Sharp QT-90W Service Manual

SPECIFICATIONS ............................................................................................................................................................. 1
VOLTAGE SELECTION ..................................................................................................................................................... 1
AC POWER SUPPLY CORD AND AC PLUG ADAPTOR ................................................................................................. 2
NAMES OF PARTS ........................................................................................................................................................... 2
HOW TO SET THE POINT "0" ON TUNER DIAL MEMORY ............................................................................................. 2
DISASSEMBLY .................................................................................................................................................................. 3
REMOVING AND REINSTALLING THE MAIN PARTS ..................................................................................................... 4
ADJUSTMENT ................................................................................................................................................................... 6
NOTES ON SCHEMATIC DIAGRAM ................................................................................................................................ 9
TYPES OF TRANSISTOR AND LED ................................................................................................................................. 9
VOLTAGE .......................................................................................................................................................................... 9
SCHEMATIC DIAGRAM .................................................................................................................................................. 10
WIRING SIDE OF P.W.BOARD ....................................................................................................................................... 12
BLOCK DIAGRAM OF IC ................................................................................................................................................. 14
PARTS GUIDE/EXPLODED VIEW
General
Power source AC 110-127/220-240 V, 50/60 Hz
DC 15 V ["D" size (UM/SUM-1, R20 or HP-2) battery x 10]
Power consumption
40 W
Output power MPO: 36 W (18 W + 18 W) (AC operation, 10 % T.H.D)
RMS: 20 W (10W + 10W) (DC operation, 10 % T.H.D)
Speakers
8 cm (3-1/8") full range speaker x 4
Output terminal
Headphones: 16 - 50 ohms (recommended: 32 ohms)
Input terminal Mixing microphone: 600 ohms
Line input: 350 mV/47 kohms
Dimensions
Width: 520 mm (20-1/2")
Height: 191 mm (7-1/2")
Depth: 216 mm (8-1/2")
Weight 4.7 kg (10.4 lbs.) without batteries
Specifications for this model are subject to change without prior notice.
Before operating the unit on mains, check the preset voltage. If the voltage is different from your local voltage, adjust the voltage
as follows. Slide the selector with a screwdriver to the appropriate voltage number. (AC 110 - 127 V or AC 220 - 240 V)
SERVICE MANUAL
STEREO RADIO CASSETTE RECORDER
CONTENTS
SPECIFICATIONS

VOLTAGE SELECTION

SHARP CORPORATION
- 1 -
QT-90W
MODEL
• In the interests of user-safety the set should be restored to its
original condition and only parts identical to those specified should
be used.
Radio
Frequency range
Tape recorder
Frequency response
Signal/noise ratio
Wow and flutter
Motor
Bias system
Erase system
This document has been published to be used
for after sales service only.
The contents are subject to change without notice.
QT-90W
No. S6143QT90W///
Page
FM: 88 - 108 MHz
SW1: 2.3 - 7.3 MHz
SW2: 7.3 - 22 MHz
MW: 526.5 - 1,606.5 kHz
60 - 12,000 Hz (Normal tape)
40 dB
0.3 % (WRMS)
DC 12 V electric governor
AC bias
Magnet erase