter 1 mV to 300 mV, 10 mega-
R1611A Dual channel
100 MHz oscillo­scope (Agillent)
S1339A RF millivolt meter 100 µV to 3V RF, 10 kHz to
*R1013B or
*R1370A
SINAD meter or
SINAD meter with RMS
True RMS metering, 200 kHz frequency counter, 32-segment bar graph with backlit display
ohm input impedance
Two-channel, 100 MHz bandwidth, 200 M sample rate/sec, 2 MB memory/ channel
1 GHz frequency range
Without RMS audio voltme­ter or With RMS audio voltmeter
Frequency/deviation meter and signal generator for wide-range troubleshooting and alignment
Digital voltmeter is recom­mended for AC/DC voltage and current measurements
meter for RF voltage measure­ments.
Audio voltage measurements
Waveform measurements
RF level measurements
Receiver sensitivity measure­ments
1-2 Test Equipment, Service Aids, and Service Tools: Service Aids

1.2 Service Aids

Table 1-2 lists service aids recommended for working on the CP150/CP200 Radios. While all of these
items are available from Motorola, most are standard shop equipment items, and any equivalent item capable of the same performance may be substituted for the item listed.
Table 1-2. Service Aids
Motorola Part
No.
RLN4460 Por table Test Set Enables connection to the audio/accessory jack.
RLN4510 Battery Interface Regulates DC current and voltage between radio and
RVN4191 Customer Programming Soft-
ware and Global Tuner Software
on CD Rom
AAPMKN4004 Programming Test Cable Connects radio to RIB (PLN4008).
AAPMKN4003 Radio-to-Radio Cloning Cable
RLN4008 Radio Interface Box Enables communications between the radio and the
5886564Z01 RF Adaptor Adapts radio’s antenna port to BNC cabling of test
0180305K08 Shop Battery Eliminator Interconnects radio to power supply.
HSN9412 Wall-Mounted Power Supply Used to supply power to the RIB (120 VAC).
Description Application
Allows switching for radio testing.
power supply.
Program customer option and channel data.
Allows a radio to be duplicated from a master radio by transferring programmed data from the master radio to the other.
computer’s serial communications adapter.
equipment.
3080369B71 or 3080369B72
6686533Z01 Knob Remover/Chassis Opener Used to remove the front cover assembly.
HKN9216 IBM Computer Interface Cable Connection from computer to RIB.
8180384N65 Housing Eliminator Allows testing of the radio outside of the housing.
Motorola Part
No.
RSX4043A TORX screwdriver Tighten and remove chassis screws
6680387A70 T6 TORX bit Removable TORX screwdriver bit
R1453A Digital readout solder station Digitally controlled soldering iron
RLN4062A Hot air workstation, 120 V Tool for hot air soldering/desoldering of surface
Computer Interface Cable Use B72 for the IBM PC AT or newer (9-pin serial
port). Use B71 for older models (25-pin serial port). Connects the computer’s serial communications adapter to the RIB (PLN4008).
Table 1-3. Recommended Service Tools
Description Application
mounted integrated circuits
June, 2005 6880309N62-C
Test Equipment, Service Aids, and Service Tools: Service Aids 1-3
Table 1-3. Recommended Service Tools (Continued)
Motorola Part
No.
Description Application
0180386A78 Illuminated magnifying glass with
lens attachment
Illumination and magnification of components
0180302E51 Master lens system
0180386A82 Anti-static grounding kit Used during all radio assembly and disassembly pro-
cedures
6684253C72 Straight prober
6680384A98 Brush
1010041A86 Solder (RMA type), 63/67,
0.5mm diameter, 1 lb. spool
0180303E45 SMD tool kit (included with
R1319A)
R1319A ChipMaster (110 V) Surface mount removal and assembly of surface
R1321A ChipMaster (220 V)
mounted integrated circuits and/or rework station shields. Includes 5 nozzles.
ChipMaster Nozzles:
6680332E83 PLCC-28* nozzle
6680332E82 PLCC-44* nozzle
6680332E94 PLCC-52 nozzle
6680332E96 PLCC-84 nozzle
6680334E67 QFP-160 nozzle
6680333E46 SOL-18 nozzle
6680332E84 SOIC-20 nozzle
6680332E87 SOL-20J nozzle
6680333E45 SOL-24 nozzle
6680333E55 TSOP-64 nozzle
* Included with ChipMaster packages
Soldering and Un-soldering IC’s
6880309N62-C June, 2005
1-4 Test Equipment, Service Aids, and Service Tools: Service Aids
Programming/Test Cable
3.5mm mono
2.5mm stereo
Figure 1-1. Programming/Test Cable
P1
2.5mm stereo and
3.5mm
3.5mm Tip (Speaker +)
3.5mm Sleeve
2.5mm Tip (Microphone)
2.5mm
2.5mm Center
1
2
5
3
4
25 POSITION
MALE CONNECTOR
P2 P3
36.0”
CABLE
P1
Orange
1
Blue
2
White
25 POSITION
FEMALE CONNECTOR
36.0”
CABLE
ohm
5
1UF,16V 5%
Spiral
3
Yellow
4
25 pin Male D Connector
P2
Components molded inside
1 5
47
24 7
33K
20 8
+
15 16 9
P3
25 pin Female
D Connector
1 15
4 11
To Test Box
To Test Box
Figure 1-2. Wiring of the Connectors
June, 2005 6880309N62-C

