Sony HCD-GRX3 / HCD-R300 / HCD-RX55 / MHC-GRX3 / MHC-R300 / MHC-RX55 Service Manual ▷ View online
— 9 —
Precaution
1. Clean the following parts with a denatured alcohol-moistened
swab:
record/playback head
record/playback head
pinch rollers
erase head
rubber belts
capstan
idlers
2. Demagnetize the record/playback head with a head
demagnetizer.
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
SECTION 3
MECHANICAL ADJUSTMENTS
Meter reading
40 to 70 g • cm
(0.56 - 0.97 oz • inch)
1 to 5 g • cm
(0.01 - 0.07 oz • inch)
55 to 140 g • cm
(0.76 - 1.94 oz • inch)
Torque
FWD
FWD
back tension
FF/REW
Torque meter
CQ-102C
CQ-102C
CQ-201B
SECTION 4
ELECTRICAL ADJUSTMENTS
1.
Demagnetize the record/playback head with a head
damagnetizer.
damagnetizer.
2.
Do not use a magnetized screwdriver for the adjustments.
3.
After the adjustments, apply suitable locking compound to the
parts adjusted.
parts adjusted.
4.
The adjustments should be performed with the rated power
supply voltage unless otherwise noted.
supply voltage unless otherwise noted.
5.
The adjustments should be performed in the order given in this
service manual. (As a general rule, playback circuit adjustment
should be completed before performing recording circuit
adjustment.)
service manual. (As a general rule, playback circuit adjustment
should be completed before performing recording circuit
adjustment.)
6.
The adjustments should be performed for both L-CH and R-
CH.
CH.
Record/Playback Head Azimuth Adjustment
(Deck A, Deck B)
(Deck A, Deck B)
Note: Perform this adjustments for both decks.
Procedure:
1.
1.
Mode : Playback
DECK SECTION
0 dB=0.775V
Tape
P-4-A100
WS-48B
Signal
10 kHz, –10 dB
3 kHz, 0 dB
Used for
Azimuth Adjustment
Tape Speed Adjustment
test tape
P-4-A100
(10kHz, –10dB)
P-4-A100
(10kHz, –10dB)
SPEAKER
terminal (JK301)
terminal (JK301)
level meter
+
–
set
— 10 —
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 2 dB of peak.
do not match for L-CH and R-CH, turn the adjustment screw
so that outputs match within 2 dB of peak.
3.
Mode: Playback
4.
After the adjustments, apply suitable locking compound to the
parts adjusted.
parts adjusted.
Adjustment Location:
Adjustment screws
REC/PB head (deck A)
or PB head (deck B)
REC/PB head (deck A)
or PB head (deck B)
test tape
WS-48B
(3kHz, 0dB)
WS-48B
(3kHz, 0dB)
Tape Speed Adjustment (Deck A)
Procedure:
1.
1.
Mode: Playback
2.
Adjust the SFR501 so that the frequency counter reads 3,000
Hz ± 90Hz.
Hz ± 90Hz.
Adjustment Location: DECK board
Sample Value of Wow and flutter
W. RMS (JIS) within 0.3%
(test tape: WS-48B)
(test tape: WS-48B)
[DECK BOARD] — Component side —
L-CH
peak
peak
R-CH
peak
peak
screw
position
position
output
level
level
within
2dB
2dB
within 2dB
L-CH
peak
peak
screw
position
position
R-CH
peak
peak
test tape
P-4-A100
(10kHz, –10dB)
P-4-A100
(10kHz, –10dB)
SPEAKER
terminal (JK301)
(L-CH)
terminal (JK301)
(L-CH)
set
L
R
oscilloscope
SPEAKER
terminal (JK301)
(R-CH)
terminal (JK301)
(R-CH)
Waveform of oscilloscope
in phase
45˚
90˚
135˚
180˚
good
wrong
SPEAKER
terminal (JK301)
terminal (JK301)
set
frequency counter
+
–
–
Tape Speed
SFR501
CN501
— 11 —
TUNER SECTION
0 dB=1µV
AM Tuning Voltage Adjustment
Procedure:
1.
