LBI-38378C
Mobile Communications
M-PA
VHF
PORTABLE FM RADIO
TABLE OF CONTENTS
REAR COVER ASSEMBLY . . . . . . . . . . . . LBI-38597
FRONT COVER ASSEMBLY (EARLIER)
AND CONTROL BOARD . . . . . . . . . . . . . LBI-38384
FRONT COVER ASSEMBLY (LATER)
LESS CONTROL BOARD . . . . . . . . . . . . . LBI-38834
CONTROL BOARD (LATER) . . . . . . . . . . . LBI-38828
VHF SERVICE SECTION . . . . . . . . . . . . . LBI-38385
Maintenance Manual
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LBI-38378
SPECIFICATIONS*
GENERAL
Frequency Bands
(FCC Type Acceptance Number)
136 - 150.8 MHz
146 - 162 MHz (AXATR-182-B5)
157 - 174 MHz (AXATR-182-C5)
DOC Number
TR-182-D2
Frequency Stability
5.0 ppm
Channel Capacity
Select Model
Scan Model
16
192
192
System Model
Maximum Frequency Separation
Channel Spacing
full bandsplit
30 kHz
Operating Temperature Range
Maximum Relative Humidity
Battery Voltage
-30°C to +60°C
90% at 55°C
7.5 Vdc (nominal)
Dimensions (H x W x D)
less battery, knobs and antenna
with Extra High Cap. Battery
Weight
140 x 69 x 38 mm (5.52 x 2.72 x 1.50")
232 x 69 x 40 mm (9.15 x 2.72 x 1.58")
less battery and antenna
with Extra High Cap. Battery
540 grams (19 ounces)
907 grams (32 ounces)
TRANSMITTER
Rated RF Power Output
High / Low RF Power Output
Maximum FM Deviation
FM Hum and Noise
Spurious and Harmonic Emissions
Audio Response
Audio Distortion
6.0 Watts
6.0 Watts / 1 Watt (programmable per channel)
±5 kHz
-45dB (companion receiver)
-75 dBc
+1 to -3dB (6 dB/octave pre-emphasis from 300 Hz to 3 kHz)
less than 3% (at 1000 Hz tone, 3 kHz deviation)
RECEIVER
Sensitivity (12 dB SINAD)
Adjacent Channel Selectivity
Critical Squelch
-116 dBm (0.35 µV)
-80dB
10dB SINAD
-78dB
-80dB
Intermodulation
Spurious and Image Rejection
Audio Output
Audio Response
Audio Distortion
500 mW (24-ohm load impedance)
+2 to -8dB (6 dB/octave de-emphasis from 300 Hz to 3 kHz)
less than 5% (at 500 mW)
* These specifications are intended primarily for the use of the serviceman. See the appropriate Specifications Sheet for
the complete specifications.
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LBI-38378
OPTIONS AND ACCESSORIES
Radios, Antennas, Batteries
Carrying Accessories
Audio Accessories
Chargers
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LBI-38378
maximum number of positions to less than sixteen
(16). It is normally factory installed for fifteen (15)
positions.
INTRODUCTION
The M-PA radio is a high quality microprocessor con-
trolled synthesized portable FM radio. M-PA operation is
highlighted by the radio’s programming versatility. This al-
lows tailored operation of the portable radio to meet the
needs of the radio system and the individual users. Three (3)
different M-PA radio models are available: Select, Scan and
System.
• Volume Control Knob - This rotatable control
provides quick and easy adjustments to the volume
level. Minimum volume levels can be programmed
into the unit. This feature prevents missed calls due to
a low volume setting.
• Monitor Button - This side-mounted button is used
to disabled squelch and if programmed for the
selected channel, it is used to toggle CG and/or T99
operation on and off.
The M-PA Select model radio is the basic version that
can be programmed with up to sixteen (16) channels. This
unit features an 8-digit alphanumeric liquid crystal display
(LCD) and a 16-position knob for channel selection. The
display is backlit for nighttime and low-level ambient light
operation.
