Mechanical Adjustments; Electrical Adjustments - Sony HCD-EH10 Service Manual

HCD-EH10
Ver. 1.1
SECTION 5

MECHANICAL ADJUSTMENTS

• Precaution
1. Clean the following parts with a denatured-alcohol-moistened
swab :
record/playback head
erase head
capstan
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, appiy 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
FWD CQ-102AS
FWD
CQ-102C
Back Tension
FF CQ-201AS
REW CQ-201B
• Tape Tension Measurement
Mode Tension Meter
FWD CQ-403A
10
pinch roller
rubber belts
idlers
Meter Reading
2.0 – 8.0 mN⋅m
(20 – 80 g⋅cm)
(0.28 – 1.12 oz⋅inch)
0.15 – 0.6 mN⋅m
(1.5 – 6.0 g⋅cm)
(0.021 – 0.083 oz⋅inch)
5.0 – 17.7 mN⋅m
(50 – 177 g⋅cm)
(0.7 – 2.48 oz⋅inch)
5.0 – 17.7 mN⋅m
(50 – 177 g⋅cm)
(0.7 – 2.48 oz⋅inch)
Meter Reading
more than 80 g
(more than 2.82 oz)
SECTION 6

ELECTRICAL ADJUSTMENTS

TUNER SECTION
[AM (MW/LW)]
Setting:
Function : TUNER
BAND button : AM
loop antenna A
AM RF signal
generator
30% amplitude
modulation by
400 Hz signal
[FM]
Setting:
Function : RADIO
RADIO BAND button: FM
MAIN board
FM RF signal
CNP802 pin 1
generator
1 kHz frequency
deviation by FM 75 kHz
MAIN board
signal
CNP802 pin 2
Output level:
as low as possible
MAIN board
JW821 (VT)
JW805 (GND)
• Repeat the procedures in each adjustment several times, and
the tracking adjustments should be finally done by the trimmer
capacitors.
• Remove FM antenna in FM adjustment.
AM VT VOLTAGE ADJUSTMENT
Adjustment Part Frequency Display Reading on Digital Voltmeter
L852 531 kHz
Confirmation 1602 kHz
AM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter
L851
FM VT VOLTAGE ADJUSTMENT
Adjustment Part Frequency Display Reading on Digital Voltmeter
L805 87.5 MHz
Confirmation 108 MHz
0 dB=1 µV
60 cm
loop antenna B
set
MAIN board
JW403
(TUNER OUT L-ch)
level meter
+
set
–
MAIN board
JW148
(GND)
digital voltmeter
10 k Ω
1.5 ± 0.1 V
7.2 ± 0.5 V
531 kHz
1.75 ± 0.1 V
6.2 ± 0.5 V