Motorola Two Way Portable Radio Ht1000 Mt2000 Mts2000 Mtx Series 68p81200c40 O Manual

							12
ReceiverTransmitterSignalling
Test
Service
MAEPF-22857-A
MAEPF-22858-O
Figure 40-3. Softpot Concept
Do NOT switch radios in the middle of any
!CAUTION 
						

							13
Perform the following procedures in the
sequence indicated.
B. Reference Oscillator Alignment
Adjustment of the reference oscillator is critical for
proper radio operation.  Improper adjustment will not
only result in poor operation, but also a misaligned radio
that will interfere with other users operating on adjacent
channels. For this reason, the reference oscillator
should be checked every time the radio is serviced.  The
frequency counter used for this procedure must have a
stability of 0.1 ppm (or better).
1. From the SERVICE menu, press F2 to select
TRANSMITTER alignment.
2. Press F2 again to select the REFERENCE OSCIL-
LATOR softpot.
3. Press F6 to key the radio. The screen will indicate
that the radio is transmitting.
4.  Measure the transmit frequency on your service
monitor.
5.  Use the UP/DOWN arrow keys to adjust the 
reference oscillator per the targets shown in 
Table 40-13.
C. Front-End Pre-Selector  (VHF/UHF only)
NOTEThis procedure is only required for tuning the front-
end filter varactors in the VHF and UHF models.  
The 800 and 900 MHz models utilize a stripline pre-
selector.  
1. Set the Test Box (RTX4005B) meter selection
switch to the “VOL” position, and connect a dc volt-
meter capable of 1mV resolution on a 2V scale to
the Test Box AC/DC meter port to monitor the
Received Signal Strength Indicator (RSSI).
2. From the SERVICE menu, press F3 to select
RECEIVER alignment.
3. Press F2  to select the FRONT END FILTER soft-
pot. The screen will indicate the receive frequencies
at which the filter is to be tuned.
4. Set the RF test generator to the first receive 
frequency  +150 Hz.  Set the RF level at the 
radio standard antenna port to 4.0 µVolts with no
modulation.
5.  Adjust the UP/DOWN arrow keys to obtain a peak
voltage on the dc voltmeter.
6. Press F8 to program the softpot value. 
7. Repeat steps 4-6 for the remaining test 
frequencies.8.  Press F10 and F2 to return to the RECEIVER
menu.
D. Rated Audio
1. Set test box (RTX-4005B) meter selection switch to
the “AUDIO PA” position and connect an ac volt-
meter to the test box ac/dc meter port.
2. Press F3  to select the RATED AUDIO softpot.  The
screen will indicate the receive test frequency to be
used.
3. Set the RF test generator to the receive test fre-
quency, and set the RF level at the radio standard
antenna port to 1mV modulated with standard test
modulation  (see Table 40-14).
4.  Adjust the UP/DOWN arrow keys to obtain rated
audio (as close as possible to 3.74 Vrms) into a
speaker (28 ohms) or equivalent resistive load.
5. Press F8 to program the softpot value. 
6.  For 900 MHz radios, go to step 7; otherwise press
F10  to return to the RECEIVER menu.
7. Now set the RF test generator to the receive test
frequency, and set the RF level at the radio stan-
dard antenna port to 1mV modulated with a 1 kHz
tone, 1.2 kHz deviation.
8. Select the Hear Clear RATED AUDIO softpot, and
adjust the UP/DOWN arrow keys to obtain rated
audio (3.74 Vrms) into a speaker (28 ohms) or
equivalent resistive load.
9. Press F8 to program the softpot value 
10.  Press F10 to return to the RECEIVER menu.
E. Squelch
1. Channel spacing determines the next key press.
Press F4, F5, or F6 (as applicable) to select the
SQUELCH softpot.
2. With no signal applied, decrease the softpot value
until squelch opens. Set the RF test generator to the
test frequency plus the following offset:
vhf:  +200Hz uhf:  +200Hz 800MHz:  +500Hz
Adjust the generator for 8 to 10dB SINAD.