• Keypad - The Scan model radio has a 4-button
keypad on its front panel that provides scan and menu
control. The menus allow selection of the current
operating mode (bank of channels) and/or channel
depending upon the radio’s programming. The menus
also allow control of various other radio features such
as selection of stored telephone interconnect numbers
for auto-dial operation, and alert tone enable/disable
control. A System model radio has a 16-button
keypad. The top four (4) buttons are identical to the
Scan model keypad, providing scan and menu
control. The lower twelve (12) buttons form a
numeric keypad that allows manual DTMF telephone
interconnect dialing and editing of telephone
interconnect numbers stored in the radio. Select
model radios do not have a keypad.
Scan and System model radios have an LCD similar to
the Select model radio. A keypad is added to these radios (4-
button on Scan model, 16-button on System model) to pro-
vide additional features not available on the Select model
radio. These radios can be programmed with up to 192 dif-
ferent radio channels. Both also provide scan capability in-
cluding dual-priority scan, and DTMF telephone
interconnect of up to ten (10) preprogrammed numbers. The
telephone numbers can be recalled at will and initiated. The
System model’s numeric keypad allows editing of the ten
preprogrammed numbers and manual DTMF telephone in-
ter-connect dialing.
FEATURES
• Scan Capability - Scan and System model radios can
be programmed for non-priority scan or dual-priority
scan operation. Scan programming options include a
keypad entered scan list or a fixed scan list. Priority
• 192-Channel Capability - Scan and System models
radios can be programmed with up to 192 channels
accessed in 12 modes (banks of channels) with 16
channels in each mode or 16 modes with 12 channels
in each mode. The Select model radio can be
programmed with a maximum of 16 channels.
scan programming options include
a
fixed
priority-one channel or the selected channel as the
priority-one channel. The radio can be programmed to
scan only the channels in the current mode (bank of
channels) or it may be programmed to scan across
modes. The Select model radio does not support scan
operation.
• Backlit Liquid Crystal Display - The 8-digit
alphanumeric
LCD
provides
programmable
customization and feedback to the operator of various
operating conditions. Status flags located above and
below the digits alert the operator to various radio
conditions such as channel busy, transmitter in
operation, or a low battery condition. Scan and
System model radios have additional status flags for
scan operation. LCD backlighting can be enabled or
disabled on a per channel basis.
• Telephone Interconnect Capability - The Scan and
System model radios can store up to ten (10)
telephone interconnect numbers for auto-dial
operation. These numbers are preprogrammed into
the Scan model radio. In the System model radio, the
numbers can be preprogrammed, operator-entered
and/or edited via the numeric keypad. The System
model’s numeric keypad also allows manual DTMF
tele phone interconnect dialing. The Select model
radio cannot initiate telephone interconnect calls.
• Rotary Control Knob - On Scan and System model
radios, the 16-position top-mounted Control Knob
allows easy selection of modes (banks of channels),
channels or Channel Guard (CG) according to how
the radio is programmed. On the Select model radio,
the Control Knob selects the operating channel. A
stop-plate may be installed under the knob to limit the
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LBI-38378
• Programmable Multi-Tone Channel Guard
• Power-Up Self-Test - At power-up the radio
automatically performs a diagnostic test on itself and
reports any found errors via the LCD.
(CTCSS) - Channel Guard tone frequencies within
the range of 67 Hz to 210.7 Hz, including all of the
standard EIA frequencies, can be programmed for
encoded/decoded operation.
• Programmable via the Universal Device Connector
(UDC) - The entire operation of the radio can be field
customized by programming the unit using an IBM
PC or compatible computer. The programmed
personality is stored in nonvolatile memory within the
radio.
• Programmable Multi-Code Digital Channel
Guard - Similar capability as with tone Channel
Guard is provided.
• Two-Tone Sequential (T99) Decode - Selective
calling decode is enabled or disabled on each
individual channel. Two (2) sets of unique de-codes
are programmable to allow large systems individual
and group call capability. Sets are selectable on a
mode (bank of channels) basis.
