Motorola MCS 2000 Operating instructions

68P81080C44-B, Issued 5/98
MCS 2000 Mobile Radio
Service Instructions
Volume 2d
900-MHz Frequency Range Specific
 1998 by Motorola, Inc., Radio Network Solutions Group
8000 West Sunrise Boulevard
Ft. Lauderdale, FL 33322

Safety 0 Revision B, 5/98
Safety Information
Every radio, when transmitting, radiates energy into the atmosphere which
may, under certain conditions, cause the generation of a spark.
All users of vehicles fitted with radios should be aware of the following
warnings:
Do not operate radio near flammable liquids or in the vicinity of explosive
devices.
To ensure personal safety, please observe the following simple rules:
Check the laws and regulations on the use of two-way mobile radios in the
areas where you drive. Always obey them. Also, when using your radio while
driving, please:
• Give full attention to driving,
• Use hands-free operation, if available and
• Pull off the road and park before making or answering a call if driving
conditions so require.
Airbag
Warning
Installation of vehicle communication equipment should be performed by a
professional installer/technician qualified in the requirements for such
installations.
An air bag’s size, shape and deployment area can vary by vehicle make, model
and front compartment configuration (e.g., bench seat vs. bucket seats).
Contact the vehicle manufacturer’s corporate headquarters, if necessary, for
specific air bag information for the vehicle make, model and front
compartment configuration involved in your communication equipment
installation.
LP Gas
Warning
It is mandatory that radios installed in vehicles fuelled by liquefied petroleum
gas conform to the National Fire Protection Association standard NFPA 58,
which applies to vehicles with a liquid propane (LP) gas container in the trunk
or other sealed off space within the interior of the vehicle. The NFPA58
requires the following:
• Any space containing radio equipment shall be isolated by a seal from the
VEHICLES EQUIPPED WITH AIR BAGS
An air bag inflates with great force. DO NOT place objects, including
communication equipment, in the area over the air bag or in the air bag
deployment area. If the communication equipment is improperly
installed and the air bag inflates, this could cause serious injury.

Revision B, 5/98 Safety 1
space in which the LP gas container and its fittings are located.
• Removable (outside) filling connections shall be used.
• The container space shall be vented to the outside.
Anti-Lock Braking System (ABS) and
Anti-Skid Braking System Precautions
Disruption of the anti-skid/anti-lock braking system by the radio
transmitter may result in unexpected vehicle motion.
Motorola recommends the following radio installation precautions and
vehicle braking system test procedures to ensure that the radio, when
transmitting, does not interfere with operation of the vehicle braking system.
Installation Precautions
1. Always provide as much distance as possible between braking modulator
unit and radio, and between braking modulator unit and radio antenna
and associated antenna transmission line. Before installing radio,
determine location of braking modulator unit in vehicle. Depending on
make and model of vehicle, braking modulator unit may be located in
trunk, under dashboard, in engine compartment, or in some other cargo
area. If you cannot determine location of braking modulator unit, refer
to vehicle service manual or contact a dealer for the particular make of
vehicle.
2. If braking modulator unit is located on left side of the vehicle, install
radio on right side of vehicle, and conversely.
3. Route all radio wiring including antenna transmission line as far away as
possible from braking modulator unit and associated braking system
wiring.
4. Never activate radio transmitter while vehicle is in motion and vehicle
trunk lid is open.
Braking System Tests
The following procedure checks for the most common types of interference
that may be caused to vehicle braking system by a radio transmitter.
1. Run vehicle engine at idle speed and set vehicle transmission selector to
PARK. Release brake pedal completely and key radio transmitter. Verify
that there are no unusual effects (visual or audible) to vehicle lights or
other electrical equipment and accessories while microphone is NOT
being spoken into.
2. Repeat step 1. except do so while microphone IS being spoken into.
3. Press vehicle brake pedal slightly just enough to light vehicle brake
light(s). Then repeat step 1. and step 2.
4. Press the vehicle brake pedal firmly and repeat step 1. and step 2.
5. Ensure that there is a minimum of two vehicle lengths between front of
vehicle and any object in vehicle’s forward path. Then, set vehicle
!
W A R N I N G
!

Safety 2 Revision B, 5/98
transmission selector to DRIVE. Press brake pedal just far enough to stop
vehicle motion completely. Key radio transmitter. Verify that vehicle
does not start to move while microphone is NOT being spoken into.
6. Repeat step 5. except do so while microphone IS being spoken into.
7. Release brake pedal completely and accelerate vehicle to a speed between
15 and 25 miles/25 and 40 kilometers per hour. Ensure that a minimum
of two vehicle lengths is maintained between front of vehicle and any
object in vehicle’s forward path. Have another person key radio
transmitter and verify that vehicle can be braked normally to a moderate
stop while microphone is NOT being spoken into.
8. Repeat step 7. except do so while microphone IS being spoken into.
9. Release brake pedal completely and accelerate vehicle to a speed of 20
miles/30 kilometers per hour. Ensure that a minimum of two vehicle
lengths is maintained between front of vehicle and any object in
vehicle’s forward path. Have another person key radio transmitter and
verify that vehicle can be braked properly to a sudden (panic) stop while
microphone is NOT being spoken into.
10. Repeat step 9. except do so while microphone IS being spoken into.
11. Repeat step 9. and step 10. except use a vehicle speed of 30 miles/50
kilometers per hour.

