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Test cassette: 448
(3180 and 70 ps)
tape: CrO2 IEC II
Measurement
test
8.
Playback of
prerecorded
tape
reference tape
scanning
8.1 Dolby-level
Tape select Cr(IEC II) | Test cassette: 448
Vout Measured at test points
Vout = 308 mV +0,5 dB
( 200 pWb/mm)
Adjustment: Tape A
left channel R 415
right cannel R 465
Test circuit 2
Adjustment: Tape B
left channel R 108
right channel R 208
Drive mechanism
A
8.2 Frequency
Test cassette: 448
Drive mechanism A
response
(3180 und 70 ps)
Assuming that bridges B 1
If Vout from the ratio
adjustment
frequency response
(R 400), B 2 (R405) leftchannel =| 14 kHz to 250 Hzis
(playback)
sections
and B 3(R.450), B 4 (R455),
> + 2B open bridges B 1
right channel are closed.
(B 400) / B 2(R 405) left
channel or B 3 (R450) /
B 4(R 455) right channel.
40 Hz and 18kHz
Drive mechanism B
Assuming that bridges B 5
(C 101), B 6(C 105) left channel
and B 7 (C 201), B 8 (C 205),
right channel are closed.
Drive mechanism B
If Vout from the ratio
14 kHz to 250 Hzis
> + 2B open bridges B 5
(C 101)/B 6 (C 105) left
channel or B 7(C 201)/
B 8(C 205) right channel.
Vout Measured at test points
2 (I.ch.), D2 (r.ch.)
250 Hz
6,3 kHz
40 Hz
Tolerance zone of
frequency response
DIN 45500 to
restricted +3 dB.
Test circuit 2
9.
HF-osclllator
tape B
9.1 HF-osclillator-
frequency
f = 83 kHz+10 KHz
Adjustment: L 1
Test point
S77
000
LX
F
- Insert cassette
- Tape select Cr (IEC Il)
- Record, pause
R1
Frequency counter
Test circuit 3
Erase voltage,
use 1:1000
capacitive voltage divider
Tape select: Me, Cr, Fe.
Br
CK_5
2A2
(Erase plug)
Verase |
L
VeErase: Me =27 mvt
10%
Cr=20,5 mVt10%
Fe =13 raV+t 10%
Test circuit 4
47
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