3. Increase the softpot until the squelch closes.
4. Monitor for squelch chatter. If chatter is present,
increase the softpot until no chatter is detected.
Press F8 to program the softpot value. Press
ENTER to select the next softpot adjustment.
5. Repeat steps 2 thru 4 for all test frequencies shown
on the screen.
BAND TARGET
VHF ± 150 Hz
UHF ± 150 Hz
800 /900 MHz ± 150 HzTable 40-13.   Reference Oscillator Alignment
Table 40-14.  Standard Test Modulation (1 kHz Tone)CHANNEL SPACING DEVIATION 
25/30 kHz 3.0 kHz
20 kHz 2.4 kHz
12.5 kHz 1.5 kHz 
						

							6. Press F10, F2, then F10 again to return to the ser-
vice menu.
F. Transmitter Power
VHF and UHF radios require two power-level
adjustments, a high-power or rated-power adjustment,
and a low-power adjustment.  The low power adjust-
ment is required since the radio may be used in a
reduced power mode, or with a vehicular adapter.
NOTE 
All power measurements are to be made at the
antenna port.
1. From the SERVICE menu, press F2 to select
TRANSMITTER alignment.
2. Press F3  to select the TRANSMIT POWER softpot.
The screen will indicate the transmit test frequen-
cies to be used.
3. Begin with the highest test frequency shown.
4. Press F6 to key the radio, and use the UP/DOWN
arrow keys to adjust the transmit power per the
value shown in Table 40-15.
5. Press F6 to dekey the radio, and then press F8 to
program the value.
6. Repeat steps 4-5 for the remaining test frequencies.
7. Press F10, then F2 to return to the TRANSMIT
menu.
G. Transmit Deviation Balance (Compensation)
Compensation alignment balances the modulation
sensitivity of the VCO and reference modulation  (syn-
thesizer low frequency port) lines. The compensation
algorithm is critical to the operation of signalling
schemes that have very low frequency components
(e.g. DPL) and could result in distorted waveforms if
improperly adjusted. 
NOTE (Secure-Equipped Only)
If a secure module is currently installed in the radio
being aligned, refer to the appendix at the rear of this
manual. Read section III, “Secure Alignment Proce-
dure”, before performing the transmit deviation
balance (compensation) procedure. 
1. Press F4  to select the TRANSMIT DEVIATION
BALANCE softpot.  The screen will indicate the
transmit test frequencies to be used.
2. Begin with the lowest test frequency shown on the
screen.
3. Set the Test Box (RTX4005B) meter selector switch
to the “MX DISC” position, and inject an 
80 Hz tone at 100 mVrms into the AC/DC MTR port.
Keep the ac voltmeter in parallel to ensure the prop-
er input signal level. 
4.  Press F6 to key the radio, and measure deviation.
Record this measurement. 
5.  Change the input tone to 3 kHz, 100 mVrms and
use the UP/DOWN arrow keys to adjust the 
deviation to within ±2% of the value recorded in 
step 4.
6. Change the input tone back to 80Hz and measure
the deviation.
7.  Repeat steps 5 and 6 until the 3 kHz tone deviation
is within ±2% of the 80Hz tone deviation.
8. Press F6 to dekey the radio, and press F8 to pro-
gram the softpot value. Press ENTER to move to
next softpot value.
9. Repeat steps 3-8 for the remaining test 
frequencies.
10. Press F10 to return to the TRANSMIT menu.
NOTE
• The step size change for step 5 is approximately
2.5% per softpot value.
• This adjustment should only be made to 
the 3kHz deviation. Do not adjust the 80Hz 
deviation.
H. Transmit Deviation Limit
1. Press F5  to select the TRANSMIT DEVIATION
LIMIT softpot.  The screen will indicate the transmit
test frequencies to be used.
2. Begin with the lowest test frequency shown on the
screen.
