Text preview for : CD321A~1.PDF part of LG CD321A~1 LG Audio cd321ax CD321A~1.PDF



Back to : CD321A~1.PDF | Home

ADJUSTMENTS
This set has been aligned at the factory and normally will not require further adjustment. As a result, it is not
recommended that any attempt is made to modificate any circuit. If any parts are replaced or if anyone tampers
with the adjustment, realignment may be necessary.


1.IMPORTANT
1. Check Power-source voltage.
2. Set the function switch to band being aligned.
3. Turn volume control to minimum unless otherwise noted.
4. Connect low side of signal source and output indicator to chassis ground unless otherwise specified.
5. Keep the signal input as low as possible to avoid AGC and AC action.


2.TUNER ADJUSTMENT
1. Test & Adjustment Points




Figure 1. Main P.C. Board

-6-
2. AM (MW) IF Adjustment

IF Genescope
IF Adjust for Adjustment
455kHz Maximum L7(See figure 3)
IC101(Pin 13 , 14 ) L4

IN OUT

Unit




455kHz
455kHz
Figure 2.AM(MW) IF Adjustment Connection Diagam Figure 3.AM(MW) IF Curve


3. AM(MW) RF(Coverage & Tracking) Adjustment

NO ITem SG Output Adjust for Adjustment
1 515kHz Maximum L5
2 Coverage 1,650kHz or 1,710kHz(U.S.A) Maximum VC1-3
3 Repeat steps 1 and 2 several times.
4 600kHz Maximum L1
5 Tracking 1,400kHz Maximum VC1-4
6 Repeat step 4 and 5 several times.

OscIlloscope
SSVM
AM Signal generator Test Loop# AM Antenna IC101(Pin 13 , 14 )
Antenna
3.28
Unit IN OUT

GND
60cm


Figure 4.AM(MW) RF Adjustment Connection Diagram



4. FM RF(Coverage & Tracking) Adjustment

NO ITem SG Output Adjust for Adjustment
1 87.35MHz(AX Band:64MHz) Maximum L4
2 Coverage 108.25MHz(AX Band:109MHz) Maximum VC1-1
3 Repeat steps 1 and 2 several times.
4 90MHz(AX Band:68MHz) Maximum L3
5 Tracking 106MHz Maximum VC1-2
6 Repeat step 4 and 5 several times.

Electronic
Voltmeter
Signal Generator PN1
Dummy IC101(Pin 13 , 14 )

8
Unit 3.2

GND GND



Figure 5. FM RF Adjustment Connection Diagram


-7-
3.TAPE DECK ADJUSTMENT
1. AZIMUTH ADJUSTMENT

Deck Mode Test Tape Test Point Adjust for Adjustment
Playback MTT-114 L/R Output R/L Maximum Azimuth adjusting screw

Electronic Dual-trace
Voltmeter synchroscope

Head
Playback Mode
L/R Output
L out
L ch CH1 CH2

Test Tape Unit
MTT-114 R ch GND


R out


Figure 6. Azimuth Adjustment Connection Diagram


3. RECORD BIAS ADJUSTMENT

Deck Mode Test Tape Test Point Adjust for Adjustment
Rec/Pause MTT-5511 Q140 EMITTER 71kHz