Motorola Professional CDM1550 LS+ Operating and maintenance manual

CDM1550•LS+™
200 MHz
700 MHz
Professional Series
Two-Way Radio Detailed Service Manual

Product Software License Agreement
THIS LICENSE AGREEMENT BETWEEN YOU, THE USER, AND MOTOROLA, APPLIES TO THE SOFT-
WARE EMBEDDED IN OR DELIVERED WITH THE ACCOMPANYING MOTOROLA PRODUCT ("SOFT-
WARE"), AND IS APPLICABLE UNLESS A SIGNED LICENSE AGREEMENT COVERING ITS SUBJECT
MATIER HAS BEEN EXECUTED BETWEEN YOU AND MOTOROLA. BY USING THE PRODUCT, YOU
ACKNOWLEDGE THAT THJS AGREEMENT HAS BEEN READ AND UNDERSTOOD AND THAT YOU
AGREE TO BE BOUND BY ITS TERMS AND CONDillONS . IF YOU DO NOT AGREE, YOU ARE NOT
LICENSED TO USE THE PRODUCT , AND IF YOU ARE THE PURCHASER OF THE PRODUCT, YOU
SHOULD IMMEDIATELY RETURN THE PRODUCT IN ITS ENTIRETY TO ITS PLACE OF PURCHASE FOR
A REFUND.
Motorola grants to You a non- exclusive license to use the SOFTWARE in the manner described in the docu-
mt!ntntion assod;. 1t ed with the produ t. Motorola retai ns ownership of the SO fT WARE including ilU pat · •nt ,
·opy,rights, a nd o lh '!' in te ll ect ual pr pt'r ty ri ght s. You may transfer this licens ~ to u se the SOFT\ t\IA RE as lo ng
as th e tran sferee agrees to be bound by th e t -e n ns of this Agreement.
You agree not to reverse engineer or create derivative works of the SOFTWARE; not to transmit the SOFT-
WARE electronically; not to modify, configure, or use the SOFTWARE in any manner not authorized by
MOTOROLA; and, except as an integral part of the product, not to rent, lease, or convey the SOFIWARE.
MOTOROLA SHALL
NOT BE LIABLE FOR INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING
FROM THE USE OF THIS SOFTWARE.
With r sp t t , th· U.S . ovetmm en l, if acqu ir• d under PAR policy (52.-27-19), the SO FT WA RE is pr JVided
with Restricted Right ond i( ncquircd und er DFARS pol i'cy (227.7202), then the SOFI 'WA RE is prov ide Ionly
with th ·omrn . rd 1 rl ~ h ls of this A p, r' 'C menl.
This license is effective until terminated. It will terminate immediately and automatically if You fail to comply
with any term of this Agreement.
You agree that this is the complete and exclusive statement of the agreement between You and Motorola and
that any modification of these terms shall be made only by mutual agreement and evidenced by written
amendment signed by both parties . This Agreement shall be governed and interpreted by the laws of the
State of Illinois, United States of America.
Computer Software Copyrights
This manual may not be reproduced, in whole or in part, in any fmm whatsoever, without the express written per-
mission ofMotorola, Inc.
The Motorola products described in this manual contain one or more computer programs . n1ese computer
programs are protected by copyright law and international treaties. Unauthorized reproduction or distribu-
tion of these programs, or any part thereof, may result in severe civil and criminal penalties, and will be pros-
ecuted to the maximum extent possible under the law . U. S. and international patents pending .
This product Is covered by one or more Issued U.S. Patents. Other Patent applications pending.

Table of Contents
Product Safety and RF Exposure Compliance .. .. ................ . .. vii
Chapter 1 Introduction
1.1 ScopeofManual......................................................................................... .. .... . .. 1-1
1.2 Warranty and Service Support................................................................ .. .. ......... 1-1
1.2.1 Warranty Period ..................................... .... ... .. . .... . .... ... . .. ................... .. .. 1-1
1.2.2 Return Instructions...................................... .. .. .. ................................... .. 1-1
1.2.3 After Warranty Period ..................................... .. ........... .. ...... .. ..... .. ..... .. .. 1-1
1.3 Related Documents .................................. .. ................... ... .. .... ... ...... .. ......... ..... ... .1-2
1.4 Technical Support...................................................... .. ... .................................. ... 1-2
1.5 Warranty and Repairs................................................ ... ... .. ...................... .... .. .. . .. .1-2
1.6 Radio Model Chart and Specifications...................... ........ ... ................................ 1-3
1.7 Radio Modellnformation.............................................
.. .. ................................ .. ... 1-3
Chapter 2 Theory of Operation
2.1 Overview.............................................................................................................. 2-1
2.2 Controller ........................................................ .. .. ........ .. .. ........... .. ............. .... ... .... 2-1
2.2.1 Radio Power Distribution .. ... .... ..... .. .............................. .. .............. .. .. . .. .. 2-2
2.2.2 Automatic On/Off ..........................................
.. .......................................2-3
2.2.3 Emergency.........................................................
.. ........ .. .. . ... ..... .. .... ... .... 2-4
2.2.4 Mechanical On/Off............................................................................
... ..2-4
2.2.5 Ignition .
.. . .. ... ... ........................................................................ ..... . ..... . ... 2-4
2.2.6 Microprocessor Clock Synthesizer.......
.. ..... .. ............... .. ...... .. ....... .. .. ... .. 2-5
2.2.7 Serial Peripheral Interface (SPI) ................
.... ........... .... ................. .. .. .... 2-5
2.2.8 SBEP Serial Interface .........................................
... ................................ 2-6
2.2.9 General Purpose lnpuUOutput
.. .......... .. ...................... ... ...... .. ...... ... ....... 2-6
2.2.1 0 Normal Microprocessor Operation ...................
.. ....... ... ............ .... .. .. ...... 2-7
2.2.11 Static Random Access Memory (SRAM) ......
.. ....... .. .. . .. .........................2-8
2.3 Controller Board Audio and Signalling Circuits
.... ............................. .... ........... .. .. 2-8
2.3.1 Audio Signalling Filter
IC with Compander (ASFIC CMP) ..................... 2-8
2.3.2 Transmit Audio Circuits......................................................
.... .. ............ .. 2-9
2.3.3 Microphone Input Path ............................................
.. . .... ........ .. .... ........ .. 2-9
2.3.3.1 PTT Sensing and TX Audio Processing .
.... .. ....... .. .. ................ 2-10
2.3.3.2 TX Secure Audio (optional) ............................ .. .... . .... .. ............ 2-10
2.3.3.3 Option Board Transmit Audio ........................... .. ........ ........ ..... 2-10
2.3.4 Transmit Signalling Circuits .......................................................... .. ... .. 2-11
2.3.4.1 Sub-Audible Data (PL/DPL) .................................................... 2-11
2.3.4.2 High Speed Data ....................................... ... .. . .. ............. .. ....... 2-12