14
Table 40-15.  Transmit Power Setting
VHF UHF
Power Test Frequencies Power Test Frequencies
Level 136-174MHz 177.975MHz  Level 450-512MHz 512-520MHz
5 W5.2 - 5.4 4.2 - 4.44 W4.2 - 4.4 3.2 - 3.4 
1 W1.2 - 1.4 1.2 - 1.41 W1.2 - 1.4 1.2 - 1.4
800 MHz 900 MHz
Power Power
Level All Test Frequencies Level All Test Frequencies
3 W3.20-3.402.9 W 2.80 - 3.00 
						

							3. With the meter selector switch (RTX4005B) set to
MIC, inject a 1 kHz tone on the AUDIO IN terminal
on the test set, 80mVrms as measured on the
AC/DC MTR port.
4. Press F6 to key the radio, and use the UP/DOWN
arrow keys to adjust the deviation per the values
shown in Table 40-16.
5. Press F6 to dekey the radio, and press F8 to pro-
gram the softpot value. Press ENTER to move to
the next softpot value.
6. Repeat steps 3-5 for the remaining frequencies
shown on the screen.
7. Press F10 to return to the TRANSMIT menu.
I. Transmit Deviation Limit Reference
NOTE 
1. This procedure is not required for 900 MHz 
models.
2. This procedure is required for VHF, UHF, and
800 MHz models with 20 kHz channel spacing
and VHF and UHF models with 12.5 kHz chan-
nel spacing.
1. Press F6  to select the TRANSMIT DEVIATION
LIMIT REFERENCE softpot.  
2. With the meter selector switch (RTX4005B) set to
MIC, inject a 1 kHz tone on the AUDIO IN terminal
on the test set, 80mVrms as measured on the
AC/DC MTR port.
3.  Press F6 to key the radio, and use the UP/DOWN
arrow keys to adjust the deviation per Table 40-17.  
4. Press F6 to dekey the radio, and press F8 to pro-
gram the softpot value.
5. Press F10 to return to the TRANSMIT menu.
J. VCO Crossover Frequency
NOTE
This procedure is only required after the field repair
of a VHF or UHF VCO. In order for a phase-locked-loop to tune very wide
bandwidths, both negative and positive control voltages
(Vcntl) are required.  This procedure sets the crossover
frequency at which the negative Vcntl (or –Vee) switch-
es from zero to negative.TX VCO Crossover
1. From the SERVICE menu, press F2 to select
TRANSMITTER alignment.
2. Press F7  to select the TRANSMIT VCO
CROSSOVER  softpot.  The screen will indicate the
transmit test frequency to be used.
3. Connect a dc voltmeter capable of 1mV resolution
to test point 5 (TP5), which is accessible through a
hole in the bottom side VCO circuitry shield.
4. Beginning with the default softpot frequency of line
2, press F6 to key the transmitter, and adjust the
UP/DOWN arrow keys until the voltage reading at
TP5 is 3.0 ±0.1 volts.  The frequency will increment
in steps of 50kHz. 
5. Press F6 again to dekey the transmitter, and press
F8 to program the softpot value.
6. Press F10 twice to return to the SERVICE menu.
RX VCO Crossover
1. From the SERVICE menu, press F3 to select
RECEIVER alignment.
2. Press F5  to select the RECEIVE VCO
CROSSOVER  softpot.  The screen will indicate the
receive test frequency to be used.
3. Connect a dc voltmeter capable of 1mVolt resolu-
tion to test point 5 (TP5), which is accessible
through a hole in the bottom side VCO circuitry
shield.
4. Beginning with the default softpot frequency of line
2, adjust the UP/DOWN arrow keys until the voltage
reading at TP5 is 3.0 ±0.1 volts.
5. Press F8 to program the softpot value.
6. Press F10 twice to return to the SERVICE menu.
K. Signalling Deviation
Transmit deviation balance compensation and
transmit deviation limit adjustments should be complet-
ed before signalling deviation is adjusted.
DTMF Tuning
1. From the SERVICE menu, press F4 to select SIG-
NALLING  alignment.
2. Press F4 again to select the DTMF softpot.
3. Press F6 to key the radio on the test frequency.
The screen will indicate that the radio is 
transmitting.
