Adjustment - Sharp QT-CD111H 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
Tape Point
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
Pin 13 of IC2 Pin 21 of IC2
FET : 2SK19 or 2SK54
D
G
S
10 kohm
Figure 7-1 VCO FREQUENCY TEST CIRCUIT
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)
TO FREQUENCY
COUNTER

ADJUSTMENT

TUNER SECTION
fL: Low-range frequency
fH: High-range frequency
• FM IF/RF
Test Stage
IF
Detection
Band Coverage
Tracking
• AM IF/RF
Test Stage
IF
Band Coverage
Tracking
• 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
AM
TRACKING
fL
fH fL
AM BAND
COVERAGE
Figure 7-2 ADJUSTMENT POINTS
– 7 –
QT-CD111H/110H
Specified
Value/Adjusting
Point
T1
T2
fL: L2
fH: TC2
88.0 MHz: L1
108.0 MHz: TC1
Specified
Value/Adjusting
Point
T3
fL: L4
fH: TC4
600 kHz: L3
1,400 kHz: TC3
Specified
Value
76 kHz ± 200 Hz
FM ROD ATENNA
VR1
VCO
13
17
IC2
T2
19
FM
DETECTION 21
L4
L2
IC1
TC4
TC2
TC3
TC1
L1
AM 1
TRACKING
fH
fH fL fH
FM
FM BAND
TRACKING
COVERAGE
Instrument
Connection
Input: Pin 1 of IC1
Output: Pin 17 of IC2
Iuput: Antenna
Output: Speaker
Terminal (CNP201
Load resistance: 8
ohms)
Instrument
Connection
Input: Antenna
Output: Pin 19 of IC2
Input: Antenna
Output: Speaker
Terminal (CNP201
Load resistance: 8
ohms)
Instrument
Connection
Pin 13, pin 21 and
ground of IC2
T3
1
AM IF
T1
FM IF
fL