Read Sony CMT-LX40I / HCD-LX40I Service Manual online
HCD-LX40i
10
SECTION 4
ELECTRICAL ADJUSTMENTS
TUNER SECTION 0 dB = 1 μV
[AM]
Setting:
Function: TUNER
Band: AM
Setting:
Function: TUNER
Band: AM
AM RF signal
generator
30% amplitude
modulation by
400 Hz signal
60 cm
set
loop antenna A
loop antenna B
[FM]
Setting:
Function: TUNER
Band: FM
Setting:
Function: TUNER
Band: FM
FM RF signal
generator
1 kHz frequency
deviation by FM 75 kHz
signal
Output level:
as low as possible
+
–
level meter
MAIN board
JW828
(GND)
MAIN board
TP (TUNER OUT L-ch)
set
MAIN board
J802 pin
MAIN board
J802 pin
digital voltmeter
JW821 (VT)
JW828 (GND)
10 k
Ω
MAIN board
• Repeat the procedures in each adjustment several times, and
the tracking adjustments should be fi nally done by the trimmer
capacitors.
capacitors.
• Remove FM antenna in FM adjustment.
AM VT VOLTAGE CONFIRMATION
Frequency Display
Reading on Digital Voltmeter
531 kHz
1.6 ± 0.3 V
1,602 kHz
7 ± 0.5 V
AM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter
L851
603 kHz
FM VT VOLTAGE ADJUSTMENT
Adjustment Part
Frequency Display
Reading on Digital
Voltmeter
L805
87.5 MHz
1.7 ± 0.1 V
Confi rmation
108 MHz
6.2 ± 0.5 V
FM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter
L804
98 MHz
FM DETECTOR ADJUSTMENT
Setting:
Function: TUNER
BAND button: FM
Setting:
Function: TUNER
BAND button: FM
set
MAIN board
TP (TUNER OUT L-ch)
TP (TUNER OUT L-ch)
MAIN board
JW828 (GND)
JW828 (GND)
Carrier frequency : 98 MHz
Modulation
Modulation
: deviation by
FM 75 kHz
Output level
: 60 dB
FM RF Signal
generator
generator
1. Tune the set to 98 MHz.
2. Adjust L806 so that modulation distortion may become the
2. Adjust L806 so that modulation distortion may become the
best in the vicinity of the maximum value where the tuner out
level becomes –15 dBs or more.
level becomes –15 dBs or more.
Adjustment Location:
L851
AM Tracking
Adjustment
JW821
(VT)
JW828
(GND)
TP
(TUNER
OUT L-ch)
J802
1
3
L804
FM Tracking
Adjustment
L805
FM VT Voltage
Adjustment
TP
(TUNER
OUT R-ch)
L806
FM Detector
Adjustment
– MAIN Board
(Component Side) –
(Component Side) –
– MAIN Board
(Conductor Side) –
(Conductor Side) –
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