JVC UX-G6 Service Manual page 58

UX-G6/FS-G6
Items
*7 Adjustment of 1.While applying 1kHz -28.8dB
recording and
playing
sensitivity
2.While recording and playing back
8 Confirmation 1.Record the test tapes ______
of recording
and playing 2.Check the output with a distortion
distortion rate
9 Confirmation 1.Halfway during recording at 1kHz
of recording
and playing
S/N ratio
2.While playing back the above,
10 Confirmation 1.Apply 400Hz signal (Ref. + 10dB)
of erasing rate
2.After rewinding the above, erase
3.Measure the ratio of the erased
11 Confirmation 1.After loading the test tape
of music
scanning
action
2.After loading the test tape
12 Confirmation While short-circuiting the
of NR effect [LINE IN] terminal input,
1.Confirm the difference of noise
2-42
Adjusting position
to the line input terminal,
confirm that the sensitivity
level at the test point
TP_____ is 0dBs.
the above, adjust the recording
signal current with VR614 (Lch)
and VR624 (Rch) so that the
sensitivity level becomes-25.5dBs.
at 1kHz and reference input.
meter while playing back the
above test tapes, and confirm that
the respective distortion rates
comply with the standard value.
and reference input, sample the
input and perform non-signal
recording.
measure the difference between
the reference recording output
and non-signal recording output
with an electronic voltmeter, and
confirm that the measurement
complies with the standard value.
from the [LINE IN] terminal.
a part of the recorded portion.
portion to the recorded portion
with an electronic voltmeter.
TMT6447, press the [PLAY] and
[FF] buttons or [REW] button.
After rewinding the tape, perform
music scanning and execute the
[PLAY] action.
TMT6447, press the [PLAY] and
[FF] buttons or [REW] button. In
this case, be sure not to perform
music scanning at the beginning
of tape winding.
level at self-recording and playing
when the Dolby is off and Dolby
B is on.
Adjusting
Reference value
position
L:VR614
Normam tape:
R:VR624
-25.5dBs
0.5dB
Chrome tame:
-25.5dBs
2dB
Normal tape:
3.0% or less
Chrome tape:
3.0% or less
Normal tape:
38dB or over
Chrome tape:
40dB or over
55dB or over
8.5dB or over
Remarks
The left and right level
difference of both normal
and chrome tape should be
within 0.5dB.
The sensitivity level should
be adjusted with normal
tape.
NR:OFF
Tape:Normal tape
Confirm the distortion rate
after adjusting the bias
current and recording level.
For measuring the erasing ratio,
connect a band pass filter(B.P.F)
between the electronic voltmeter
on the deck.
1kHz0VU Deck
Band pass
+20dB recording/
filter(B.P.F)
input erasing
Electronic
voltmeter
In this case, use the CCIR
ARM filter.