Sony WM-D6 - Electrical Adjustments

| WM-D6 WM-D6
3-2. ELECTRICAL ADJUSTMENTS Tape Speed Adjustment
Note: Perform this adjustment after the Record/
playback Head Azimuth Adjustment.
Note: The adjustment should be performed in
the order given in this service manual.
The adjustments should be performed
for both L-CH and R-CH.
Procedure:
speed checker
LFM-30
Mode: playback -
or
digital frequency
counter
@ Set the TAPE switches according to the tape as
follows.
Tape TAPE switch
TYPE I
e Switches and controls should be set as follows
unless otherwise specified.
DOLBY NR Switch: OFF
TAPE switch: TYPE I
test tape
WS-4
(3 kHz, 0 dB)
8
ae pe fe
k LINE OUT
1. Set SPEED TUNE switch to OFF.
2. Unsolder the solder bridge and open the
bridged patterns shown below.
3. Turn RV601 so that frequency reading be-
comes in 3,090 Hz + 10 Hz.
4. Resolder the adjustment patterns opened in
step 2 above. Now frequency reading should be
3,000 Hz + 9 Hz.
5. Set SPEED TUNE switch to ON, and SPEED
TUNE control to its center position.
@ Standard Record:
Deliver the standard input signal level to the
input jack and set the REC LEVEL control to
obtain the standard output signal level.
Standard Input Level
6. Turn RV603 so that frequency reading be-
comes in 3,000 Hz + 10 Hz.
7. Set SPEED TUNE control to maximum posi-
tion in ‘“S” direction. Now frequency reading
should be below 2,884 Hz.
8. Set SPEED TUNE control to maximum stop in
“F” direction. Now the frequency should be
above 3,120 Hz.
9. Set SPEED TUNE control back to center posi-
tion.
LINE IN
source impedance 10kQ
: 0.25V
input level (—104B)
Standard Output Level
load impedance
output level
Adjustment Location:
— main board —
SPEED TUNE
F--S
SPEED TUNE
ON-— OFF
Record/playback Head Azimuth Addustment
Playback Level Adjustment
Procedure:
Note: Perform this adjustment before the Tape
Speed Adjustment. wi ie A
(333 Hz, 0dB) A id
Procedure:
1. Mode: playback i
VOLUME control: not-distorted-output
position LINE OUT
Specification:
LINE OUT level: 0.32 V
(-7.8 dB +0.2 dB)
Check that the LINE OUT level does not
change in playback mode while changing the
mode from playback to stop several times.
test tape
P-4-A81
(6.3 kHz, -10 dB)
L-CH 47kQ oscilloscope
Adjustment Location:
— main board —
LINE OUT
Screen pattern
135° = 180°
wrong
in-phase 45° 90°
good
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 0.5 dB.
within
0.5dB
R-CH
peak
Screw
position
—» angle
L-CH R-CH
peak peak
3. After adjustment, apply locking compound to
the adjusted screw.
Adjustment Location:
adjustment screw