JVC R-S77 User manual

SERVICE MANUAL
RS77
DIGITAL SYNTHESIZER
STEREO RECEIVER
SuperA\
No. 2520
FEB. 1980

Contents
—_
. Specifications ............ 00. eee eee
2. Names and Their Functions
2-(1) FrontPanel............00.00eeee
10. Printed Circuit Board Ass’y and Parts List
10-(1) TXX-267 Main Amp., Power Supply and
Other Functions Split P.C.
2-(2) RearPanel..............0-000000s 3 Board Ass‘y........-----5 10
3. Removal Procedures 10-(2) TXX-268 Equalizer, S.E.A. and Other
3-(1) Top Cover and Bottom Plates ......... 4 Functions Split P.C. Board
3-(2) Power Transistors ..........0.00005 4 ASS. sacsps0a eb htt d dino ee ae 13
4. Main Parts Location 10-(3) TXX-269 Logic and Counter P.C. Board
4-(1) Top View ...... 2.2.00 cee ee eee eee 5 NSS*Y eased a aby ae ae 15
4-(2) Front View ...........00 cee eeee 5 10-(4) TAP-283 S.E.A. Control P.C. Board
4-(3) Rear View...... 2... cece ee es 5 ASS Ye ea Ode GbE ete 8 17
5. Exploded View and Part Numbers ........... 6 10-(5) TFM-924 FM/AM Tuner P.C. Board
6. Block Diagram of Digital Synthesizer ......... 7 ASS'Y ce ee ee 18
7. Pin-plug to Pin-jack Connections Diagram ...... 7 11. Accessories List .......-...-.-2 02.0 ee eae 21
8.
FM/AM
Tuner
Alignment
Procedures
12.
Packing
Materials
and
Part
Numbers..........
21
8-(1) FM Section ..............20e 000s 8 13. R-S77 Schematic Diagram .........--0 0000s 22
8-(2) AM Section............0000ce eae 9 14. Parts List with Specified Numbers for
9.
Power
Amplifier
Idling
Current
Adjustment
Designated
Areas
.......
0.
0c
eee
eee
eee
24
Procedure ..... 00.0 e eect eect ee ne eene 9
Warning:
When replacing the parts marked with A\ , be sure to use the designated parts to ensure safety.
1. Specifications
FM Tuner Section (Figures are based upon IHF Standard)
Tuning Range : *87.9 MHz — 107.9 MHz
(87.5—108.0 MHz for 50 KHz step)
: 10.3 dBf (1.8 wV/300 Q)
Amplifier Section
RMS Power
(Both channels driven,
from 20 Hz to 20 kHz
with 0.005 %
: 60 W per channel at 8 Q2
Usable Sensitivity (IHF)
50 dB Quieting Sensitivity
Mono : 14.8 dBf (3 wV/300 Q) RMS Power : 65 W per channel at 8 Q
Stereo : 37.2 dBf (40 uV/300 22) (Both channels driven,
Distortion at 1 KHz)
Mono : 0.15 % (1 kHz) Total Harmonic Distortion : 0.005 % at rated power
Stereo : 0.3 % (1 kHz) 20 Hz — 20 kHz, 8 Q
Signal to Noise Ratio 0.001 % at rated power 1 kHz,
Mono : 80 dB (68 dB, DIN) 8
Stereo : 70 dB (62 dB, DIN) Input Sensitivity/Impedanc
Selectivity : 80 dB, +400 kHz Phono : 2.5 mV/47 kQ
(65 dB, 300 kHz, DIN) Aux : 180 mV/43 kQ
: 1.0 dB
: 100 dB at 98 MHz
: 78 dB at 98 MHz
: 45 dB at 1 kHz
Capture Ratio
IF Rejection
Image Rejection
Stereo Separation
: 180 mV/43 kQ
(180 mV/43 kQ, DIN)
Tape Play
S.E.A. Graphic Equalizer
Center Frequencies : 40 Hz, 250 Hz, 1 kHz, 5 kHz
AM Tuner Section and 15 kHz
Tuning Range : *530 kHz — 1620 kHz Control Range - £12 dB
(522 kHz—1611 kHz for 9 kHz step) Signal to Noise Ratio : Phono 77 dB
: 250 pV/m, 50 uwV
(External Antenna)
: 50 dB
: 0.5 % at 10 mV/m
: 63 dB +10 kKHz(60 dB +9 kHz, DIN)
(Note) *U.S.A. & CANADA
(New IHF 75 cB)
Tape Play 98 dB
(New IHF 75 dB)
: See page 24
Usable Sensitivity (IHF short-circuited
A network)
Signal to Noise Ratio
Distortion
Selectivity
Power Consumption
Design and specifications subject to change without notice.