• Simple Remote Control Capability - External
accessories can be connected to the UDC such as a
headset, a speaker-mic or a lanyard. Connection of
the speaker-mic allows the operator to remotely
control PTT operation and audio level of the external
speaker. An antenna jack is located on the UDC for
the connection of a remote mounted antenna such as
when the radio is used in a vehicular charger.
• Channel Busy Lockout - Personality information
includes transmit disable capability on a channel
where carrier activity is present This feature is
selectable on a per channel basis.
• Meets MIL-810C and D Specifications - The sturdy
die-cast aluminum case is designed to seal out
moisture, blowing rain and other harsh environmental
factors.
• GE-STAR Compatibility - The radio can be
programmed to transmit GE-STAR at PTT key, at
PTT unkey, or both. 16,384 individual ID codes are
available.
• Battery Packs - Several different battery pack sizes
and capacities are available.
• Emergency Signalling Feature
-
GE-STAR
emergency signalling can be enabled by the red
Emergency/Home Button on the top of the radio or it
can be enabled by a lanyard connected to the UDC.
• Available Options - These options include the
antennas, audio accessories, batteries, carrying
accessories, chargers, lanyards, and the vehicular
chargers.
• Home Button - The radio can be programmed to
switch to a home mode or channel (depending on
Control Knob’s programming) when the red
Emergency/Home Button on the top of the radio is
pressed.
DESCRIPTION
Two major assemblies form an M-PA radio. The Front
Cover Assembly contains all of the microprocessor circuitry,
audio circuitry and the operating controls. The Rear Cover
Assembly houses the RF circuitry which includes the trans-
mitter, receiver and the frequency synthesizer. The assem-
blies are electrically interconnected by two single-in-line
type connectors. When mated together, the assemblies form
a weather resistant diecast aluminum case that protects the
radio’s circuitry from harsh outside environments.
• Programmable Carrier Control Timer
-
A
programmable transmit timer will automatically
disable the transmitter and provide an alerting tone
after time-out. This feature prevents radio damage and
unnecessary channel traffic in the event of a "stuck"
mic. The CCT is reset on every PTT.
• Programmable Transmit Power Level - Transmitter
power level is PC programmable into the radio (high
or low) on a per channel basis.
Power is provided by a battery pack that slides and
locks on to the bottom of the radio. The radio’s on/off
switch is located on the battery pack.
• Squelch Tail Elimination - Squelch and audio
circuits are designed so that annoying squelch pops
which may occur at the end of received messages are
minimized. This feature is compatible with existing
STE systems.
The antenna screws on to the top of the unit A side an-
tenna connection is also provided at the UDC for an external
antenna or for test purposes. This UDC antenna connection
is also utilized for external antenna operation when the radio
is locked in the vehicular charger.
• Alert Tones - Alert tones prompt the operator of
various radio conditions such as key pressed, CCT
time-out or a low battery.
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LBI-38378
Figure 2 - Scan Model
Figure 1 - System Model
Figure 3 - Select Model
Figure 4 - Side View (All Models)
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LBI-38378
nal antenna can be mounted to the unit via the UDC. When
an antenna is connected to the UDC, the antenna on the top
of the radio is disabled.
REAR COVER ASSEMBLY
The Rear Cover Assembly houses the RF Board in the
die-cast aluminum case. The complete assembly consists of
the VHF RF Board, aluminum case, top antenna jack, side
(UDC) antenna jack and various hardware.
BATTERY PACKS
The battery pack connects to the bottom of the unit and
delivers a nominal 7.5 Volts dc to the radio. A recessed
on/off switch for the radio is located on the battery pack. An
internal fuse located in the radio’s Battery Plate protects the
radio and battery from excessive current draw. The battery
packs are available in several different capacities and sizes.
The RF Board’s circuitry includes the transmitter, re-
ceiver and the frequency synthesizer. This FM circuitry is
under complete control of the microprocessor circuits. Con-
trolling data sent to this assembly from the Control Board
includes serial synthesizer data loading, transmitter/receiver
enabling and a transmitter power level signal. The RF Board
outputs the demodulated audio and a synthesizer lock status
line to the Control Board. During transmitter operation, the
RF power appears at the top antenna jack (or the UDC jack
if the appropriate adapter plug is inserted). The Rear Cover
Assembly maintenance manual contains a detailed circuit
analysis, mechanical, outline and schematic diagrams for
this assembly.
