Sony ICF-CDK70 Service Manual ▷ View online
ICF-CDK70
13
SECTION 5
ELECTRICAL ADJUSTMENTS
TUNER SECTION
0 dB=1
µV
[AM]
Setting:
Function: RADIO
Band: AM
Setting:
Function: RADIO
Band: AM
AM RF signal
generator
30% amplitude
modulation by
400 Hz signal
Output level:
as low as possible
Put the lead-wire
antenna close to
the set.
+
–
level meter
set
6 7
MAIN board
CN303 pin
MAIN board
CN303 pin
[FM]
Setting
Function: RADIO
Band: FM
Setting
Function: RADIO
Band: FM
FM RF signal
generator
75 kHz frequency
deviation by 1 kHz
signal
Output level:
as low as possible
+
–
level meter
MAIN board
CN303 pin
MAIN board
CN303 pin
set
6 7
0.01 F
TU board
TP (GND)
TU board
TP (ANT)
digital voltmeter
TP (VT)
TP (GND)
100 k 7
TU board
• Repeat the procedures in each adjustment several times, and
the tracking adjustments should be fi nally done by the trimmer
capacitors.
capacitors.
AM IF ADJUSTMENT
Adjust for a maximum reading on level meter
T1
450 kHz
AM VCO VOLTAGE ADJUSTMENT
Adjustment Part
Frequency Display
Reading on Digital
Voltmeter
L4
530 kHz
1.0 ± 0.1 V
Confi rmation
1,710 kHz
5.3 ± 0.4 V
AM TRACKING ADJUSTMENT
Adjustment for a maximum reading on level meter
L3
620 kHz
CT3
1,400 kHz
FM IF ADJUSTMENT
Adjust for a minimum reading on level meter
T2
10.7 MHz
FM VCO VOLTAGE ADJUSTMENT
Adjustment Part
Frequency Display
Reading on Digital
Voltmeter
L2
108 MHz
3.0 ± 0.2 V
Confi rmation
87.5 MHz
1.3 ± 0.2 V
FM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter
L1
87.5 MHz
CT1
108 MHz
Adjustment Location: TU board (See page 14)
ICF-CDK70
14
– TU BOARD (Component Side) –
– TU BOARD (Conductor Side) –
L4
AM VCO Voltage Adjustment
L2
FM VCO Voltage Adjustment
FM Tracking Adjustment
T1 AM IF Adjustment
T2 FM IF Adjustment
L1
CT1
AM Tracking Adjustment
L3
CT3
TP (VT)
TP (GND)
TP (ANT)
Adjustment Location:
ICF-CDK70
15
CD SECTION
RF SIGNAL CHECK
Procedure:
1. Connect the oscilloscope to TP (RF) and TP (VC) on the CD
Procedure:
1. Connect the oscilloscope to TP (RF) and TP (VC) on the CD
board.
2. Insert the disc (PATD-012) (Part No. : 4-225-203-01).
3. Press the [
3. Press the [
u
] button.
4. Confi rm that the oscilloscope waveform is as shown in the fi g-
ure below. (eye pattern)
A good eye pattern means that the diamond shape (
◊) in the
center of the waveform can be clearly distinguished.
• RF signal reference waveform (eye pattern)
VOLT/DIV: 0.2 V (with the 10: 1 probe in use.)
TIME/DIV: 200 ns
0.7 to 1.7 Vp-p
When observing the eye pattern, set the oscilloscope
for AC range and raise vertical sensitivity.
Connecting Location:
IC701
TP (VC) TP (RF)
– CD Board (Conductor Side) –
ICF-CDK70
16
MEMO
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