Dimensions and Weight
Dimensions
Areas
Height _| Width
12.0 cm (4-23/32") | 48.0 cm (18-29/32") | 38.2 cm (15-1/16”)
11.9 em (4-11/16") |45.2 om (17-13/16”) | 38.2 om (15-1/16")
Weight
Depth Net
10.8 kg (23.8 Ibs.)
10.6 kg (23.3 Ibs.)
U.S.A., Canada & U.S. Military Market
All Other Countries
R-S77
No. 2520
4

@ POWER switch
ON: Press to turn the power on. During the
first 3 or 4 seconds after the POWER
switch is turned on, no sound will be
heard until you hear the “click” of the
relay operation. This is not due to any
defect in the unit. The built-in power
protection circuit operates to mute the
switching noise for speaker protection.
STAND BY: When the power cord is plugged into an
AC outlet, the STAND BY indicator (5)
lights to show that the memory circuit is
operating. As long as this indicator
remains lit, the preset stations are not
subject to cancellation or alteration. The
preset data are maintained even in the
case of a power failure or when the power
cord is disconnected, if the period of non-
applied power does not exceed a couple
of days.
@@® TUNING buttons
Auto tuning
Up-scanning button: When this button is pressed, the
tuned-in frequency changes in the direction of increas-
ing frequencies. Use this button to search the upper
frequency broadcast. Scanning (Auto Tuning) stops
automatically when the next FM (or AM) station is
pulled in. This tuned-in frequency is displayed digitally
by the frequency indicator.
Even if you continue to press this button, scanning
stops at some stations that can be tuned-in, but if it is
not your desired station, press the Up button again.
Press the Up-scanning button and then press the Down-
scanning button to select stations by down-scanning.
Down-scanning button: Press to tune in the direction
of decreasing frequencies. Use this button to search the
lower frequency station. Functions are identical with
those of the up-scanning button.
Note: Scanning begins by pressing the Up or Down
button, re-depressing it stops scanning.
=
2. Names and Their Functions
2-(1) Front Panel
Fig. 1
Manual tuning
Manual tuning is possible by pressing the Auto-Manual
scanning switch (10). Pressing the Up-Down-scanning
buttons, the tuned-in frequency changes in 200 kHz
steps for FM reception (50 kHz steps for Europe and
Australia) or 10 kHz steps for AM (9 kHz steps for
Europe and Australia). Tapping this button changes the
tuner step by step, continuous pressing (more than
0.5 sec.) changes tuning in a high speed scanning
sequence which stop when released.
@) Left and right channel power indicator
These LED’s indicate the output power in watts. The
values in watts are indicated per channel when one
pair of speakers having an impedance of exactly
8 ohms is being driven.
® STAND BY indicator
Lights when the POWER switch (1) is set to OFF
(STAND BY).
© Frequency indicator
The tuned-in frequency is displayed digitally. Four
digits (kHz) are displayed for AM reception and five
digits (MHz) (for continental Europe) or four digits
(MHz) (for U.S.A., Canada and other countries) are
displayed for FM reception.
@ MEMORY indicator
When the MEMROY button is pressed, this MEMORY
indicator lights to show that the unit is ready to
register the preset station to memory.
MEMORY switch
Press this switch and the memory indicator will light to
show that this unit is ready to receive a memory
setting. (This switch is a non-lock type.) Pressing the
station select button while the MEMORY indicator is
lit (for about 5 sec.) makes it possible to memorize the
station being received. When the MEMORY indicator
is not lit, the memory function does not operate.
@) Scanning indicator
This green indicator lights when you make auto or
manual tuning with the Up or Down buttons (2), (3).
R-S77
No.2520

AUTO-MANUAL SCAN switch
Press this switch in for MANUAL tuning and press
again to set to the out position for AUTO tuning.
