Adjustment - Sharp QT-CD131H Service Manual

MECHANISM SECTION
• Driving Force Check
Torque Meter
PLAY: TW-2412
• Torque Check
Torque Meter
Play: TW-2111
Fast Forward: TW-2231
Rewind: TW-2231
• Head Azimuth
Torque Meter
MTT-114
• Tape Speed
Adjusting
Test
Point
Tape
MTT-111 In motor
TAPE SECTION
Position of each switch or control
Volume control
Function switch
X-BASS
• Bias Oscillation
Adjustment Point Specified Value
82 kHz ± 6 kHz
L301
• Playback Amplifier Sensitivity Check
Test Tape Specified Value
1.8 V ± 3 dB
MTT-118
AM TRACKING
fL fH
TC1
L3
AM BAR
ANTENNA
R7
FM IF
L1
FM RF
T1
1
IC1
Figure 7-2 ADJUSTMENT POINTS
Specified Value
Over 120 g
Specified Value
25 to 65 g.cm
60 to 130 g.cm
60 to 130 g.cm
Specified Value
Output: Speaker Terminal
(CNP201 Load resistance: 8 ohms)
Specified Instrument
Value Connection
3,000 ± 90 Hz
Output: Speaker
Teaminal
(CNP201 Load
resistance: 8 ohms)
Max
Tape/Power Off
On
Instrument
Connection
Pin 2 of CNP201
– 6 kHz
Instrument Connection
Speaker Terminal
(Load resistance: 8 ohms)
FM ROD ANTENNA
AM BAND
COVERAGE
R26
T2
L4
FM DET.
19 17 13
21
IC2
TP1
1
L2
T3
AM IF
FM BAND
COVERAGE

ADJUSTMENT

TUNER SECTION
fL: Low-range frequency
fH: High-renge frequency
• FM RF
Signal generator: 1 kHz, 75 kHz dev., FM modulated
Test Stage Frequency
Band
Coverage
RF
*1. Input: Antenna, Output: TP1
*2. Input: Antenna, Output: Speaker Terminal
• Detection
Signal generator: 10.7 MHz, FM sweep generator
Test
Stage
IF
• AM IF/RF
Signal generator: 400 Hz, 30%, AM modulated
Test Stage Frequency
IF
Band
Coverage
Tracking
*1. Input: Antenna, Output: Pin19 of IC2
*2. Input: Antenna, Output: Speaker Terminal
*3. Input: Input is not connected,
• VCO Frequency
Adjusting Point
VR1
Note:
After preparing the test circuit shown in Fig. 7-1, connect the
Pin 13, Pin 21 and ground of the IC2 with the test circuit, and
measure the value. At this time, apply a standard unmodulated
signal input and adjust the VCO.
MAIN PWB
Pin 13 of IC2
TP2
VR1
G
VCO
Figure 7-1 VCO FREQUENCY TEST CIRCUIT
– 7 –
Frequency
Display
— 87.50 MHz
98.00 MHz 98.00 MHz
(10~30 dB)
Frequency Frequency
Display
10.7 MHz 98.00 MHz
Frequency
Display
450 kHz 1,620 kHz
— 522 kHz
600 kHz 600 kHz
1,400 kHz 1,400 kHz
Specified
Value
76 kHz ± 200 Hz
Pin 21 of IC2
FET : 2SK19 or 2SK54
D
S
10 kohm
QT-CD131H/132H
Setting/
Instrument
Adjusting
Connection
Parts
(fL): L2 *1
3.4 ± 0.1 V
L1 *2
Setting/
Instrument
Adjusting
Connection
Parts
T1(Turn Input: Pin 1 of
the core of IC1
T1 fully Output: TP2
counter-
clockwise.
Setting/ Instrument
Adjusting Connection
Parts
T3 *1
(fL): L4 *3
1.0 ± 0.1 V
(fL): L3 *2
(fH):TC1
Output: TP1
Instrument
Connection
Pin 13, pin 21 and
ground of IC2
TO FREQUENCY
COUNTER