Read Sharp QT-CD121H (serv.man2) Service Manual online
– 8 –
QT-CD121H/112H
Instrument
Connection
MECHANISM SECTION
• Driving Force Check
PLAY: TW-2412
Over 120 g
Torque Meter
Specified Value
• Torque Check
Torque Meter
Specified Value
Play: TW-2111
25 to 65 g.cm
Fast Forward: TW-2231
60 to 130 g.cm
Rewind: TW-2231
60 to 130 g.cm
• Tape Speed
MTT-111 In motor
3,000
±
90 Hz
Output: Speaker
Teaminal
(CNP201 Load
resistance: 8 ohms)
Teaminal
(CNP201 Load
resistance: 8 ohms)
Instrument
Connection
Specified
Value
Test
Tape
TAPE SECTION
Position of each switch or control
Volume control
Max
Function switch
Tape/Power Off
X-BASS
On
• Bias Oscillation
• Playback Amplifier Sensitivity Check
Instrument Connection
Test Tape
MTT-118
1.8 V
±
3 dB
Speaker Terminal
(Load resistance: 8 ohms)
(Load resistance: 8 ohms)
Specified Value
ADJUSTMENT
TUNER SECTION
fL: Low-range frequency
fH: High-range frequency
fH: High-range frequency
• FM IF/RF
IF
T1
Detection
T2
Band Coverage
fL: L2
fH: TC2
fH: TC2
Tracking
88.0 MHz: L1
108.0 MHz: TC1
108.0 MHz: TC1
Test Stage
Specified
Value/Adjusting
Point
Instrument
Connection
Input: Pin 1 of IC1
Output: Pin 17 of IC2
Output: Pin 17 of IC2
Iuput: Antenna
Output: Speaker
Terminal (CNP201
Load resistance: 8
ohms)
Output: Speaker
Terminal (CNP201
Load resistance: 8
ohms)
• VCO Frequency
Specified
Value
Instrument
Connection
VR1
76 kHz
±
200 Hz
Pin 13, pin 21 and
ground of IC2
ground of IC2
Adjusting Point
Note:
After preparing the test circuit shown in Fig. 8, 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.
After preparing the test circuit shown in Fig. 8, 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.
Figure 8 VCO FREQUENCY TEST CIRCUIT
• Head Azimuth
Torque Meter
Specified Value
MTT-114
Output: Speaker Terminal
(CNP201 Load resistance: 8 ohms)
(CNP201 Load resistance: 8 ohms)
Adjusting
Point
Adjustment Point
Specified Value
L301
82 kHz
±
6 kHz
Pin 2 of CNP201
IF
T3
Input: Antenna
Output: Pin 19 of IC2
Output: Pin 19 of IC2
MW Band
fL: L4
Input: Antenna
Coverage
fH: TC4
Output: Speaker
Terminal (CNP201
Load resistance: 8
ohms)
Terminal (CNP201
Load resistance: 8
ohms)
Test Stage
Specified
Value/Adjusting
Point
Instrument
Connection
• MW/SW IF/RF
MW Tracking
600 kHz: L3
1,400 kHz: TC3
1,400 kHz: TC3
SW Band
fL: L6
Coverage
fH: TC5
SW Tracking
6.5 MHz: L5
16 MHz: TC6
16 MHz: TC6
QT-CD121H
Instrument
Connection
Adjustment Point
Specified Value
L301
82 kHz
±
6 kHz
Pin 2 of CNP201
– 6 kHz
QT-CD112H
Pin 13 of IC2
Pin 21 of IC2
D
G
S
10 kohm
TO FREQUENCY
COUNTER
COUNTER
FET : 2SK19 or 2SK54
IF
T3
Input: Antenna
Output: Pin 19 of IC2
Output: Pin 19 of IC2
Band Coverage
fL: L4
Input: Antenna
fH: TC4
Output: Speaker
Terminal (CNP201
Load resistance: 8
ohms)
Terminal (CNP201
Load resistance: 8
ohms)
Test Stage
Specified
Value/Adjusting
Point
Instrument
Connection
• AM IF/RF
Tracking
600 kHz: L3
1,400 kHz: TC3
1,400 kHz: TC3
QT-CD121H
QT-CD112H
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