Grundig RR 420 CD Bedienungsanleitung Seite 12

Einstellvorschriften / Adjustment Procedures
3. Tuner
Measuring instruments: Signal Generator, Sweep Generator, Oscilloscope, Frequncy Counter.
Function switch: Radio
Adjustment
1. AM IF Couple in a sweep signal of 468kHz to L301 (ferrite aerial)
via a loop aerial.
Oscilloscope to testpoint
Band switch: MW
2. MW Oscillator Var. capacitor to limit stop: MW f
Couple in a standard signal to L301 (ferrite aerial) via a
loop aerial, (f
Oscilloscope to testpoint
Band switch: MW
3. MW Aerial MW 600kHz, MW 1400kHz
bandpass Couple in a standard signal to L301 (ferrite aerial) via a
loop aerial, (f
Oscilloscope to testpoint
Band switch: MW
4. LW Oscillator Var. capacitor to limit stop: LW f
Couple in a standard signal to L304 (ferrite aerial) via a
loop aerial, (f
Oscilloscope to testpoint
Band switch: LW
5. LW Aerial LW 160kHz, LW 250kHz
bandpass Couple in a standard signal at to L304 (ferrite aerial) via
a loop aerial, (f
Oscilloscope to testpoint
Band switch: LW
6. FM IF Couple in a sweep signal of 10.7MHz via 10nF to test-
point
Oscilloscope to testpoint
Band switch: FM
7. FM Oscillator Var. capacitor to limit stop: FM f
Couple in a standard signal via a 10nF capacitor to (FM
ant.) testpoint
possible).
Oscilloscope to testpoint
Band switch: FM
8. FM Aerial FM 90MHz, FM 106MHz
bandpass Couple in a standard signal via a 10nF capacitor to (FM
ant.) testpoint
possible).
Oscilloscope to testpoint
Band switch: FM
9. FM MPX (Stereo) Couple in a standard signal of 98MHz, unmodulated via
a 10nF capacitor to (FM ant.) testpoint
Frequency counter to testpoint
Band switch: FM
2 - 4
Preparations
(IC301 Pin11).
1
526.5kHz, f
u
= 1kHz, m = 30%, U as low as possible).
a
mod
(IC301 Pin11).
1
= 1kHz, m = 30%, U as low as possible).
a
mod
(IC301 Pin11).
1
148.5kHz, f
u
= 1kHz, m = 30%, U as low as possible).
a
mod
(IC301 Pin11).
1
= 1kHz, m = 30%, Ua as low as possible).
mod
(IC301 Pin11).
1
.
C
(IC301 Pin11).
1
87.5MHz, f
u
= 1kHz, ∆f = 22.5kHz, U
, (f
D
mod
(IC301 Pin11).
1
= 1kHz, ∆f = 22.5kHz, U
, (f
D
mod
(IC301 Pin11).
1
.
2
D
L301
FM-ANT.
MAIN BOARD
T303
T304
IC302
R312
VR301
2
Adjust T304 to maximum.
1606.5kHz At f (526.5kHz) adjust to maximum with T301.
o u
At f (1606.5kHz) adjust to maximum with CT304.
o
Repeat this adjustment.
At 600kHz adjust to maximum with L301 (MW antenna coil
move).
At 1400kHz adjust to maximum with CT303.
Repeat this adjustment.
283.5kHz At f (148.5kHz) adjust to maximum with T305.
o u
At f (283.5kHz) adjust to maximum with TC306.
o
Repeat this adjustment.
At 160kHz adjust to maximum with L304 (LW antenna coil
move).
At 250kHz adjust to maximum with TC305.
Repeat this adjustment.
With T303 and T302 adjust to maximum ans symmetry.
108MHz At f (87.5MHz) adjust to maximum with L303.
o u
At f (108MHz) adjust to maximum with CT302.
o
as low as Repeat this adjustment.
a
At 90MHz adjust to maximum with L302 (bend).
At 106MHz adjust to maximum with CT301.
as low as Repeat this adjustment.
a
Set the frequency to 76kHz ± 100Hz with VR301.
.
D
Tuner 420
L304
CT301 CT303
L302
CF301
CT304
TC305
CT302
L303
T301
1
SW301
11
TC306
T305
IC301
T302
C 1
RR 420 CD
Adjustment Process
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