SAMSUNG ST48 Alignment and Adjustments

1. Alignment and Adjustments

1-1 Tuner

Samsung Electronics 1-1

FM Stereo Adjustment

L-CH/R-CH : Maximum(Figure 1-3)

SSG FREQ.

Frequency

Adjustment point

98MHz

SVR100

Figure1-3 FM Stereo Separation Adjustment

Figure1-1 IF CENTER and THD Adjustment

FM SSG

75Ω Dummy

5KΩ

Stereo Modulator (Pilot 10%)

OUT

Oscilloscope

FM antenna

SET

Speaker Terminal

EXT

GND

VTVM

FM SSG

Output GND

Speaker Terminal

FM Antenna Terminal

Distortion Meter

Input

SET

Input

output

Oscilloscope

FREQ:1KHz MOD : 40KHz DEV

FM IF Adjustment

L-CH/R-CH : Maximum(Figure 1-1)

SSG FREQ.

Frequency

Adjustment point

10.7MHz

87.5MHz

T101

T103(Green)

FM TRACKING Adjustment

L-CH/R-CH : Maximum(Figure 1-3)

SSG FREQ.

Frequency

Adjustment point

90MHz,106MHz

L101,TC100

FM Coverage Adjustment

L-CH/R-CH : Maximum(Figure 1-3)

SSG FREQ.

Frequency

Adjustment point

87.5MHz,108.5MHz

L102,TC101

1-2 Samsung Electronics

1-1-1 Test Equipment

1-1-2 Pre-Adjustment

1-1-3 AM(MW) Adjustment

1. AM Standard Signal Generator (S.S.G) : 400Hz, 30% MOD

2. Oscilloscope

3. VTVM

4. Frequency counter

5. Loop antenna

6. Dummy load (3Ω)

7. DC voltmeter

1. Check the source voltage

2. Press TUNER/BAND to select the AM(MW) function.

3. Set the EQ/S.BASS control to OFF position.

4. Set the volume control to approximaterly 50mw

Intermediate frequency (IF) adjustment

AM frequency coverage adjustment

AM tracking adjustment

Figure 1-4

Connect DC voltmeter to AM VT(OR10) and GND

Figure 1-5

455 KHz

600 KHz

Figure 1-4

SET

60 cm

AM Signal Generator

Test Loop Antenna

Speaker Terminal

VTVM

OUT

GND

Oscilloscope

AM-ANT

Figure 1-5

SET

AM VT(OR10)

GND

Input

DC Voltmeter

600 KHz

L105(BAR ANT)

515 KHz

1400 KHz 1400 KHz TC102

TC103

1650KHz

515 KHz

T102(White)

T100(Red)

1.0V

Maximum output

4.6V

Remark

FREQ. Setting

Adjust. PointSSG.FREQ.Item

Step

Connection

Alignment and Adjustments

1-2 Cassette Deck

Dummy Load(3Ω)

1-2-1. Recording BIAS adjustment

1) Connect frequency counter to C402 (See Fig.1-6)and press the Record button.

2) Adjust T400 (BIAS OSC COIL) until frequency counter reads 39.5~40.5KHz.

1-2-2. Tape AZIMUTH adjustment

1) Connect the equipments as per Fig.1-8 to adjust the tape azimuth with test tape (recorded at 6.3KHz : MTT-113N)

2) Play the test tape after inserting in DECK.

3) Adjust the azimuth ajustment screw of left side of record/play head for maximum output and for the same channel phase. (see Fig.1-7)

1-2-3. Tape speed adjustment

1) Connect the equipments as shown in Fig.1-8 adjust the tape speed with test tape (recorded at 3KHz : MTT-111N)

2) Adjust SVR OF MOTOR until frequency counter reads 3KHz±1%.

Fig.1-6 Recording bias adjustment

Fig.1-8

Fig.1-7 Azimuth speed adjustment

80KHz

FREQUENCY COUNTER

PRE/REC PART

C402

Adjustment

Adjustment screw

R/P head

UNIT UNDER TEST

VTVM

OSCILLOSCOPE

FREQUENCY COUNTER

3000Hz