Radio contacts located on the top of the pack include
switched power, ground, the speaker enabling contacts and a
continuous power contact In addition, four contacts are lo-
cated on the rear of the battery pack. These four contacts
provide connections to the slip-in type chargers or vehicular
chargers/repeaters while the battery pack is still connected
to the unit The battery charging contacts are diode protected
from external shorts.
FRONT COVER ASSEMBLY
The chargers utilize an internal thermistor in the battery
pack to sense temperature and automatically control charge
rate of the battery. This allows for a maximum charge rate
without overheating the battery pack. All battery packs can
be charged in less than 1 1/2 hours with the rapid type
chargers. Nominal full charge time in a standard charger is
14 hours. The Service Section contains a detailed outline
and schematic diagram of a typical battery pack. Further
service information for the battery packs is also presented in
the Service Section.
The Front Cover Assembly houses all of the operating
controls and the digital control circuitry for the radio. Board
assemblies used in this assembly include the Control and
LCD Boards and flex circuits include the Keypad, UDC and
Speaker Flex circuits. The speaker, microphone and Battery
Plate are also a part of this assembly. The complete assem-
bly is housed in the die-cast aluminum front cover. Scan and
System model radios are equipped with a keypad on the
front panel.
Chargers are available with nominal charge times of one
hour (rapid) and fourteen hours (standard). Combinations
include single (1) and multi (5 or 6) position, standard and
rapid charge units. In addition, the vehicular chargers simul-
taneously charge the battery while the radio is operating.
The Control Board located in the Front Cover Assembly
is the largest and most complex board in the Front Cover
Assembly. It contains all microcomputer and audio circuitry
which controls the radio. See the maintenance manuals spe-
cific to the Control Board or the Front Cover Assembly for
service information on the related assembly.
The battery packs should be fully charged in an appro-
priate charger before they are placed into service. This ap-
plies to new battery packs received from the factory and to
battery packs that have been stored for long periods of time.
A fully charged battery pack should have an open-terminal
voltage greater than 7.5 Volts (typically 9.0 Vdc). A battery
ANTENNAS
Antennas are selected based on the operating frequency
range of the radio. Table 1 lists the available antennas which
mount in the antenna jack on the top of the radio. An exter-
TABLE 1 -VHF ANTENNAS
USABLE FREQ.
RANGE (MHz)
OPTION
NUMBER
COLOR
BANDS
PART NUMBER
TYPE
136-151
146-162
157 - 174
PANC1B
PANC1C
PANC1D
19B234804P1
19B234804P2
19B234804P3
Helical
Helical
Helical
Brown
Red
Orange
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LBI-38378
pack in need of a charge will cause the low battery "BAT"
status flag on the radio to turn on. This flag will turn on
when the battery pack’s voltage drops below approximately
6.8 Volts. The low battery alert tone will also be heard when
the battery pack needs charging.
FEATURES PROGRAMMABLE ON A PER
CHANNEL BASIS
• Transmit and Receive Frequencies
• 8-Character Alphanumeric Display (Channel
Designator)
RECHARGEABLE BATTERY PACK
DISPOSAL
• Tone or Digital Channel Guard Encode/Decode
• Type 99 Tone Decode Enabled or Disabled
• Transmit Power Level High or Low
• Transmit STE On or Off
The product that you have purchased contains a re-
chargeable battery. The battery is recyclable. At
the end of its useful life, under various state and
local laws, it may be illegal to dispose of this bat-
tery into the municipal waste stream. Check with your local
solid waste officials for details in your area for recycling op-
tions or proper disposal. Call Toll Free 1-800-822-9362 for
information and /or procedures for returning rechargeable
batteries in your state.
