JVC TD-W717TN - Electrical Adjustments; Dolby Circuit Checking; Playback Level Check; Playback Frequency Response Adjustment

TD
-
W
717
TNC
/
J
TD
-
W
718
BKA
/
B
/
E
/
EN
/
G
/
U
/
UT
Electrical
Adjustment
Procedure
Item
Check
and
Adjustment
Input
signal
(
Frequency
,
level
)
Output
raise
value
,
deviation
value
1
Cheking
DOLBY
circuit
(
Rec
.
mode
)
(
BIAS
-
CUT
)
Signal
input
:
LINE IN
Cal
.
level
:
400
Hz
,
-
8
dBs
Output
terminal
TP
:
NR
IC
831
@
&
(
§
)
1
kHz
,
cal
.
-
40
dB
+
5.7
dB
±
2
dB
DOLBY
B
(
Rec
)
5
kHz
,
Cal
.
-
20
dB
+
3.5
dB
±
1.5
dB
0.5
1
kHz
,
Cal
.
0
dB
±
i
.
odB
pin
.
+
16.2
dB
±
2
dB
1
kHz
,
Cal
.
-
40
DOLBY
C
(
Rec
)
5
kHz
,
Cal
.
-
20
+
2.9
dB
±
2.5
dB
1
kHz
,
Cal
.
OdB
±
1
dB
Item
Conditions
Adjustment
and
Confirmation
Standard
Adjusting
*
2
Play
back
level
check
Play
back
VTT
727
.
Check
that
the
level
at
LINE
OUT
is
-
4.5
dBs
±
1
dB
.
Difference
between
Lch
and
Rch
must
be less
than
1
dB
at
LINE
OUT
.
LINE
OUT
-
4.5
dBs
±
1
dB
Phone
Out
-
14.5
dBs
±
2
dB
Test
tape
VTT
727
:
400
Hz
}
Deck
@
L
:
VR
116
R
:
VR
216
Deck
@
L
:
VR
111
R
:
VR
211
*
3
Playback
frequency
response
adjustment
Test
tape
TMT
735
:
1
kHz
/
12.5
kH
2
VTT
739
:
1
kHz
/
63
Hz
Play
back
TMT
735
test
tape
,
and
adjust
VR
116
,
VR
216
(
deck
[
¥
]
)
and
VR
111
,
VR
211
(
deck
[
A
]
)
so
that deviation
of
12.5
kHz
to
that
of
1
kHz
is
0
±
0.5
dB
(
deck
A
)
and
0
±
0.5
dB
(
deck
B
)
.
Then
,
play
back
VTT
739
test
tape
to
confirm
that
deviation
of
63
Hz
to
1
kHz
is
+
2
±
3
dB
.
with
12.5
kHz
as
reference
,
0
+
0.5
dB
(
deck
[
A
]
)
and
0
±
0.5
dB
(
deck
[
B
]
)
at
1
kHz
63
Hz
(
check
)
:
+
2
±
3
dB
Deck
\
B
\
L
8451
Deck
|
Al
L
8401
Tape
:
Metal
Mode
:
REC
Frequency
counter
Input
impedance
:
more
than
1
MQ
.
(
See
pagel
8
)
Deck
[
B
]
TP
:
CN
846
pin
1
Deck
0
TP
:
CN
841
pin
1
*
4
Bias
frequency
adjustment
Connect
frequency
counter
to
the
CN
846
(
deck
[
B
]
)
and
CN
841
(
deck
[
A
]
)
and
adjust
L
8451
(
deck
{
B
\
)
and
L
8401
(
deck
[
A
]
)
so
that the
counter
reads
95
kHz
.
95
kHz
±
0.5
kHz
Deck
[
A
]
L
:
L
1401
R
:
L
2401
DeckH
L
:
L
1451
R
:
L
2451
DC
.
Voltmeter
Deck
|
A
]
TP
:
CN
841
Deck
H
TP
:
CN
846
*
5
Slave
oscillation
(
HX
PRO
)
adjustment
This
step
must
be
performed
after
the bias
frequency
adjustment
.
Load
a
metal
tape
and
set
the
deck
to
the
recording
mode
.
1
.
Adjust
for
deck
[
A
]
Adjust
L
1401
and
L
2401
to
minimize
respec
-
tive
voltages
of CN
841
(
PIN
3
-
4
)
at
Lch and
(
PIN
3
-
5
)
at
Rch
.
2
.
Adjust
for
deck
[
B
]
Adjust
L
1451
and
L
2451
to
minimize
respec
-
tive
voltages
of CN
846
(
PIN
3
-
4
)
at
Lch and
(
PIN
3
-
5
)
at
Rch
.
Minimum
20
(
No
.
4358
)