Tuner Section - Sony CFD-E75 Service Manual

CFD-E75

TUNER SECTION

[AM]
Setting:
Function : RADIO
RADIO BAND button : AM
Put the lead-wire
AM RF signal
antenna close to
generator
the set.
30% amplitude
modulation by
400 Hz signal
Output level:
as low as possible
[FM]
Setting:
Function : RADIO
RADIO BAND button: FM
TUNER board
FM RF signal
TP (ANT)
generator
0.01 µF
22.5 kHz frequency
deviation by 400 Hz
TUNER board
signal
TP (GND)
Output level:
as low as possible
TUNER board
TP (VT)
TP (GND)
• 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.
16
0 dB=1 µV
POWER board
CNP392 pin 1
level meter
3.2 Ω
+
set
–
POWER board
CNP392 pin 2
POWER board
CNP392 pin 1
level meter
3.2 Ω
+
set
–
POWER board
CNP392 pin 2
digital voltmeter
100 k Ω
AM IF ADJUSTMENT
Adjust for a maximum reading on level meter
T1
AM VCO VOLTAGE ADJUSTMENT
Adjustment Part Frequency Display Reading on Digital Voltmeter
L4 530 kHz
Confirmation 1,710 kHz
AM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter
L3
CT3
FM IF ADJUSTMENT
Adjust for a minimum reading on level meter
T2
FM VCO VOLTAGE ADJUSTMENT
Adjustment Part Frequency Display Reading on Digital Voltmeter
L2 108 MHz
Confirmation 87.5 MHz
FM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter
L1
CT1
Adjustment Location: TUNER and POWER board (See page 16)
450 kHz
1.0 ± 0.05 V
5.3 ± 0.7 V
620 kHz
1,400 kHz
10.7 MHz
3.0 ± 0.2 V
1.3 ± 0.3 V
87.5 MHz
108 MHz