Chapter 2 DC Power Distribution

2.1 DC Regulation and Distribution

A block diagram of the DC power distribution throughout the radio is shown in Figure 2-1.
Audio
Power
Amplifier
Accessories
20 pin Connector
Keypad/Option Board
7.5V
Battery
5V
5V
Vdda
Vddd
LCD
Driver
RF AMP, IF AMP,
ASFIC_CMP
RX/TX Buffers
IFIC
FRACTN VCOBIC
UNSWB+
Fuse
3.3V
Reg.
LI Ion
PA, Driver
PCIC(ALC)
MECH.
SWB+
Low Battery
Detect
Control
On/Off Switch
SWB+
Antenna
Switch
Vdda
Regulator
Vddd
Regulator
Tx
Led
MCU, ROM
and EEPROM
Regulator
Figure 2-1. DC Power Distribution Block Diagram
Battery voltage enters at connector J301 and is routed through fuse F301 to become USWB+. VR301 protects against ESD, and D301 provides reverse polarity protection. This voltage is routed to:
• FET switch Q170 in the TX power control circuit (turned on during transmit)
• TX power amplifier module U110 (via R150)
• input pins of regulators U310, U320 and U330
• FET switch Q493 (turned on whenever the radio is on)
• on-off switch S444 (part of on-off-volume control) to become SWB+
2-2 DC Power Distribution: DC Regulation and Distribution
When the radio is turned on, SWB+ is present and is applied to:
• transistor switch Q494 (pins 1 and 6) which turns on Q4 93
• RX audio power amplifier U490
• voltage divider R420/R421 and port PE0, a microprocessor A/D input which measures battery voltage and radio on/off status
The output of FET switch Q493 is applied to the control pins of regulators U310, U320 and U330, turning them on. The following regulators are used:
Table 2-1. Voltage Regulators
Reference No. Description Type
U310 5 V Regulator TK71750S
U320 Digital 3.3 V Regulator LP2986
U330 3 V Regulator TK71730S
The 5 V source is applied to:
• RX back end circuitry
• synthesizer super filter input and charge pump supply
• RED/GRN LEDs
• RX audio buffer U510
• portions of ASFIC U451
The 5 V source is also applied to FET switches Q311 and Q312. Q311 is turned on by Q313 when RX_ENA (from U401 pin 49) is high, and supplies the "5R" source to the RF front end stages Q21­Q22, and the VCO RX injection buffer Q280. Q312 is turned on by Q313 when TX_ENA (from U40 1 pin 50) is high, and supplies the "5T" source to the first transmitter stage Q100.
The digital 3.3 volt source from U320 (D_3.3 V) is applied to:
• microprocessor U401
• EEPROM U402
• flash ROM U404
The 3 V regulated source from U330 is applied to:
• synthesizer IC U201
• VCO/buffer IC U251
• portions of ASFIC U451
• microphone bias circuitry
While the radio is turned on, port PH3 (U401 pin 44) is he ld high. When the radio is turn ed off, SWB+ is removed and port PE0 (U401 pin 67) goes low, initiating a power-down routine. Port PH3 (pin 44) remains high, keeping the voltage regulators on via Q493 and Q494, until the operating state of the radio has been stored in EEPROM and other turn-off data functions have been completed. PH3 then goes low, turning off Q494 and Q493, and all regulated voltages are removed.
June, 2005 6880309N62-C

