SHARI=
SERVICE MANUAL
!34429QT-50ZW/
QT-50Z(VV)
QT-50Z(P)
QT-50Z(GR)
Photo: QT-502(W)
In the interests of user-safety the set should be restored to its
original condition and only parts identical to those pacified be
used.
f
Page
SPECIFICATIONS..
............................................. 2
NAMES OF PARTS .............................................. 2
DISASSEMBLY ................................................. 3
VOLTAGE SELECTION ...........................................
3
STRINGING OF DIAL CORD ...................................... 4
MECHANICAL ADJUSTMENT ...................................... 4
CIRCUIT ADJUSTMENT ........................................
5,6
SCHEMATIC DIAGRAM. ........................................
7,8
NOTES ON SCHEMATIC DIAGRAM. ................................. 9
WIRING SIDE OF
P.W.BOARD
.................................. 9,
IO
EXPLODED
VIEW............................................11,12
REPLACEMENT PARTS LIST .................................. 13 - 16
INDEX TO
CONTENTS
-T
SHARP CORPORATION
GENERAL
Power source:
Output power:
Semiconductors:
Dimensions:
Weight:
FOR A COMPLETE DESCRIPTION OF THE OPERATION OF THIS UNIT,
PLEASE REFER TO THE
OPERATlON
MANUAL.
SPECIFICATIONS
TAPE RECORDER
ACllOV-127Vand220V-
240 V,
50160
Hz
DC 9V
(UM/SUM-2
or
RI4
type
x 6)
MPO; 7.2 W
(3.6W
+
3.6W)
(AC operation)
RMS;
4.6 W (2.3 W + 2.3 W)
(DC operation, 10% distortion)
PMPO; 14 W (7 W + 7 W)
(AC operation)
5
ICS
1 Transistors
10 Diodes
2 LEDs
Width; 402 mm
(15-I 3/l
6”)
Height; 137 mm
(5-7/16”)
Depth; 81 mm (3-31’16”)
1.7 kg (3.75
Ibs.)
without batteries
Tape:
Compact cassette tape
Frequency range:
50 Hz - 10,000 Hz
Signal/noise ratio:
36
dB
Input impedance:
External mic; 600 ohms
Output level and
loaded impedance:
Headphones; 8 ohms - 32 ohms
RADIO
Frequency range:
AM; 526.5
kHz -
1606.5
kHz
SW,;
2.3 MHz - 7.3 MHz
SW ;
7.3 MHz - 22 MHz
FM; 87.6 MHz -
108
MHz
SPEAKERS
Speakers:
9 cm
(3-l/2”) x
2
Specifications for this model are subject to change without
prior notice.
1.
Volume Control
2.
Balance Control
3. Tone Control
4. Function Selector Switch
5.
Pause Button
6. Stop/Eject Button
7. Fast Forward Button
8. Rewind Button
9. Play Button
10. Record Button
11. FM Mode Selector
12. Band Selector
NAMES
OF
PARTS
13. Tuning Control
14. Power Indicator
15. FM Stereo Indicator
16. Digital Tape Counter and Counter Reset Button
17. Cassette Compartment
18. Fine Tuning
19. Built-in Microphone
20. External Microphone Jacks
21.
FM/SW
Telescopic Rod Antenna
22. Headphones Jack
23. AC Power Supply Socket
24. Battery Compartment Lid
Figure 2-l FRONT PANEL
Figure 2-2 REAR PANEL
l
This unit is provided with a carring belt, but it is not depicted in the following Figures.
-2-
DISASSEMBLY
l
This unit is provided with a carring belt, but it is not
depicted in the following Figures.
Caution on Disassembly
Follow the below-mentioned notes when disassembling the
unit and reassembling it, to keep its safety and excellent
performance:
1. Take cassette tape out of the unit.
2. Be sure to remove the power supply plug from the wall
outlet before starting to disassemble the unit and remove
the batteries from the unit.
3. Take off nylon bands or wire holders where they need
be removed when disassembling the unit. After servicing
the unit, be sure to rearrange the leads where they were
before disassembling.
4. Take sufficient care on static electricity of integrated
circuits and other circuits when servicing.
STEP
REMOVAL
PROCEDURE
1
Front cabinet
1. Battery compart-
ment lid. . . . . .
(A) x
1
ZScrew..
. . . .
(B)x6
3. Open the cassette
holder. . . . . .
(C)
4. Open the
2
3
Mechanism block 1. Tape counter drive
Main
P.W.Board
cabinet . . . . . . (D)
5. Socket. . . . . .
(E) x
1
belt . . . . . . . .
(F) x
1
2. Screw . . . . .
IG) x
2
3. Socket. . . . (HI x 2
l.Screw.
. . . . . .
(11x8
2. Tip. . . . . . . .
(J) x
2
I
3-2
3-3
3-4
*
Set the mechanism in such a way as that the record/play-
back selector lever is positioned as shown in Fig. 3-5.
Figure 3-5
VOLTAGE
SELECTION
Before operating the unit on mains, check the preset voltage.
If the voltage is different from your local voltage, adjust the
voltage as follows: Slide the AC power supply socket cover by
slightly loosing the screw to the visible indication of the side
of your local voltage.
Figure 3-l
Figure 3-2
fFixl
Mechanism Block
d
(Glx2
Figure 3-3
Main
P,W.B.