ii
2.3.4.3 Dual Tone Multiple Frequency (DTMF) Data ........................ ... 2-12
2.3.5 Receive Audio Circuits .........................................................................2-13
2.3.5.1 Squelch Detect.........................................................................2-13
2.3.5.2 Audio Processing and Digital Volume Control .........................2-13
2.3.5.3 Audio Amplification Speaker(+) Speaker(-) ...........................2-14
2.3.5.4 Handset Audio .........................................................................2-14
2.3.5.5 Filtered Audio and Flat Audio...................................................2-15
2.3.5.6 RX Secure Audio Option..........................................................2-15
2.3.5.7 Option Board Receive Audio....................................................2-15
2.3.6 Receive Signalling Circuits...................................................................2-16
2.3.6.1 Sub-Audible Data (PLIDPL) and High Speed Data Decoder
... 2-16
2.3.6.2 Alert Tone Circuits ...................................................................2-16
2.3.6.3 Voice Storage Option...............................................................2-17
2.4 200 MHz Receiver Front-End.............................................................................2-18
2.4.1 Receiver Front End ..............................................................................2-18
2.4.2 Receiver Back End...............................................................................2-19
2.5 Transmitter Power Amplifier (PA)
25 W .............................................................2-19
2.5.1 Power Controlled Stage ......................................
.. ...... .. .......................2-20
2.5.2 Pre-Driver Stage...................................................................................2-20
2.5.3 Final Stage ....................................................................... .. ... ...............2-20
2.5.4 Directional Coupler .. .............................................. .. .... ... ......................2-20
2.5.5 Antenna Switch ....................................................................................2-20
2.5.6 Harmonic Filter .....................................................................................2-21
2.5.7 Power Control.......................................................................................2-21
2.6 Frequency Synthesis..........................................................................................2-21
2.6.1 Reference Oscillator..................................................
.. .........................2-21
2.6.2 Fractionai-N Synthesizer..............................,.......................................2-22
2.6.3 Voltage Controlled Oscillator
(VC0) .....................................................2-23
2.6.4 Synthesizer Operation ..........................................................................2-24
2.7 700 MHz Receiver Front-End.............................................................................2-25
2.7.1 Receiver Front-End .........................
.. ...................................................2-25
2.7.2 Receiver Back-End.............................
... ........................................ ... .... 2-25
2.8 Transmitter Power Amplifier (PA)
15 W .............................................................2-26
2.8.1 Power Controlled Stage ..................................................
.... .................2-26
2.8.2 Driver Stage .........................................................................................2-27
2.8.3 Final Stage .................................. .. .............. ... ................................... .. .2-27
2.8.4 Antenna Switch ....................................................................................2-27
2.8.5 Harmonic Filter
... ........ ... .............. ... ................................... .. .................2-27
2.8.6 Bi-Directional Coupler ..........................................................................2-27
2.8.7 Power Control.......................................................................................2-27
2.9 Frequency Synthesis..........................................................................................2-28
2.9.1 Reference Oscillator.............................................................................2-28
2.9.2 Fractionai-N Synthesizer......................................................................2-28
2.9.3 Voltage Controlled Oscillator
(VC0) .....................................................2-29
2.9.4 Synthesizer Operation..........................................................................2-31
.)

