![background image](http://html.mh-extra.com/html/sony/hcd-ep305/hcd-ep305_service-manual_420648011.webp)
11
HCD-EP305
SECTION 4
MECHANICAL ADJUSTMENTS
SECTION 5
ELECTRICAL ADJUSTMENTS
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
demagnetizer. (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
parts adjusted.
5.
The adjustments should be performed with the rated power
supply voltage unless otherwise noted.
Torque Measurement
Tape Tension Measurement
Mode
Torque Meter
Meter Reading
FWD
CQ-403A
more than 100 g
(more than 3.53 oz)
PRECAUTION
1.
Setting
MEGA BASS switch : OFF
TAPE DECK SECTION
0 dB=0.775 V
Test tape
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)
Type
Signal
Used for
WS-48A
3 kHz, 0 dB
Tape Speed Adjustment
P-4-A063
6.3 kHz, –10 dB
Head Azimuth Adjustment
Record/Playback Head Azimuth Adjustment
Procedure:
1.
Mode: Playback
level meter
test tape
P-4-A063
(6.3 kHz, –10 dB)
set
HEADPHONE board
PHONES jack (JK401)
32
Ω
+
–
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.
3.
Mode: Playback
4.
After the adjustments, apply suitable locking compound to the
parts adjusted.
Screw
position
L-CH
peak
within
1dB
Output
level
L-CH
peak
R-CH
peak
within
1dB
Screw
position
R-CH
peak
test tape
P-4-A063
(6.3 kHz, –10 dB)
L-CH
R-CH
HEADPHONE board
PHONES jack (JK401)
oscilloscope
V
H
+ +
–
–
screen pattern
in phase
good
wrong
45
°
90
°
135
°
180
°
32
Ω
32
Ω
set
www. xiaoyu163. com
QQ 376315150
9
9
2
8
9
4
2
9
8
TEL 13942296513
9
9
2
8
9
4
2
9
8
0
5
1
5
1
3
6
7
3
Q
Q
TEL 13942296513 QQ 376315150 892498299
TEL 13942296513 QQ 376315150 892498299