Chapter 3 Controller Theory of Operation

3.1 Controller

The controller provides the following functions:
• interface with controls and indicators
• serial bus control of major radio circuit blocks
• encoding and/or decoding of selective signaling formats such as PL, DPL , MDC1200 a nd Quik­Call II
• interface to CPS programming via the microphone connector
• storage of customer-specific information such as channel frequencies, scan lists, and signaling codes
• storage of factory tuning parame ters such as tra nsmitter powe r and de viation, r eceiver squelch sensitivity, and audio level adjustments
• power-up, power-down and reset routines
Figure 7-3 (VHF) shows the interconnection between the controller and the various other radio
blocks. Figure 7-9 show the connections between the following circuit areas which comprise the controller block:
• microprocessor circuitry
• audio circuitry
• DC regulation circuitry (refer to Chapter 2, DC Regulations and Distribution.)
• rotary and pushbutton controls and switches
• option board interface
The majority of the circuitry described below is contained in the (VHF) Mi croprocessor Circuitry schematic diagrams (Figure 7-10). Portions are also found in the Audio and DC Regulation schematics (Figures 7-11 and 7-12).

3.1.1 Microprocessor Circuitry

The microprocessor circuitry includes microprocessor (U401) and associated EEPROM, S-RAM (not used in PR400 models), and Flash ROM memories. The following memory IC's are used:
Table 3-1. Radio Memory Requirements
Reference No. Description Type Size
U402 Serial EEPROM AT25128 16K x 8
U403 Static RAM (not used)
U404 Flash ROM AT49LV001N_70 V 128K x 8
3-2 Controller Theory of Operation: Controller
3.1.1.1 Memory Usage
Radio operation is controlled by software that is stored in external Flash ROM memory (U404). Radio parameters and customer specific information is stored in external EEPROM (U402). The operating status of the radio is maintained in RAM located within th e microprocessor . When the radio is turned off, the operating status of the radio is written to EEPROM before operating voltage is removed from the micropro cessor. See section “3.1.1.7 Microprocessor Power-Up, Power-Down and
Reset Routine” on page 3-3 for a discussion of the power-down routine.
Parallel communication with U403 and U404 is via:
• address lines A(0)-A(16), from U401 port F ADDR0-ADDR13 and port G XA14-XA16
• data lines D(0)-D(7), from U401 port C DATA0-DATA7
• chip-select for U403, from PH6 (U401 pin 41)
• chip-enable for U404, from PH7 (U401 pin 38)
• output enable for U404, from PA7 (U401 pin 86)
• write-enable for both U403 and U404, from PG7_R/W (U401 pin 4)
Serial communication with U402 is via:
• the SPI bus (see section “3.1.1.3 Serial Bus Control of Circuit Blocks” on page 3-2)
• chip-select for U402, from PD6 (U401 pin 3)
3.1.1.2 Control and Indicator Interface
Ports PI3 and PI4 are outputs which control the top-mounted LED indicator. When PI3 is high, the indicator is red. When PI4 is high, the indicator is green. When both are high, the indicator is amber. When both are low, the indicator is off.
Pressing the side-mounted PTT button (S441) provides a lo w to port PJ0 (U401 pin 71), which indicates PTT is asserted. Side-mounted option buttons 1 and 2 (S442 and S443) are connected to Ports PJ6 (pin 77) and PJ7 (pin 78), respectively.
3.1.1.3 Serial Bus Control of Circuit Blocks
The microprocessor communicates with other circuit blocks via a SPI (serial peripheral interface) bus using ports PD2 (data into uP), PD3 (data out of uP) and PD4 (clock). The signal names and microprocessor ports are defined in Table 3-2.
Table 3-2. SPI Bus Signal Definitions
Signal Name Microprocessor Port Microprocessor Pin
SPI-DATA_IN PD2-MISO U401 Pin 99
SPI_DATA_OUT PD3-MOSI U401 pin 100
SPI_CLK PD4-SCK U401 pin 1
These signals are routed to:
• the audio filter IC (U451) to control internal functions such as gain change betwee n 25 kHz and
12.5 kHz channels, transmit or receive mode, volume adjustment, etc.
• the synthesizer IC U201 to load receive and transmit channel frequencies
• option board connector J460-1 for internal option configuration and control
• serial EEPROM U402 (both SPI_DATA_IN and SPI_DATA_OUT are used).
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Controller Theory of Operation: Controller 3-3
In order for each circuit block to respond only to the data intended for it, each peripheral has its o wn chip select (or chip enable) line. The device will only respond to data when its enable line is pulled low by one of the microprocessor ports, as follows:
• port PD5 (U401 pin 2) for the audio filter IC
• port PH0 (U401 pin 47) for the synthesizer IC
• port PD6 (U401 pin 3) for the serial EEPROM.
3.1.1.4 Interface to RSS Programming
