LG tw-863ax Service Manual adjust

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1. IMPORT ANT

(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

3. ADJUSTMENTS

L7

L2

L50
L70

TC51

L51

L1

L3
TC71

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(2) AM(MW) IF Adjustment

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

(4) FM RF (Coverage & Tracking) Adjustment

IF Adjust for Adjustment

455kHz Maximum L7 (See figure 2)

Figure 1. AM(MW) IF Adjustment Connection Diagram

Figure 3. AM(MW )RF Adjustment Connection Diagram

Figure 4. FM RF Adjustment Connection Diagram

Figure 2. AM(MW) IF Curve

NO ITem SG Output Adjust for Adjustment

1 515kHz Maximum L3
2 1,650kHz or 1,710kHz(U.S.A) Maximum VC1-3
3 Repeat steps 1 and 2 several times.
4 600kHz Maximum L4
5 1,400kHz Maximum VC1-4
6 Repeat steps 4 and 5 several times.

Tracking

Coverage

NO ITem SG Output Adjust for Adjustment

1 87.35MHz(AX Band: 64MHz) Maximum L2
2 108.25MHz(AX Band: 109MHz) Maximum VC1-2
3 Repeat steps 1 and 2 several times.
4 90MHz(AX Band: 68MHz) Maximum L1
5 106kHz Maximum VC1-1
6 Repeat steps 4 and 5 several times.

Tracking

Coverage

IC 101 (Pin ⑬, ⑭)

IC 101 (Pin ⑬, ⑭)

IC 101 (Pin ⑬, ⑭)

L4

455kHz

Unit

AM Signal Generator

AM Signal Generator

Test Loop
Antednna

Test Loop
Antenna

AM Antenna

8Ω

8Ω

GND

GND

PN1

Dummy

GND

Electrionic
Voltmeter

60mm

IN OUT

SSVM

Osacilloscope

Unit