Revision B, 5/98 List of Effective Pages A
LIST OF EFFECTIVE PAGES
MCS 2000 Mobile Radio Service Instructions
Volume 2d
900-MHz Frequency Range Specific Information
Motorola Publication Number 68P81080C44-B
I ssue Dates of Original and Revised Pages are:
Revision O: March 1996
Revision A: November 1996
Revision B: May 1998
The Number of pages in this publication is 104 consisting of the
following:
Note: The letter O in the Revision Letter column of the table above denotes an original page. Original pages
ARE NOT identified as such in the page footors except by the absence of a change letter and date.
Page Number Revision Letter Page Number Revision Letter
Front cover O 1 through 90 B
Inside front cover (blank) O Questionnaire (Front) O
Title B Questionnaire (Back) O
Safety 0 through
Safety 2 B Inside Back Cover (Replacement Parts
Ordering)
B
A and B B Back Cover (Not
Markedwith Revision
Letter
A
i and ii B

B Revision B, 5/98
NOTES

Revision B, 5/98 Table of Contents i
Table of Contents
- Safety Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Safety 0
- List of Effective Pages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A
- List of Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ii
- List of Tables. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ii
1- Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
2- Theory of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Block Diagram Level Theory of Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Receiver Detailed Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Transmitter Detailed Functional Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Synthesizer Detailed Functional Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Controller Detailed Functional Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Dc Power Control and Regulation Detailed Functional Description. . . . . . . . . . . . . . . . . . . . . . . 17
3 - Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
4 - Reference Drawings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33

ii List of Figures/List of Tables Revision B, 5/98
List of Figures/List of Tables
Figure 1. 900-MHz Radio Functional Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Figure 2. Transceiver Board Section Locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
Note : Troubleshooting charts are listed on page 19; Component location illustrations, schematic dia-
grams, and parts lists are listed on page 33 .
List of Tables
Table 1. Transceiver Board Kit Numbers v.s. Service Manual Page Numbers for
Specific Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Table 2. Schematic Diagrams Interconnection List. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Revision B, 5/98 Introduction 1
Introduction 1
This publication (Service Manual Volume 2d, Motorola Publication
68P81080C44) provides frequency-range-specific information for the
12-Wattand30-WattMCS2000radiosforwhichthetransceiverboard
kit numbers are listed in Table 1. These radios all operate in the 900-
MHz frequency range. The coverage in this publication includes both
non-data-capable and data-capable radios.
This publication is a companion volume to Service Manual Volume 1
for MCS 2000 Radios, Motorola Publication 68P81083C20, which
provides non-frequency-range-specific information for all MCS 2000
Radios. Service personnel must have both Volume 1 and Volume 2a of
this Service Manual in order to have all service information for
12-Watt and 30-Watt MCS 2000 Radios that operate in the 900-MHz
frequency range.
There are other Volume 2 service manuals (e.g., Volume 2a, 2b, 2c),
which cover models of the MCS 2000 Radio for other frequency ranges
and power levels. Refer to Volume 1 of this service manual for a list of
the manuals related to operation and maintenance of all models of the
MCS 2000 Radio, and the Motorola publication numbers for those
manuals.
Hereafter in this manual, the MCS 2000 Radio is referred to as the
radio. The specific hardware portions of the radio covered in this
volume of the service manual are as follows:
• Receiver Front End
• Receiver Intermediate Frequency (IF)
• Receiver Back End
• 12-Watt Power Amplifier
• 30-Watt Power Amplifier
• Synthesizer
This volume (Volume 2d) of the service manual covers the following
five topics for the specific hardware portions of the 900-MHz radios:
• Theory of operation
• Troubleshooting
• Component locations
• Parts lists

2 Introduction Revision B, 5/98
• Schematic diagrams and associated interconnect information
The five topics listed above for the controller section and for the
control heads are covered in Volume 1 of this service manual,
Motorola Publication Number 68P81083C20.
All the radios covered in this service manual contain a single circuit
card assembly (a printed circuit board with components mounted),
which is called the transceiver board. The transceiver board in each
version of the radio is identified by a unique Motorola kit number
(e.g., FLF5591A). The kit number varies according to the RF output
power level of the radio (12-Watts or 30-Watts) and also according to
whether or not the radio is data capable. Table 1 on pages 3 and 4
crossreferences each kit number covered in this service manual to the
page number where the specified information is located.