The radio can be programmed, or the programmed information can be read, using a computer with CPS (Customer Programming Software) connected to the radio via a RIB (radio interface box) or with the RIB-less cable. Connection to the radio is made via the microphone connector (part of accessory connector J471). The SCI line connects the programming contact (J471 pin 6) to ports PD0_RXD (data into uP, pin 97) and PD1_TXD (data out of uP, pin 98). Transistor Q410 isolates the input and output functions by allowing PD1 to pull the line low , but does not af fect incoming data from being read by port PD0. This isolation allows high-speed 2-wire pr ogramm ing via TP401 and TP402 for factory programming and tuning.
3.1.1.5 S t orage of Customer-Specific Information
Information that has been programmed using CPS, such as channel frequencies or selective signaling codes, are stored in the external EEPROM, where it is retained permanently (unless reprogrammed) without needing DC power applied to the microprocessor.
3.1.1.6 Sensing of Externally-Connected Accessories
Port PJ1 is used to detect the presence of externally connecte d accessor ies. Port PJ1 (U401 pin 72) is normally low, unless accessories (lapel speaker microphone, lightweight headset, etc.) are used with the radio. This port is used to detect an accessory PTT or auto sensing of a VOX accessory.
If VOX is programmed into the radio channe l codeplug information, and PJ1 is high during power-u p, the radio will activate VOX operation. If a low is present at port PJ1 during power-up, the radio will use this port as an external PTT indicator.
3.1.1.7 Microprocessor Power-Up, Power-Down and Reset Routine
On power-up, the microprocessor is held in reset until the digital 3.3 V regulator (U320 pin 5) provides a stable supply voltage. Once the dig ital supply reaches steady st ate and releases the re set line (U320 pin 7), the microprocessor begins to start up. The ASFIC_CMP (U451) has already started running and is providing the startup clock to the microprocessor. After reset release by all circuits, the software within the microprocessor begins executing port assignments, RAM checking, and initialization. A fixed delay of 100 ms is added to allow the audio circuitry to settle. Next, an alert beep is generated and the steady state software begins to execute (buttons are read, radio circuits are controlled).
When the radio is turned off, SWB+ is removed and port PE0 (U401 pin 67) goes low, initiating a power-down routine. Port PH3 (pin 44) remains high, keeping the voltage regulators on via Q493 and Q494, until the operating state of the radio has been stored in EEPROM. PH3 then goes low, and all regulated voltages are removed.
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3-4 Controller Theory of Operation: Controller
The microprocessor reset line (pin 94) can be controlled directly by the digital 3.3 V regulator (U320 pin 7), the microphone jack (part of accessory connector J471) via Q472 and Q471, and the microprocessor itself. U320 pulls the reset line low if the digital 3.3 V source loses regulation. This prevents possible MOS latch-up or overwriting of registers in the microprocessor because the reset line is higher in voltage than the microprocessor VDD ports (U401 pins 12, 39, 59, 88). The microprocessor can drive the reset line low if it detects a fault condition such as an expired watchdog timer, software attempting to execute an infinite loop, unplanned hardware inputs, static discharge, etc. Finally, the Q471 can pull the reset line low during use of the programming cable and CPS by the application of a sufficiently negative voltage to the microphone connector tip contact (J471 pin 4), however this reset method is not utilized.
3.1.1.8 Boot Mode Control
When power-up reset occurs, the microprocessor will boot into either normal or flash mode depending on the logic level of ports MODA (U401 pin 58) a nd MODB (pin 57). T he Flash Adapter is a programming accessory which provides negative 9 volts dc via a 1K resistor to microphone connector J471 pin 4. This turns on Q471 and Q472 via D471 and VR472, pulling MODA and MODB low and allowing booting in the flash mode by cycling power to reset the radio. Software upgrades can then performed by loading the new software code into Flash ROM U404.
3.1.1.9 Microprocessor 7.3975 MHz Clock
The 7.3975 MHz clock signal (uP_CLK) is provided from the ASFIC_CMP (U451 pin 28). Upon startup the 16.8MHz crystal provides the signal to the ASFIC_CMP, which sends out the uP_CLK at
3.8MHz until a steady-state condition is reached and the clock is increased to 7.3975MHz for the microprocessor.
3.1.1.10 Battery Gauge
Various battery types are available having different capacities. The different battery types contain internal resistors connected from the BATT_CHARGE contact to ground (which is routed to the microprocessor as BATT_DETECT). A voltage divider is formed with R255 pro ducing a different DC voltage for each battery type, which is read by microprocessor port PE2 (pin 65). This allows the software to recognize the battery chemistry being used and adjust the battery gauge fo r best accuracy.