• Channel Busy Lockout Enabled or Disabled
• Carrier Control Timer
• Backlight On or Off
• Alert Tones On or Off
• Switch Crystal Frequency Enabled or Disabled
• GE-STAR Enabled or Disabled
• GE-STAR sent with Channel Guard
• Channel on Default/Fixed Scan List*
UNIVERSAL DEVICE CONNECTOR
The UDC is located on the side of radio just above the
PTT and Monitor Buttons. Various equipment such as the
audio accessories can be connected to the radio via the
UDC. The programming equipment is also connected to it
when the personality is programmed into the radio. The
UDC furnishes an excellent first-check-point for initial
bench checks without the need to disassemble the radio. Ta-
ble 2 lists all pins and their appropriate function. When the
radio is turned on it senses the resistance value between
UDC pins 9 and 1 and switches the appropriate circuits to
provide proper radio-to-accessory operation.
FEATURES PROGRAMMABLE ON A PER
MODE BASIS*
• Channel Data
• 8-Character
Alphanumeric
Display
(Mode
Designator)
• Type 99 Group Set Selection (One or Two)
• Priority-One and Priority-Two Scan Channels
• DTMF Enabled or Disabled
PROGRAMMING
The radio’s personality is programmed using an IBM
PC or compatible computer. A full-screen portable PC can
be used for field programming. The Programming Manual
and Software is TQ-3339 and TQ-4339. TQ-3339 is sup-
plied with 5-1/4 inch floppy disks and TQ-4339 is supplied
with 3-1/2 inch disks. This software uses a series of screens
and windows to guide you through a programming session.
See TQ-3339 or TQ-4339 for further programming details.
PC Programming Adapter TQ-3370 and Programming Ca-
ble TQ-3311 will also be required. These items provide in-
terface and connection between the PC and the radio when
the personality is transferred from the PC into the radio.
• GE-STAR Channel
•
Home Channel
FEATURES PROGRAMMABLE ON AN
OVERALL RADIO BASIS
• Minimum Volume Level
• Power-Up Beep On or Off
• Transmit Backlight On or Off
• Backlight On or Off when in Vehicular Charger
• GE-STAR And GE-STAR Emergency Options
NOTE
After programming or reprogramming the radio, dis-
connect the programming cable and turn the radio off
and then back on. This action will take the radio out of
programming mode and restore normal operation.
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LBI-38378
TABLE 2 - UDC PIN FUNCTIONS
PIN
NAME
INPUT OR
OUTPUT
USE
1
GROUND
UDC RX AUDIO
SWBATT
-------
Output
Output
Input
Case Ground
3
Test Point For Speaker Audio
Switched Accessory Power
External Microphone PTT Input
For Programming
4
5
EXT PTT
6
TX DATA
RX DATA
SPARE
Input
7
Output
For Programming
8
9
UDC VOLT
T/R
-------
Output
Output
Input
Option/Accessory Sense Pin
Low = Transmit, High = Receive
Low = Audio Muted
10
11
12
13
34
UDC MUTE
EXT MIC HI
EXT EMER
UDC DISCR
External Microphone Audio Input
Lanyard Connection
Input
Output
Test Point For RX Audio
Figure 5 - UDC Pin-Out
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LBI-38378
• Two individual Type 99 Tone Group Sets
INTRINSICALLY SAFE USAGE
• Control Knob selects Channels, Modes or Channel
Selected portable radios with appropriate factory in-
stalled F4 Options are certified as Intrinsically Safe by the
Factory Mutual Research Corporation. Intrinsically Safe ap-
proval includes Class I, II, III, Division 1 hazardous loca-
tions in the presence of Groups C, D, E, F and G
atmospheres. Non-Incendive approval includes Class I, Di-
vision 2 hazardous locations in the presence of Groups A, B,
C and D atmospheres.
Guard*
• Menu Selections*
• Home Mode or Home Channel (depending on
Control Knob programming) or Disabled*
• Scan Enabled or Disabled*
• Scan with Channel Guard Enabled or Disabled*
• Scan Across Modes Enabled or Disabled*
Hazardous locations are defined in the National Electri-
cal Code. Useful standards NFPA 437A and NFPA 437M
for the classifications of hazardous areas can be ordered
from the National Fire Protection Association, Batterymarch
Park, Quincy, MA 02269.