iii
2.10 Control Head (COM1550•LS+) .......................................................................... 2-31
2.1 0.1 Power Supplies ..................................................................... .. ..... ........ 2-31
2.10.2 Power On I Off............................................................................... ... . .. 2-32
2.1 0.3 Microprocessor Circuit ................................. .. .................. .. .................. 2-32
2.10.4 SBEP Seriallnterface................................................... .... ...... ... .......... 2-32
2.1 0.5 Keypad Keys.......................................... ... ........................... .. . ... .. .. ...... 2-33
2.10.6 Status LED
and Back Light Circuit................ .. ...................... .. .. ... ........ 2-33
2.1 0. 7 Liquid Crystal Display (LCD)................................................................ 2-33
2.1 0.8 Microphone Connector Signals........................................................ .. .. 2-34
2.1 0.9 Speaker................................................................................ .. .. ............ 2-35
2.1 0.1 0 Electrostatic Transient Protection .. ....... .. .................... ..... ............ .... .. .. 2-35
2.11 PassPort Trunking Controller Board (PTCB) .. .. . .. ........ .................................... .. 2-35
Chapter 3 Maintenance
3.1 Introduction ...................................................................... .. .................................. 3-1
3.2 Preventive Maintenance .. ... .... ........................ .. ............. ... .. ... ... ........................... 3-1
3.2.1 Inspection................................ ... ............................ .. . .. ........................... 3-1
3.2.2 Cleaning........... .. ................ ... ........... .. ... .. ....... .. ......... .. ......................... .. 3-1
3.3 Safe Handling of CMOS and LDMOS................................ .. .... . .. .. ............. .. ..... .. .3-2
3.4 General Repair Procedures and Techniques ........................ .... ..... .... .. .. .... . .... .. .. 3-2
3.5 Recommended Test Tools.......
.. . ... .......................................................... ... .. .... ... 3-5
3.6 Receiver Troubleshooting Chart (200 MHz) ..............................................
.. .... .... 3-6
3.7 Receiver Troubleshooting Chart (700 MHz) ............ .. .......... .... ........ .. ..... .. .. .. .. ..... 3-8
3.8 Transmitter Troubleshooting Chart (200 MHz) ............................
.. .................. .. 3-10
3.9 Transmitter Troubleshooting Chart (700 MHz) .................................................. 3-11
3.10 Synthesizer Troubleshooting Chart (200 MHz)............ .. ... .. ............................... 3-12
3.11 Synthesizer Troubleshooting Chart (700 MHz)............. .. .. .............. ... ....... .. .. ... .. 3-13
3.12 VCO Troubleshooting Chart (200 MHz)............................................................. 3-15
3.13 VCO Troubleshooting Chart (700 MHz)...................................... .... ..... .. ............ 3-16
Chapter 4 Schematic Diagrams, Overlays,
and Parts Lists
4.1 Introduction....................................... .. ............................................................... .. 4-1
4.1.1 Notes For All Schematics and Circuit Boards........................................ 4-1
Figure 4-1. CDM1550•LS+ Control Head Top Overlay ..................................... .. ... 4-3
Figure 4-2. CDM1550•LS+ Control Head Bottom Overlay ................................. .. .. 4-4
Figure 4-3. CDM1550•LS+ Control Head Schematic Diagram .......
.. ............... .. ..... 4-5
Figure 4-4. CDM1550•LS+ Control Head Keypad Schematic ................................4-6
Figure 4-5. CDM1550•LS+ Control Head Backlight Schematic ... .. ............... .. ........ 4-7
Figure 4-6. CDM1550•LS+ Control Head Display Schematic .....
.. .........................4-8
CDM1550•LS+ Control Head Parts List.......................................................................4-9
Figure 4-7. 200 MHz Main Board Top Side PCB ............................... ... .. .. ............4-11
Figure 4-8.
200 MHz Main Board Bottom Side PCB ................................... .... .. .. .4-12
Figure 4-9. 200 MHz Receiver Front
End Schematic Diagram .............. .. .. .. ........ 4-13

iv
Figure 4-10. 200 MHz Receiver IF Schematic Diagram .............................. .. .... .. ... 4- 14
Figure 4-11. 200 MHz Transmitter Power Amplifier Schematic Diagram ..............4-15
Figure 4-12. 200 MHz Fractionai-N Synthesizer Schematic Diagram ..
.. ......... ... .. .. 4-16
Figure 4-13. 200 MHz Voltage Controlled Oscillator Schematic Diagram ...........
.. .4-17
Figure 4-14. 200 MHz Overall Controller Schematic Diagram ................... .. .... .. .....4-18
Figure 4-15. 200 MHz Microprocessor Schematic Diagram ............
.. .....................4-19
Figure 4-16. 200 MHz Audio Schematic Diagram
.. ........... .... .................... ........ .. .. ..4-20
Figure 4-17. 200 MHz Interface
and Connectors Schematic Diagram .. .. . ... .. ......... 4-21
Figure 4-18. 200 MHz Power Supply Schematic Diagram .. .............................. ...... 4-22
200 MHz Radio Parts List........................... .... ...... .. .... ... ...... .. .... ...... ..... .... .......... ... ... .A-23
Figure 4-19. 700 MHz Main Board Top Side PCB ........ ... ...... .... ........ .. ....... .. ..........4-27
Figure 4-20. 700 MHz Main Board Bottom Side
PCB ............... ... ..... .. ....... .... .........4-28
Figure 4-21. 700 MHz Receiver Front
End Schematic Diagram .. ..... .... ..... .... ..... .. ..4-29
Figure 4-22. 700 MHz Receiver
IF Schematic Diagram ................................ .. . ... ...4-30
Figure 4-23. 700 MHz Transmitter Power Amplifier Schematic Diagram ..........
.... .4-31
Figure 4-24. 700 MHz Fractionai-N Synthesizer Schematic Diagram .. .............. .. .. 4-32
Figure 4-25. 700 MHz Voltage Controlled Oscillator Schematic Diagram
.. ... .. . .. . .. .4-33
Figure 4-26. 700 MHz Overall Controller Schematic Diagram
... ...................... .. ... .. 4-34
Figure 4-27. 700 MHz Microprocessor Schematic Diagram ........
.. ....................... .. 4-35
Figure 4-28. 700 MHz Audio Schematic Diagram .................
... ...................... .. .......4-36
Figure 4-29. 700 MHz Interface
and Connectors Schematic Diagram ...... .. ... ........4-37
Figure 4-30. 700 MHz Power Supply Schematic Diagram
.. ..................... .... .. ...... .. .4-38
700 MHz Radio Parts List.................................................... .... ....... .. ..........................4-39
Figure 4-31. PassPort Trunking Controller Board Side 1 &2
... .... ..........................4-45
Figure 4-32. PassPort Trunking Controller Board Schematic Diagram ..................4-46
_)