Record Playback Selector Spring
Figure 3-4
-3-
STRINGING OF DIAL
CORD
Pulley
(227)
1. Turn the drum fully in the direction A shown in Fig.
4-1
and stretch its cord over the parts in the numerical order.
2. The turn the tuning control shaft fully in the direction
B
shown in Fig. 4-l and fix its pointer as shown in Fig. 4-2.
Figure 4-l
MECHANICAL ADJUSTMENT
E.V:
ELECTRONIC VOLTMETER
DUAL-TRACE
SY NCROSCOPE
ITEM USING JIGIADJUSTMENT REMARKS (CHECK)
POINTS
More than 150
g
Tape
tention
megurering
cassette
TW-2412
Torque meter
Play
-rw-2111
Fast-forward
TW-2231
Rewind
TW-2231
Driving
power
Torque
(Play:
30-60
g-cm)
(Fastforward
:
80-140
g-cm)
(Rewind
:
80-l
40 g-cm)
1
HEADPHONES
JACK
IRIGHT)
Figure 4-3 AZIMUTH
RECORD/PLAYBACK
HEADPHONES
..-..
FRECXJENCY
HEAD
.lAtiK
PLAY BACK
/
COUNTER
M
Azimuth
Tape
spa&
TEST TAPE
m-r-1
11
Figure 4-4 TAPE SPEED
TEST
TAPES
1
TORQUE METER
FOR COMPACT CASSETTE
COMPACT
CASSETTE TYPE
TITLE
FLUTTER
MODEL
FREQUENCY/
LEVEL
APPLICATION
Tape
speed,
MTT-1113 kHr,
-10
-10
Wow and flutter
check
MODEL
MEASUREMENT
RANGE
APPLICATION
TW-2111
lo-
16Ogcm
Normal : Playback torque
1.5-log-cm
Normal :
Back
tension
TW-2121
lo- 1OOgcm
Reverse : Playback torque
1.5 -
log-cm
Reverse : Back tension
TW-223 1
30 - 200 g-cm Fast-forward, Rewind torque
AZIMUTH
MTT-113
6.3 kHz,
-10
dB
MTT-113C
8 kHz, -10 d6
Head arimuth
MTT-I 14
10
kHz, -10 d6
adjustment
DISTORTION
MTT-118
1 kHz, -10
dB
Distortion check
level adjustment
TW-2412
o-3oog
TW-2422
o-3oog
Normal
:
Driving power
Reverse : Driving power
1 U&‘L’ELI MTT-150 1 Dolby B-Type / DoIN NR B-type 1
Tone 200
m&/m
level adlustment
BLANK
MTT-502
Record frequency
-
check
-4-
SE-ll-ING
Volume control: Maximum Balance
controk
Center
POSITION OF
Tone control: Center Function selector switch: Tape
SWlTCH
AND
KNOB
I
ITEM
/
INPUT /
ADJI.$- 1
REMARKS (CHECK)
(
PLAYBACK AMP- Test
tape
LIFIER
1.35v
SENSITIVITY
NTT-11 BN
AM
LF/RF
ADJUSTMENT
CIRCUIT ADJUSTMENT (TUNER
SECTION)
IIGNAL GENERATDR
400 Hr. 30%. AM modulated
FRE-
DIAL
AD
TEf
SyAyE
QUE- POINTER JUST-
REMARKS
NCY SElTlNG
MENT
4M
IF
AM RF
SWt
RF
SWz
RF
Figure 5-l PLAYBACK AMPLIFIER SENSITIVITY
Lowest
7
2.25
L7
Band
MHZ
frequency
coverage
8
7.4 MHz
Highest
frequency
TC4
Adjust for
maximal output.
9
2.6 MHz
2.6 MHz
L4
-
Tracking
10
6.0 MHz
6.0 MHz
TC3
11
Repeat steps
7,B,9
and 10 until no further
improvement can be made.
Figure 5-2 AM IF
Figure 5-3 AM RF
Figure 5-4 SW RF
FM IF/RF ADJUSTMENT
FM mono
4OOHz.
30%. FM modulated
-
DIAL
‘OINTEF
;ElTlNG
High
frequency
I
I.
i I
i
‘ur
until no
i
turn the core of
T2
counter-clockwise
before taking it out
oi
this bobbin.
2.Adjust for best “IF”
Figure 6-l FM IF
1
IF
I
I
10.7
MH
Y
-%7-
curve.
T2
IAdjust
for
best”S’ curve.
ther improvement can be made.
Lowest
frequency
10.7 MHZ
Highest
Adjust for maximal output
Figure 6-2 FM “IF” CURVE
Figure 6-3 FM “S” CURVE
88 MHz
108
MHz
8
IRepeat
steps 4. 5 and 6. 7 until no further Improvement can be made
;I
I O
1
=
GND
GNO
VCO FREQUENCY ADJUSTMENT
Figure 6-4 FM RF
SIGNAL GENERATOR
400 Hz, 30%. FM unmodulated
(mono signal)
DIAL
FREQUENCY POINTER
ADJUST-
MENT
REMARKS
SETrING
FM
IC3
SlGNAL
GENERATOR
FREO"UENCY
COUNTER
52
(See c&e$-6)
Figure 6-5 FM STEREO
FM mono position
98 MHz at 54
dB
98 MHz
FM stereo position
(unmodulated)
VRl
Adjust for 19.00
kHz
+ 200
Hz.
Figure 6-6 FM DUMMY
t
TPl
Figure 6-7 ADJUSTMENT POINTS
-6-
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