6-3
Bias and recording current
Fe recording current
Cr02 recording current
Cr02 bias
Fe bias
�
Bang&Oiufsen
Activate CrOz and Rec. Pause.
Adjust
12R242
(l2Rl42) unt:i132 m V
is measured across
12R201
(12R101)
with
an
AF voltmeter.
Load the
Fe
tape for w
hi
ch the bias adjustment is wanted
and
ac
t
i
vate Fe.
Connect
a
t
one generator to the tape input and set it to deliver 333Hz in the
1
V range.
Adjust the record
p
o
t
ent
i
o
meter until 580 m
V
is measured with an AF
voltmeter
in
12TP1 ( 12TP2).
While recording and
replaying
333Hz, adjust 12R227 (12Rl27)
until580
m
V
i
s
measured
in
12TP1 ( 12TP2) during recording and replaying respectively.
Load the Croz tape
for
w
hi
c
h the bias adjustment
-
is wanted and activate Cr02.
Follow the instructions
for
Fe
recording current, only make the adjustment
with
12R228
(1
2R 1
28
)
.
R213
@
Rl13
12
PB.-REC.
C201
CIOI
Ba1s
Ll'vel
R24\Q]m;@
TP4
TP3
L1
JB
�
B1as
1as Trap
Fre-q
C2305:)
@@
�CIJO
L
203 L 103
L202®®L102
R.-c
Boost
Rll
-D-
Re<:. Currenl
Rec Current
Fe R R
ec
.
Curren
t
Fe L
Set a tone generator to deliver 333 Hz 100 m
V.
Adjust the record potentiometer until25 m
V
is measured in 12TP1 (12TP2).
While recording and replaying 333Hz and 15 kHz, adjust 12R242 (12R142) to
the same level at 333Hz and 15 kHz measured in 12TP1 (12TP2).
(Less bias
will
result in treble lift, more bias in treble cut).
Cr02 bias
must
alr
ea
d
y
have been adjusted.
By short-circuiting 12Rll
or
12R12 or both and switching from Cr02 to Fe it is
ensured that the level across 12R201 (12R101), measured with an AF
voltmeter, is between 5. 5
and
6.
5
dB
lower at Fe than at CrOz. (Less
resistance
will gi
v
e
more bias, more resistance
will
give less).
Check CrOz and Fe recording current.
•
•
�
•
•
6-1
ELECTRICAL ADJUSTMENTS
TAPE RECORDER SECTION
Height
Azimuth
Speed
Playback level
VU
meter
Bang&Oiufsen
The references apply to the RH channel (the bracketed references apply to the
LH channel).
Make adjustments in position Fe and without Dolby NR, if not otherwise
instructed.
NOTE! If pw
12
has been removed during the adjustments,
switching between Playback and Record must be made manually
with the switch on pw
12.
It is of special importance to switch from Record to Playback if
erasing is to be prevented.
If tape and erase heads are to be replaced the head heights must be checked
with adjustment tool 1 and 2 from tool kit 3624020.
Head misalignment can be corrected with the washer subjacent to the head
fixtures. The following washers can be used:
2624052 0. 1 mms
2624053 0. 2 mms
2624054 0. 3 mms
Degauss tape and erase heads. Connect an AF voltmeter to 12TP1 (12TP2).
Load azimuth tape 6780036.
B
Activate Play.
Adjust the screw B till max. and equal output for RH and LH channels (mean
value 12TP1 (12TP2)).
B
Load wow tape 6780037.
Adjust to correct speed with the motor potentiometer B as read on the drift
meter of a wow meter in 12TP1.
Make the adjustment in a mid-tape position.
Load level tape 6780035.
Connect an AF voltmeter to 12TP1 (12TP2).
Activate Play.
Adjust 12R213 (12R11'3) until725 m
V
is measured in 12TP1 (12TP2).
Connect tone generator to the tape input and adjust it to deliver 200 m
V.
Activate Rec. Pause and adjust Rec potentiometer to read 580
rnV
in 12TP1
(12TP2).
Adjust 13R6 so that the LED just glows for 0 dB .
•
•
"
•
•
Summary of Contents for BEOCENTER 2000
Page 1: ......
Page 14: ...Bang Oiufsen 18100 18101 I _ 18158 4 4 18151 18152 ...
