Tuner Section - Sony CFD-S28L Service Manual

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3 7 63 1515 0

TUNER SECTION

[MW/LW]
Setting:
Function : RADIO
BAND button : MW or LW
Put the lead-wire
AM RF signal
antenna close to
generator
the set.
set
30% amplitude
modulation by
400 Hz signal
Output level: as low as possible
[FM]
Setting:
Function : RADIO
BAND button: FM
FM RF signal
generator
0.01 µ F
22.5 kHz frequency
deviation by 400 Hz
signal
Output level: as low as possible
TE
L 13942296513
TUNER board
JW17
• Repeat the procedures in each adjustment several times, and the
tracking adjustments should be finally done by the trimmer ca-
pacitors.
• Remove FM antenna in FM adjustment.
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0 dB=1 µV
level meter
32 Ω
+
–
2 jack (J301)
level meter
antenna terminal
32 Ω
+
set
–
2 jack (J301)
digital voltmeter
100 k Ω
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8
AM IF ADJUSTMENT
Adjust for a maximum reading on level meter
T1
MW VCO VOLTAGE CONFIRMATION
Frequency Display
531 kHz
1,611 kHz
MW TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter
L3-1
CT3
LW VCO VOLTAGE ADJUSTMENT
Adjustment Part Frequency Display Reading on Digital Voltmeter
L4 279 kHz
Confirmation 153 kHz
LW TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter
L3-2
CT5
FM VCO VOLTAGE ADJUSTMENT
Adjustment Part Frequency Display Reading on Digital Voltmeter
L2 108 MHz
Q Q
3 6 7 1 3
Confirmation 87.5 MHz
FM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter
L1
CT1
Adjustment Location: TUNER board (See page 15)
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– 14 –
2 9 9 4 2 8
450 kHz
Reading on Digital Voltmeter
+ 0.7 V
0.8
– 0.5 V
+ 1.2 V
5
– 0.6 V
621 kHz
1,404 kHz
5.3 ± 0.1V
+ 0.3 V
0.7
– 0.4 V
162 kHz
261 kHz
4.3 ± 0.1 V
1 5 0 5 8 2 9 9 4
1.6 ± 0.4 V
87.5 MHz
108 MHz
m
co
9 9
2 8 9 9