4.  Measure the DTMF deviation on your service 
monitor.
5.  Use the UP/DOWN arrow keys to adjust the DTMF
deviation per table 40-16.
6. Press F6 again to dekey the radio.
7.  Press F8 to program the softpot value; press F10
to return to the SIGNALLING menu.
15
Table 40-16.  Transmit Deviation LimitBAND DEVIATION (KHZ)
VHF/UHF/800 MHz 4.30 - 4.60
900 MHz 2.20 - 2.30
Table 40-17.  Transmit Deviation Limit ReferenceCHANNEL SPACING DEVIATION (KHZ)
20 KHz 3.40 - 3.60
12.5 KHz 2.20 - 2.30  
						

							Trunking High Speed Signalling
1. From the SERVICE menu, press F4 to select SIG-
NALLING  alignment.
2. Press F3 to select the TRUNKING HIGH SPEED
softpot.
3. Press F6 to key the radio on the test frequency.
The screen will indicate that the radio is 
transmitting.
4.  Measure the TRUNKING HIGH SPEED deviation
on your service monitor.
5.  Use the UP/DOWN arrow keys to adjust 
the TRUNKING HIGH SPEED deviation per 
Table 40-18.
6. Press F6 again to dekey the radio.
7.  Press F8 to program the softpot value; press F10  to
return to the SIGNALLING menu.MDC 1200 
1. From the SERVICE menu, press F4 to select SIG-
NALLING  alignment.
2. Press F4 to select the MDC softpot.
3. Press F6 to key the radio on the test frequency.
The screen will indicate that the radio is 
transmitting.
4.  Measure the MDC deviation on your service 
monitor.
5.  Use the UP/DOWN arrow keys to adjust the MDC
deviation per table 40-16.
6. Press F6 again to dekey the radio.
7.  Press F8 to program the softpot value; press F10
twice to return to the SERVICE menu.
The radio alignment procedure is now complete; the
radio may be disconnected and returned to service.16
Table 40-18.  Signalling Deviation
CHANNEL SPACING (KHZ) DTMF TRUNKING MDC
25 / 30 3.05-3.45 2.5-3.5 3.40-3.75
20 (VHF/UHF) 2.44-2.76            2.0-2.8               2.6-3.0
20 (821-824, 866-869) 2.44-2.76           2.0-2.8               2.6-3.0
12.5 1.55-1.85           1.40-1.75          1.640-1.875 
						

							17
A. General
Since this product disassembles and reassembles
without the use of any screws, it is important for the
technician to pay particular attention to the snaps and
tabs, and how parts align with each other.
NOTE
In the disassembly/reassembly procedure, the num-
bers in parentheses refer to call-out numbers in the
referenced figures.
B. Disassembly to Board Level
1. Turn off the radio.
2. Remove the battery (see Figure 40-4).
a. Hold the radio such that the battery is tilted
down.
b. Press down on the two battery-release levers.
c. With the release levers pulled down, the top of
the battery will fall away from the radio.
d. Remove the battery completely from the radio.
3. Loosen the antenna by turning it in a counterclock-
wise direction, and remove it from the radio.
4. Remove the volume on/off knob and the channel
selector switch knob by pulling them off their
respective switch shafts.
NOTE
Both knobs slideon and off but fit very snug on their
respective switch shafts. A small flat blade screwdriv-
er may be necessary to help pry the knobs loose.
Take care not to mar the surrounding radio surface.
SECTION VI. DISASSEMBLY AND REASSEMBLY
THIS RADIO CONTAINS STATIC-SENSITIVE DEVICES.
DO NOT OPEN THE RADIO UNLESS PROPERLY
GROUNDED. TAKE THE FOLLOWING PRECAUTIONS
WHEN WORKING ON THIS UNIT.
1. Store and transport all complementary metal-oxide
semiconductor (CMOS) devices in conductive material
so that all exposed leads are shorted together. Do not
insert CMOS devices into conventional plastic snow
trays used for storage and transportation of other semi-
conductor devices.
