GRUNDIG Service
FREAXX 20 RRCD 4202
2 - 4
2. Tuner
Measuring instruments:
Signal generator, sweep generator, oscilloscope, frequency counter.
Function switch: Radio
Adjustment
Preparations
Adjustment Process
Adjust to
maximum
with
T501.
At f
u
(515kHz) adjust to
maximum
with
L504
.
At f
o
(1635kHz) adjust to
maximum
with
VCT501(D)
.
Repeat this adjustment alternately.
At 600kHz
adjust to
maximum
with
L506
(MW aerial coil,
move).
At 1400kHz
adjust to
maximum
with
VCT501(C)
.
Repeat this adjustment alternately.
At f
o
(292kHz) adjust to
maximum
with
TC501
.
At 153kHz
adjust to
maximum
with
L505
(LW aerial coil,
move).
At 261kHz
adjust to
maximum
with
TC502
.
Repeat this adjustment alternately.
At f
u
(87.35MHz) adjust to
maximum
with
L503
.
At f
o
(108.25MHz) adjust to
maximum
with
VCT501(C)
.
Repeat this adjustment alternately.
At 88MHz
adjust to
maximum
with
L502
(bend).
At 106MHz adjust to
maximum
with
VCT501(D)
.
Repeat this adjustment alternately.
Couple in a
sweep signal
of 465kHz to
L506
(ferrite aerial)
via a loop aerial.
Oscilloscope
to testpoint
TP5
/ TP4 (GND).
Band switch: MW
Var. capacitor to limit stop: MW f
u
515kHz, f
o
1635kHz
Couple in a
standard signal
to
L506
(ferrite aerial)
via a
loop aerial, (f
mod
= 1kHz, m = 30%, U
a
as low as possible so
that the signal is just visible).
Oscilloscope
to testpoint
TP5
/ TP4 (GND).
Band switch: MW
MW 600kHz, MW 1400kHz
Couple in a
standard signal
to
L506
(ferrite aerial) via a
loop aerial, (f
mod
= 1kHz, m = 30%, U
a
as low as possible so
that the signal is just visible).
Oscilloscope
to testpoint
TP5
/ TP4 (GND).
Band switch: MW
Var. capacitor to limit stop: f
o
292kHz
Couple in a
standard signal
to
L505
(ferrite aerial) via a
loop aerial, (f
mod
= 1kHz, m = 30%, U
a
as low as possible so
that the signal is just visible).
Oscilloscope
to testpoint
TP5
/ TP4 (GND).
Band switch: LW
LW 153kHz, LW 261kHz
Couple in a
standard signal
to
L505
(ferrite aerial) via a
loop aerial, (f
mod
= 1kHz, m = 30%, U
a
as low as possible so
that the signal is just visible).
Oscilloscope
to testpoint
TP5
/ TP4 (GND).
Band switch: LW
Var. capacitor to limit stop: FM f
u
87.35MHz, f
o
108.25MHz
Couple in a
standard signal
via a 10nF capacitor
to
testpoint
TP1
/ TP2 (GND) (f
mod
= 1kHz,
∆
f = 22.5kHz, U
a
as low as possible so that the signal is just visible).
Oscilloscope
to testpoint
TP5
/ TP4 (GND).
Band switch: FM
FM 88MHz, FM 106MHz
Couple in a
standard signal
via a 10nF capacitor
to
testpoint
TP1
/ TP2 (GND) (f
mod
= 1kHz,
∆
f = 22.5kHz, U
a
as low as possible so that the signal is just visible).
Oscilloscope
to testpoint
TP5
/ TP4 (GND).
Band switch: FM
1. AM IF
2. MW Oscillator
3. MW Aerial
bandpass
4. LW Oscillator
5. LW Aerial
bandpass
6. FM Oscillator
7. FM Aerial band-
pass
Summary of Contents for freaxx 20
Page 14: ...GRUNDIG Service FREAXX 20 RRCD 4202 3 2 Verdrahtungsplan Wiring Diagram...
Page 21: ...GRUNDIG Service FREAXX 20 RRCD 4202 3 9 LA 9242 M LC 78602 R...
Page 25: ...GRUNDIG Service FREAXX 20 RRCD 4202 4 1 Explosionszeichnungen und Ersatzteilliste 1...
Page 26: ...GRUNDIG Service FREAXX 20 RRCD 4202 4 2 TK 20FX S866 902 CS 21 S 2 63 100 63 200...