3.1.2 Audio Circuitry

3.1.2.1 Transmit and Receive Low-Level Audio Circuitry
The majority of RX and TX audio processing is performed by U451, the Audio Filter IC (ASFIC_CMP), which provides the following functions:
• Tone PL/Digital PL encode and decode filtering
• Tone PL/Digital PL rejection filter in RX audio path
• TX pre-emphasis amplifier
• TX audio modulation limiter
• Post-limiter (splatter) filter
• TX deviation adjust (digitally-controlled attenuators)
• Programmable microphone gain attenuator
• RX audio volume control (digitally controlled attenuator)
• Carrier squelch adjustment (digitally controlled attenuator)
• Microprocessor output port expansion
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Controller Theory of Operation: Controller 3-5
• 2.5 volt dc reference source
• Microprocessor clock generation (from the 16.8 MHz reference oscillator input)
The parameters of U451 that are programmable are selected by the microprocessor via the CLOCK (U451 pin 21), DATA (U451 pin 22) and chip enable (U451 pin 20) lines.
RX audio buffer U510 amplifies the audio level from the DEMOD output of the IFIC before being applied to the audio filter IC input (DISC, U451 p in 2). The buffer is DC coupled to avoid corruption of low-frequency data waveforms such as DPL. Because such waveforms are polarity sensitive, this buffer is configured as a single-stage inverting amplifier (U510-1 only) for VHF models where high­side first injection is used, or is configured as a two-stage non-inver ting amplifie r (U510-1 and -2 ) for UHF models using low-side first injection. The gain of the buffer is 1.5 times or 3.5 dB.
U480 and associated components are not used. Stage U480-1 is bypassed by jumper R487. Volume adjustment is performed by a digital attenuator within U451. The volume control (10KO, part
of S444) is connected to D_3.3 V and ground via R506 and R507. When the volume control is rotated, it varies the dc volt age applie d to micr oprocessor A/D input por t PE1 (U4 01 pin 66) between approximately 0 volts dc at minimum volume to 3.3 volts dc at maximum volume. Depending on this voltage, the appropriate setting of the digital volume attenuator is selected. This technique is less susceptible to noise than a conventional analog volume control.
3.1.2.2 Audio Power Amplifier
The audio power amplifier IC U490 amplifies receiver audio from U451 pin 41 to a level sufficient to drive a loudspeaker. U490 is a bridge amplifier delivering 3.46 volts rms between pins 5 and 8 without distortion, which is sufficient to develop 500 milliwatts of audio power into the internal 24 ohm speaker or an external 24 ohm load. The audio power amplifier is muted whenever speaker audio is not required to reduce current drain. The audio amp is muted when U451 pin 14 is low. When U451 pin 14 is high, U490 pin 1 is pulled low by Q490, enabling the audio amplifier.
Because the power amplifier is a bridge-type, neither speaker terminal is gro unded. Care should be taken that any test equipment used to measure the speaker audio voltage does not ground either speaker output terminal, otherwise damage to the audio power amplifier IC may result. When a 24­ohm load resistor is used it should be connected between the tip and the sleeve of accessory jack J471 (3.5mm port), never to ground. External SPKR plug insertion mechanically disconnects the internal speaker. Volta ge measurements using test equipment that is not isolated from ground may be made from one side of the speaker or load r esistor (either the tip or the sle eve of J471) to chassis ground, in which case the voltage indicated will be one half of the voltage applied to the speaker or load resistor . The Motorola RLN44 60 Port able Test Set and AAPMKN4004 Programming T est Cable provide the proper interface between the radio's ungrounded audio output and ground-referenced test equipment.
3.1.2.3 Internal Microphone Audio Voice Path
Microphone audio from internal microphone is routed from J470-1 via C475, L471, and C470 to the ASFIC_CMP mic audio input (MICINT, U451 pin 46). During transmit, Q470 is turned on by a low at U451 pin 35, providing dc bias for the internal MIC via R478. External MIC plug insertion mechanically disconnects the internal microphone. External MIC audio is coupled through L4 71 and C470 to the mic audio input. An input level of 10 mV at J471 pin 4 produces 200 mV at the output of U451 pin 40, which corresponds to 60% deviation.
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3-6 Controller Theory of Operation: Controller
3.1.2.4 PTT Circuits
The internal side-mounted PTT switch (S441) is sensed directly by microprocessor port PJ0 (U401 pin 71). External mic PTT is sensed by measuring the current drawn through the accessory connector (J471-4) by the mic cartridge (which is in series with the accessory PTT switch). This current is drawn through the base (pin 5) and emitter (pin 4) of a transistor in Q470, causing its collector (pin 3) to supply a logic-high to microprocessor port PJ1 (pin 72).
3.1.2.5 VOX Operation
VOX audio accessories do not have a PTT switch. Instead, the mic cartridge is wired directly from J471-4 to ground. If the radio has been programmed for VOX operation an d the VOX accessory is plugged in prior to turning the radio on, the current drawn by the cartridge will turn on Q470 (pins 3­4-5) and a logic high will be seen at port PJ1 at turn-on. The microprocessor then assumes VOX operation, with PTT controlled by the presence of audio at the mic cartridge. A dc voltage proportional to the audio level at the input of the ASFIC_CMP (U451 pin 46) is fed to a n A/D in put of microprocessor U401 (pin 62). During VOX operation, PT T is activate d whe n the dc leve l exceeds a preset threshold.
3.1.2.6 Battery Charging Through Microphone Jack
A wall-type charging power supply may be connected to the 2.5 mm microphone jack (p art of accessory connector J451). The voltage present at the tip contact (pin 4) is app lied to the center charging contact of the battery via diode D470. Another diode, internal to the battery, applies this voltage to the (+) battery terminal. Only the recommended charger and battery type should be charged in this manner.
Different battery types contain internal resistors connected from the BATT_CHARGE contact to ground, which is routed to the microprocessor as BATT_DETECT. A voltage divider is formed with R255 producing a DC voltage which is read by microprocessor port PE2 (pin 65). This allows the software to recognize the battery chemistry being used and adjust the battery gauge fo r best accuracy. The value of R255 is chosen so that the voltage at the BATT_CHARGE node (cathode of D470) is never low enough to turn on the EXT_MIC_PTT sense transistor (part of Q470).
3.1.2.7 Programming and Flashing Through Microphone Jack
The ring contact on the 2.5 mm microphone jack is used for reading, pr ogramming or re-flashing the radio using CPS. This contact (J471 pin 6) is routed to port s PD0_RXD (data into uP, pin 97) and PD1_TXD (data out of uP, pin 98). Transistor Q410 isolates the input and output functions by allowing PD1 to pull the line low, but does not affect incoming data from being read by port PD0.
To re-flash the radio (ov erw rit e th e software in the F lash ROM wi th ne w so ftware), the ra dio mu st power up in the boot mode. This is accomplished by using a flash adapter acce ssory, which provides SCI communication with the programming ring contact (J471 pin 6) and also allows a negative voltage (negative 9 volts dc via a 1K resistor) to be applied to the tip contact (J471 pin 4). This voltage is sufficient to turn on the base-emitter junction (pins 1 and 2) of Q472 via L471, D471, VR472 and R471. Pin 6 of Q472 goes high, turning on Q471 (pins 3 and 4) and pulling the BOOT_ENA line (ports MODA and MODB of the microprocessor) low. Cycling power generates a reset which causes the radio to boot in the flash mode.
June, 2005 6880309N62-C