2. Ground the working surface of the service bench to pro-
tect the CMOS device. We recommend using the
Motorola Static Protection Assembly (part number
0180386A82), which includes a wrist strap, two ground
cords, a table mat, and a floor mat. 
3. Wear a conductive wrist strap in series with a 100k
resistor to ground. Replacement wrist straps that con-
nect to the bench top covering are Motorola part
number RSX-4015.
4. Do not wear nylon clothing while handling CMOS
devices.
5. Neither insert nor remove CMOS devices with power
applied. Check all power supplies that are to be used
for testing CMOS devices to be certain that there are no
voltage transients present.
6. When straightening CMOS pins, provide ground straps
for apparatus used.
7. When soldering, use a grounded soldering iron.
8. If at all possible, handle CMOS devices by the package
and not by the leads. Prior to touching the unit, touch an
electrical ground to remove any static charge that you
may have accumulated. The package and substrate
may be electrically common. If so, the reaction of a dis-
charge to the case would cause the same damage as
touching the leads.
MAEPF-22524-A
Figure 40-4.
!
CAUTION 
						

							5. Separate the front cover assembly from the internal
electronics (chassis) (see Figure 40-5).
a. Insert a small, flat-blade screwdriver or like
instrument in the slotted area at the bottom cen-
ter of the radio. Take care not to mar the O-ring
sealing area on the housing.
b. Pry the bottom of the chassis free from the
cover by pushing the screwdriver down and
rotating the handle of the screwdriver over and
behind the base of the radio. This prying action
forces the thin inner plastic wall toward the base
of the radio, which releases the two chassis
base tabs.
NOTE
A flexible ribbon cable (front cover/display flex),
which connects to the front cover assembly and
the chassis, keeps you from completely separat-
ing the two units.
c. Lay the chassis down, and rotate the front
cover back and partially away from the chassis
(see Figure 40-6).
6. Disconnect the front cover display flex from the con-
nector on the chassis.
NOTEA special locking connector secures the flex to the
chassis (see Figure 40-7).
18
MAEPF-22571-O
LETTERI
REQUIR
Chassis
Assembly
Front Cover
Assembly Small Flat Blade
Screwdriver
JWB 3/4/92
MAEPF-22571-O
Figure 40-5.
Figure 40-6.
MAEPF-22572-O
Front Cover/
Display FlexFront Cover
Assembly
Chassis
Assembly
MAEPF-22572-O
Top Corner
Pry Here
Top Corner
Pry HereFlex Locked
in ConnectorFlex Released
From Connector
1/8”
MAEPF-22573-O
Figure 40-7. 
						

							19
a. Use a small, thin, flat-blade screwdriver (or like
instrument) to help raise the sliding portion of
the connector approximately 1/8 of an inch from
its seated position. A slight prying action, alter-
nating back and forth on the top corners of the
connector, achieves the best results for unlock-
ing the connector.
b.  Remove the flex from the chassis connector.
7. Remove the contoured O-ring/antenna bushing seal
from the chassis.
8. Disconnect the controls flex from the connector on
the controller board by following the procedure in
step 6a and 6b.
NOTEA large portion of the controls flex is attached to the
large metal shield (front shield) with adhesive. Do not
remove the controls flex from the front shield unless
it is absolutely necessary.
9. As a unit, separate the control top, the front shield,
and the controls flex from the chassis and circuit
boards (see Figure 40-8).
NOTE
Four large tabs secure the front shield to the chassis
and hold the RF board and the controller board in the
chassis. a. Loosen the front shield by prying each of the
four tabs away from the chassis. Be careful not
to pry the tabs any more than is necessary to
free them from their respective retaining slots.
To completely loosen the shield from the chas-
sis, a slight lifting and clockwise twisting action
may be required.
b. Insert a small, flat-blade screwdriver in the
recessed area of the control top and pry the
control top slightly away from the chassis.
c. Completely remove the control top/front
shield/controls flex unit from the chassis.10. Carefully remove the RF board and the controller
board from the chassis.
