Rotel RT-955 Service manual

Quality Uncompromised

®

Technical

Manual

Table of Contents

Specification......................................1

Parts List ...........................................2~5

Adjustment........................................6~12

PCB Assembly ..................................13~15

Schematic Diagram ..........................16~22

Specification

FM Tuner

Usable Sensitivity: 12.2 dBf
50dB Quieting Sensitivity: 20.2 dBf (mono)

Signal to Noise Ratio (at 65 dBf): 75 dBf (mono)

Harmonic Distortion (at 65 dBf): 0.2 % (mono)

Frequency Response: 10 Hz - 15 kHz, ± 3 dB
Capture Ratio: 2.0 dB
Alternate Channel Selectivity: 47 dB (± 400 KHz)
Spurious Response Ratio: 90 dB
Image Rejection Ratio: 80 dB
IF Rejection Ratio: 80 dB
AM Suppression Ratio: 55 dB
Stereo Separation (100Hz/1 KHz/10 KHz): 40 dB/45 dB/35 dB
Output level: 1.2V
Antenna Input: 75 ohms unbalanced

AM Tuner

Usable Sensitivity: 300 μV/m
Selectivity: 25 dB
Harmonic Distortion : 0.5 %
Image Rejection Ratio: 45 dB
Signal to Noise Ratio: 48 dB
Output level: 165 mV
Antenna Input: Loop Antenna

General

Power Consumption: 10 Watts
Power Requirements (AC): 120 volts, 60 Hz (USA version)

Weight: 3.7 kg/8.2 lb.
Dimensions (W x H x D): 440 x 72 x 286 mm

AM/FM STEREO TUNER

RT-955

45.3 dBf (stereo)

72 dBf (stereo)

0.3 % (stereo)

230 volts, 50 Hz (European version)

173/8" x 27/8" x 111/4"

