Sony ST-SB920 - Service Manual

ST-SB920
AEP Model
UK Model
SERVICE MANUAL
FM STEREO FM-AM TUNER
MICROFILM
SPECIFICATIONS
FM tuner section
Frequency range 87.5 – 108.0 MHz
Aerial terminals 75 Ω, unbalanced
Intermediate frequency 10.7 MHz
Sensitivity at 26 dB quieting
(mono) 10.3 dBf, 0.9 µV/75 Ω
at 46 dB quieting
(stereo) 38.5 dBf, 23 µV/75 Ω
Usable sensitivity (IHF) 10.3 dBf, 0.9 µV/75 Ω
S/N at 40 kHz deviation
80 dB (mono), 76 dB (stereo)
Harmonic distortion WIDE
0.035 % (mono), 0.045 (stereo)
NARROW
0.055 % (mono), 0.075 (stereo)
Frequency response 30 Hz – 15 kHz
(+0.3/–0.7 dB)
Separation 50 dB at 1 kHz
Selectivity at 400 kHz
WIDE 85 dB
NARROW 90 dB
at 300 kHz
WIDE 45 dB
NARROW 70 dB
Output at 40 kHz deviation 600 mV
AM tuner section
Frequency range MW: 522 – 1,611 kHz (9 kHz step)
LW: 144 – 288 kHz (1 kHz step)
Intermediate frequency 450 kHz
Usable Sensitivity (with AM loop aerial)
MW: 200 µV/m
LW: 700 µV/m
Signal-to-noise ratio MW: 54 dB (50 mV/m, 999 kHz)
LW: 50 dB (50 mV/m, 216 kHz)
Harmonic distortion 0.3% (50 mV/m, 400 Hz)
Selectivity 50 dB
General
Power requirements 220 – 230 V, AC 50/60 Hz
Power consumption 12 W
Input impedance 75 Ω
Input connector IEC-male
Dimensions 430 × 86 × 295 mm (w/h/d)
Weight 3.95
Supplied accessories Audio cord (1)
AM loop aerial (1)
FM wire aerial (1)
EON connecting cord (1)
Design and specifications are subject to change without notice.

Summary

SECTION 1 GENERAL

SECTION 2 TEST MODE

Circuit Check Mode

Procedure for enabling and performing circuit checks.

Display Tube Check and KEY Check mode

Procedure for checking display tube patterns and key input functionality.

SECTION 3 ELECTRICAL ADJUSTMENTS

Precautions in Repairing

FM Discriminator ADJUSTMENT

Procedure for tuning the FM discriminator for optimal performance.

Stereo Level Adjustment

Procedure for adjusting the stereo signal level.

Stereo Separation Adjustment

Procedure for adjusting stereo separation between channels.

Narrow Gain Adjustment

Procedure for adjusting gain in narrow band mode.

FM Meter Level Adjustment

AM SECTION

AM Meter Level Adjustment

IC PIN FUNCTION (DISPLAY BOARD)

IC701 System Control (µPD780205 GF-040-3 BA)

IC BLOCK DIAGRAMS (TUNER BOARD)

Sony ST-SB920 Specifications

General

Type	Stereo Tuner
Tuning Bands	FM, MW
MW Tuning Range	531 - 1602 kHz
AM Sensitivity	300 µV/m
Signal to Noise Ratio (FM)	80 dB
Signal to Noise Ratio (AM)	50 dB
Distortion (AM)	0.5%
Power Consumption	15 W
FM Tuning Range	87.5 - 108 MHz
Frequency Response	20 Hz - 15 kHz
Dimensions	430 x 85 x 340mm