@) SCAN LEVEL switch (LOCAL, DX)
Normally this switch is set to LOCAL so that scanning
stops automatically upon receiving only those stronger
signals. 1f you want to scan all weak signal stations, set
this switch to DX.
@ Station select buttons/Station indicators
These buttons are used to select one of the preset
stations or to preset the station for an individual chan-
nel. When one of these buttons is pressed, the LED
indicator on the corresponding button lights to indicate
which channel is in operation. If one of these buttons
is pressed when the MEMORY switch (8) is pressed in,
the station which is being received will be ‘‘“Memorized”.
One of the station select buttons can be used in
common for one FM station and one AM station.
If you change the mode from radio reception to any
other mode including power-off and back to radio
reception, the station previously selected with the
station select buttons remains tuned in. However,
unless the station select buttons are pressed, station
indicators will not light, but the scanning indicator
will light instead.
eo”. Poe
PROTECTION CIRCUIT
US PAT WO. 9691627
FM/AM OPERATION
Presetting to selected station (FM or AM)
1. Press the POWER switch to ON ( =).
2. Press the source select switch FM (or AM) to ON (=).
3. Tune to a desired station by pressing the ‘““TUNING”
buttons for AUTO or MANUAL TUNING.
4, Press the MEMORY switch ( -— ). (The memory indicator
lights.)
5. Press one of the station select buttons (=).
6. Make the same pre-tuning procedure (steps 3, 4, 5) for
the remaining channels. Pre-tuning is possible up to 12
different stations (6 FM stations and 6 AM stations).
7. Press the desired station select button for listening (=).
(This indicator on the corresponding button lights to
indicate which channel is in operation.)
Listening to FM broadcasts
1. Press the POWER switch to ON (-—).
2. Select the speaker system with the SPK-1 or SPK-2
switch.
3. Press the FM button to ON (=).
4. Press the desired station select button (= ).
5. Adjust the volume and balance to your requirements and
use the S.E.A. controls to obtain the tone you want to
hear.
aoe euecTmOUE |
eos meses cov POUIANT ow
Sooo Eeveer Aeron = FT a E PAR LUSAGER. SIDRESSER A UN
‘US PAT NO. 3566204 eas PARATEUR COMPETENT.
CAUTION: SPEAKER IMPEDANCE 1A
‘MANUFACTURED 8 | VICTOR COMPANY OF JAPAN. LTD. . ——
®
@ TAPE DIN socket (REC/PLAY) @ AM channel spacing switch
(Provided on sets for the Europe, Australia and U.K.)
@ Voltage selector
(Not provided on sets for U.S.A., Canada, Europe,
Australia and U.K.)
@ AC outlet
(Not provided on sets for Continental Europe, the
United Kingdom and Australia.)
R-S77
No.2520
(Provided on sets for the U.S.A., Canada, etc. Set this
switch according to AM channel spacing of your
country.)
©) Fuse holder
(Not provided on sets for U.S.A., Canada, Europe,
Australia and U.K.)
Note:
@ The AC outlet is not switched off by the front panel
power switch. Connect it to a component which only
uses power when operating, like a record turntable.
=o

3. Removal Procedures
3-(1) Top Cover and Bottom Plates
for U.S.A., Canada and U.S. Military Market
Screw
E23388-002
E65550-003
Serve (Ueper) Top Cover (Metal)
SBSB3008N
Screw
£65550-002
Goamecte
ad
Screw
(Lower)
(Right)
E65550-003
Screw (Upper)
ED92940-001
Cosmetic Board
(Left)
E65550-002
E300819-001
Screw (Lower)
Bottom Plate
2 Fig. 3
>
E47227-012
Foot i i Screw
23388-001
7
1
SBSB3008N
Seni
et
§_sBs8301
0z
Top
Cover
(Metal)
Screw
crew
SBSB3008Z SBSRS0002 E61660-001
Screw Screw Screw
re
for All Other Areas eadoend-ooi
Side Fitting
E300819-001
Bottom
Plate
E61660-001
Screw
E300884-001
Side
Fitting
E300820-001
Bottom
Plate
oe
|
£47227-012
SBSB3008Z
ae
——
Screw
SBSB3008Z
SBSB30102Z
Fig.
