UMS 1 / UMS 2
Abgleich / Alignment
GRUNDIG Service
2 - 9
Adjustment
Preparations
Adjustment Procedure
9. Head current
(coarse)
10.Head current
(fine)
11.Bias voltage
(coarse)
12.Frequency
adjustment
during recording
13.Distortion factor
With
SVR104
(left channel) and with
SVR204
(right
channel) set to test points
L. REC
und
R. REC
6.0mV
.
When recording on Fe IEC I-cassettes the voltage must be
4.5mV
.
V
o
=
23mV
at the test points
L. DOLBY
and
R. DOLBY
during recording.
On playing back the recording made on the cassette
recorder, a voltage level of
23mV
±
0.5dB
must be present
at the test points
L. DOLBY
and
R. DOLBY
.
If the level differs from the value above re-adjust the head
current control
SVR104
(left channel) or
SVR204
(right
channel) during recording.
When recording on Fe IEC I-cassettes the voltage must be
23mV
±
1dB
.
With Cr-cassettes, set the voltage level to
14.5mV
at test
point
L. REC
or
R. REC
. with
SVR103
(left channel) and
SVR203
(right channel)
With Fe-cassettes the voltage must be
12mV
.
When
playing back
the recording the levels at the test
points
L. DOLBY
and
R. DOLBY
must not differ by more
than 0.5dB.
If V
o
f
2
to V
o
f
1
is higher than 0.5dB correct the bias.
Re-adjust with
SVR103
(left channel) or
SVR203
(right
channel).
V
o
f
2
(12.5kHz)
V
o
f
1
(400Hz)
Distortion analyzer
to test point
L.
LINE OUT
or
R. LINE
OUT
(47k
Ω
termination).
Function: Playback-Start
Dolby off
Distortion factor measured on playing back the recording
made:
Fe
IEC I
K
3
≤
1.5%
CrO
2
IEC II K
3
≤
2.5%
≈
10k
10k
AUX
L
R
≈
10k
10k
AUX
L
R
≈
10k
10k
AUX
L
R
AF-voltmeter
to test point
L.
REC
(left channel) or to test
point
R. REC
(right channel).
Connect
AF-generator
to
AUX
sockets.
V
i
= 50mV, f
=
1kHz
.
Switch the bias off by short-circuiting the base and emitter
of transistor
T123
(OPT 1).
Insert a recordable cassette, Cr (IEC II).
Function: AUX
Record-Start
Dolby off
AF-voltmeter
to test point
L. DOLBY
(left channel) or to
test point
R. DOLBY
(right channel).
Insert a recordable cassette, Cr (IEC II).
Connect
AF-generator
to
AUX
sockets.
V
i
= 50mV, f
=
400Hz
.
Function: AUX
Record-Start
Dolby off
–
Playback-Start
AF-voltmeter
with a 1:1000 capacitive voltage divider to
test point
L. REC
(left channel) or
R. REC
(right channel).
Insert a recordable cassette Fe or Cr.
Function: Record-Star
AF-voltmeter
to test point
L. DOLBY
(left channel) or to
test point
R. DOLBY
(right channel).
Insert test cassette 448 A, side B (blank part) Cr (IEC II) or
similar tape.
Connect
AF-generator
to
AUX
sockets.
V
i
= 23mV, f
1
=
400Hz,
f
2
=
12.5Hz
.
Function: AUX
Record-Start
Dolby off
–
Playback-Start
Connect
AF-generator
to
AUX
sockets.
V
i
= 500mV, f
=
333Hz
.
Insert test cassette 448 A,
side B (blank part) Cr (IEC II)
or similar tape.
Function: AUX
Record-Start
Dolby off
≈
10k
10k
AUX
L
R
= 0dB
±
0.5dB