1.
Set the reception frequency of the unit to 530 kHz.
2.
Adjust L105 for 1.2 ± 0.05 V reading on the DC voltmeter.
3.
Set the reception frequency of the unit to 1,710 kHz.
4.
Confirm that the voltage reading on the DC voltmeter is within
8.0 ± 0.5 V.
8.0 ± 0.5 V.
Adjustment Location: MAIN board (See page 12)
AM Tracking Adjustment
Procedure:
1.
1.
Tune the set to 600 kHz.
2.
Set the output of AM RF SSG so that the input level of the set
will become 60 dB (µV/m).
will become 60 dB (µV/m).
3.
Adjust L104 so that when the waveform on the oscilloscope is
maximum, no noise appears.
maximum, no noise appears.
4.
Tune the set to 1,400 kHz.
5.
Adjust CT102 so that when the waveform on the oscilloscope
is maximum, no noise appears.
is maximum, no noise appears.
• Repeat the procedures in each adjustment several times, and the
tracking adjustment should be finally done by the trimmer
capacitors.
capacitors.
Adjustment Location: MAIN board (See page 12)
FM Tuning Voltage Adjustment
DC voltmeter
Procedure :
1.
1.
Set the reception frequency of the unit to 87.5 MHz.
2.
Adjust L103 for 1.2 ± 0.05V reading on the DC voltmeter.
3.
Set the reception frequency of the unit to 108 MHz.
4.
Confirm that the voltage reading on the DC voltmeter is within
7.8 ± 0.5V.
7.8 ± 0.5V.
Adjustment Location: MAIN board (See page 12)
TP1
+
IF
G
VT
Main board
DC voltmeter
Main board
–
F
G
VT
G
VT
TP1
+
–
AM RF SSG
loop antenna
set
loop antenna
(Supplied accessories)
(Supplied accessories)
60 cm
AM ANTENNA
terminal (JK101)
terminal (JK101)
30% amplitude
modulation by
400 Hz signal
modulation by
400 Hz signal
Field strength dB (
µ
V/m) =SSG output level dB (
µ
V/m) –26 dB.
— 12 —
FM Tuned Level Adjustment
set
Procedure:
1.
1.
Supply a 28 dB 98 MHz signal from the ANTENNA terminal.
2.
Tune the set to 98 MHz.
3.
Adjust SFR101 to the point (moment) when the TUNED
indicator will change from going off to going on.
indicator will change from going off to going on.
Adjustment Location: MAIN board
FM Tracking Adjustment
Procedure:
1.
Tune the set to 90 MHz.
2.
Adjust L102 so that when the waveform on the oscilloscope is
maximum, no noise appears.
maximum, no noise appears.
3.
Tune the set to 106 MHz.
4.
Adjust CT101 so that when the waveform on the oscilloscope
is maximum, no noise appears.
is maximum, no noise appears.
• Repeat the procedures in each adjustment several times, and the
tracking adjustment should be finally done by the trimmer
capacitors.
capacitors.
Adjustment Location: MAIN board
Adjustment Location
[MAIN BOARD] — Component side —
Carrier frequency : 90 MHz, 106 MHz
Modulation
Modulation
: AUDIO 1kHz, 75kHz deviation (100%)
Output level
: 20 dB (at 75
Ω
open)
FM RF SSG
Carrier frequency : 98 MHz
Modulation
Modulation
: AUDIO 1 kHz, 75 kHz
deviation (100%)
Output level
: 28 dB (at 75
Ω
open)
FM ANTENNA terminal
(JK101)
(JK101)
75
Ω
coaxial
SFR101
FM Tyned Level
AM Tuning
Voltage
Voltage
IC103
TP1
IC102
L105
IC101
CT102
L103
AM
Tracking
Tracking
L104
L102
CT101
FM
Tracking
Tracking
JK101
FM Tuning
Voltage
Voltage
JK301
FM ANTENNA terminal (JK101)
SPEAKER terminal (JK301)
FM RF SSG
set
oscilloscope
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