v
List of Figures
Figure 2-1.
Figure 2-2.
Figure 2-3.
Figure 2-4.
Figure 2-5.
Figure 2-6.
Figure 2-7.
Figure 2-8.
Figure 2-9.
Figure 2-10.
Figure 2-11.
Figure 2-12.
Figure 2-13.
Figure 2-14.
Figure 4-1.
Figure 4-2.
Figure 4-3.
Figure 4-4.
Figure 4-5.
Figure 4-6.
Figure 4-7.
Figure 4-8.
Figure 4-9.
Figure 4-10.
Figure 4-11.
Figure 4-12.
Figure 4-13.
Figure 4-14.
Figure 4-15.
Figure 4-16.
Figure 4-17.
Figure 4-18.
Figure 4-19.
Figure 4-20.
Figure 4-21.
Figure 4-22.
Figure 4-23.
Figure 4-24.
Figure 4-25.
Figure 4-26.
Figure 4-27.
Figure 4-28.
Figure 4-29.
Figure 4-30.
Figure 4-31.
Figure 4-32.
Controller Block Diagram.................... .. .. .................... .. ........................... 2-1
DC Power Distribution Block Diagram .......... ... ......... .. ....... .. ... ................. 2-3
Transmit Audio Paths .................................
.. ...... ... .. ................................ 2-9
Transmit Signalling Paths...........................
.. ......................................... 2-11
Receive Audio Paths .......................................
.. ................... ... .............. 2-13
Receive Signalling Paths....................
.... .. ........... ... ............................... 2-16
200 MHz Receiver Block Diagram..... .. .... .............................................. 2-18
200 MHz Transmitter Block Diagram..................................................... 2-19
200 MHz Synthesizer Block Diagram .................................................... 2-22
200 MHz VCO Block Diagram ............................................................... 2-23
700 MHz Receiver Block Diagram.............................................. .. ......... 2-25
700 MHz Transmitter Block Diagram..................................................... 2-26
700 MHz Synthesizer Block Diagram .................................................... 2-29
700 MHz VCO Block Diagram ............................................................... 2-30
CDM1550•LS+ Control Head Top Overlay.............................................. 4-3
COM1550•LS+ Control Head Bottom Overlay......................................... 4-4
CDM1550•LS+ Control Head Schematic Diagram ........... .. ........ .... ....... .. 4-5
COM1550•LS+ Control Head Keypad Schematic
.. ..... .. .. .... ... .... .. ......... .. 4-6
CDM1550•LS+ Control Head Backlight Schematic ... ............. ... .............. 4-7
CDM1550•LS+ Control Head Display Schematic.................................... 4-8
200 MHz Main Board Top Side PCB ...................... .. ............................. 4-11
200 MHz Main Board Bottom Side PCB............................. .. .............. ... 4-12
200 MHz Receiver Front End Schematic Diagram ...... .. .. ......... .. ........... 4-13
200 MHz Receiver IF Schematic Diagram ............................................ 4-14
200 MHz Transmitter Power Amplifier Schematic Diagram .. .. ............. 4-15
200 MHz Fractionai-N Synthesizer Schematic Diagram .... .. ............. .. .. 4-16
200 MHz Voltage Controlled Oscillator Schematic Diagram .... ... .... .. .... 4-17
200 MHz Overall Controller Schematic Diagram ............... .. .. .. . ... .......... 4-18
200 MHz Microprocessor Schematic Diagram ..................... .. . ... ...... .. ... 4-19
200 MHz Audio Schematic Diagram................................. ... .................. 4-20
200 MHz Interface and Connectors Schematic Diagram .
... .... .. ............ 4-21
200 MHz Power Supply Schematic Diagram .. ................................. .. .. .. 4-22
700 MHz Main Board Top Side PCB .......................... .. ........... .. ...... ... ... 4-27
700 MHz Main Board Bottom Side PCB ................................................ 4-28
700 MHz Receiver Front End Schematic Diagram .................... .. ... .. .. ... 4-29
700 MHz Receiver IF Schematic Diagram .......................................... .. 4-30
700 MHz Transmitter Power Amplifier Schematic Diagram ......
.. ........ .. 4-31
700 MHz Fractionai-N Synthesizer Schematic Diagram ...... .. ......... .. .. .. 4-32
700 MHz Voltage Controlled Oscillator Schematic Diagram ................. 4-33
700 MHz Overall Controller Schematic Diagram ............ .. ..................... 4-34
700 MHz Microprocessor Schematic Diagram .. .............. .. ...... .. ............ 4-35
700 MHz Audio Schematic Diagram................... .. ............................... .. 4-36
700 MHz Interface and Connectors Schematic Diagram .. .... ... .... .. ... .... 4-37
700 MHz Power Supply Schematic Diagram ... ...................................... 4-38
PassPort Trunking Controller Board Side 1 &2 ...............
.. ....... ... .. ....... 4-45
PassPort Trunking Controller Board Schematic Diagram ..................... 4-46

vi
List of Tables
Table 1-1.
Table 1-2.
Table 3-1.
Related Documents.................................................................................. 1-2
Radio Model Number............................................................................... 1-3
Recommended Test Tools...
.. ......... .. . .. ...... .. .. ... ... ..... .. . .. ... .. ....... .. ......... .. . 3-5
)

Safety-vii
PRODUCT SAFETY AND RF EXPOSURE COMPLIANCE
Caution
Before using this product, read the operating instructions for safe usage contained in the
Product Safety and RF Exposure booklet enclosed with your radio.
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 number
68P81095C99) 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.·

