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Measurement
test
* Continuation
13. Extemal-and
noise voltage
tape B
. MPX-filter
F101/F102
check tape B
. Level indicator
tape B
16. Dubbing fre-
quency re-
sponse
. Dubbing level
recording from
tape
. Adjustment
Quick-Sensor
- Insert cassette
-Dolby NR off/on
- Record, start.
- sort:
Me
Insert cassette.
MASTER CONTROL
and LEVEL controls to
maximum.
- Insert Cr cassette
- Dolby off.
- Record, start.
Tape A
Insert Cr-test cas-
sette 448
(frequency response-
tape section).
Tape B
Insert a capable
Cr-cassette
- Press Dubbing button
normal, to start tape A
playback, tape B
record.
LINE OUT-level
maximum
f = 333 Hz
V tn = approx. 500 mV
- Turn the MASTER CON-
TROL to maximum,
Adjust the LEVEL so that
the left or right red + 3 dB
level indicator just goes
out, i.e. 260 mV+0,5 dB
at test point O2 or D2.
fy =315Hz
fy =19kHz
Vin =ca.57mV
fy = 315 Hz
Vin = ca. 500 mV
Test cassette 448
(3180 ps und 70 ps)
CrOg IECH
Frequency response
transfer a tape A to
tape B
Playback the just made
recordings (tape B).
Record the 315 Hz recor-
ding, part 2 on the test
tape from tape A to
tape B.
Insert blank cassette
without tape.
Test parameter
Tape: Me
external voltage effective
curve A effective
Vin : Testcircuit 6
Vout! Testcircuit 2
V
02
D2
Vout
|
Vin
t
r.ch.
Vin: Test circuit 6
V
O02
D2
Vout: Test circuit 2
Measurements as described
under 8.2
Vout
4
Vout: Test circuit 1
4
Test point
Quick-2L3
v-duick
(V)
Cooling fin
trafo board
Dolby
off
Dolby B on
Dolby C on
Dolby
off
Dolby Bon
Dolby C on
Vout, f4 = 245mV
=0dB
Vout, f2 = 12,25 mV
= -26dB
If the Vout fais larger
the MPX-fiter F101/
F 201 minimum
MASTER CONTROL-
potentiometer to maxi-
mum.LEVEL controls
regulator leftand right
mustbe so adjusted
(recording) that the
Vout = 260 mV measured
at test points O2 and D2,
so that the luminous
fields + 3 dB just to light
up.
Adjust R 751 (left channal)
and R 752 (right channel).
Tolerance zone of fre-
quency response
DIN 45500 to restricted
+3 dB.
250 Hz
6,3 KHz
5dB
768
Output voltage, tape B
DUBBING NORMAL:
1250 mV + 10B
DUBBING HIGH:
1250 mV + 10B
Adjust R 711 such that
+3,5 V measured at test
point 2L3 against
cooling fin traip board
(- 7,5V).
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