Sony TC-WE675 Service Manual page 9

Record/Playback Head Azimuth Adjustment
Procedure:
1. Forward Playback Mode
test tape
P-4-A100
(10 kHz, –10 dB)
set
LINE OUT
2. Turn the adjustment screw for the maximum output levels. If
these levels do not match, turn the adjustment screw until both
of output levels match together within 1 dB.
within
output
L-CH
1 dB
level
peak
R-CH
peak
screw
L-CH
position
peak
3. Playback Mode
test tape
P-4-A100
(10 kHz, –10 dB)
L-CH
set
R-CH
Screen Pattern
In phase 45˚
good
4. Change the reverse playback mode and repeat the steps 1 to 3.
5. After the adjustment, lock the adjustment screws with suitable
locking compound.
Adjustment Location: – record/playback head –
reverse side
adjustment screws
DECK A DECK B
level meter
47 kΩ
within
1 dB
screw position
R-CH
peak
oscilloscope
47 kΩ
V H
47 kΩ
LINE OUT
90˚ 135˚ 180˚
wrong
forward side
Tape speed Adjustment
Adjust DECK A first
Procedure:
– Forward Playback Mode –
test tape
WS-48B
(3 kHz, 0 dB)
set
LINE OUT
(High speed adjustment)
1. Press the PITCH CONTROL button to set to OFF .
2. Set to test mode. (Refer to page 11.)
3. Press the H button to playback.
4. Press the HIGH/NORMAL button to playback at double speed.
5. Adjust RV316 (DECK A), RV416 (DECK B) so that the fre-
quency counter reading becomes 5,980 ± 80 Hz.
(Normal speed adjustment)
6. Press the H button to playback.
7. Press the HIGH/NORMAL button to playback at normal speed.
8. Adjust RV317 (DECK A), RV417 (DECK B) so that the fre-
quency counter reading becomes 3,000 ± 90 Hz.
(Pitch control adjustment) (DECK A)
9. Press the PITCH CONTROL button to set to ON .
10. Set PITCH CONTROL knob to mechanical center.
11. Press the H button to playback.
12. Adjust RV318 so that the frequency counter reading becomes
2,990 ± 90 Hz.
Adjustment Location: MAIN board (See page 14.)
Sample value of wow and flutter
W.RMS (JIS) less than 0.3% .
(test tape : WS-48B)
Playback Level Adjustment
Procedure:
– Forward Playback Mode –
test tape
P-4-L300
(315 Hz, 0 dB)
set
Adjust DECK A : RV111 (L-CH), RV211 (R-CH) and
DECK B : RV121 (L-CH), RV221 (R-CH) so the level meter read-
ing becomes the adjustment limits below.
Adjustment Value:
LINE OUT level : –7.7 dBs ± 0.5 dB (0.301 to 0.338 V)
Level difference between channels : within 0.5 dB
Confirm that the LINE OUT level does not change in playback mode
while changing the mode from playback to stop several times.
Adjustment Location: MAIN board (See page 14.)
TC-WE675
DECK A DECK B
frequency counter
47 kΩ
DECK A DECK B
level meter
47 kΩ
LINE OUT
9