Sony HCD-GN88D Service Manual page 20

HCD-GN88D
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.
within
L-CH
1dB
peak
Output
level
R-CH
peak
Screw
position
L-CH
peak
3. Mode: Playback
test tape
P-4-A100
(10 kHz, –10 dB)
pin 1
L-CH
MAIN
L
board
CN301
R
set
R-CH
pin 3
waveform of oscilloscope
in phase 45 °
good
4. After the adjustments, apply suitable locking compound to the
pats adjusted.
Adjustment Location: Playback Head (Deck A).
Record/Playback/Erase Head (Deck B).
forward
20
within
1dB
Screw
position
R-CH
peak
oscilloscope
pin 2
V H
90 ° 135 ° 180 °
wrong
reverse
Tape Speed Adjustment
DECK B
Procedure:
Mode: Playback
test tape
MAIN board
WS-48B
AUDIO OUT jack (J730)
(3 kHz, 0 dB)
L-CH, R-CH
set
1. Insert the WS-48B into the deck B.
2. Press the H button on the deck B.
3. Adjust the tape speed adjustment control inside motor so that
frequency counter reads 3,000 ± 90Hz.
Sample value of wow and flutter W.RMS (JIS) less than 0.3%
WS-48B
Adjustment Location:
Tape speed Adjustment
frequency counter
+
–
Tape speed adjustment
control inside motor