Motorola Astro Digital Mobile Radio Xtl5000 Basic 6881096c73 O Manual

							Chapter 2 Basic Maintenance
2.1 Introduction
This section of the manual describes preventive maintenance, handling precautions, and some basic 
repair procedures and techniques. Each of these topics provides information vital to the successful 
operation and maintenance of your radio.
NOTE:For board- and component-level repair of the radio, refer to the Detailed Service Manual (see 
”Related Publications” on page xii).
2.2 Preventive Maintenance
Radios are shipped from the factory with a worst-case frequency error of ±500 Hz for 700–800 MHz. 
These specifications are tighter than the more stringent FCC requirements of ±1.5 ppm for the 700–
800 MHz bands. For radios that have been in storage for over six months from the factory ship date, 
the reference oscillator should be checked when the radio is initially deployed to the field. It is 
strongly recommended that the reference oscillator be checked every time the radio is serviced or at 
least once a year, whichever comes first. The crystal contained in the reference oscillator naturally 
drifts over time due to its aging characteristic. Periodic (annual) adjustment of the reference oscillator 
is important for proper radio operation. Improper adjustment can result in both poor performance and 
interference with other users operating on adjacent channels.
2.2.1 Inspection
Check that the external surfaces of the radio are clean, and that all external controls and switches 
are functional. A detailed inspection of the interior electronic circuitry is not needed.
2.2.2 Cleaning
The following procedures describe the recommended cleaning agents and the methods to be used 
when cleaning the external and internal surfaces of the radio. External surfaces include the control 
head and radio chassis. These surfaces should be cleaned whenever a periodic visual inspection 
reveals the presence of smudges, grease, and/or grime. Internal surfaces should be cleaned only 
when the radio is disassembled for servicing or repair.
The only recommended agent for cleaning the external radio surfaces is a 0.5% solution of a mild 
dishwashing detergent in water. The only factory recommended liquid for cleaning the printed circuit 
boards and their components is isopropyl alcohol (70% by volume).
2.2.2.1  Cleaning External Plastic Surfaces
The detergent-water solution should be applied sparingly with a stiff, non-metallic, short-bristled 
brush to work all loose dirt away from the radio. A soft, absorbent, lint-free cloth or tissue should be 
used to remove the solution and dry the radio. Make sure that no water remains entrapped near the 
connectors, cracks, or crevices.The effects of certain chemicals and their vapors can have harmful results on 
certain plastics. Aerosol sprays, tuner cleaners, and other chemicals should 
be avoided.
!
C a u t i o n 
						

							June 11, 20036881096C73-O
2-2Basic Maintenance: Handling Precautions
2.2.2.2  Cleaning Internal Circuit Boards and Components
Isopropyl alcohol may be applied with a stiff, non-metallic, short-bristled brush to dislodge embedded 
or caked materials located in hard-to-reach areas. The brush stroke should direct the dislodged 
material out and away from the inside of the radio. Be careful not to break off electrical components.
Alcohol is a high-wetting liquid and can carry contamination into unwanted places if an excessive 
quantity is used. Make sure that controls or tunable components are not soaked with the liquid. Do 
not use high-pressure air to hasten the drying process, since this could cause the liquid to puddle 
and collect in unwanted places.
Upon completion of the cleaning process, use a soft, absorbent, lint-free cloth to dry the area. Do not 
brush or apply any isopropyl alcohol to any plastic parts.
NOTE:Always use a fresh supply of alcohol and a clean container to prevent contamination by 
dissolved material (from previous usage).
2.2.3 General Radio Care and Handling Precautions
 Avoid physical abuse: do not pound, drop, or throw the radio. It may damage exposed parts 
such as controls and connectors.
 Do not connect accessories other than Motorola compatible equipment as they may damage 
the radio.
 The use of any mini-UHF adaptor not listed in this manual can damage the RF antenna 
connector and lead to radio failure and may void the warranty.
 Operating the radio without an antenna cable attached may lead to radio failure and may void 
the warranty.
2.2.4 RF Power Amplifier (RF PA) Heatsinking
You should never transmit unless the printed-circuit board (PCB) DC/RF clips and internal screws 
are installed in the chassis. Doing so can result in immediate failure of RF PA devices or greatly 
reduced RF PA device life. You also can transmit for short periods with the chassis eliminator if it is 
used properly.
2.3 Handling Precautions
Complementary metal-oxide semiconductor (CMOS) devices, and other high-technology devices, 
are used in this family of radios. While the attributes of these devices are many, their characteristics 
make them susceptible to damage by electrostatic discharge (ESD) or high-voltage charges. 
Damage can be latent, resulting in failures occurring weeks or months later. Therefore, special 
precautions must be taken to prevent device damage during disassembly, troubleshooting, and 
repair. Handling precautions are mandatory for this radio, and are especially important in low-
humidity conditions. DO NOT attempt to disassemble the radio without observing the following 
handling precautions:
 Eliminate static generators (plastics, Styrofoam, etc.) in the work area.
 Remove nylon or double-knit polyester jackets, roll up long sleeves, and remove or tie back 
loose-hanging neckties.
 Store and transport all static-sensitive devices in ESD-protective containers.
 Disconnect all power from the unit before ESD-sensitive components are removed or inserted 
unless otherwise noted.
 Use a static-safeguarded workstation, through the use of an anti-static kit (Motorola part 
number 01-80386A82). This kit includes a wrist strap, two ground cords, a static-control table 
mat and a static-control floor mat. 
						