4
Screw
Screw
3-(2) Power Transistors
© TXX-267-1
Main Amp. P.C.
fi Board Ass’y
Front Panel
@ Heatsink
Rear Panel
Procedures:
Step 1: Remove the bottom plate from chassis and 2 screws
@ from heatsink @.
Step 2: Remove 4 screws @).
Step 3: Raise TXX-267 () from chassis as arrowed on Fig. 5
and then resolder the power transistor’s leads.
Step 4:Remove 4 screws ©) and heatsink from TX X-267
and then replace the power transistors.
@—s @ Fig. 5
R-S77
a
No.2520

4.
Main Parts Location
4-(1) Top View
(i Speaker Terminal P.C. Board Ass‘y
TXX-267-6
@)Power Transformer /\,
See page 24.
@) Main Amp, P.C. Board Ass‘y
TXX-267 D-1
(Refer to page 10.)
@ Electrolytic Capacitor
(8700uF/56V)
QEZ0060-878E
(0 Bar Antenna Coil
E03721-009
@)Power Supply P.C. Board Ass'y
TXX-2670-2
(Refer to page 10.)
(@) FM/AM Tuner P.C. Board Ass’y
TFM-9240
(Refer to page 18.)
@ Shield Cover
E23466-001
S.E.A.
OFF
Board
Ass‘y
©
Logic
&
Counter
P.C.
Board
Ass‘y
TXX-268-3
TXX-26901-1
oe = < (Refer to page 15.)
(@ Power Indicator Driver
P.C. Board Ass‘y Fig. 6
TXX-267-4
4-(2) Front View
(B Slide Knob (Front Panel Ass'y @Slide Knob (@Pushbuttons Ass’y
E67130-001 See page 24 E66619-001 E300928-001
R-S77
DIGITAL SYNTHESIZER STEREO RECEIVER Supe 2\,
SHA REC YAMS) TAPE 2 MOMOVEA MAHER LOLIDIMESS Aun cone von Aa CaN EO
" ~ ~ a i"
@) Pushbutton Headphone Jack Pushbutton Pushbutton
Pushbutton
E66162-001
QMS6302-102
Deer
16-001
E67269-001
©
E67116-001
.
Fig.
7
4-(3) Rear View
Q5) Pin-jack Ass‘y Q}) Bar Antenna Coil 8 Top Cover (Metal) Rear Panel AC Outlets A\
Q)DIN
Socket
(4
pins)
E03721-009
See
page
24.
@
See
page
24,
See
page
24
See page 24. E03591-41F
EAMUFACTURED #] VICTOR COMPANY OF JAPAN, L10. TOKYO, JAPAN,
@Pin-jack Ass‘y (4) Antenna Terminal Fuse Holder/\ AC Voltage Selector @3) Speaker Terminal (22) Power Cord A\
(4 pins) E03572-021 See page 24 See page 24 A E03572-007EM See page 24.
E03591-41F A :
A\:
Safety
Parts
Qi)
Strain
Relief
A\
See page 24. Fig. 8
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Block Diagram of Digital Synthesizer
EM EM 1C303 uPB553C F.L. Display
Tuning osc
Woltege Freq. | ECL 1/16. 1/17
Presealer
Li 1%
AM OSC Devided FM
Freq. OSC Freq.
-=
AM . liramere
Tuning counter
Voltage
4.5 MHz
SS X'tal
Resonator
ee ee ee ee Quatre
Programed in osc
FM 6 + last CH Micro Computer Freq.
AM 6 + last CH
Memory
CH1 —6 key 1C302 uPD1703-011 :
Memory key Fig. 10
7. Pin-plug to Pin-jack Connections Diagram
TXX-267-6
Speaker Terminal
P.C. Board Ass‘y
TXX-267-2
Power Supply
P.C. Board Ass’y
(See page 10) —_ i902 (See page 10)
——|
vin TXX-268-2
J801| Pin-jack
Power Transformer P.C. Board Ass’y
See page 24 reo1( A — (See page 13)
| f l fl fl f l l | l | =
TXX-267-1
104
P103
TFM-924
Main Amp. P.C. Board Ass’‘y
(See page 10)
FM/AM Tuner
P.C. Board Ass‘y
8
3104
2|(]
DY
se02
(See
page
18)
p701
i
[]
[3803
=
en
ee
P901c3
Br
eee
aie
|
TX
X-267-3
TXX-268-1
Speaker & STAND-BY Switch
P.C. Board Ass‘y
So
Equalizer & Switch
P.C. Board Ass’y
R-S77
No.2520
(See page 11) — (See page 13)
TXX-268-3
SEA P.C. Board Ass’y TAP-283 _
(See
page
14)
SEA
Control
P.C. Board Ass’'y (a sama A
(See page 17) fF
Connectors Table
TX X-269-1
Ral TO Bi <a Logic & Counter
In-piug Location iso Location P.C. Board Ass’y
Sone! abeereie) (See page 16)P803
P101 TFM-924 J101 TXX-269-1
P102 TFM-924 J102 TXX-269-1
P103 TFM-924 J103 TXX-269-1
P104 TFM-924 J104 TXX-268-1 +TXXD685
P201 TFM-924 J201 TXX-269-1 Seco :
P301
TXX-269-1
|
J301
TXX-268-5
ee.
