GRUNDIG Service
2 - 3
Abgleichvorschriften / Adjustment Procedures
RR 430 CD
2. Tuner
Measuring instruments: Signal generator, sweep generator, oscilloscope.
Function switch: Radio
Adjustment
Preparations
Adjustment Process
Adjust to maximum with T501.
At tuning minimum (515kHz)
adjust with T502 and at
tuning maximum (1630kHz) adjust with VC501-C to
maximum output.
Repeat this adjustment alternately.
At 558kHz
adjust to maximum with L504 (MW aerial coil,
move).
At 1440kHz
adjust to maximum with VC501-D.
Repeat this adjustment alternately.
At tuning maximum (292kHz) adjust with TC502 to
maximum output.
At 153kHz
adjust to maximum with L505 (LW aerial coil,
move).
At 261kHz
adjust to maximum with TC501.
Repeat this adjustment alternately.
At tuning minimum (87,35MHz)
adjust with L502 and at
tuning maximum (108,25MHz) adjust with VC501-A to
maximum output.
Repeat this adjustment alternately.
At 88MHz
adjust to maximum with L503 (bend).
At 106MHz adjust to maximum with VC501-B.
Repeat this adjustment alternately.
Couple in a sweep signal of 455kHz to L504 (ferrite aerial)
via a loop aerial.
Oscilloscope to testpoint
TP 5
(IC501 Pin 7).
Band switch: MW
MW f
u
515kHz, f
o
1630kHz
Couple in a standard signal to L504 (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 the headphone socket.
Band switch: MW
MW 558kHz, MW 1440kHz
Couple in a standard signal to L504 (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 the headphone socket.
Band switch: MW
LW f
u
142kHz, 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 the headphone socket.
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 the headphone socket.
Band switch: LW
FM f
u
87.35MHz, f
o
108,25MHz
Couple in a standard signal via a 10nF capacitor to
testpoint
TP 1
/
TP 2
(GND) (f
mod
= 1kHz,
∆
f = 22.5kHz,
U
a
as low as possible so that the signal is just visible).
Oscilloscope to the headphone socket.
Band switch: FM
FM 88MHz, FM 106MHz
Couple in a standard signal via a 10nF capacitor to
testpoint
TP 1
/
TP 2
(GND) (f
mod
= 1kHz,
∆
f = 22.5kHz,
U
a
as low as possible so that the signal is just visible).
Oscilloscope to the headphone socket.
Band switch: FM
1. AM IF
2. MW Oscillator
3. MW Aerial
bandpass
4. LW Oscillator
5. LW Aerial
bandpass
7. FM Oscillator
8. FM Aerial
bandpass
VC501
L502
T501
T502
L505
L504
TC502
TC501
L503
D
A
B
C
TP 1
TP 5
TP 2