							6881096C73-OJune 11, 2003
Basic Maintenance: Handling Precautions2-3
NOTE:Be sure that the table and floor mats are properly grounded.
When these items are not readily available, observing the following techniques will minimize the 
chance of damage:
 If a static-sensitive device is to be temporarily set down, use a conductive surface for 
placement of the device.
 Make skin contact with a conductive work surface first and maintain this contact when the 
device is set down or picked up.
 Always wear a conductive wrist strap when servicing this equipment. The Motorola part number 
for a replacement wrist strap that connects to the table mat is 42-80385A59.
 For additional information, refer to Service and Repair Note SRN-F1052, Static Control 
Equipment for Servicing ESD Sensitive Products, available from the Literature Distribution 
Center.
Motorola
Literature Distribution Center
2200 Galvin Drive, Suite 2218
Elgin, IL 60123
(847) 783-2522
(847) 783-2523/2524 (Fax) 
						

							June 11, 20036881096C73-O
2-4Basic Maintenance: Handling Precautions
Notes 
						

							Chapter 3 Basic Theory of Operation
3.1 Introduction
The ASTRO XTL 5000 radio combines the controller and RF sections into a single board and 
contains three modules: a daughtercard, RX VCO module, and TX VCO module. It is important to 
correctly identify the malfunctioning region before replacing expensive modules. To assist with radio 
repair, descriptions of the sections contained on the XTL 5000 uniboard are listed below.
3.2 General Overview
The XTL 5000 radios are wideband, synthesized, fixed-tuned radios and are available with 700 and 
800 MHz bands. All XTL 5000 radios are capable of both analog operation (12.5 kHz, 20 kHz, and 
25 kHz bandwidths) and ASTRO mode operation (12.5 kHz bandwidth).
The XTL 5000 radios contain the following assemblies and sections:
 Control-Head Assembly (Dash- or Remote-Mount)—is connected directly to the front of the 
transceiver or remotely by the interconnect board and control cable. This assembly contains a 
vacuum fluorescent (VF) display, VF driver, microprocessor and serial bus interface.
 Power Amplifier (PA) section—contains the antenna switch, directional coupler/ detector, and 
amplifier(s).
 Front-End Receiver section—contains the preselector, low-noise amplifier (LNA), and mixer.
 IF section—contains the receiver intermediate-frequency (IF) amplifier/filter and the digital 
receiver back-end integrated circuit (IC).
 Frequency Generation section—contains the synthesizer, voltage controlled oscillators (VCOs), 
reference oscillator, and receive and transmit buffers.
 Controller section—combines a VOCON board and a Command board, into a single section, 
and contains the following elements: 
- Voltage regulators, data communication circuitry (RS232, USB, and SB9600)
- Daughtercard module (Microprocessor, FLASH IC, SRAM IC)
- Modulation D/A conversion circuitry
- CODEC audio circuitry
- TX power-control circuitry
- Emergency circuitry
- V.I.P input/output paths
- Secure interconnect board interface
- Front connector interface for control heads and remote-mount interconnect boards (I.B)
- Rear connector for additional accessories
- DC power-in plug 
						

