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ADJUSTMENT
A MAIN C.B
5
4
3
6
VT GND
TC201
TP1(VT)
TC202
TP2 (LCH)
TP3 (RCH)
L251
BAR ANT
9
2
B JACK C.B
8
<TUNER SECTION>
1. AM IF Adjustment
IFT251 .................................................................. 450kHz
2. FM IF Adjustment
TC202 ................................................................ 10.7MHz
3. AM VT Check
Settings : • Test point :
TP1 (VT)
Method :
Set to AM 531kHz<AH>, 530kHz<AU>
and check that the test point voltage is
1.3V ± 0.3V. Then set to AM 1602kHz<AH>,
1710kHz<AU> and check that the test point
voltage is within 6.7 ~ 8.2V<AH>,
6.5 ~ 8.0V<AU>.
4. FM VT Check
Settings : • Test point :
TP1 (VT)
Method :
Set to FM 87.5MHz and check that the test
point voltage is 3.6V ± 0.4V. Then set to FM
108.0MHz<AH>, 108.1MHz<AU> and check
that the test point voltage is within 6.8 ~ 9.0V.
5. AM Tracking Adjustment
L251 ..................................................................... 630kHz
TC251 ................................................................. 1440kHz
6. FM Tracking Adjustment
TC201 ............................................................... 87.5MHz
SFR701
5
7
DOLBY GND
VR251
TC251
IC251
11 12
IFT251
1
PHONES
J402
7. FM VCO Adjustment
Settings : • Adjustment location :
VR251
Method :
Connect a frequency counter to pin 11 and 12
of IC251, adjust VR251 for VCO to 19kHz ±
100Hz.
<TAPE PLAYER SECTION>
8. Tape Speed Adjustment
Settings : • Test tape :
TTA–100
• Test point :
PHONES JACK
(J402)
• Volume :
MAX.
• Adjustment location : SFR701
Method :
Play back the test tape and adjust SFR701 for
3015Hz ± 10Hz(FWD) and 3015Hz ± 45Hz
(REV).
9. Dolby Level Check
Settings : • Test tape :
TTA-200
• Test point :
TP2(Lch), TP3(Rch)
• Volume :
MIN.
• DOLBY SW :
OFF
Method :
Connect an electrolytic capacitor (10uF/16V)
to measured instrument and test point, check
the voltage for 31.6mV ± 1dB.
27
PRACTICAL SERVICE FIGURE
<TUNER SECTION>
<FM SECTION>
Sensitivity :
8
(IHF, THD 3%)
Less than 17dB
[at 87.5 / 98.5 / 108.0MHz]
Distortion :
Less than 3% (at input 54dB)
Less than 5% (at input 110dB)
[at 98.5MHz]
Stereo separation :
More than 16dB
[at 98.5MHz]
Auto stop level :
20dB ± 6dB
[at 98.5MHz]
Intermediate frequency : 10.7 / 10.75MHz ± 0.05MHz
<AM SECTION>
Sensitivity :
(S/N 10dB)
Less than 58dB
[at 630kHz]
Less than 56dB
[at 999 / 1440kHz]<AH>
[at 1000 / 1440kHz]<AU>
S/N ratio :
More than 26dB
(Input 74dB)
[at 630kHz]
More than 27dB
[at 999 / 1440kHz]<AH>
[at 1000 / 1440kHz]<AU>
Distortion :
Less than 5% (at input 74dB)
Less than 10% (at input 120dB)
[at 999 / 1440kHz]<AH>
[at 1000 / 1440kHz]<AU>
Auto stop level :
60dB ± 7dB
[at 999 / 1440kHz]<AH>
[at 1000 / 1440kHz]<AU>
Intermediate frequency : 450kHz ± 3kHz
<TAPE SECTION>
Tape speed :
3015Hz ± 50Hz
Wow & flutter :
Less than 0.52% (RMS)
Take-up torque :
20 ~ 30g-cm (FWD, REV)
F.F torque :
70 ~ 150g-cm
Rew torque :
70 ~ 150g-cm
Back tension :
1.0 ~ 3.0g-cm (FWD, REV)
S/N ratio :
More than 43dB (PB, DC)
More than 20dB (REC/PB, DC)
Distortion :
Less than 3.0% (PB, DC)
Less than 7.0% (REC/PB, DC)
Noise level :
Less than 3.0mV (PB, DC, MAX.)
Less than 0.3mV (PB, DC, MIN.)
Erasing Ratio:
More than 45dB
Dolby level :
31.6mV ± 1dB
Dolby NR effect :
More than 8.5dB (B-TYPE)
Frequency response :
63Hz +2/–6dB ~ 8kHz ± 4dB
(NORMAL, PB)
63Hz +2/–6dB ~ 10kHz ± 4dB
(CRO2, PB)
125Hz –4/–12dB ~ 8kHz +3/–12dB
(REC/PB)
Test tape :
MTT–15070
TTA–100
TTA–200
TTA–210
TTA–320(NORMAL)
TTA–310(CRO2)
TTA–601
TTA–610
28
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