JVC KD-V6 - Page 9

7* Recording |1) Apply a 1kHz input of around
level —10dBs signal to the LINE IN
jacks and adjust the recording con-
trol so that LINE OUT is —4 dBs.
2) After checking that the PEAK
HOLD meter is at OdB, perform
OdB recording on both left and
right channels using normal tape.
3 Adjusting | Standard
| tems | Adjustment point vale Remarks
4 Peak meter | 1) Set the monitor switch to SOURCE.
checking 2) Set the OUTPUT LEVEL control to
MAX.
3) Apply a signal to LINE and adjust
the attenuator and confirm that
OdB meter indicator lights when
the LINE OUT is —4.0 cBs.
4) Lower the attenuator level by 20 dB VR301,
The level difference between the left
and right channels should be within
1 dB for normal and CrO2 tapes. Per-
form the adjustment using normal tape,
the level difference between chrome
tapes and metal tapes should be less
than 1.5 dBs and the level difference
between the left and right channels
and
adjust
VR301
and
VR401
so
401
3)
When
playing
back
the
recorded
|
VR103,
should
be
less
than
1.0
dB.
that
the
—20
dB
meter
lights.
Display
signals,
adjust
the
recording
signal
203
5)
Check
that
the
0
dB
indicator
lights
|
board
current
with
VR103
and
203
so
again.
that
O
dB
is
obtained.
BeEBiae
1)
Apply
1Q
in
series
to
the
erase
8
Checking
of}
1)
When
LINE
OUT
is
—4
dBs,
record
Normal
tape;
|
This
check
should
be
done
after
the
oscillating
head.
recording
a
1kHz
signal
so
that
the
peak
less
than
2.5%|
adjustment
of
bias
current
and
record-
frequency
|
2)
Connect
a
VTVM
to
both
terminals
signal
meter
shows
0
dB.
CrO2
tape;
ing
level.
of
a
12
resistor
and
connect
the
distortion
|
2)
Check
the
output
with
a
distortion
less
than
3%
output
of
the
VTVM
to
COUNTER.
meter
and
confirm
that
it
is
in
the
Metal
tape;
3)
Use
a
metal
tape
and
set
the
unit
to
range
of
standard
value.
less
than
2%
the
REC
PAUSE
mode.
Checking
1)
Record
a
1kHz,
OdB
peak
hold
;|
Set
the
recording
control
to
maximum
4) Adjust OSC BLOCK L901 and set L901
to 81 kHz + 1 kHz.
6 Rec/Play 1) Set the monitor switch to SOURCE. Reference
frequency |2) Apply a 1kHz signal of around frequencies:
response —20 dBs to LINE IN. 1kHz,0+3dB
3) Adjust the INPUT LEVEL control at 50 kHz
and set LINE OUT to —4 dBs. 0+3dB at
4) Lower the attenuator level by 20 dB. 12.5 kHz
5) Use a-normal tape and set the unit
to the recording mode.
6) Set the monitor switch to TAPE.
recording
S/N ratio
meter input. Stop the input by dis-
connecting the terminal during
recording and perform non-signal
recording.
2) Play back the recorded part. Mea-
sure the ratio of the 0 dB recorded
part to the non-signal recorded part
using VTVM and check that the
value conforms to the standard
value.
1) Apply a1 kHz signal from the LINE
and apply an input of around —21 dB
(an input of indicating O peak hold
Chrome tapes;| meter) to the line input jacks.
more than
42 dB
More than Connect a B.P.F. (Band Pass Filter)
10 Checking
7)
Record
1
kHz
then
50
Hz,
12.5
kHz
erasing
IN
jacks
and
adjust
the
recording
65
dB
between
the
deck
and
VTVM
for
and
when
playing
the
tape
back,
ad-
coefficient
volume
so
that
the
level
meter
indi-
measurement.
just
VR104
and
204
so
that
the
cates
0
dB.
Use
a
metal
tape
for
checking.
50 Hz and 12.5 kHz outputs are in
the range of standard values, using a
1 kHz signal as reference. (Ordinari-
ly adjust so that the 1kHz and
12.5 kHz outputs are the same.)
8) Use metal tape and record 1 kHz
and 12.5 kHz, then play back the
tape, adjust VR106 and 206 so that
the levels are the same.
9) Use a CrOz tape and record 50 Hz,
1 kHz and 12.5 kHz then play back
the tape and check that they are in
the range of standard values.
2) Perform recording with the signal
boosted by 20 dB.
3) Rewind the recorded part and erase
part of the recording.
4) Measure the ratio of the recorded
part to the erased part using a
VTVM.
Tape deck
(recording,
erasing)
Electronic
voltmeter
Input
(1 kHz0 VU
+20 dB)
(1 kHz)
Band pass Filter
Adjustment and checking
Frequency level Increase in output Deviation
Checking of
— DY: INPUT; LINE IN 1 kHz Cal —40 dB +5.7 dB + 1dB
Response (dB) —_ Increase in high frequencies | ow pias current When the bias current is not recording recording | Test points; TP102, 201 5 kHz Cal —20 dB +3.5dB+1.5dB
aajusted properly, mereeotaind CAOCUNE Dolby C | Testing reference level; 1 kHz Cal OdB+1dB
gs
Aporapaats
bias
client
cheractonstis/
ate.
abcchowsy
jan
vesarding
recording
|
400
Hz,
—6
dBs
1
kHz
Cal
—40
dB
+17
dB
+
1.5
dB
Decrease
in
high
frequencies
High
bias
current
the
left.
mode)
(=
Cal.
level)
5
kHz
Cal
—20
dB
+3.5
dB
+
1.5
dB
0
50Hz
1
kHz
12.5
kHz
Frequencies
1
kHz
Cal
O0dB+1dB
No. 4230 9