SHINSEN-BLD. 4F 10-10 SHINSEN-CHO, SHIBUYA-KU,
TOKYO 150-0045, JAPAN

Serial. NO.
Beginning

Y-329A-00065C/S-S

Parts List-1

SYMBOL PARTS NO. DESCRIPTION SYMBOL PARTS NO. DESCRIPTION

X-1273-01 PCB ASSEMBLY

ANT200
ANT201
C201.202
C203
C204

ANTENNA TERMINAL 1P
ANTENNA TERMINAL 3P

0.01UF

0.022UF
100UF/16V

ANTENNA-A
ANTENNA-B
CERAMIC CAPACITOR
CERAMIC CAPACITOR
ELECTRIC CAPACITOR

C304
C306-308
C309
C311.312
C313

0.047UF

0.022UF
220PF

0.022UF
47UF/16V

CERAMIC CAPACITOR
CERAMIC CAPACITOR
CERAMIC CAPACITOR
CERAMIC CAPACITOR
ELECTRIC CAPACITOR

C205.206
C207-210
C211.212
C213
C214

C215
C216
C217
C218
C219

C221
C222
C223-236
C237
C238-241

C242
C243
C245.246
C247
C248

C249
C250.251
C252
C253
C254

33PF-CH
1000PF

0.022UF

0.01UF

3.3UF/50V

0.022UF
100UF/16V

0.022UF
47UF/16V

0.022UF

0.022UF
47UF/16V

0.022UF
100PF

0.047UF

150PF

0.022UF

0.022UF
1UF/50V

0.022UF

1UF/50V

0.022UF
100UF/16V

0.022UF
1UF/50V

CERAMIC CAPACITOR(CH TYPE)
CERAMIC CAPACITOR
CERAMIC CAPACITOR
CERAMIC CAPACITOR
ELECTRIC CAPACITOR

CERAMIC CAPACITOR
ELECTRIC CAPACITOR
CERAMIC CAPACITOR
ELECTRIC CAPACITOR
CERAMIC CAPACITOR

CERAMIC CAPACITOR
ELECTRIC CAPACITOR
CERAMIC CAPACITOR
CERAMIC CAPACITOR
CERAMIC CAPACITOR

CERAMIC CAPACITOR
CERAMIC CAPACITOR
CERAMIC CAPACITOR
ELECTRIC CAPACITOR
CERAMIC CAPACITOR

ELECTRIC CAPACITOR
CERAMIC CAPACITOR
ELECTRIC CAPACITOR
CERAMIC CAPACITOR
ELECTRIC CAPACITOR

C314
C316
C317
C318
C319

C321
C322
C323.324
C325
C326

C327
C328
C329
C330
C401

C402-404
C405.406
C407.408
C409
C411

C412
C413
C414
C415.416
C417

0.022UF
1000PF

0.047UF-M

0.056UF-M

0.022UF

100UF/16V

0.01UF

0.022UF

3.3UF/50V

4.7UF/50V

1UF/50V
470PF

0.047UF

0.022UF-M

0.022UF

47UF/16V

0.0033UF

0.01UF
10UF/50V

4.7UF/50V

10UF/50V

4.7UF/50V

0.022UF-M

0.0033UF-M

0.0068UF-M

CERAMIC CAPACITOR
CERAMIC CAPACITOR
MYLAR CAPACITOR
MYLAR CAPACITOR
CERAMIC CAPACITOR

ELECTRIC CAPACITOR
CERAMIC CAPACITOR
CERAMIC CAPACITOR
ELECTRIC CAPACITOR
ELECTRIC CAPACITOR

ELECTRIC CAPACITOR
CERAMIC CAPACITOR
CERAMIC CAPACITOR
MYLAR CAPACITOR
CERAMIC CAPACITOR

ELECTRIC CAPACITOR
CERAMIC CAPACITOR
CERAMIC CAPACITOR
ELECTRIC CAPACITOR
ELECTRIC CAPACITOR

ELECTRIC CAPACITOR
ELECTRIC CAPACITOR
MYLAR CAPACITOR
MYLAR CAPACITOR
MYLAR CAPACITOR

C255
C257
C259
C260
C261

C262
C263
C264.265
C266
C267

C268.269
C270
C271
C272
C273

C274
C275
C276
C278.279
C280

C281
C282-284
C285
C301
C302

0.047UF

0.022UF

0.047UF
680PF

0.47UF/50V

1UF/50V

0.047UF
1UF/50V

0.01UF

0.022UF

0.47UF/50V

4.7UF/50V

0.047UF

0.01UF

0.022UF

10UF/50V
68PF
330PF
10UF/50V
270PF

33UF/35V
100UF/16V

0.022UF
470PF-POLY
18PF-CH

CERAMIC CAPACITOR
CERAMIC CAPACITOR
CERAMIC CAPACITOR
CERAMIC CAPACITOR
ELECTRIC CAPACITOR

ELECTRIC CAPACITOR
CERAMIC CAPACITOR
ELECTRIC CAPACITOR
CERAMIC CAPACITOR
CERAMIC CAPACITOR

ELECTRIC CAPACITOR
ELECTRIC CAPACITOR
CERAMIC CAPACITOR
CERAMIC CAPACITOR
CERAMIC CAPACITOR

ELECTRIC CAPACITOR
CERAMIC CAPACITOR
CERAMIC CAPACITOR
ELECTRIC CAPACITOR
CERAMIC CAPACITOR

ELECTRIC CAPACITOR
ELECTRIC CAPACITOR
CERAMIC CAPACITOR
FILM CAPACITOR
CERAMIC CAPACITOR(CH TYPE)

