D-NF400/NF401
11
11
SECTION 5
ELECTRICAL CHECK
CD SECTION
The CD section adjustments are done automatically in this set.
In case of operation check, confirm that focus bias.
Precautions for Check
1. Perform check in the order given.
2. Use YEDS-18 disc (Part No.: 3-702-101-01) unless otherwise
indicated.
3. Power supply voltage requirement: DC4.5 V in DC IN jack.
(J401)
HOLD switch
: OFF
Connecting and Checking Location:
Focus Bias Check
Condition:
• Hold the set in horizontal state.
Connection:
Procedure:
1. Connect the oscilloscope to the test points TP601 (RF) and
TP498 (GND) on the MAIN board.
2. Set a disc. (YEDS-18)
3. Push the
N X
button.
4. Check the oscilloscope waveform is as shown below.
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 : 100 mV (With the 10:1 probe in use)
TIME/DIV : 500 ns
To watch the eye pattern, set the oscilloscope to AC range and
increase the vertical sensitivity of the oscilloscope for easy watch-
ing.
5. Stop revolving of the disc motor by pressing the
x
button.
oscilloscope
(AC range)
+
–
MAIN board
TP601 (RF)
TP498 (MAIN_GND)
2 k
Ω
RF level
0.45 to 0.65 Vp-p
TP601
(RF)
TP498
(MAIN_GND)
– MAIN Board (Conductor Side) –
TUNER SECTION
0 dB=1
µ
V
[AM]
Setting:
Band switch : AM
[FM]
Setting:
Band switch : FM
• Repeat the procedures in each adjustment several times, and the
frequency coverage and tracking adjustments should be finally
done by the trimmer capacitors.
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
32
Ω
MAIN board
i
jack (J301)
FM RF signal
generator
22.5 kHz frequency
deviation by 400 Hz
signal
Output level: as low as possible
+
–
level meter
set
32
Ω
0.01
µ
F
MAIN board
TP (FM ANT)
MAIN board
i
jack (J301)
digital voltmeter
100 k
Ω
TP8 (VT)
TP498 (MAIN_GND)
MAIN board
( ): AEP, UK, East European, E, Australian Models
AM FREQUENCY COVERAGE CONFIRMATION
Adjustment Part
Frequency Display
Reading on Digital Voltmeter
Confirmation
530 (531) kHz
1.0
±
0.5 V
Confirmation
1,710 (1,602) kHz
7.3
±
1.0 (6.8
±
1.0) V
AM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter
L3
620 kHz
CT3
1400 kHz
( ): AEP, UK, East European, E, Australian Models
FM FREQUENCY COVERAGE CONFIRMATION
Adjustment Part
Frequency Display
Reading on Digital Voltmeter
Confirmation
87.5 (108.0) MHz
5.1
±
0.5 (8.7
±
0.5) V
FM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter
L1
98.0 MHz
TV TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter
L5
ch10/97.75 MHz
(D-NF400: US, Canadian models only)
TP428
(MAIN_GND)
L3
CT3
AM Tracking
Adjustment
– MAIN Board (Conductor Side) –
– MAIN Board (Component Side) –
TP8
(VT)
D-NF400: US,
Canadian models
L1 FM Tracking
Adjustment
L5 TV Tracking
Adjustment
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TEL 13942296513 QQ 376315150 892498299
TEL 13942296513 QQ 376315150 892498299