Safety-viii
This page intentionally left blank

Chapter 1
Introduction
1.1 Scope of Manual
This manual is intended for use by service technicians familiar with similar types of equipment. It
contains service information required for the equipment described and is current as of the printing
date. Changes that occur after the printing date are incorporated by a complete manual revision or
alternatively, as additions.
Note: Before operating or testing these units, please read the Safety Information Section in the
front of this manual.
1.2 Warranty and Service Support
1-1
Motorola offers long term supportfor its products. This support includes full exchange and/or repair of
the product during the warranty period, and service/repair or spare parts support out of warranty. Any
"return for exchange" or "return for repair" by an authorized Motorola dealer must be accompanied by
a warranty claim form. Warranty claim forms are obtained by contacting customer service.
1.2.1 Warranty Period
The terms and conditions of warranty are defined fully in the Motorola dealer or distributor or reseller
contract. These conditions may change from time to time and the following notes are for guidance
purposes only.
1.2.2 Return Instructions
In instances where the product is covered under a "return for replacement" or "return for repair"
warranty, a check of the product should be performed prior to shipping the unit back to Motorola. This
is to ensure that the product has been correctly programmed or has not been subjected to damage
outside the terms
of the warranty.
Prior to shipping any radio back to a Motorola warranty depot, please contact the appropriate
customer service for instructions. All returns must be accompanied by a warranty claim form,
available from your customer services representative. Products should be shipped back in the original
packaging, or correctly packaged to ensure
no damage occurs in transit.
1.2.3 After Warranty Period
After the Warranty period, Motorola continues to support its products in two ways:
Firstly, Motorola's Accessories and Aftermarket Division (ADD) offers a repair service to both end
users and dealers at competitive prices.
Secondly, Motorola's service department supplies individual parts and modules that can be
purchased by dealers who are technically capable
of performing fault analysis and repair.

1-2 Introduction
1.3 Related Documents
The following documents are directly related to the use and maintainability of this product.
Table 1-1. Related Documents
Title
200/700 MHz Professional Radio Mobile
Level 1&2 Basic Service Manual- English
1.4 Technical Support
Part Number
6864110R16
Technical support is available to assist the dealer/distributor and self-maintained customers in
resolving any malfunction which may be encountered. Initial contact should be by telephone to
customer resources wherever possible. When contacting Motorola technical support, be prepared to
provide the product model number and the unit's serial number. The contact locations and telephone
numbers are listed below.
Motorola Radio Support Center
3761 South Central Avenue
Rockford, IL 61102-4294
1-800-227-6772
1-815-489-1000
Motorola Toronto Service Center
400 Matheson Blvd. W,
Mississauga, Ontario, Canada L5R 3M1
1-800-543-3222
1-416-756-5841
1-888-331-9872 (Fax)
Motorola U.S. Federal Government Depot
4395 Nicole Drive
Lanham, MD 20706
1-800-969-6680
1-301-731-6676
1.5 Warranty and Repairs
For warranty and repairs, contact Motorola Technical Support as listed below. Be prepared to provide
the product model number and the unit's serial number.
Some replacement parts, spare parts, and/or product information can be ordered directly. If a
complete Motorola part number is assigned to the part, and it is not identified as "Depot ONLY", the
part is available from Motorola Accessories and Aftermarket Division (AAD). If no part number is
assigned, the part is not normally available from Motorola. If the part number is appended with an
asterisk, the part is serviceable by a Motorola depot only. If a parts list is not included, this generally
means that no user-serviceable parts are available for that kit or assembly.Technical Support the
product
model number and the unit's serial number.
Parts Order Entry:
7:00A.M. to 7:00 P.M. (Central Standard Time)
Monday through Friday (Chicago, U.S.A.)
To Order Parts:
.)

Introduction 1-3
1-800-422-4210, or 847-538-8023
1-800-826-1913, or 410-712-4907 (U.S. Federal Government)
TELEX: 280127
FAX: [phone]
FAX: [phone] (U.S. Federal Government)
(U.S.A.) after hours or weekends:
1-800-925-4357
Motorola Parts
Accessories and Aftermarket Division
(United States and Canada)
Attention: Order Processing
2200 Galvin Dr.
Elgin, IL 60123
Parts Identification
1-800-422-4210 menu 3
1.6 Radio Model Chart and Specifications
The radio model charts and specifications are located in the Basic Service Manual listed under the
Related Documents paragraph of this chapter.
1. 7 Radio Model Information
AA
t
Q)
(/)
=>
-ell
c
....
Q)
c
ell
0
....
0
0
:2:
II
~
The model number and serial number are located on a label attached to the back of your radio. You
can determine the RF output power, frequency band, protocols, and physical packages from these
numbers. The example below shows one portable radio model number and its specific characteristics.
Table 1·2. Radio Model Number
Example: AAM25MHF4DP5AN
Type of
Model Freq. Power Physical Channel Protocol
Unit Series Band Level Packages Spacing
M 25 M H F 4 DP
t (200 MHz) 1 to CDM1550•LS+ 12.5 kHz PassPort
25W
or
J!2
5 1 to
:c
0 (700 MHz)
15W
:::2:
II
::e
Feature Model Model
Level Revision Package
5 A N
4 Chan.,
64 Chan,
128 Chan.

