Adjustment - Sharp GX-CD130C Service Manual

GX-CD30/30C/130/130C
MECHANISM SECTION
• Driving Force Check
Torque Meter
PLAY: TW-2412
• Torque Check
Torque Meter
Play: TW-2111 30 to 60 g.cm
Fast Forward: TW-2231
Rewind: TW-2231
• Tape Speed
Test Tape Specified
Nomal MTT-111 3,000
± 30 Hz
speed
TAPE SECTION
Position of each switch or control
Volume control
Beat cancel
Function/Power switch
• Bias Oscillation Check
Beat cancel
• Erase Current Check
Resistor for measurement: 1 ohm
• Playback Amplifier Sensitivity Check
Test Tape Specified Value
1.8 V ± 3 dB
MTT-118
FM
TRACKING

ADJUSTMENT

Specified Value
Tape 1: Over 50 g
Tape 2: Over 100 g
Specified Value
Tape 1 Tape 2
30 to 60 g.cm
80 to 135 g.cm
80 to 135 g.cm
Instrument
Value Connection
Speaker
terminal
(Load resistance:
6 ohms)
Max
A
Tape/Off
Specified Value
A: 82 + 10 kHz / -6 kHz
B: -2 ± 2 kHz
C: +3 ± 2 kHz
Specified Value
50 ± 25 mV
Instrument Connection
Speaker Terminal
(Load resistance: 6 ohms)
AM TRACKING
fH
fH
fL
TC3
TC1
L1
FM RF
1
IC1
T1
FM IF
Figure 8-2 ADJUSTMENT POINTS
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. 8-1, 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.
Pin 13 of IC2 Pin 21 of IC2
D
G
S
Figure 8-1 VCO FREQUENCY TEST CIRCUIT
fH
fL COVERAGE
L4
VCO
VR1
TC4 L2
T2
TC2
FM DET
19
21 17 13
IC2
1
AM IF
T3
– 8 –
Specified Instrument
Value/Adjusting Connection
Point
T1
Input: Pin 1 of IC1
Output: Pin 17 of IC2
T2
fL: L2 Iuput: Antenna
fH: TC2
Output: Headphones
Socket (Load
88.0 MHz: L1
resistance: 32 ohms)
108.0 MHz: TC1
Specified Instrument
Connection
Value/Adjusting
Point
T3 Input: Antenna
Output: Pin 19 of IC2
fL: L4 Input: Antenna
fH: TC4 Output: Headphones
600 kHz: L3 Socket (Load
1,400 kHz: TC3 resistance: 32 ohms)
Specified Instrument
Value Connection
76 kHz ± 200 Hz
Pin 13, pin 21 and
ground of IC2
FET : 2SK19 or 2SK54
TO FREQUENCY
10 kohm
AM BAND
fL FM BAND
fH COVERAGE
COUNTER