• Priority-One Scan Channel is the Selected Channel,
Fixed Channel or Keypad Entered Channel*
• Ten (10) Telephone Numbers and Names*
• DTMF Options*
BATTERY PACKS
Only battery packs identified with a green latch shall be
used with a portable radio that is rated and labeled as Fac-
tory Mutual Intrinsically Safe. Use of non-specified battery
packs voids Factory Mutual approval. The following battery
pack options are approved for use in intrinsically safe ra-
dios:
* Scan and System models only
OPERATOR MANUAL
Complete operating details for the M-PA radios are in-
cluded in LBI-38377. This operator’s manual contains de-
tailed operating procedures for the Select, Scan and System
model radios.
PAPA1F
Rechargeable Battery Pack,
(19A704860P6)
Extra High Capacity (Tall Case)
PAPA1G
(19A704850P6)
Rechargeable Battery Pack,
High Capacity (Short Case)
OPERATING TIPS
ACCESSORIES
Antenna location and condition is important when using
a VHF radio. Operating the radio in low areas of terrain, un-
der power lines or bridges, inside of a vehicle or in a metal
or steel framed building can severely reduce the range of the
unit Mountains and buildings can also reduce the range of
the unit.
The accessories that follow are approved for use with
intrinsically safe radios. Use of accessories other than those
listed voids Factory Mutual approval.
PAAB1A
(19B801 508P3)
Headset/Microphone
Earpiece Kit
In areas where transmission or reception is poor, some
improvement maybe obtained by insuring that the antenna is
vertical. Moving a few yards in another direction or moving
to a higher elevation may also improve communication. Ve-
hicular operation can be aided with the use of an externally
mounted antenna.
PAAC1A
(19B801 508P2)
PAAC1B
(19B801508P8)
GE-STAR Lanyard
Speaker/Microphone
Battery condition is another critical factor in the trouble
free operation of a portable radio. Observe the procedures
listed in the Service Section to insure the battery packs do
not develop the "Memory Effect".
PAAE1A
(19B801508P1)
PAAE1B
(19B801508P4)
Speaker/Microphone with
GE-STAR Lanyard
Always observe all of the Federal Communication
Commission’s rules and regulations during any service or
operating procedure.
PAAE 1C
Speaker/Microphone/Antenna
(19B801 508P6)
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LBI-38378
PANC1B
(19B234804P1)
Antenna, 136 - 151 MHz, Helical
Antenna, 146 - 162 MHz, Helical
Antenna, 157 - 174 MHz, Helical
PREVENTIVE MAINTENANCE
Antenna
PANC1C
(19B234804P2)
The antenna and antenna contact should be kept clean
and free from dirt or corrosion. If the antenna contact should
become dirty or corroded, communication range could be
reduced.
PANC1D
(19B234804P3)
PAHC1C
PAHC1D
PAHC1E
Belt Clip
Battery Packs
Swivel Mount with Belt Loop
Insure the battery packs are properly maintained. Do
not over or under charge them on a regular basis. Verify the
contacts are clean and free of corrosion.
Case, Leather, with Belt Loop
(Short Case)
PAHC1F
PAHC1G
PAHC1H
PAHC1K
PAHC5R
Case, Leather, with Belt Loop
(Tall Case)
Mechanical
Since portable radio units are subject to shock and vi-
bration, check for loose plugs, knobs, screws, etc.
Case, Leather, with Swivel Mount and
Belt Loop (Short Case)
Transmitter Check
Case, Leather, with Swivel Mount and
Belt Loop (Tall Case)
Check transmit frequency and deviation. Normally
these checks are made when the unit is first put into opera-
tion. They should be repeated after the first month of opera-
tion, then annually.
Shoulder Strap, Leather, with
Mounting Plate
Holster, Plastic.
Receiver Check
Receiver sensitivity should be checked periodically as
an indication of overall receiver operation.