1-4 Introduction
This page intentionally left blank
_)

_)
2-1
Chapter 2
Theory
of Operation
2.1 Overview
This chapter provides a detailed theory of operation for the radio and its components. The radio is
designed as a single board unit consisting
of a transmitter, receiver, and controller circuits. The
board also accepts one additional option board that can provide functions such as secure voice/
data, voice storage, or a signalling decoder.
A control head, mounted directly on the front
of the radio or remotely connected by an extension
cable, provides a user interface for controlling the various features
of the radio. The control head
contains LED indicators, microphone connector, and buttons depending on the radio type, display,
and speaker.
The rear
of the radio provides connections for a power, antenna, and accessory cable. The
accessory cable provides connections for items such as an external speaker, emergency switch,
foot operated
PTT, and ignition sensing, etc.
2.2 Controller
The radio controller, shown in Figure 2-1, is divided into three main functions:
Digital control
Audio processing
Voltage regulation.
The digital control section
of the radio consists of a microprocessor (IJP), support memory, support
logic, signal MUX ICs, on/off circuit, and general purpose input/output circuits.
To Synthesizer
16.8 MHz
Reference Clock
from Synthesizer
5V
from Synthesizer
Mod Out
r----
--- -------,
Audio/Signalling
ASFIC_CMP
External
Microphone
External
Speaker
Section (5V_RF)
-or----__;;,
____ .J
Internal
Speaker
To RF Section .... l--------------1
IJP Clock
... SCI to
rDigital - - = - = = =I == .:;- , Accessory &
I R L 1 Control Head
I SV AM I I I Connector
1 Regulator I 1 EEPROM r HC11
FLO I 1
I (5VD) I I FLASH 1- I I
~ ------~---- -~.J
Figure 2-1. Controller Block Diagram

2-2 Theory of Operation
2.2.1 Radio Power Distribution
The de power distribution throughout the radio board is shown in Figure 2-2. Voltage regulation for
the controller is provided by four separate devices:
U0651 (MC78M05) +5 volts
U0641 (LM2941) +9.3 volts
U0611 (LM2941) +12 volts
VSTBY 5V (a combination
of R0621 and VR0621)
U3211 Additional 5 volt regulator located in the
RF section.
The
de voltage applied to connector J0601 supplies power directly to the following:
Electronic on/off control
RF power amplifier
12 volt regulator
9.3 volt regulator
Audio PA
5.6 volt stabilization circuit
9.3 volt regulator (U0641) supplies power
to the 5 volt regulator (U0651) and 6 volt voltage
divider Q0681
Regulator U0641 generates the 9.3 volts required by some audio circuits, the RF and power control
circuits. Input and output capacitors C0641 and C0644 I C0645 are used to reduce high frequency
noise. Resistors R0642 I R0643 set the output voltage of the regulator. If the voltage at pin 1 is
greater than 1.3 volts the regulator output decreases and if the voltage is less than 1.3 volts the
regulator output increases. This regulator output is enabled by a 0 volt signal on pin 2. Transistors
00661, Q0641, and R0641 are used to disable the regulator when the radio is turned off.
Voltage regulator U0651 provides 5 volts operating voltage for the digital circuits. Operating voltage
is from the regulated 9.3volts supply. Input and output capacitors (C0651 I C0652 and C0654 I
C0655) reduce high frequency noise and provide proper operation during battery transients. Voltage
sense device U0652 or alternatively U0653 provides a reset output that goes to 0 volts if the
regulator output goes below 4.5 volts. This resets the controller to prevent improper operation.
Diode D0651 prevents discharge of C0652 by negative spikes on the 9.3 volt supply.
Transistor Q0681 and resistors R0681 I R0682 divide the regulated 9.3 volts down to about 6 volts.
This voltage supplies the 5 volt regulator, located on the RF section. By reducing the supply voltage
ofthe regulator, the power dissipation is divided between the RF section and the controller section.
The VSTBY signal, derived directly from the supply voltage by components R0621 and VR0621,
buffers the internal RAM. Capacitor C0622 allows the battery voltage to be disconnected for several
seconds without losing RAM information. Dual diode D0621 prevents radio circuits from discharging
this capacitor. When the supply voltage is applied to the radio, C0622 is charged via R0621 and
D0621. When the radio is switched on, the
IJP enters the wrong mode ifthe voltage across C0622 is
still too low. The regulated 5 volts charges C0622 via diode D0621.

Theory ofOperation
FLT_A+
5VD
Figure 2-2. DC Power Distribution Block Diagram
5VI
VDDA
2-3
The INT SW B+ voltage from switching transistor 00661 provides power to the circuit controlling the
audio PA output. The voltage is monitored by the IJP through voltage divider R0671/R0672 and the
line battery voltage. Diode VR0671 limits the divided voltage to 5.6 volts to protect the IJP.
Regulator U0611 generates the voltage for the switched supply voltage output (SWB+) at accessory
connector J0501, pin 13. U0611 operates as a switch with voltage and current limit. Resistors
R0611 /R0612 set the maximum output voltage to 16.5 volts. This limitation is only active at high
supply voltage levels. The regulator output is enabled by a 0 volt signal at 00661, pin 2. 00641 and
R0641 disable the regulator when the radio is turned off. Input and output capacitors C0603 and
C0611/C0612 reduce high frequency noise.
Diode VR0601 protects against transients and reverse polarity of the supply voltage.
2.2.2 Automatic On/Off
The radio software and/or external triggers turn the radio on or off without direct user action. For
example, automatic turn on when ignition is sensed and off when ignition is off.
00661 provides the INT SW B+ voltage to the various radio circuits and to enable the voltage
regulators via transistor 00641 which contains a pnp and an npn transistor that provide an
electronic on/off switch. The switch is on when the collector of the npn transistor within 00661 is low.
When the radio is offthe collector is at supply voltage level. This effectively prevents current flow
from emitter to collector of the pnp transistor. When the radio is turned on the voltage at the base of
the npn transistor is pulled high and the pnp transistor switches on (saturation). With the INT SWB+
voltage now at supply voltage level, transistor 00641 pulls pin 2
of the voltage regulators U0611 and
U 0641 to ground level, enabling their outputs.
The electronic on/off circuits are enabled by the IJP through ASFIC CMP port GCB2, line DC
POWER ON, emergency switch (line EMERGENCY CONTROL), the mechanical On/OffNolume
knob on the control head (line ON OFF CONTROL), or the ignition sense circuits (line IGNITION
CONTROL). If any
of the four paths cause a low at the collector of the npn transistor within 00661,
the electronic "ON" is engaged.

