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Verfügbare Sprachen
Verfügbare Sprachen
PA2/PA3
11. AF head current | AF voltmeter to test point © D1 (left channel) or test point | With AF Generator output set the level at the test points ©
adjustment during | © D2 (right channel).
D1 and © D2 during recording to 75mvV.
recording
Insert test cassette 448 A, side B (blank part), Cr IEC II or
similar tape.
On playing back the recording made on the cassette
recorder, a voltage level of 75mV+0.5 dB must be present
at the test points © D1 and © D2.
AF generator to Pin 2 and 4 of P106.
f = 400Hz.
If the level differs from the value above re-adjust the head
current control R169 (left channel) or R182 (right channel)
during recording.
Function: Dolby off, ALC off, Record-Pause
AF voltmeter to test point © D1 (left channel) or test point
© D2 (right channel).
Insert test cassette 448 A, side B (blank part) Cr IEC II or
similar tape.
AF generator to Pin 2 and 4 of P106.
f, = 400Hz, f, = 12.5kHz.
With AF Generator output set the level at the test points ©
D1 and © D2 during recording to U, = 13mV.
12. Frequency
adjustment during
recording
When playing back the recording the levels at the test
points O D1 and © D2 must not differ by more than 0.5aB.
If Uf, to U,f, is higher than 0.5dB correct the bias with
R245 left channel, or R246 right channel.
Function: Dolby off, ALC off, Record-Pause
AF voltmeter with a 1:1000 capacitive voltage divider to
test point O TPS (left channel, head connector P101/5) or
© TP6 (right channel, head connector P101/2).
Insert a recordable cassette Fe or Cr.
The bias voltage depends on the type of tape and the
frequency response setting.
13. Bias voltage
Adjustment range:
Fe
=10- 15mV approx.
CrO,
= 15 - 25mV approx.
Function: Record-Start
AF voltmeter to test point © D1 (left channel) or test point
© D2 (right channel).
Insert a recordable cassette, Fe or Cr tape.
14. Distortion factor
With AF Generator output set the level at the test points ©
D1 and © D2 during recording to U, = 245mvV.
Distortion analyzer to Pin 5 of P106 (L) or Pin 1 of
P106 (R).
Function: Playback, Dolby off
Distortion factor measured on playing back the recording
made:
Fe
IECI
K,<1.5%
CrO,
IEC Il K,< 2.0%
AF generator to Pin 2 and 4 of P106.
f = 333Hz.
Function: Dolby off, ALC off, Record-Pause
a -
oa o
Audioplatte
Audio Board
Flt
Aufn. Sperrkreis
F112
abias Filter
> Kopfstrom
-—
Head
Current
Vormagnetisierung
Pre-magnetization
LINE
OUT
R
C206
R
LINE
INR
a
—_
[oJ
nD
P105
Ln i}
Osz. Frequenz
Osc. Frequency
LINE
INL
LINE
OUTL
| ae'
Wiedergabepegel
Playback
Level
F102
F101
a
a a
wo
ror)
Logikplatte
R482
Logic Board
Bandgeschwindigkeit
Tape Speed
wo
=]
t+
Q
ALC OFF
B407
Tuner
Test Equipment:
Sweep generator, Test generator, Stereo coder, AF-generator, Oscilloscope, Digital voltmeter, AF-Voltmeter, Distortion meter
Note:
The frontend is a completely preadjusted module. Only the IF filter must be adjusted to the IF amplifier (1). The values of the tuning voltages are:
87.5MHz = typ. 1.6V min 1.3V; 108MHz = typ. 8.0V max 9V
1. IF Filter
FM, 98MHz.
Adjust F1 @ to maximum and symmetry.
Sweep generator 98MHz to aerial socket. Level approx.
2. Demodulator
100nV / 75Q, Af = +200kHz.
3. Station search
Oscilloscope to testpoint '.
FM, 98MHz
Test generator 98MHz to aerial socket. Level approx.
100uV / 75Q, Af = +200kHz.
Distortion meter to AF output.
Adjust F7 @ to minimal Distortion (typ. 0.12%, max.
0.2%).
FM, 98MHz.
Test generator 98MHz, U,,. = 100.V/75Q to aerial socket.
Digitalvoltmeter to testpoint ©).
Adjust R 123 © to 1.2V + 0.05V.
FM
Stereocoder, left channel modulated, to aerial socket.
AF voltmeter to AF output, right channel.
Adjust R 69 © to minimum.
Control the left AF output with modulated right channel.
4. Stereo Crosstalk
FM
AF generator 114kHz, approx. 100mV to the input of F2 ©
(Pin 2).
AF voltmeter to the output of F2 © (Pin 4).
Adjust F2 © to minimum.
5. Adjacent channel
filter
Test generator to aerial socket; FM, f,,,, = 38kHz.
6. 38 kHz Filter
AF voltmeter to AF output.
7.19 kHz Filter
Test generator to aerial socket; FM, f,,, = 19kHz.
Adjust F9 @ (left channel) and F11 @ (right channel) to
AF voltmeter to AF output.
minimum.
8. MW Oscillator
MW, 531kHz
Adjust L18 WD to 1.1V.
Digitalvoltmeter to testpoint ©).
9. MW PF Circuits
MW
Adjust C3 Gd and F6 GD at 1449kHz and L1 GiD at
Test generator via 120-150yH parallel to frame aerial; AM, | 558kHz to maximum. Repeat the adjustment reciprocally,
U,, = 3uV, m = 30%, fg = 1kHz.
end with 1449kHz.
AF voltmeter to AF output.
FM
Adjust F9 @ (left channel) and F11 © (right channel) to
minimum.
Amplifier
Test Equipment:
Digital voltmeter
ee
ee
ee
1. Quiescent Current | No Input Signal. Volume to Minimum. Switch on the set for
at least 2 minutes.
Left channel:
Digitalvoltmeter between testpoints Al and BI.
Right channel:
Digitalvoltmeter between testpoints Ar and Br.
Adjustment Procedure
Left channel:
Adjust with R516 for 3mV +0.5mV.
Right channel:
Adjust with R522 for 3mV +0.5mV.
GRUNDIG Service
2-7
Amplifier
GRUNDIG Service
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