MAINTENANCE
The M-PA radio is a very reliable unit and will normally
provide many years of trouble-free service. The recom-
mended Preventive Maintenance procedures that follow
should be performed when a technician comes in contact
with a unit. Component level troubleshooting information is
contained in the Service Section.
Cleaning
If the unit requires an external cleaning use mild soap
and a damp cloth. Avoid abrasive cleaners or chemicals
which may damage the plastic or rubber surfaces on the
unit.
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LBI-38378
TABLE 3 - TORQUE SPECIFICATIONS
DISASSEMBLY / REASSEMBLY
In the event internal service is required, disassemble the
radio in accordance with the following outlined steps. See
Figures 6 - 10.
LOCATION
LB-IN.
Rear/Front Cover Assembly Screws
5.0
Reassemble the unit by following the steps in reverse
order. Observe screw lengths and do not over tighten the
screws when reassembling the unit. Torque specifications
are listed in Table 3.
Rear Cover Assembly
Antenna Insert
10.0
10.0
4.0
10.0
1.5
UDC RF Connector
RF Board/Eggcrate Screws
PA Support Screws
CAUTION
ALWAYS remove the battery pack before disassem-
bling the unit to avoid blowing the fuse or causing
other component damage.
Antenna Switch (SW1) Screw
Front Cover Assembly
Knob Set Screws (earlier)
Knob Set Screws (later)
Group/Channel and Volume Nuts
UDC Ground Screw
3.0
5.0
8.0
4.0
3.0
This radio contains CMOS ICs that can be damaged
by static electricity. Observe static handling precau-
All M1.6 and M2 Screws
Tools Required
• TORX T6 Driver
• M1.5 Hex Driver or Wrench
• Needle-Nose Pliers
• Small Flat-Blade Screwdriver
• Spanner Wrench (top antenna jack)
• Spanner Wrench (UDC antenna jack)
• Spanner Wrench (volume control and group/channel
switch)
Front and Rear Cover Separation
Lay the radio face down and loosen the four (4) Torx
screws (A) on the back of the radio; complete screw re-
moval is not necessary. See Figure 6. Separate the covers by
carefully lifting the Rear Cover Assembly straight-up to
avoid bending the connector pins between the RF and Con-
trol Boards.
When reassembling the unit, verify the rubber gasket
surrounding the perimeter of the cover is in good condition
and it is in the groove. Also verify the connector pins align
properly. For proper operation, the screws should be tight-
ened so there is no gap between the covers. It is recom-
mended that the top screws be tightened first while
squeezing the radio together to ensure the gap is completely
closed. The bottom screws can then be tightened.
Figure 6 - Front And Rear Cover Separation
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LBI-38378
the chip component side of the board that secure it to the
casting.
RF Board Access
Holes are located in the RF Board shield for alignment
of the Reference Oscillator (U3), Modulation Balance pot
(R18), VCO Modulation pot (R19), 2nd Local Oscillator
Adjustment (T1), and the Quadrature Detector Adjustment
(T2). To align these items, shield removal is not necessary.
Reassemble the unit in reverse order. Observe screw
lengths.
Control Board Access
If removal of the RF Board from the case is necessary,
first remove the UDC antenna jack and the top RF antenna
jack with appropriate spanner wrenches. Next, remove the
five (5) Torx screws (B) that secure the shield then lift and
remove the shield. Remove the two (2) remaining Torx
screws (C) near the Power Amplifier Module. The RF Board
and eggcrate casting can now be lifted from the Rear Cover
to gain access to the chip component side of the board. If
necessary, the RF Board can be separated from the eggcrate
casting. Remove the two (2) Torx screws that secure the
Power Amplifier Module and remove the four (4) screws on
To gain partial access to the Control Board, remove the
five (5) screws (D) securing the shield and board. An earlier
Front Cover Assembly has an additional screw located just
below connectors J4/P4 (DD). See Figure 8. Remove the
shield.
