Adjustment Procedures - Grundig CDM 800 Serviceanleitung

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Adjustment Procedures

1. Tuner
Measuring Instruments: Signal generator, Sweep generator, Oscilloscope, Digital voltmeter.
Adjustment
Couple in a sweep signal of 450kHz to L110 (ferrite aerial)
1. AM IF
via a loop aerial.
Oscilloscope to testpoint TP4 (IC102 Pin 18).
Band switch: MW
2. MW Oscillator MW, 522kHz
Digital Voltmeter to Testpoint TP3 (C104).
Band switch: MW
3. MW Aerial MW 588kHz, MW 1440kHz
Couple in a standard signal to L110 (ferrite aerial) via a
bandpass
loop aerial, f
that the signal is just visible.
Oscilloskope to AF output.
Band switch: MW
4. FM IF FM, 88MHz
Couple in a standard signal to Testpoint TP1 (CN101A),
= 1kHz, ∆f = 22.5kHz, U
f
mod
signal is just visible.
Oscilloskope to AF output.
Band switch: FM
5. FM Oscillator FM, 87.5MHz
Digital Voltmeter to Testpoint TP3 (C104).
Band switch: FM
6. FM Aerial FM 88MHz, FM 106MHz
Couple in a standard signal to Testpoint TP1 (CN101A),
bandpass
= 1kHz, ∆f = 22.5kHz, U
f
mod
signal is just visible.
Oscilloskope to AF output.
Band switch: FM
7. 19kHz Filter FM 88MHz
Couple in a standard signal to Testpoint TP1 (CN101A),
f = 19kHz.
mod
Oscilloskope to TP5 (left channel) and TP6 (right channel).
Band switch: FM
CN102 CN101
L101
IC101
T100 TC101
CD80-01-09
2 - 4
Preparation
= 1kHz, m = 30%, U as low as possible, so
a
mod
as low as possible, so that the
a
as low as possible, so that the
a
L102
FE101
TC161
IC102
T163
Adjust to maximum with T101.
At 522kHz adjust to 1.7V
Check: At 1611kHz <10V.
At 588kHz adjust to maximum with L110 (move MW aerial
coil).
At 1440kHz adjust to maximum with TC161.
Repeat this adjustment alternately.
Adjust to maximum with T100.
At 87.5MHz adjust to 2.7V
At 88MHz adjust to maximum with L102 (bend).
At 106MHz adjust to maximum with TC101.
Repeat this adjustment alternately.
Adjust to minimum with T103 (left channel) and T104
(right channel).
CN101A TP1
TP3
C104
Pin19/TP2
T101
T104
Pin18/TP4
TP6
Adjustment Process
±
0.1V with T163.
±
0.1V with L101 (bend).
T103
TP5
GRUNDIG Service
CDM 800