CCF 23
Einstellvorschriften / Adjustment Procedures
GRUNDIG Service
2 - 5
Adjustment
Preparations
Adjustment Procedure
10.MPX-filter
(19kHz stereo
pilot tone)
Deck B
11.Frequency
response on
Playback
Deck A/B
12.AF head current
adjustment
during recording
Deck B
13.Frequency
adjustment
during recording
Deck B
14.Bias voltage
Deck B
15.Distortion factor
Deck B
Set the LINE IN-level during Record-Pause so that at
315Hz the voltage measured at the test points
D1 and
D2 is V
o
= 388mV (= 0dB).
At 19kHz = V
o
≤
12mV (
≤
–30dB).
Adjust with F103 (left channel) or F104 (right channel).
Deck B:
If the levels V
o
f
1
(315Hz) and V
o
f
2
(12.5kHz) at
D1 and
D2 differ by more than
±
1.5dB cut the bridges B1
(C103), B2 (C107) left channel, and the bridges B3
(C104), B4 (C108) right channel respectively.
Deck A:
If the levels V
o
f
1
(315Hz) and V
o
f
2
(12.5kHz) at
D1 and
D2 differ by more than
±
1.5dB cut the bridges B5
(C109), B6 (C114) left channel, and the bridges B7
(C111), B8 (C115) right channel respectively.
V
o
f
2
(12.5kHz)
V
o
f
1
(315Hz)
With the level control (RECORD LEVEL) set the level at
the test points
D1 and
D2 during recording to 120mV.
On playing back the recording made on the cassette recorder,
a voltage level of 120mV
±
0.5dB must be present at the test
points
D1 and
D2.
If the level differs from the value above re-adjust the head
current control R232 (left channel) or R233 (right channel)
during recording.
When recording on Fe IEC I-cassettes the voltage must be
120mV
±
1dB.
With the level control (RECORD LEVEL) set the level at the
test points
D1 and
D2 during recording to V
o
= 22mV.
When playing back the recording the levels at the test
points D1 and
D2 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 R296 left channel, and R295 right channel
respectively.
V
o
f
2
(12.5kHz)
V
o
f
1
(400Hz)
The bias voltage depends on the type of tape and the
frequency response setting.
Adjustment range:
Fe
= 10 - 15V
CrO
2
= 18 - 25V
With the level control (RECORD LEVEL) set the level at the
test points
D1 and
D2 during recording to V
o
= 388mV.
Distortion analyzer to LINE OUT L or LINE OUT R sockets
(47k
Ω
termination).
Function: Playback-Start
Dolby off
Distortion factor measured at the LINE OUT sockets at
47k
Ω
on playing back the made recording:
Fe
IEC I
K
3
≤
1.5%
CrO
2
IEC II
K
3
≤
2.0%
Connect the AF-generator to LINE IN sockets.
(f
1
= 315Hz, f
2
= 19kHz, V
i
= 115mV
±
1.5dB).
AF-voltmeter to test point
D1 (left channel) and test
point D2 (right channel) respectively.
Insert a recordable cassette,
Cr tape (IEC II), in Deck B.
Function: Record-Pause
Dolby off
Level control to "maximum"
AF-voltmeter to test point
D1 (left channel) and test
point D2 (right channel) respectively.
Insert test cassette 448 A.
Play back the 315Hz / 12.5kHz frequency recording on the
tape.
Dolby off
AF-voltmeter to test point
D1 (left channel) and test
point D2 (right channel) respectively.
Insert test cassette 448 A, side B (blank part), Cr IEC II or
similar tape.
AF-generator to LINE IN sockets.
V
i
= 500mV, f = 400Hz.
Function: Record-Pause
Dolby off
–
Record-Srart
–
Playback-Start
AF-voltmeter to test point
D1 (left channel) and test
point D2 (right channel) respectively.
Insert test cassette 448 A, side B (blank part) Cr IEC II or
similar tape.
AF-generator to LINE IN sockets.
V
i
= 500mV, f
1
= 400Hz, f
2
= 12.5kHz
Function: Record-Pause
Dolby off
–
Record-Start
–
Playback-Start
AF-voltmeter with a 1:1000 capacitive voltage divider to
test point
TP 5 (left channel, head connector P102/1)
and
TP 6 (right channel, head connector P102/6)
respectively.
Insert a recordable cassette Fe or Cr.
Function: Record-Start.
AF-voltmeter to test point
D1 (left channel) and test
point D2 (right channel) respectively.
Insert a recordable cassette, Fe or Cr tape.
AF-generator to LINE IN sockets.
V
i
= 500mV, f = 333Hz.
Function: Record-Pause
Dolby off
–
Record-Start
= +1
±
0.5dB
≈
10 k
10 k
LINE IN
= 0dB
±
0.5dB
≈
10 k
10 k
LINE IN
≈
10 k
10 k
LINE IN