C501
C502
C503
C504
C505

C506.507
C508
C509
C511
C512

C513.514
C515
C516
CL201.202
CL203

CL204
CL271
CL273
CL277
CR201.202

CR203
CR204
CR271
CR273
CR277

3300UF/35V
47UF/50V

0.068UF-M

4.7UF/50V

0.068UF-M

0.022UF
10UF/50V

0.022UF
47UF/16V
220UF/16V

47UF/16V
47UF/35V

2.2UF/50V
22UF/16V

0.0039UF-M

1000PF
270PF
120PF
100PF
22UF/16V

0.0039UF-M
1000PF
270PF
120PF
100PF

ELECTRIC CAPACITOR
ELECTRIC CAPACITOR
MYLAR CAPACITOR
ELECTRIC CAPACITOR
MYLAR CAPACITOR

CERAMIC CAPACITOR
ELECTRIC CAPACITOR
CERAMIC CAPACITOR
ELECTRIC CAPACITOR
ELECTRIC CAPACITOR

ELECTRIC CAPACITOR
ELECTRIC CAPACITOR
ELECTRIC CAPACITOR
ELECTRIC CAPACITOR
MYLAR CAPACITOR

CERAMIC CAPACITOR
CERAMIC CAPACITOR
CERAMIC CAPACITOR
CERAMIC CAPACITOR
ELECTRIC CAPACITOR

MYLAR CAPACITOR
CERAMIC CAPACITOR
CERAMIC CAPACITOR
CERAMIC CAPACITOR
CERAMIC CAPACITOR

2

Parts List-2

SYMBOL PARTS NO. DESCRIPTION SYMBOL PARTS NO. DESCRIPTION

CF201.202
CF203
CF204
CF205
CF301

D201
D202-205
D208
D209-212
D301.302

D303-305
D307.308
D401
D501-505
D506

D507
D508
D509
D510
D511

F501.502
FFE200
IC201
IC202
IC203

FM FILTER 10.7MM-A
FM FILTER 10.7MJA10-A
FM FILTER 10.7MM-A
CSB456F11
SFPS450H

1N4004
1N4148
ZENER 5.1V
1N4148
KV1236Z

1N4148
1N4148
ZENER 5.1V
1N4004
ZENER 30V

ZENER 6.2V
ZENER 12V
1N4148
ZENER 5.6V
1N4004

036 5ST500
FTA4-460H
LC72191M
LA1235
LA1235

FM IF CERAMIC FILTER
FM IF CERAMIC FILTER
FM IF CERAMIC FILTER
CERAMIC RESONATOR
FILTER FOR AM

SWITCHING DIODE
SWITCHING DIODE
ZENER DIODE
SWITCHING DIODE
VARACTOR DIODE

SWITCHING DIODE
SWITCHING DIODE
ZENER DIODE
SWITCHING DIODE
ZENER DIODE

ZENER DIODE
ZENER DIODE
SWITCHING DIODE
ZENER DIODE
SWITCHING DIODE

MINI FUSE 250V T500MA
FM FRONT-END
PLL IC
SIGNAL METER IC
FM IF IC

Q503
Q504
Q505
Q506
QL201

QR201
R201
R202
R203.204
R205

R207.208
R211-213
R214-218
R222
R223

R224
R225
R226
R231.232
R233

R236
R238
R239
R240
R241

KTC3198Y
DTC114Y
DTA114Y
KTC3198Y
KTD1303

KTD1303

4.7K
82R
100K
1K

100K
220R
1K
220R
560R

10K

5.6K
330R
220R
1K

330R
27K
330R
150R
470R

TRANSISTOR
TRANSISTOR
TRANSISTOR
TRANSISTOR
TRANSISTOR

TRANSISTOR
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%

RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%

RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%

RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%

IC204
IC205
IC301
IC401
IC501

✰

ICM101
J321
JACK1
JACK2

L201-206
L207
L500
LFL200
LFR200

Q201.202
Q204
Q206.207
Q209
Q211

Q212
Q213-216
Q219
Q222
Q223

LA3450
NJM072DE
LA1245
LA2230
NJM317F

HEAT SINK(24X17X30)
LTV817

4.7K
MINI JACK
RCA 2P

56UH

20.8MH
56UH
KLM5B2-T
KLM5B2-T

KTC3198Y
DTA114Y
DTA114Y
2SC1740S
2SC1740S

2SK192GR
KTC3195Y
KTC3198Y
DTC114Y
2SK117

MPX IC
DUAL OP AMP
AM IF IC
RDS IC
REGULATOR IC

REG.IC HEAT SINKER
PHOTO COUPLER IC
RESISTOR 5%
MULTI-ROOM JACK
RCA JACK

INDUCTOR
FTZ COIL
INDUCTOR
MPX LPF COIL
MPX LPF COIL

TRANSISTOR
TRANSISTOR
TRANSISTOR
TRANSISTOR
TRANSISTOR

FET
TRANSISTOR
TRANSISTOR
TRANSISTOR
FET

R242
R243
R244
R245
R246

R247
R248
R249
R250
R257.258

R259
R260
R261
R262
R263

R264
R265.266
R271
R272.273
R274

R275
R276
R277
R278
R279

330R
15K
390R

6.8K

3.3K

22R
390R
330R

4.7K
330R

6.8K

3.3K
39R
390R
330R

4.7K
330R
330R
100K
18K

47K
1K
10R(1W)
10K

3.3K

RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%

RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%

RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%

RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%

RESISTOR 5%
RESISTOR 5%
WATT RESISTOR
RESISTOR 5%
RESISTOR 5%

Q225
Q301
Q302
Q501
Q502

DTA114Y
2SK192GR
DTA114Y
DTC114Y
BKTA1267Y

TRANSISTOR
FET
TRANSISTOR
TRANSISTOR
TRANSISTOR

R281
R282
R283
R284.285
R286

3

18K
1K
10K
120K

3.3K

RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%

Parts List-3

SYMBOL PARTS NO. DESCRIPTION SYMBOL PARTS NO. DESCRIPTION

R288
R289
R291.292
R297
R298

R299
R300
R301.302
R303
R304

R305
R306.307
R308
R309
R311

R312
R313
R314
R316.317
R318

R319
R320
R321
R401.402
R403

5.6K
10K
100K

4.7K
22R

1M

1.5K
100K
100R
820R

470R
220R
10K
100K
100R

1K

4.7K
2K
220R
82R

10K
100K
10K
560R
680R

RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%

RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%

RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%

RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%

RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%

RL203
RL204
RL205
RL206
RL294

RL295
RM101
RR201
RR202
RR203

RR204
RR205
RR206
RR294
RR295

RLY201.202
TC301
TC302
TL201
TL202

TL301
TL302
TL303
TL304
VR201

8.2K
470R
100K

3.3K
180K

100K
270R

3.3K

6.8K

8.2K

470R
100K

3.3K
180K
100K

G5A-237P DC12V
TRIMER 10P(WHITE)
TRIMER 20P(RED)
FM-DET-A
FM-DET-B

AM-OSC1
AM-ANT2
AM-IFT1
AM-IFT2
VR.47K

RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%

RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%

RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%

RELAY
VARIABLE CAPACITOR
VARIABLE CAPACITOR
FM DET.COIL
FM DET.COIL

AM OSC.COIL
AM ANT .COIL
AM IFT COIL
AM IFT COIL
VARIABLE RESISTOR

R404
R405
R406
R407
R408

R409
R410
R411
R412
R413

R501
R502
R503
R504
R505

R506
R507
R508
R509
R511

R513
R514
R515
R516
R517

1K
3M
1K

5.6K

3.3K

10K
3M
33K
10K
22K

4.7K
10K
82R
270R
200R

1.8K
330R(1W)
10K
270R(1W)
1K

22K
10K
100R
12K
10K

RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%

RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%

RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%

RESISTOR 5%
WATT RESISTOR
RESISTOR 5%
WATT RESISTOR
RESISTOR 5%

RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%

VR203
VR204
VR205
VR206
VR301

VR401
XTL201
XTL401

C101-107
C110.111
C112
C113
C114.115

C116
C117
C118
C119
C121

D101-107
D118
ENC101
FL101
Q101

VR.22K
VR.1M
VR.470K
VR.4.7K
VR.22K

VR.10K
XTAL 7.2MHZ
CSB456F15

X-1273-02 PCB ASSEMBLY

100PF

0.047UF
22UF/16V(SE TYPE)

0.1UF
820PF

0.1UF
820PF
1000PF
100PF

0.1UF

1N4148
1N4148
EC16B24202
SVR-12MM18(35S/12G)
KTC3198Y

VARIABLE RESISTOR
VARIABLE RESISTOR
VARIABLE RESISTOR
VARIABLE RESISTOR
VARIABLE RESISTOR

VARIABLE RESISTOR
CRYSTAL
CERAMIC RESONATOR

CERAMIC CAPACITOR
CERAMIC CAPACITOR
ELECTRIC CAPACITOR
CERAMIC CAPACITOR
CERAMIC CAPACITOR

CERAMIC CAPACITOR
CERAMIC CAPACITOR
CERAMIC CAPACITOR
CERAMIC CAPACITOR
CERAMIC CAPACITOR

SWITCHING DIODE
SWITCHING DIODE
VR ENCODER
VFD FOR RDS/RBDS
TRANSISTOR

R518
R519
R520
RL201
RL202

4.7K
56K
47K

3.3K

6.8K

RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%

R101-135
R136
R137-143
R146-149
R150.151

4

120K
10K
1K2
47K
2R2

RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%

Parts List-4

SYMBOL PARTS NO. DESCRIPTION SYMBOL PARTS NO. DESCRIPTION

X-1273-06 PCB ASSEMBLY

R152
R155.156
R157
R158-163
R164

SW101-112
SW114-116
SW118-120
SW122-124
SW126-128

10K
10K
47K
10K
1K2

TACT SWITCH(SKHVBH)
TACT SWITCH(SKHVBH)
TACT SWITCH(SKHVBH)
TACT SWITCH(SKHVBH)
TACT SWITCH(SKHVBH)

RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%

TACT SWITCH
TACT SWITCH
TACT SWITCH
TACT SWITCH
TACT SWITCH

C601-605
D601-604
IC601
JACK3

1UF/50V
ZENER 12V
MAX232CPE
DB9 JACK(MALE)

OTHERS

011 FP-504
012 SK4-06A00
012 4TQF-15
014 C-4550A02
014 4TQN-12B#5

ELECTRIC CAPACITOR
ZENER DIODE
RS232 DRIVER IC
DB9 JACK

FRONT PANEL ASSY
KNOB 33F
POWER BUTTON 14X14
UPPER COVER
BOTTOM BOARD

U101
U102
XT101

CM101
QM101
RM102
RM103
RM104

RMC201

C540
SW201

TF201

CXP82832-182Q
AT24C16
CST10.00MTW

X-1273-03 PCB ASSEMBLY

10UF/16V(SE TYPE)
KTC3198Y
100R
150R

4.7K

CRV1M352-00B

X-1273-04 PCB ASSEMBLY

0.0047UF/400V
POWER SW.TV-5

X-1273-05 PCB ASSEMBLY

022 T-1065N01

CPU
EEP ROM
RESONATOR 10.0MHZ

ELECTRIC CAPACITOR
TRANSISTOR
RESISTOR 5%
RESISTOR 5%
RESISTOR 5%

REMOTE CONTROL SENSOR

SPARK KILLER(AC CERAMIC)
SWITCH

POWER TRANSFORMER

015 RP-360
019 4TSH-19#2
021 RLA145A00
034 SEL1124R
069 C-4629A01

072 4TR-2489
072 4TR-2875
072 4TR-3228
072 C-4620A01
072 C-4622A01

072 C-4623A01
072 C-4624A01
081 SK4-10A00
081 TZ-164-1
092 RR-T91

PRINTED REAR CHASSIS
PLASTIC FOOT 50F
AM LOOP ANTENNA
LED
AC INLET

3.5MM PLUG SHIELD CORD
RCA PIN CORD
T TYPE ANTENNA
AC CORD SET for STD
AC CORD SET for AUSTRALIA

AC CORD SET for UK
AC CORD SET for CEE
INSIDE CARTON
STYROL SIDE MOULDING
REMOTE UNIT

5

Adjustment

■ FM

* Necessary measurement equipment

RDS/STEREO Multiplexer 1 unit
FM/AM Signal Generator 1 unit
Audio Signal Analyzer 1 unit
Oscilloscope 1 unit
Digital Volt Meter (DVM) 1 unit

(A) Center adjust

❏ RDS/STEREO Multiplexer Setting

– MODE : MONO
– Audio Frequency : 1KHz

❏ FM Signal Generator Setting

– Deviation : 75KHz
– Radio Frequency : 98.0MHz
– Output Level : 66dB

❏ RT955 Setting

– FM Frequency : 98.0MHz
– Antenna Selection : A
– FM MODE : MONO
– IF MODE : WIDE

Oscilloscope

Monitor

Audio
Signal
Analyzer

L-CH

(or R-CH)

FM
Signal
Generator

BACK

(FM-DET -B)
TL 202

TL 201
(FM-DET -A)

Jack 2 Ant-B

(ANT 201)

IC 203

R 282

Ant-A

(ANT 200)

DVM

(+)

(-)

FRONT

q Turn FM Signal Generator Modulation on
w Connect DVM (+)(-) terminals to both ends of resistor R282 and measure the volt.
e Make this measured volt '0' by adjusting TL201(FM-DET-A Coil).

(The adjustment should be within ±2mV)
r After this adjustment, measure THD(Total Harmonic Distortion) with Audio
Signal Generator.
t Adjust THD to minimum point with TL202(FM-DET-B Coil).
(THD should be within 0.5%)

Stereo
Multiplexer

6