2-4 Theory of Operation
2.2.3 Emergency
The emergency switch (J0501, pin 9), when engaged, grounds the base of Q0662 via the
EMERGENCY CONTROL line. This switches Q0662 off and resistor R0662 pulls the collector of
Q0662 and the base of Q0663 to levels above two volts. Transistor Q0663 then switches on and
pulls the collector of the npn transistor within Q0661 to ground level This enables the voltage
regulators via Q0641 . When the emergency switch is released, R0541 pulls the base of Q0662 up to
0.6 volts causing the collector of transistor Q0662 to go low (0.2 volts), switching Q0663 off.
While the radio is on, the ~P monitors the voltage at the emergency input on the accessory
connector via pin 60 and the GP5 IN ACC9 line. Three different conditions can exit: no emergency,
emergency, and open connection to the emergency switch. If no emergency switch is connected or
the connection to the emergency switch is broken, the resistive divider R0541/R0512 sets the
voltage to about 4.7 volts. If an emergency switch is connected, a resistor to ground within the
emergency switch reduces the voltage on line GP5 IN ACC9 to inform the ~P that the emergency
switch is operational. An engaged emergency switch pulls line GP5 IN ACC9 to ground level. Diode
D0179 limits the voltage to protect the ~P input.
While the EMERGENCY CONTROL signal is low and INT SW 8+ is on, the ~P starts execution,
reads thatthe emergency input is active through the voltage level of line GP5 IN ACC9, and sets the
DC POWER ON output of the ASFIC CMP, pin 13 to a logic high. This keeps Q0661 and Q0641
switched to allow a momentary press of the emergency switch to power up the radio. When the ~p
has finished processing the emergency press, it sets the DC POWER ON line to a logic 0. This turns
off Q0661 and the radio turns off. Notice that the ~Pis alerted to the emergency condition via line
GP5 IN ACC9. Ifthe radio is already on when the emergency is triggered, the DC POWER ON
signal is already high.
2.2.4 Mechanical On/Off
This refers to the on/off/volume knob located on the control head which is used to turn the radio on
and off and control the volume.
If the radio is turned off and the on/off/volume knob is pressed, line ON OFF CONTROL (J0401, pin
11) goes high and switches the radio's voltage regulators on as long as the button is pressed. The
~Pis alerted through line ON OFF SENSE (U01 01, pin 6) which is pulled to low by Q0110 while the
on/off/volume knob is pressed. In addition, an interrupt is generated at ~P . pin 96. The ~p asserts
line DC POWER ON via ASFIC CMP, pin 13 high which keeps the radio switched on. The ~P
switches the radio off by setting DC POWER ON to low via ASFIC CMP pin 13.
2.2.5 Ignition
Ignition sense prevents the radio from draining the vehicle's battery because the engine is not
running.
When the IGNITION input (J0501, pin 10) goes above 5 volts, Q0661
is turned on via line IGNITION
CONTROL. Q0661 turns on INT SW B+ and the voltage regulators by turning on Q0641 and the ~P
starts execution. The IJP is alerted through line GP6 IN ACC1 0. While the on/off button is pressed, a
high signal turns Q0181 on, which pulls IJP, pin 74 to low. If the software detects a low state it
asserts DC POWER ON via ASFIC, pin 13 high which keeps Q0661 and Q0641 and the radio
switched on.
When the IGNITION input goes below 3 volts, Q0181 switches off and R0181 pulls IJP. pin 74 to
high.This alerts the software to switch offthe radio by setting DC POWER ON to low.The next time
the IGNITION input goes above 5 volts the above process is repeated.