NOTE
The RF board and the controller board are connected
together with a jumper flex. The connection is made
more rigid using a hard plastic cover that snaps
across the top of the jumper flex (see Figure 40-9).
C. Disassembly of Control Top
1. Remove the rubber controls seal from the control
top.
2. Turn the control top such that the black switch hous-
ing cover is facing up.
a. Five retaining clips hold the switch housing
cover to the switch housing. Clips 1, 2, 
and 3 are important during disassembly (see
Figure 40-10).
NOTE
To perform step 2b, two tools will be required;
your thumbnail or small, flat-blade screwdriver,
and a pen, pencil, or another small, flat-blade
screwdriver.
b. Using your thumbnail or small, flat-blade screw-
driver, lift the tab that covers the base of the
LED approximately 1/16 of an inch from its
seated position. While applying constant lifting
pressure there, (in order) release clips 1, 2, and
3 with the other tool.
Four (4)
Large Tabs
ILLUSTRATORENGI DATEDESCRIPTION
LETTERING S EDITORCHEC DATE
Jedi Disassembly PEH
2/21/92
C
JWB 3/4/92
Fig. 20-6
Figure 40-8.
MAEPF-22574-O
MAEPF-22575-O
Hard Plastic
Cover
Chassis RF BoardController
Board
Figure 40-9.
MAEPF-22575-O
Switch Housing
Cover
Switch
Housing
Lift
TabClip 1
Clip 2 Clip 3Clip 4Clip 5
MAEPF-22576-O
Figure 40-10.
MAEPF-22576-O 
						

							c. The cover will pop loose from the switch 
housing.
3. Push the three switches and the LED out of the
switch housing.
4. The remainder of the controls flex is attached to the
switch housing with adhesive. Do not remove the
flex from the switch housing unless it is absolutely
necessary.
D. Disassembly of Front Cover Assembly
1. On top display model radios only, release the dis-
play board by using a “press and pull” action on the
top two corners of the display board. Press down on
the two top corners of the display board and pull the
top of the board away from the two corner retaining
tabs. The display board will free itself from the
retaining tabs and two retaining slots in the front
cover housing.
2. Remove the edge connector (part of the front cover
flex, located behind the universal connector), by
sliding it out of the plastic rails that hold it in place. A
slight prying action, alternating back and forth on
the bottom corners of the connector, achieves the
best results.
3. Remove the speaker retainer bracket, speaker,
microphone, and front cover flex from the front
cover housing (see Figure 40-11).
NOTEThe speaker and front cover flex are held in position
with a three-leg retainer bracket. The legs of the
bracket are secured by slots in the front cover. When
removing the retainer bracket, use caution not to
damage the speaker.a. Disengage the retainer bracket leg that points
toward the bottom of the front cover from its
retaining tab.(1) Insert a small, flat-blade screwdriver under
the base of the bracket leg near the ring.
(2) Lift the bracket leg until it pops loose from
under its retaining tab.
b. Lift the freed leg of the retainer bracket and use
it to pull the remaining two legs of the bracket
out and away from their respective slots in the
front cover housing.
c. Pull the rubber microphone boot, containing the
microphone, from its seated position. Unless
you are replacing the microphone, leave the
microphone in the boot.
4. Remove, if necessary, and replace the sound
dampening pad.
5. As necessary, replace the speaker and/or micro-
phone while out of the front cover housing.
NOTE
If the microphone is replaced, ensure that the micro-
phone is reinstalled back into the rubber boot with
the microphone port facing the round hole at the bot-
tom of the boot.
6. On front display model radios only, notice that the
keypad/display board is secured to the front cover
housing using six tabs, three small tabs on one side
and three larger tabs on the universal connector
side. Remove the keypad/display board by inserting
a small flat-blade screwdriver in the circuit board
slot provided (slot nearest the top retaining tab on
the universal connector side of the  radio, see Fig-
ure 40-12). A slight prying action will release the
keypad/display board. If applicable, remove the rub-
ber keypad.
NOTE
Be careful not to mar the front cover housing O-ring
sealing area. Doing so will compromise the sealing
integrity of the radio.