							June 11, 20036881096C73-O
3-2Basic Theory of Operation: Controller Section
3.3 Controller Section
3.3.1 Introduction
The XTL 5000 radio is primarily a uniboard design, consisting of isolated topside and bottomside 
controller sections and various RF sections. The controller section will be discussed here in basic 
terms, to assist in the overall understanding of what is contained in the controller section, and a 
simplified purpose of its elemental parts. Some limited warnings and recommendations are offered 
for prevention of common repair-induced damage.
The controller section combines the elements of a VOCON board, with the elements of a command 
board. The controller section also contains a daughtercard module. We distinguish the entire 
controller section into 2 parts: the daughtercard module and the surrounding controller region.
3.3.2 Location
The controller section is located on the far side of the board, with critical parts arranged on the top 
and bottom sides of the uniboard. (see 
Figure 3-1 below, with component-filled areas denoting 
controller section).
Figure 3-1.  Controller Sections
3.4 Daughtercard Module
This module contains primarily three parts: microprocessor, FLASH IC, and SRAM IC.
NOTE:The three parts on the daughtercard module are highly susceptible to ESD and moisture 
damage. Extreme care is advised.Troubleshooting of the controller section usually requires the removal of the 
uniboard from the chassis. Whenever this board is removed, any 
transmitting of the RF section, whether intentional or accidental (trunking 
affiliation), can cause permanent destruction or degradation of various RF 
components. Such damage may not be visually noticeable, but can impact 
the radios performance and reliability.
DAUGHTERCARD
       MODULE
SIDE 1 SIDE 2
!
C a u t i o n 
						

							6881096C73-OJune 11, 2003
Basic Theory of Operation: Surrounding Controller Region 3-3
3.4.1 Microprocessor
The microprocessor consists of an MCORE-based controller and a DSP that communicates with the 
memory ICs via a 16-bit data bus. It also communicates to peripheral ICs on the main board via an 
SSI and SPI bus. This microprocessor contains a fixed amount of one-time programmable ROM and 
a small section of RAM. However, the microprocessor does not contain the radio software setting as 
programmed in the Customer Programming Software (CPS) or the firmware as installed at the 
factory. The only purpose of this IC is for interpretation and processing of the content inside the 
FLASH IC. Therefore, this part may be replaced as is without the need to reflash the radio.
There are six clocks supplied to the daughtercard, a 16.8 MHz master clock (CKIH), a 32 kHz real-
time clock (CKIL), a 20 kHz RX frame-sync clock, a 48 kHz TX frame-sync clock, a 1.2 MHz RX data 
clock, and a 2.4 MHz TX data clock. The microprocessor also generates the digital audio bus clocks: 
a 512 kHz data clock and an 8 kHz frame-sync clock.
3.4.2 FLASH IC
The FLASH IC is the firmware storage IC. Programming this IC is accomplished using one of three 
input paths:
 2-wire RS232 directly from a computers serial port to the radio’s rear connector data cable, 
HKN6160
 2-wire RS232 through an HKN6155 programming cable at the control head’s 10-pin 
microphone port
 2-wire RS232 through an HKN6155 programming cable at the Remote Mount Interconnect 
board’s 10-pin flash port.
NOTE:In remote-mount configurations, the control head 10-pin microphone port is disabled for any 
kind of programming.
NOTE:It is recommended thatFLASH IC replacement is not supported as a field repair option. If this 
part is removed, the radio must be reflashed and retuned. This is because the FLASH IC must 
be hard-boot loaded at the factory to allow the programming of a unique file.
3.4.3 SRAM IC
The SRAM IC is only used by the microprocessor to perform its memory operations and is not 
upgradeable to a larger SRAM IC.
3.5 Surrounding Controller Region
3.5.1 Introduction
The surrounding controller region contains the regulated power, audio, and data translation 
hardware.
This hardware allows a computer to program the radios features, maintain an active control of the 
RF sections, and make necessary mode and audio adjustments as related to feedback from a 
control head device. if you choose to reflash the radio (reflash the IC), DO NOT interrupt the 
process; otherwise, you might corrupt the FLASH IC and need advanced 
technical support to revive your radio.
!
C a u t i o n 
						

