JVC KD-V6 - Page 8

(4) marked © is a special nut for playback azimuth
adjustment.
(5) marked X is a special nut for the record head height
adjustment.
(6) marked X is a special nut for the record head tilt
adjustment.
(7) marked O is a special nut for the record head azimuth
adjustment.
3. Adjusting methods
Perform the following adjustment procedure after head
assembly replacement.
1) Play head azimuth
e Connect the LINE OUT jacks to an electronic volt-
meter (two-meter VTVM).
e Play test tape TMT-702 and adjust the screw 4 so
that the output of electronic voltmeter is optimized.
2) Record head azimuth
e Connect the LINE OUT jacks to a two-meter VTVM.
e Observe the simultaneous monitor output with the
two-meter VTVM while recording a 14 kHz signal at
QO VU —20dB and adjust the screw 7 so that the
output is maximum.
Note: Perform this adjustment using the stable middle
part of side A of TS-5 (UD) and also confirm it
using TS-6 (SA) and TS-7 (ME).
The above adjustments are recommended to check after
fixing the mechanical section to the cabinet.
Adjustment
Motor speed] Play back test tape VTT712 and connect
adjustment | electronic counter to the LINE OUT jacks
of deck to measure the speed then adjust
the semi-fixed resistor on the motor P.C.
board by turning it so that the reading of
the meter is 3,000 Hz.
Play VTT712 and plug the wow/flutter
meter into the LINE OUT jacks of the
deck then confirm that the reading of the
meter is less than 0.08% (WRMS).
Wow/flutter
Playback Measure using the torque testing cassette
torque tape CTH-N.
Fast-forward| Set the unit in the fast forward mode and
torque measure the torque in the same way as
above.
Rewind Set the unit in the rewind mode and mea-
torque sure the torque in the same way as above.
Music scan | 1. Music scan operation should be per-
check formed when using TMT-6447 tape.
2. Music scan operation should not be
performed when using TMT-6448 tape.
Adjusting | Standard
points value
Remarks
Semi-fixed| 3,000 Hz |When the electronic counter is incorpo-
resistor on
motor P.C.
rated in the wow/flutter meter, just con-
nect the electronic counter to the input
jacks of the meter.
Even when it is within a standard value,
if its variation becomes more than 0.08%
(WRMS), repairs are required because of
possible claims.
40—
70 g-cm
More than
80 g-cm
More than
80 g-cm
el |
4. Positions of electrical adjustment
Display P.C. board
VR301_VR4OI
L ‘@r ‘Or R
(mera |
—20dB Adj.
Front
Amplifier P.C. board
t
L202
- Skewing
fein Rec. Level Adj. s
Front
VvRI03
‘Metal
Rec.
EO
Adj.
VR203 —~
AO VR206 VRIOg Adj.
ee! CP
Ic909
Bias
current
Adj.
1€203
1C506
[al
Bias
frequeno
:
CN506
CN903
eve
M
i=milues
PB.
EQYAG):
CNSO4
CNSOI
vR101
VR201
1C101
1¢502
CNS02
a
eee
te
t—1— P.B. Level Adj.
VR102 VR202
oF | ca i
aR
1¢501
Fig. 10
5. Electrical circuit adjustment procedure
Perform the electrical circuit adjustment after the tape transport and head angle adjustments.
Adjustment should be performed in the order 1,2,3,...
Set the MPX: OFF, output volume control to maximum when measuring.
: Adjusting | Standard
1 Playback 1) Set the Dolby NR switch to OFF.
level 2) Set the monitor switch to TAPE.
adjustment | 3) Play back test tape VTT-664 and
adjust VR102 and VR202 so that
the output level at LINE OUT is
—4 dBs.
Play back test tape VTT739 (1 kHz, Reference
Playback
frequency
|
10
kHz)
and
adjust
VR101
and
VR202
frequency
response
so
that
outputs
of
1
kHz
and
10
kHz
eae
t
are
the
same.
10
kHz
°
SKEWING | 1) Set the monitor switch to SOURCE. | VR903
coil 2) Apply a 17.5 kHz signal of around | (Input
adjustment —20 dB to the LINE IN jacks. level)
3) Adjust the input level control with | VR901
the Dolby NR switch set to OFF so | (Balance)
that the output of the LINE OUT
jacks is —4 dBs.
4) Set the NR switch to ON and Dolby
C NR switch to ON.
5) Adjust L102 and L202 so that the L102,
output at the LINE OUT jacks is 202
—4 dB.
6) Check that level difference is within
+0.5 dB in the frequency range of
10 kHz to 20 kHz.