Grundig EC 4790 CD, Руководство по обслуживанию

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EC 4790 CD Abgleichvorschriften / Adjustment Procedures
GRUNDIG Service 2 - 2
k
Adjustment Procedures
Test equipment: DC Voltmeter, Test Generator, AF Voltmeter, Sweep Generator
1. MW Oscillator
2. LW Oscillator
3. MW Band Pass
4. LW Band Pass
5. AM IF
6. FM Oscillator
7. FM Stop Generator
8. FM Band Pass
8. FM IF
10. Field Strength
Level
MW;
Connect a DC Voltmeter to FMP639.
LW;
Connect a DC Voltmeter to FMP639.
Connect a Test Generator to aerial input; MW; Frequency
1404kHz; f
mod
= 1kHz; m = 30%; E´ = 30
µ
V (30dB
µ
V).
Connect an AF Voltmeter to Loudspeaker Output.
Connect a Test Generator to aerial input; LW; Frequency
153kHz; f
mod
= 1kHz; m = 30%; E´ = 30
µ
V (30dB
µ
V).
Connect an AF Voltmeter to Loudspeaker Output.
Connect a Test Generator to aerial input; MW; Frequency
1008kHz; f
mod
= 1kHz; m = 30%; E´ = 30
µ
V (30dB
µ
V).
Connect an AF Voltmeter to Loudspeaker Output.
FM;
Connect a DC Voltmeter to FMP24.
Connect a Sweep Generator to aerial input; FM; Center
frequency 93.5MHz;
∆
f = 100kHz; E´ = 1mV (60dB
µ
V); no
modulation.
Connect an Oscilloscope to FMP115.
Connect a Test Generator to aerial input; Frequency
87.8MHz; f
mod
= 1kHz; dev. 22.5kHz; E´ = 3
µ
V (10dB
µ
V).
Connect an AF Voltmeter to Loudspeaker Output.
Connect a Test Generator to aerial input; Frequency
93.5MHz; f
mod
= 1kHz; dev. 22.5kHz; E´ = 3
µ
V (10dB
µ
V).
Connect an AF Voltmeter to Loudspeaker Output.
Connect a Test Generator to aerial input; Frequency
93.5MHz; no modulation; E´ = 100
µ
V (40dB
µ
V).
Connect DC Voltmeter between FMP121 (+) and
FMP122 (-).
Align with L612A
2
at 531kHz for 1.2V
±
20mV.
Check at 1602kHz for 7.5V
±
0.5V.
Align with L613A
3
at 135kHz for 1.0V
±
20mV.
Check at 279kHz for 5.0V
±
0.5V.
Align with L603A
4
for maximum AF Voltage.
Align with L604A
5
for maximum AF Voltage.
Align with F601A
1
for maximum AF Voltage.
Align with L04
7
at 93.5MHz for 2.85V
±
20mV.
Align F105
!
for a symmetrical stop impulse.
93.5MHz
+5V
0V
∆
f =
±
25kHz
Align alternating with L03
0
and L01
9
for maximum
AF Voltage.
Align with F101
8
for maximum AF Voltage.
Align with CR105
6
for +425mV
±
20mV.
Adjustment Preparation Adjustment Procedure
For adjustment use the aerial dummies for AM resp. FM.
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EMK
Rg
50
Ω
Kabel
50
Ω
37.5
Ω
55
Ω
15pF
150
Ω
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37.5
Ω
60pF
E´
E´= EMK - 26dB
AM
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EMK
Rg
50
Ω
Kabel
50
Ω
10
Ω
45
Ω
10nF
60
Ω
75
Ω
E´
E´= EMK - 6dB
FM