Chapter 4 136-162 MHz VHF Theory Of Operation

4.1 Introduction

This chapter provides a detailed theory of operation for the radio components. Schematic diagrams for the circuits described in the following paragraphs are located in Chapter 7 of this manual.

4.2 VHF Receiver

The VHF receiver covers the range of 136-162 MHz and provides switchable IF bandwidth for use with 12.5 kHz or 20/25 kHz channel spacing systems. The receiver is divided into two major blocks as shown in Figure 4-1.
•Front End
• Back End
Preselector
RX from
Antenna Switch
from Synthesizer

4.2.1 Receiver Front-End

Incoming RF signals from the antenna are first routed throug h the harmonic filter and ante nna switch, part of the transmitter circuitry, before being applied to the receiver front end. The receiver front end consists of a preselector filter, RF amplifier, an interstage filter, and a double-balanced first mixer.
The preselector filter is a fixed-tuned 4-pole design using discrete elements (L1-L4 and C1-C9) in a series/shunt resonator configuration. It has a 3 dB bandwidth of 43 MHz, an in sertion loss of 2 dB and image attenuation of 37 dB at 226 MHz, with increasing attenuation at higher frequencies. Diode CR1 protects the RF amplifier by limiting excessive RF levels.
The output of the filter is matched to the base of RF amplifier Q21, which provides 18 dB of gain and a noise figure of 2 dB. Operating voltage is obtained from the 5R source, which is turned off during transmit to reduce dissipation in Q21. Current mirror Q22 maintains the operating current of Q21
RF
Filter
First LO
Recovered Audio
Figure 4-1. VHF Receiver Block Diagram
Amp
RSSI
Interstage
Filter
Inj Filter
Ceramic
Resonator
1st Mixer
Demodulator
Crystal
Filter
6G
Switching
6E
IF
Amp
BW_SEL
Cer Fltr
4E
4-2 136-162 MHz VHF Theory Of Operation: VHF Receiver
constant at 6.2 mA regardless of device and temperature variations, for optimum dynamic range and noise figure.
The output of the RF amplifier is applied to the interstage filter, a fixed-tuned 3-pole series-coupled resonator design having a 3 dB bandwidth of 54 MHz and insertion loss of 1.8 dB. This filter has an image rejection of 40 dB at 226 MHz, with increasing attenuation at higher frequencies.
The output of the interstage filter is connected to the passive double-balanced mixer consisting of components T41, T42, and CR41. This mixer has a conversion loss of 7 dB. High-side injection from the frequency synthesizer is filtered by L40-L41 and C40-C44 to remove second harmonic energy that may degrade half-IF spurious rejection performance. The injection filter has a 3 dB bandwidth of 52 MHz and an insertion loss of 1.5 dB. The filtered injection signal is applied to T42 at a level of +6 dBm.
The mixer output is applied to a diplexer network (L51-L52, C51, R51) which ma tches the 44 .85 MHz IF signal to crystal filter FL51, and terminates the mixer into 50at all other frequencies

