JVC TD-X102 - Page 10

KD-X1
A/B/C/E/G/E/J/
|
Checking
record/
play back
distortion
play back the recorded part,
and check so that Line out ter-
minal level become O + 2.5 dB.
2. If the standard value cannot be
obtained, adjust the recording
level using R139, 140, 141 and
142 in combination (for L-ch),
and R239, 240, 241 and 242
(R-ch), respectively.
. Record a 1kHz, —8dB signal to
LINE IN terminals and perform
recording with the multi-peak
becomes to 0.
2. Play back the recorded part. Check
the output with a distortion meter
to see if the value conforms to the
standard value.
NORM
Item
Adjustment
mes
Ray
Remarks
Checking
Record
1
kHz,
50
Hz
and
12.5
kHz
|
For
Reference
This
checking
should
be
performed
record/
signals
at
an
input
level
of
0
dB
to
|
NORM
frequency;
for
normal
tapes
and
for
both
right
playback
—20
dB.
tape;
1
kHz
and
left
channels.
frequency
Play
back
the
tape.
Lch
B102
1.
Bias
current
adjustment
for
a
response
Check
to
see
that
the
50
Hz
and
B103
cassette
deck
should
generally
be
12.5
kHz
signal
output
deviations
fall
B104
0+3dBat
performed
referring
to
the
record/
within
the
standard
range,
using
the
|
Reh
ee
50
Hz
playback
frequency
response.
1
kHz
signal
output
as
a
reference.
B204
|
0+3dBat
This
is
Sai
the
ein!
i
eas
:
12.5
kHz
sponse
of
a
cassette
deck
depends
i
are
eara
7.
more
greatly
upon
the
bias
cur
=
rent
than
does
that
of
an
open
a
ix
reel
deck.
3
;
2.
If
the
bias
current
is
not
proper-
5
Sven
cea
ete
ly
adjusted,
the
record
and
play-
z
Decrease
in
high
frequencies
back
characteristics
become
as
a
(with
a
larger
bias
current)
shown
left.
50
Hz
1
kHz
12.5
kHz
Frequency
(Hz)
|
——.
3
|
Checking
1.
Apply
a
1
kHz
-23
+3
dBV
Sig-
O+2.5dB
|The
level
difference
between
left
recording
nal
to
the
LINE.
in
terminals,
and
right
channels
for
SF/NORM
level
tape
and
chrome
tape
should
be
less
than 3 dB. Perform the adjustment
using a normal tape, level difference
between recording and playback for
SA/CrO2 and metal tapes, should
be less than 3 dB, and that between
left and right channels should also
be less than 3 dB.
tape; Less
Less than 3%
Metal tape;
Less than 2%
(THD)
following bias current and record-
than
2.0%
ing
level
checking.
CrO2 tape;
Be sure to perform this checking
5 | Checking
signal to
noise ratio
playback
in recording/
2. Play back the recorded part.
1. Record a1 kHz, 0 dB signal.
Stop the input by disconnecting
from the terminal to perform non-
signal recording.
Measure the O dB recording output
and the non-signal recording output
for comparison using an electronic
voltmeter.
Check to see if the value conforms
to the standard value.
NORM,
CrO2 and
Metal tapes; ||
More than
42 dB
Apply an output (—72 dBs) to the
MIC terminals with the recording
evel controls set to maximum so
that the multi-peak indicator be-
comes 0 dB.
Checking
erasing
coefficient
8 (No. 4243)
+
1. Apply a 1 kHz signal to the LINE
2. Perform recording with the signal
3. Erase a part of the recording.
4. Measure the output difference be-
IN terminals. Adjust the recording
level controls until the multi-peak
indicator becomes 0 dB.
enhanced by 20 cB.
tween the erased part and non-
erased part to compare with an
electronic voltmeter.
Ll
More than
65 dB
For the measuring, connect a band
pass filter between the deck and the
electronic voltmeter.
Tape deck
(recording,
erasing)
Input i
(1 kHz OdB
+ 20 dB)
Electronic
voltmeter
Band pass
filter
(1kHz)
: