Hitachi HT 20 S Service Manual
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Extracted text from Hitachi HT 20 S Service Manual (Ocr-read)
Page 1
@ HITACHI
SERVICE MANUAL
SAFETY PRECAUTIONS
TY
No.245 EGF
HT-2OS
CONTENTS
SPECIFICATIONS ...... 1
FEATURES ........................ 3
SERVICE POINTS .................... 3
ADJUSTMENTS ....... 4
EXPLODED VIEW ...... 8
REPLACEMENT PARTS LIST ..... 9,11
CIRCUIT DIAGRAM ................. 10
PRINTED WIRING BOARD ............. 11
The following precautions should be observed when servicing.
1. Since many parts in the unit have special safety related characteristics, always use genuine Hitachi replacement parts.
Especially critical parts in the power circuit block should not be replaced with other makes.
Critical parts are marked with A in the schematic diagram and circuit board diagram.
2. Before returning a repaired unit to the customer, the service technician must thoroughly test the unit to ascertain that it is
completely safe to operate without danger of electrical shock.
SPECIFICATIONS
Type
Pl atter
Motor
Speed
SIN
Wow 81 Flutter
Effective length
Overhang
Tracking error
Adjustable force range
(scale)
Acceptable cartridge
weight
Lead wire capacitance
Accessory HITACHl
cartridge
Cartridge
2-speed belt drive system
Aluminum alloy dlecast, 310 mm outer
diameter
DC servo motor
2 speeds, 33-1/3 and 45 rpm
70 dB lDlN-B)
035% WRMS
220 mm
15 mm
20
0 - 3 9/1 turn of the balance weight
(directly readable in 0,1 9 steps]
4~9g
140pF
Dual magnet type (MTGS) (far U,S.A. &
Canada}
Movmg magnet type (M115) (except
U.S.At & Canada)
Frequency response
Output voltage
Channel difference
Channel separation
Tracking force
Stylus tip
Power source
Power consumption
Dimension
Weight
Other devices
10 7 25,000 Hz
25 mV (M735) or 3 mV (MT'15)
at 1 kHz 50 rnm/sec.
1 dB at 1 kHz
23 dB at 1 kHz
15 7 2.5 g (recommended 2 9)
Diamond stylus lDS-ST35 or DS-STIS)
120 V 60 Hz for U.S.A. 84 Canada standard
220 V 50 Hz for Europe standard
240 V 50 HZ for UK 8: Australia standard
110-120/220-240 V 50/60 Hz for Asia 8!
Latin America countries
3 Watts
435 1W) x 365 (D) x 110 (H) mm
(1771/8 X14~3/8 x 4-11/32
4 kg l8_8 lbs.)
Auto return, auto cut, antirskating, track-
ing force direct-reading balance weight,
viscous damped cueing.
SPECIFICATIONS AND PARTS ARE SUBJECT TO CHANGE FOR IMPROVEMENT.
BELT DRIVE TURNTABLE
February 1981
TOYOKAWA WORKS