JVC RV-NB10BB, Руководство по обслуживанию

Страница: 28 / 103

1-28 (No.MB519)
4.2.3 Reference values for electrical function confirmation items
4.2.4 Tape recorder section
4.2.5 Reference values for confirmation items
Items Measurement method
1. While changing over to and from BIAS 1 and 2,
confirm that the frequency is changed.
2. With the recording and playback mechanism, load
the test tape (AC-514 to TYPE ), and set the
mechanism to the recording and pausing conditions
in advance.
3. Confirm that the BIAS TP frequency on the circuit
board is 100kHz 6kHz.
1. With the recording and playback mechanism, load
the test tapes (AC-514 to TYPE and AC-225 to
TYPE ), and set the mechanism to the recording
and pausing condition in advance.
2. After setting to the recording conditions, connect
1M in series to the eraser head on the recording
and playback mechanism side, and measure the
eraser current from both of the eraser terminal.
Recording
bias frequency
Eraser current
(Reference
value)
*Recording and
playback side forward
or reverse
*Test tape :
TYPE AC-514
*Measurement
terminal :
BIAS TP on circuit
board
*Recording and
playback side forward
or reverse
*Recording mode
*Test tape :
AC-514 and AC-225
Measurement
terminal :
Both of the eraser
head
100kHz
6kHz
TYPE
:120mA
TYPE
:75mA
Measurement
conditions
Standard
values
Adjusting
positions
1. Playback the test tape TMT7036 (10kHz).
2. With the playback mechanism or recording &
playback mechanism, adjust the head azimuth
screw so that the forward and reverse output
levels become maximum. After adjustment, lock
the head azimuth at least by half a turn.
3. In either case, this adjustment should be
performed in both the forward and reverse
directions with the head azimuth screw.
<Constant speed>
Adjust VR37 so that the frequency counter reading
becomes 3,010Hz 15Hz when playing back the
test tape VT712 (3kHz) with the playback
mechanism or playback and recording mechanism
after ending forward winding of the tape.
Confirmation
of head angle
Confirmation
of tape speed
Test tape :
TMT7036 (10kHz)
Measurement
output terminal :
Speaker terminal
Speaker R :
headphone terminal
Test tape :
VT712 (3kHz) or
TMT7036 (3kHz)
Measurement
output terminal :
Headphone terminal
Maximum
output
Tape speed
of decks
: 3,010Hz
15Hz
Adjust the
head
azimuth
screw only
when the
head has
been
changed.
VR37
Measurement
conditions
Measurement method
Standard
values
Adjusting
positions
Items
Standard
values
Adjusting
positions
When the test tape VT712 (3kHz) has been played
back with the playback mechanism or recording and
playback mechanism at the beginning of forward
winding the frequency counter reading of wow & flutter
should be 0.25% or less (WRMS). Wow & flutter 0.25% or
less
(WRMS) Both the
playback
and
recording
& playback
mechanism
Measurement
conditions
Measurement method
Items