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10.
Frequency
3
responce
|
tape B
10.1 Frequency
|
a) Record
V._, = approx.500 mV
responce
- Insert Crtest cassette
+15dB
adjustment
448 A, side B, (blank
Test circuit 5
tape section,
IEC il
potentiometers (RECORD
LEVEL) such thatthe volta-
new (U 564 W) or
t - 315 Hz
ge V. = 245 mV measured
ae
. sagas
. Ae a
D1 (I.ch.) and
-
Dolby
e)
2
r.ch.
- . Record, start
]
resp. at f,= 315 Hz
|
Reduce voltage V,_ from
the test signal generator
by 20 dB.
@
|
Te levels of V.,.,, (815 Hz)
and Von jo (12.5 kHz) must
not differ by more than
+0 dB to +1 dB.
if V,, to V,, is greater than
1 dB, readjust the bias with
C 145 (left channel) and/or
C 148 (right channel).
Test circuit 5
b) Plaback, start
Playback of the recording|
pq.
made under 10.1a)
Test circuit 2
10.2 Frequency
insert cassette:
|
(o
a
er
ae
responce
Cr, IEC Il (S 4592 A)
check
Cr, IEC iinew
;
7
(U 564 W)
Me, IEC IV (E912BH)
Fe, IEC | (R 732 DG)
a
40 Hz
14 kH
Test circuit. 1
3
Tolerance zone of frequen-
cy response DIN 45500
Distortion factor | -. Insert Cr-, Fe-, Me-
| f = 333 Hz
-V,,: TestcircuitS
.
Distortion factors:
tape B
cassette
|
Vin= approx. 1150mV_
| - Vout Pest circuit 2 (record)
Crnew:
K, <3%
measured when
Channels are mea- | Adjust the RECORD LE-| -
|
7
the 3dBLEDisjust}
sured individually
VEL so that the left or right
inactive.
- Dolby NR off
+ 3 GB level indicator just
A level of
- Record, start
goes out,i.e.310mV
[ | .
200 pWb/mm.
————
+ 0.5 dB at test point D1 or} |
SSS
Tape:
- Recording playback | D2.
Ps
- Vout Test circuit 1, (see above)
IEC inew
——s | -- Dolby NR off
|
|
950 mV+1dB
|
IEC |
|
- Insert the CR-, Fe-
:
.
eo
IECIV
=.
|
and Mecassettein |
|
succession
'
- Playback, start.
External- and
- Insert cassette
je
x
Tape: Cr
mt
7
|
noise voltage
|
- Dolby NR off/on
|
external voltage effective
Dolby
off
§ 2514dB
tape B
|
- Record, start.
|
|
—
DolbyBon
255 0B
_ (with regard to the
—_
DolbyC on.
> 57 cB
distortion factor)
|
|
or
|
curve A effective
Dolby
off
§
255dB
Dolby B on
263dB
Dolby C on
271dB
tape: Fe
Dolby
off
> 50 dB
external voltage effective
Dolby B on
254 dB
Dolby C on
> 56 dB
curve A effective
Dolby
off
>51 dB
Dolby B on
>61 dB
Dolby C on
267 dB
46
|
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