Many of the test points on the Control Board are acces-
sible at this point; however, the Front Cover Assembly
should not be powered-up without first reinstalling the
screw into the lower right-hand hole to ground the board.
Also, the three (3) screws securing the top flex connectors
need to be reinstalled for good flex connections. USE CAU-
Figure 8 - Control Board Access
Figure 7 - RF Board Access
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LBI-38378
TION: Installation of screws that are longer than the origi-
nals may damage the LCD Board, flex circuits or the
threads.
UDC Flex/UDC/Monitor Button/PTT Switch
Assembly Removal
If UDC Flex/UDC/Monitor Button/PTT Switch assem-
bly removal is necessary, first un-solder the microphone.
With a spanner wrench, remove the UDC securing screw
(the UDC ground pin). Remove the insulator (foam or plas-
tic) on the inside side-rail of the case. Lift the UDC/Monitor
Button/PTT Switch assembly from the side of the case and
slide the flex through the slot
To remove the Control Board, remove the Torx screw
(E) in the lower left-hand corner that supplies battery power
to the board. An earlier Front Cover Assembly has an addi-
tional screw located just below connectors J1/P1 (EE). Lift
the board and carefully unplug Speaker Flex plug P3 from
J3 on the Control Board. Avoid bending this or any other
flex circuits at sharp angles. The Control Board may now be
removed. Note the battery power and ground connections at
the bottom of the board where the screws have been re-
moved.
Earlier Front Cover Assembly Keypad Flex
Removal
To remove the Keypad Flex, first remove the UDC
Flex/UDC/Monitor Button/PTT Switch assembly as pre-
viously stated. Next remove the knobs using the hex driver.
Unscrew the two (2) screws securing the top panel and lift
and remove the panel. Lift the Emergency Button Board by
carefully unplugging J6 from P6. With a spanner wrench,
remove the nuts securing the volume and channel controls
and carefully slide the controls inside the radio. Unscrew the
two (2) screws (G and GG) and remove the J10/P10 Zebra
strip securing plate (HH). See Figure 10. The Keypad Flex
is now free for removal.
Speaker, Microphone and Flex Circuit Access
Remove the Control Board as previously stated and
then remove the six (6) Torx screws that secure the die-cast
shield. Remove the die-cast shield by lifting the top end first
and sliding it towards the top of the radio. The internal
speaker, microphone, Keypad and UDC Flex circuits are
now partially accessible. See Figure 9.
Figure 10 - Keypad Flex And LCD Board Access
Figure 9 - Speaker, Microphone And Flex Circuit Access
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LBI-38378
BLOCK DIAGRAM
Figure 11 - Rear Cover Assembly Block Diagram
16
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LBI-38378
BLOCK DIAGRAM
Figure 12 - Front Cover Assembly (Earlier) And Control Board Block Diagram
17
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LBI-38378
Later Front Cover Assembly Keypad Flex Removal
Speaker Flex Removal
To remove the Keypad Flex, first remove the UDC
Flex/UDC/Monitor Button/PTT Switch assembly as pre-
viously stated. Next remove the screw securing the emer-
gency switch support (G) then remove the support. Remove
the knobs using the hex driver. With a spanner wrench, re-
move the nuts securing the volume and channel controls and
carefully slide the controls inside the radio. Unscrew the
two (2) screws that secure the J10/P10 connection at the
bottom of the LCD Board. Remove the screws, the plate and
the rubber pad. The Keypad Flex is now free for removal.
In order to replace the Speaker Flex, it must be un-sol-
dered from the speaker and the Battery Plate.
LCD Board Access
To remove the LCD Board, partial removal (actually re-
positioning of the top areas) of the Keypad Flex is required.
UDC Flex/UDC/Monitor Button/PTT Switch assembly re-
moval is not necessary.
After the top areas of the Keypad Flex have been freed
as previously outlined, the LCD Board can be removed. At
this point is the disassembly process an earlier Front Cover
Assembly has two (2) screws on the left side as view from
the back (J and JJ) and a later assembly has a single screw
in the upper left-hand side (J). See Figure 10.
Printed in U.S.A.
18
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