							June 13, 20036881096C73-O
3-4Basic Theory of Operation: Surrounding Controller Region
NOTE:A control head is not necessary for the function of the radio (in special application 
configurations), but the controller section is critical for the RF sections to function. This is an 
important point since repairs and troubleshooting of the RF sections usually requires that the 
controller section is operating correctly.
3.5.2 Voltage Regulation
The uniboard contains the following voltage regulators: 9 V, 5 V, 3 V, 2.85 V, 1.85 V, and 1.55 V.
The radio’s A+ supply is regulated down to additional supplies for various blocks (frequency 
generation unit (FGU), receiver, transmitter power amplifier, and controller). Specifically, A+ is used 
to regulate three separate 9.3-volt supplies, one for the FGU and receiver circuitry, one for the 
transmitter power amplifier circuitry, and one for the controller sections.
 The FGU and receiver circuitry use the 9.3-volt supply to further regulate a common 5-volt supply and two separate 3-volt supplies, one for the FGU and one for the Abacus III IC.
 The transmitter power amplifier uses its 9.3-volt supply directly for its pre-amplifier and to a 3- volt supply for most of the ALC (automatic level control).
 The controller uses the 9.3-volt supply to power the microphone, part of a RS232 translator,  and to provide voltage to the 5-volt regulator, which supplies the 2.85 V, 1.85 V, and 1.55 V 
supplies.
- The 2.85-volt regulator supplies most of the digital logic circuitry on the controller, as well as the I/O of the microprocessor.
- The 1.85-volt regulator supplies the FLASH and SRAM circuitry.
- The 1.55-volt regulator supplies the core of the microprocessor.
3.5.3 Emergency
Circuity exists to support emegency switch operation. While the radio is ON, emergency can be 
activated to alert dispatch.
NOTE: This feature is either visual or can be set to covert, and is programmable through the CPS 
(customer programming software). This functionality is dependent on CPS version and 
customer demand for feature availability.
3.5.4 Front and  Rear Connectors
The surrounding controller section contains the front and rear connections to allow interfacing with 
existing and future accessories.
These custom connectors are optimized to meet voltage and current requirements for existing 
accessories and for the compatible flexes that are used with the XTL 5000 radio.
NOTE:It is not recommended to insert non-Motorola parts or flexes into these connectors. 
						

							6881096C73-OJune 11, 2003
Basic Theory of Operation: Surrounding Controller Region 3-5
3.5.4.1  Audio
The audio circuitry of the controller section contains the following:
Audio PA
 Codec
 MIC Audio
 DSP controlled EEPOTS
 AUX RX, AUX TX, and external speaker paths
 FILT audio.
This allows interfacing to the existing accessories made by Motorola, such as VRS, SIREN, and 
Consolette. It also allows for select compatibility with aftermarket modems.
3.5.4.2  Program Cable
If the programming cable is used with a standard legacy control head, circuitry found in the controller 
section provides the voltage-translated boot RX and boot TX communication paths, as well as the 
cable-detection circuit.
3.5.4.3  SB9600
Just as on many Motorola products, an SB9600 communication bus exists on the XTL 5000 radio. 
Hence, many Motorola SB9600 accessories are compatible with the radio. These lines include 
BUS+, BUS-, Busy, and RESET. These lines are available at connectors J5 and J6.
3.5.4.4  VIP
VIP-IN and VIP-OUT lines are available at the front and two VIP-out lines are located at the rear. 
Their purpose is to drive relays to control external logical devices, or to logically communicate 
directly to the XTL 5000 microprocessor. Their most versatile usage is in conjunction with a DEK, but 
this is not mandatory.
NOTE:Please see the VIP section of the ASTRO XTL 5000 700–800 MHz Digital Portable Radio 
Detailed Service Manual for configurations and voltage level requirements.
3.5.4.5  RS232
UART_A can be selected as a standard 4-wire RS232 or 4-wire USB slave device. The UART_B is 
defaulted to use SB9600 lines so that all legacy control heads and SB9600 accessories are 
compatible with the radio.
3.5.4.6  One-Wire
One-wire technology is embedded in the radio for future compatibility with upcoming smart 
accessories. 
						