_)
Theory of Operation 2-5
2.2.6 Microprocessor Clock Synthesizer
The clock source for the 1-1P system is generated by the ASFIC CMP (U0221 ). Upon power-up the
synthesizer IC (FRAC-N) generates a 16.8 MHz waveform that
is routed from the RF section to the
ASFIC CMP, pin 34. For the main board controller the ASFIC CMP uses 16.8 MHz as a reference
input clock signal for its internal synthesizer. The ASFIC
CMP, in addition to the audio circuit, has a
programmable synthesizer which can generate a synthesized signal ranging from 1200Hz to
32.769MHz in 1200Hz steps.
When power is first applied, the ASFIC CMP generates its default 3.6864MHz CMOS square wave
UP CLK (on U0221, pin 28) and this is routed to the 1-1P (U0101, pin 90). After the 1-1P starts
operation, it reprograms the ASFIC CMP clock synthesizer to a higher UP CLK frequency (usually
7.3728 or 14.7456 MHz) and continues operation.
The ASFIC CMP may be reprogrammed to change the clock synthesizer frequencies at various
times depending on the software features that are executing.
In addition, the clock frequency of the
synthesizer
is changed in small amounts if there is a possibility of harmonics of this clock source
interfering with the desired radio receive frequency.
The ASFIC CMP synthesizer loop uses C0245, C0246 and R0241
to setthe switching time and jitter
of the clock output. If the synthesizer cannot generate the required clock frequency it switches back
to its default 3.6864MHz output.
Because the ASFIC CMP synthesizer and the
1-1P do not operate without the 16.8 MHz reference
clock, the synthesizer and the voltage regulators should be checked first in debugging the system.
The
1-1P uses crystal oscillator Y0131 and associated components to form a real time clock used to
display the time on control heads (with display) or as time stamp for incoming calls or messages.
The real time clock
is powered from the voltage VSTBY to keep running while the radio is switched
off. If
the radio is disconnected from the supply voltage, the time must be reset.
2.2.7 Serial Peripheral Interface (SPI)
The 1-1P communicates to many ofthe IC's through its SPI port. This port consists of SPI TRANSMIT
DATA (MOSI) (U0101, pin 100), SPI RECEIVE DATA (MISO) (U01 01, pin 99), SPI CLK (U0101, pin
1) and chip select lines going to the various ICs. The BUS is a synchronous bus, in that the timing
clock signal CLK is sent while SPI data (SPI TRANSMIT or RECEIVE) is sent. Therefore, whenever
there
is activity on either SPI TRANSMIT DATA or SPI RECEIVE DATA there should be a uniform
signal on CLK.
The SPI TRANSMIT
DATA sends serial data from the 1-1P to a device, and SPI RECEIVE DATA is
sends data from a deviceto the
IJP. On the controller there are two ICs on the SPI BUS: ASFIC CMP
(U0221, pin 22), and EEPROM (U0111, pin 5). In the RF section there are two ICs on the SPI BUS:
FRAC-N Synthesizer, and the Power Control
IC (PCIC). The SPI TRANSMIT DATA and CLK lines
going to the RF section are filtered by L0481/R0481 and L0482/R0482 to minimize noise. The chip
select line CSX from U0101, pin 2 is shared by the ASFIC CMP, FRAC-N Synthesizer, and PCIC.
Each of these IC's check the SPI data and when the sent address information matches the IC's
address, the data that follows is processed. The chip select lines for the EEPROM (EE CS), voice
storage (VS CS), expansion board (EXP1 CS, EXP2 CS) and option board (OPT CS) are decoded
by the address decoder
UO 141.
When the
1-1P needs to program any of these IC's it brings the chip select line CSX to a logic 0 and
then sends the proper data and clock signals. The amount
of data sent varies, for example the
ASFIC CMP can receive up to 19 bytes (152 bits) while the PCIC can receive up to 6 bytes (48 bits).
After the data is sent, the chip select line is returned to logic
1.

2-6 Theory of Operation
The option board interfaces are different in that the 1-1P can also read data back from devices
connected.The timing and operation
of this interface is specific to the option connected, but the
general pattern is as follows:
Option board generates a service request via J0551, pin 29, line
ROY, and IJP, pin 79
The main board asserts a chip select for that option board via U0141,pin 14, line OPT CS,
J0551 ,pin 30
The main board 1-1P generates the CLK (J0551 , pin 3)
The main board 1-1P writes serial data via J0551 , pin 15 and reads serial data via J0551, pin 16
When data transfer is complete the main board terminates the chip select and CLK activity
2.2.8 SBEP Serial Interface
The SBEP serial interface allows the radio to communicate with the Customer Programming
Software (CPS), or the universal tuner via the Radio Interface Box (RIB). This interface connects to
the microphone connector via control head connector (J0401, pin
8) or to the accessory connector
J0401, pin 17 and comprises BUS+. The line is bi-directional, meaning that either the radio or the
RIB can drive the line. The 1-1P sends serial data via pin 98 and 00101 and it reads serial data via pin
97. Whenever the
1-1 P detects activity on the BUS+ line, it starts communication.
In addition, the SBEP serial interface is used to communicate with a connected control head. When
a control head key is pressed or the volume knob is rotated, the line ON OFF CONTROL goes high.
This turns on transistor
00110 which pulls line ON OFF SENSE and 1-JP, pin 6 to ground level. In
addition, an interrupt is generated via R01 09 (for SELECT 5 I MDC models) and IJP, pin 96. This
indicates that the control head wants
to start SBEP communication. The 1-1P then reads the registers
of the Universal Asynchronous Receiver Transmitter (UART) U0125 to determine that the interrupt
source was the control head.
If the interrupt source was from the control head, the 1-1P requests the
data from the control head. The control head starts sending and after all data has been sent,the ON
OFF CONTROL line goes low.
The control head ignores any data on BUS+ during SBEP
communication with the CPS or universal tuner.
2.2.9 General Purpose Input/Output
The controller provides eight general purpose lines (DIG1 through DIGS) available on the accessory
connector J0501
to interface the external options. Lines DIG IN 1,3,5,6, are inputs, DIG OUT 2 is an
output and DIG
IN OUT 4,7 ,8 are bidirectional. The software and the hardware of the radio model
define the function of each port.
DIG IN 1 can be used as external PTT input or others, set by the CPS. The 1-1P reads this port via pin
77 and
00171 .
DIG OUT 2 can be used as normal output or external alarm output, set by the CPS. Transistor
00173 is controlled by the 1-1P via ASFIC CMP, pin 14.
DIG IN 3 is read by IJP, pin 63 via resistor R0176
DIG
IN 5 can be used as normal input or emergency input, set by the CPS. The 1-1P reads this port
via R0179 and
1-JP, pin 60. Diode D01791imits the voltage to protect the 1-1P input.
DIG IN 6 can be used as normal input, set by the CPS. The 1-1P reads this port via, pin 74 and
00181.
DIG IN OUT 4,7,8 are bidirectional and use the same circuit configuration. Each port uses an output
transistor
00177,00183,00185 controlled by JJP, pins46, 47, 53. The ports are read by IJP, pins 75,
54, 76.
To use one of the ports as input the 1-1P must turn offthe corresponding output transistor.
In addition the signals from DIG IN 1, DIG IN OUT 4 are fed to the option board connector J0551
and the expansion board connector J0451.