20
MAEPF-22577-A
Small Flat Blade
Screwdriver
Speaker
Retainer BracketRetaining
Tab
Front Cover
Assembly
Sound
Dampening
Pad
MAEPF-22577-A
Figure 40-11.
Keypad/Display
Board
Six Retaining
Tabs
Insert Screwdriver
Blade in This Slot
Universal
Connector
MAEPF-23486-OMAEPF-23486-O
Figure 40-12. 
						

							21
E. Reassembly
Reassembly is the reverse of disassembly. Some
suggestions and illustrations are provided to help you
more easily reassemble the radio.
1. Keypad/Display Board 
(front display model radios only)
a. If applicable, replace the rubber keypad.
b. Place the keypad/display board into the front
cover housing at an angle such that the three
small slots on the edge of the board slide under
the three mating retaining tabs. Ensure that the
board slides underthe tabs.
c. Near the three larger slots on the other side of
the board, use finger pressure to push and
press that side of the board down until it snaps
into place under the three large retaining tabs.
2. Front Cover Assembly
a. Place the speaker and microphone into their
respective positions in the front cover. Make
sure that the speaker is seated properly in the
recessed area provided.
b. Press the rubber microphone boot into its
respective recessed area in the front cover
housing. The little rubber flap in the back of the
rubber boot should fold up to cover the micro-
phone insertion opening.
c. Reinstall the speaker retainer bracket (see 
Figure 40-13).
(1) Position the spring bracket over the speak-
er, and toward the top of the front cover
housing; insert the appropriate two legs of
the bracket into their respective slots 
(2) Grasp the center portion of the spring
bracket (ring area) with thumb and 
forefinger.
(3) While holding the ring area of the spring
bracket at approximately the same height
as the speakers base, push the remaining
leg down and into its respective slot.
d. Orient the edge connector so that its gold con-
tacts face the gold contacts of the housing.
Align the edge connector with the respectiveslots in the housing, and slide the connector
down into place. Ensure that the edge connec-
tor is fully seated into position.
e. On top display model radios only, seat the dis-
play board by inserting the two display board
tabs into their mating slots in the front cover
housing. Push the top of the display board
toward the top of the radio until the front cover
housing retaining tabs engage the display
board and secure it into position.
3. Chassis
Inside of the chassis where the RF board fits is a
protruding block that functions as the PA heatsink.
To help provide maximum heat transfer, ensure that
the PA heatsink block (top surface) is coated with a
thin film of thermal compound (Motorola part 
number 1110022A55).
Place the RF board and controller board into the
chassis. Ensure that the plastic cover that more
rigidly holds the two boards together is snapped into
place.
4. Control Top
a. Reinstall the switches and LED into the switch
housing.
b. Reinstall the switch housing cover onto the
switch housing by sliding tabs 4 and 5 of the
cover into their respective clips on the housing.
Then press down on the cover to engage tabs
1, 2, and 3.
5. Control Top/Front Shield/Controls Flex as a Unit to
Chassis
a. Slide the control top into the appropriate posi-
tion in the chassis, and place the front shield
into position over the chassis and circuit boards.
b. Check to see that the four large tabs of the front
shield are aligned with the respective slots on
the sides of the chassis, then snap the front
shield in place. Ensure that the shield is fully
seated, especially in the PTT switch area.
c. Slide the connector end of the controls flex into
the special locking connector mounted on the
control board. Ensure that the flex is fully seat-
ed into the board connector and secure the
connection.
NOTE
View the flex connection at a slight angle from
the bottomof the radio (see Figure 40-14). If
the flex is fully seated, the orange circuit plating
will be parallel with the connector top surface
and three reliefs in the plating will make the flex
plating appear to be separated. If the orange
plating of the flex is not parallel with the connec-
tors top surface, or the three reliefs are raised
enough to see plating under them, then the flex
is not fully seated.
Figure 40-13.
1.  Inset Legs
Into Slots2.  Grasp Clip
Here and Here,Then Push Leg Into Slot
MAEPF-22578-O