							June 11, 20036881096C73-O
3-6Basic Theory of Operation: Analog Mode of Operation
3.6 Analog Mode of Operation
3.6.1 Receive Operation
When the radio is receiving, the signal comes from the antenna through the RF PA output network 
located in the power amplifier section to the front-end receiver assembly. The signal is then filtered, 
amplified, and mixed with the first local oscillator signal generated by the receiver voltage controlled 
oscillator (VCO). The resulting intermediate-frequency (IF) signal is fed to the IF circuitry where it is 
again filtered and amplified. This amplified signal is passed to the Abacus III IC where it is mixed with 
the second local oscillator to create the second IF at 2.25 MHz. The analog IF is processed by an 
analog-to-digital (A/D) converter located within the digital back-end IC, where it is converted to a 
digital bit stream and decimated down to an I/Q digital sample. This digital signal is then passed on 
to the DSP, where filtering and discrimination are performed in the software. For a voice signal, the 
DSP routes the digital voice data to the Codec for conversion to an analog signal. The signal passes 
through a Log Pot to the audio power amplifier, which drives the speaker. For signaling information, 
the DSP decodes the message and passes it to the microcomputer.
3.6.2 Transmit Operation
When the radio is transmitting, microphone audio is passed to the gain control, and then to the 
Codec, where the signal is digitized. The Codec passes digital data to the DSP, where pre-emphasis 
and low-pass (splatter) filtering is done. The DSP returns this signal to the Codec and the signal is 
then passed to a digital-to-analog (DAC) converter where it is reconverted into an analog signal. The 
signal is then passed through a switched capacitor filter IC and then to the synthesizer IC as a 
modulation signal for the transmitter voltage controlled oscillators. Also, transmitted signaling 
information is accepted by the DSP from the microcomputer, coded appropriately, and passed to the 
Codec, which handles it the same as a voice signal. Modulation information is passed to the 
synthesizer along the modulation line. A modulated carrier is provided to the RF power amplifier, 
which transmits the signal under dynamic power control.
3.7 ASTRO Mode of Operation
In the ASTRO mode (digital mode) of operation, the transmitted or received signal is limited to a 
discrete set of deviation levels, instead of continuously varying. The receiver handles an ASTRO-
mode signal identically to an analog-mode signal up to the point where the DSP decodes the 
received data.
In the ASTRO receive mode, the DSP uses a specifically defined algorithm to recover information.
In the ASTRO transmit mode, microphone audio is processed the same as an analog mode with the 
exception of the algorithm the DSP uses to encode the information. This algorithm will result in 
deviation levels that are limited to discrete levels.
3.8 Control Head Assembly
3.8.1 Display (W4, W5, and W7 Control Heads)
The W4, W5, and W7 control-head assemblies have an 8-character, alphanumeric, vacuum 
fluorescent display. The anodes and the grids operate at approximately 34 Vdc when on and 0 Vdc 
when off. The filament operates at approximately 24 Vrms. The voltage for the display is generated 
by a fixed-frequency, variable duty-cycle controlled “flyback” voltage converter. The switching 
frequency is approximately 210 kHz. The internal microprocessor controls the voltage converter, 
which provides approximately 3.7 Vdc to the vacuum fluorescent (VF) driver and approximately 
2.4 Vrms to the VF display.