Sony CMT-EP50 / HCD-EP50 Service Manual ▷ View online
11
HCD-EP50
SECTION 4
MECHANICAL ADJUSTMENTS
SECTION 5
ELECTRICAL ADJUSTMENTS
Tape Speed Adjustment
Setting:
Function: TAPE
Function: TAPE
Procedure:
1. Playback WS-48B (tape center) in the FWD state.
2. Adjsut the volume in CAPSTAN/REEL motor so that the fre-
1. Playback WS-48B (tape center) in the FWD state.
2. Adjsut the volume in CAPSTAN/REEL motor so that the fre-
quency counter reading becomes 3,000 Hz.
Specified Value: 2,970 to 3,030 Hz
3. Confirm that the frequency at the beginning and that at the
end of tape winding are between 2,955 to 3,045 Hz.
Adjustment Location:
PRECAUTION
1. Setting
MEGA BASS switch : OFF
TAPE DECK SECTION
0 dB=0.775 V
Test tape
Type
Signal
Used for
WS-48B
3 kHz, 0 dB
Tape Speed Adjustment
P-4-A100
10 kHz, –10 dB
Head Azimuth Adjustment
frequency counter
test tape
WS-48B
(3 kHz, 0 dB)
WS-48B
(3 kHz, 0 dB)
set
MAIN board
SPEAKER terminal (CN17)
SPEAKER terminal (CN17)
–
+
47 k
Ω
CAPSTAN/REEL
motor
motor
Tape Speed
Adjustment
Adjustment
Mode
Tension Meter
Meter Reading
FWD
CQ-403A
more than 100 g
(more than 3.53 oz)
• Tape Tension Measurement
PRECAUTION
1. Clean the following parts with a denatured-alcohol-moistened
swab :
record/playback head
pinch roller
erase head
rubber belts
capstan
idlers
2. Demagnetize the record/playback head with a head demagne-
tizer. (Do not bring the head magnetizer close to the erase head.)
3. Do not use a magnetized screwdriver for the adjustments.
4. After the adjustments, apply suitable locking compound to the
4. After the adjustments, apply suitable locking compound to the
parts adjusted.
5. The adjustments should be performed with the rated power
supply voltage unless otherwise noted.
• Torque Measurement
Mode
Torque Meter
Meter Reading
2.95 – 6.86 mN•m
FWD
CQ-102C
(30 – 70 g•cm)
(0.42 – 0.97 oz•inch)
0.15 – 5.39 mN•m
FWD
CQ-102C
(1.5 – 5.5 g•cm)
Back Tension
(0.021 – 0.076 oz•inch)
more than 5.89 mN•m
FF
CQ-201B
(more than 60 g•cm)
(more than 0.83 oz•inch)
more than 5.89 mN•m
REW
CQ-201B
(more than 60 g•cm)
(more than 0.83 oz•inch)
12
HCD-EP50
2. Turn the adjustment screw and check output peaks. If the peaks
do not match for L-CH and R-CH, turn the adjustment screw
so that outputs match within 1dB of peak.
so that outputs match within 1dB of peak.
3. Mode: Playback (FWD)
4. Repeat step 1 to 3 in playback (REV) mode.
5. After the adjustments, apply suitable locking compound to the
5. After the adjustments, apply suitable locking compound to the
parts adjusted.
Screw
position
position
L-CH
peak
peak
within
1dB
1dB
Output
level
level
L-CH
peak
peak
R-CH
peak
peak
within
1dB
1dB
Screw
position
position
R-CH
peak
peak
test tape
P-4-A100
(10 kHz, –10 dB)
P-4-A100
(10 kHz, –10 dB)
L-CH
R-CH
MAIN board
SPEAKER terminal (CN17)
SPEAKER terminal (CN17)
oscilloscope
V
H
+ +
–
–
screen pattern
in phase
good
wrong
45
°
90
°
135
°
180
°
47 k
Ω
47 k
Ω
set
Record/Playback Head Azimuth Adjustment
Procedure:
1. Mode: Playback (FWD)
1. Mode: Playback (FWD)
level meter
test tape
P-4-A100
(10 kHz, –10 dB)
P-4-A100
(10 kHz, –10 dB)
set
MAIN board
SPEAKER terminal (CN17)
SPEAKER terminal (CN17)
47 k
Ω
+
–
–
Adjustment Location: Record/Playback Head.
Note: Refer to “3-7. CASSETTE LID” (see page 10)
13
HCD-EP50
no mark : EXCEPT AEP, UK, Chinese models
< > : AEP, UK, Chinese models
< > : AEP, UK, Chinese models
AM IF ADJUSTMENT
Adjust for a maximum reading on level meter
T1
450 kHz
AM FREQUENCY COVERAGE ADJUSTMENT
Adjustment Part
Frequency Display
Reading on Digital Voltmeter
T8
530 kHz
1.3
±
0.1 V
<531 kHz>
Confirmation
1,710 kHz
7.8
±
0.5 V
<1,602 kHz>
<7.1
±
0.5 V>
AM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter
T6
603 kHz
TC1
1,404 kHz
FM FREQUENCY COVERAGE ADJUSTMENT
Adjustment Part
Frequency Display
Reading on Digital Voltmeter
L901
87.5 MHz
2.4
±
0.1 V <1.4 to 1.6 V>
<Confirmation>
Confirmation
108 MHz
6.8
±
0.5 V <7.3 to 8.5 V>
FM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter
L902
90.1 MHz
TC901
106.1 MHz
(EXCEPT AEP, UK, Chinese models)
Adjustment Location: MAIN board (See page 14)
TUNER SECTION
0 dB=1
µ
V
[AM]
Setting:
Function
Function
: TUNER
Band switch : AM
[FM]
Setting:
Function
Function
: TUNER
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.
done by the trimmer capacitors.
AM RF signal
generator
30% amplitude
modulation by
400 Hz signal
Output level: as low as possible
modulation by
400 Hz signal
Output level: as low as possible
Put the lead-wire
antenna close to
the set.
antenna close to
the set.
+
–
–
level meter
set
32
Ω
MAIN board
SPEAKER terminal (CN17)
SPEAKER terminal (CN17)
FM RF signal
generator
22.5 kHz frequency
deviation by 400 Hz
signal
Output level: as low as possible
deviation by 400 Hz
signal
Output level: as low as possible
+
–
–
level meter
set
32
Ω
0.01
µ
F
MAIN board
FM ANT
FM ANT
MAIN board
SPEAKER terminal (CN17)
SPEAKER terminal (CN17)
digital voltmeter
100 k
Ω
MAIN board
TP (FM VT)
TP (AM VT)
TP (AM VT)
Ver 1.1
14
HCD-EP50
Adjustment Location and Connecting Points
– MAIN BOARD (Component Side) –
T8
AM Frequency
Coverage Adjustment
T1
AM IF Adjustment
AM Tracking Adjustment
{
TC1
T6
T6
– MAIN BOARD (Conductor Side) –
TP
(FM VT)
TP
(AM VT)
U1
U2
L902
}
FM Tracking Adjustment
TC901
L901 FM Frequency Coverage Adjustment
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