4.2.2 Receiver Back-End

The receiver back end is a dual conversion design. High IF selectivity is provided by FL51, a 4-pole fundamental mode 44.85 MHz crystal filter with a minimum 3 dB bandwidth of + 6.7 kHz, a maximum 20 dB bandwidth of ±12.5 kHz, and a maximum insertion loss of 3.5 dB. The output is matched to IF amplifier stage Q51 by L53 and C93. Q5 1 provides 16 dB of gain and a noise figure of 1.8 dB. The dc operating current is 1 mA. The output of Q51 is applied to the input of the receiver IFIC U51. Diode CR51 limits the maximum RF level applied to the IFIC.
The IFIC is a low-voltage monolithic FM IF system incorporating a mixer/oscillator, two limiting IF amplifiers, quadrature detector, logarithmic received signal strength indicator (RSSI), voltage regulator and audio and RSSI op amps. The second LO frequency, 44.395 MHz, is determined by Y51. The second mixer converts the 44.85 MHz high IF frequency to 455 kHz.
Additional IF selectivity is provided by two ceramic filters, FL52 (between the second mixer and IF amp) and FL53 or FL54 (between the IF amp and the limiter input). The wider filter FL53 is used for 20/25 kHz channel spacing, and the narrower filter FL54 is used for 12.5 kHz channels. When the BW_SEL line is high, the two upper diodes in packages D51 and D52 are forward biased, selecting FL53 for 20/25 kHz channels. When the BW_SEL line is low, the two lower diodes in packages D51 and D52 are forward biased, selecting FL54 for 12.5 kHz channels.
FL52 FL53 FL54
Number of Elements: 4 6 6 Insertion Loss: 4 dB 4 dB 4 dB 6 dB Bandwidth: 15 kHz 15 kHz 9 kHz 50 dB Bandwidth: 30 kHz 30 kHz 22 kHz Stopband Rejection: 27 dB 47 dB 47 dB
Ceramic resonator Y70 provides phase vs. frequency characteristic required by the quadrature detector, with 90 degree phase shift occurring at 455 kHz. Buffer Q70 provides a lower driving impedance from the limiter to the resonator, improving the IF waveform and lowering the distortion of the recovered audio signal. The recovered audio level at the DEMOD output is 120 mV rms (25 kHz channel, 3 kHz deviation) or 60 mV rms (12.5 kHz chan n el, 1. 5 kHz devia tio n) . An ad dit ion a l RSSI output provides a DC voltage level that is proportio nal to RF signal level. This volt age is measured by an A/D converter contained in the microprocessor (PE4_AN4, U401 pin 63).
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136-162 MHz VHF Theory Of Operation: VHF Transmitter 4-3

4.3 VHF Tr ansmitter

The VHF transmitter covers the range of 136-162 MH z. Depen ding on mo del, the output po wer of the transmitter is either switchable on a per-channel basis between high power (5 watts) and low power (1 watt), or is factory preset to 2 watts. The transmitter is divided into four major blocks as shown in
Figure 4-2.
• Power Amplifier
• Harmonic Filter
• Antenna Matching Network
• Power Control
USWB+
TX_INJ
(From VCO)
TX_ENA
PWR_SET
5T
Q100
Power Control
VGG
Power Amplifier Module U110
Figure 4-2. VHF Transmitter Block Diagram

4.3.1 Transmit Power Amplifier

The transmitter power amplifier has three stages of amplification. The first stage, Q100, operates in Class AB from the 5T source. It provides 13 dB of gain and an output of 20 mW. The current drain is typically 25mA. Components C105-C107 and L103 match the output of Q100 to the 50 input of the module U110.
U110 is a two stage Silicon MOS FET power amplifier module. Drain voltage is obtained from UNSW B+ after being routed through current-sense resistor R150 in the power control circuit. The output power of the module is controlled by varying the DC gate bias on U110 pin 2 (VGG).

4.3.2 Antenna Switch

VDD
RX_IN
(To Receiver)
Antenna
Switch
Harmonic Filter
Antenna
Matching
Network
J140 Antenna Jack
Antenna
The antenna switch consists of two pin diodes, D120 and D121. In the rece ive mode, both diodes are off. Signals applied at the antenna or at jack J140 are routed, via the harmonic filter, through network C122-C124 and L121, to the receiver input. In the transmit mode, Q170 is on and TXB+ is present, forward-biasing both diodes into conduction. The diode current is 50 mA, set by R120-R122. The transmitter RF from U110 is routed through D120, and via the harmonic filter to the antenna jack. D121 conducts, shunting RF power and preventing it from reaching the receiver. L121 is selected to appear as a 1/4 wave at VHF, so that the low impedance of D121 appears as a high impedance at the junction of D120 and the harmonic filter input. This provides a high series impedance and low shunt impedance divider between the power amplifier output and receiver input.

4.3.3 Harmonic Filter

The harmonic filter consists of components C130- C136 and L130-L132. The harmonic filter is a seven-pole elliptical low-pass configuration, optimized for low insertion loss, with a 3 dB frequency of approximately 180 MHz and typically less than 0.8 dB insertion loss in the passband.
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4-4 136-162 MHz VHF Theory Of Operation: VHF Frequency Generation Circuitry

4.3.4 Antenna Matching Network

The harmonic filter presents a 50 impedance to antenna jack J140. A matching network, made up of C140-C141 and L140, is used to match the antenna impedance to the harmonic filter. This optimizes the performance of the transmitter and receiver into the impedance presented by the antenna, significantly improving the antenna's efficiency.

4.3.5 Power Control

The power control circuit is a dc-coupled amplifier whose output is the dc gate bias voltage (VGG) applied to the two stages of the RF power amplifier U110.
The output power of the transmitter is adjusted by varying the setting of the power-set DAC cont ained in the ASFICcmp IC (DACG, U451 pin 6). This PWR_SET voltage is applied to U150 pin 3.
Stage U150-2 compares the voltage drop across current sense resistor R150 to the voltage drop across resistor R151 caused by current flow through Q150, and adjusts its output (pin 7) to maintain equal voltages at pins 5 and 6. Thus the current flow through Q150, and hence its emitter voltage, is proportional to the current drawn by stage U110, which is in turn proportional to the transmitter output power. The emitter voltage of Q150 is applied to U150 pin 2, where it is compared to the power set voltage PWR_SET at pin 3.
The output of U150 pin 1 is divided by R110 and R111 and applied as a gate voltage to the power amplifier U110. By varying this gate voltage as needed to keep the voltages at U150 pins 2 and 3 equal, power is maintained at the desired setting. Excessive final current, for example due to antenna mismatch, causes a lowering of the voltage at U150 pin 6, an increased voltage at pin 2, and a lowering of the voltage at pin 1 and of the gate voltage VGG. This prevents damage to the final stage due to excessive current.

4.4 VHF Frequency Generation Circuitry

The frequency generation system, shown in Figure 4-3, is composed of two circuit blocks, the Fractional-N synthesizer IC U201, the VCO/Buffer IC U251, and associated circuitry. Figure 4-4 shows the peripheral interconnect and support circuitry used in the synthesizer block, and Figure 4-5 details the internal circuitry of the VCOBIC and its interconnections to the surrounding components. Refer to the schematic to identify reference designators.
The Fractional-N synthesizer is powered by regulated 5 V and 3 V provided by U310 and U330 respectively. 5 V is applied to U201 pins 13 and 30, and 3 V is applied to pins 5, 20, 34 and 36. The synthesizer in turn generates a super-filtered 4.5 V supply (VSF, from pin 28) to power U251. In addition to the VCO, the synthesizer also interfaces with the logic and ASFICcmp circuits. Programming for the synthesizer is accomplished through the microprocessor SPI_DATA_OUT, SPI_CLK, and SYNTH_CS (chip select) lines (U409 pins 100, 1 and 47 respectively). A logic high (3 V) from U201 pin 4 indicates to the microprocessor that the synthesizer is locked.
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