Heer
eee
P302 TXX-269-1 | J302 TXX-267-2 ee page Fig. 11
P501 TAP-283 | J501 TXX-268-5 .
P701 TXX-267-1 | J701 TX X-268-3
P801 TXX-267-2 | J801 TXX-268-1
P802 TXX-267-1 | J802 TXX-268-3
P803 TXX-367-1 | J803 TXX-268-1

8. FM/AM Tuner Alignment
er
P102
TC201
om
TC202
T201
IC
201
T202
Procedures
VR101 ©
P103
P104
T203
VR102
Alignment Location of TFM-924 FM/AM Tuner P.C. Board Ass’y
Fig. 12
Frequency
Counter
Loop
Antenna AM SSG
3 Receiver
FM 75 2: 75 Q PAD
Fig. 13
8-(1) FM Section
Sensitivity
Low Frequency
1.
2.
3;
4.
5.
6.
Connect an RF generator to the antenna terminals on
the rear panel through a dummy antenna.
Set an RF generator to 90 MHz, a modulation of 1 kHz
and a deviation of 75 kHz to provide an input of 2 uV.
Connect a VTVM and an oscilloscope to the Rec. out
jacks on the rear panel.
Set the frequency display to 89.9 MHz.
Adjust L104 so that ‘“’V. TUNE” -TP116 indicate 3.7
V by VTVM.
Adjust three coils L101, L102 and L103 in the tuning
gang to maximize the output.
High Frequency
7.
10.
11.
Set the RF generator to 106 MHz, a modulation of
1kHz and a deviation of 75 kHz to provide an input
of 2uV.
. Set the Frequency Display to 105.9 MHz.
. Adjust TC104 so that ‘‘V. TUNE” TP116 indicate 18.0
V by VTVM.
Adjust the FM trimmers TC101, TC102 and TC103 in
the tuning gang to maximize the output.
Repeat these high and low frequencies adjustment
alternately until maximum sensitivity is obtained.
Distortion Meter
Oscilloscope
Descriminator, Distortion and Signal Gain
w
NOoS
co
. Press to FM position.
Connect an RF generator, 1 kHz modulation and a
75 kHz deviation to the antenna terminals on the rear
panel through a dummy antenna.
Connect an oscilloscope, Distortion Meter and VT VM
to the Rec. out jacks on the rear panel.
Set the RF generator to 97.9 MHz.
Set the Frequency Display to a 97.9 MHz.
Connect aDC VTVM between TP111 and 112.
Adjust the core indicated arrow A of T7101 for DC
VTVM reading of 0 (zero) mV.
Adjust the core indicated arrow B of T101 so that the
distortion is minimized at a value less than 0.4 %.
Multiplex and Stereo Separation
Multiplex
1.
Set the stereo signal generator as follows: 400 Hz
modulation frequency, 7.5kHz deviation pilot,
67.5 kHz main and sub carriers. Connect its output to
the RF generator.
. Connect an RF generator to the antenna terminals
through a dummy antenna.
. Connect a VTVM, an oscilloscope and a distortion
meter to the Rec. out jacks on the rear panel.
Set the RF generator to 97.9 MHz and output of 1 mV.
Set the frequency display to 97.9 MHz.
. Connect the frequency counter to 19 kHz Test Point
(TP110).
Switch off the pilot signal of stereo modulator.
Adjust VR103 so that the frequency counter indicates
19 kHz (0 ~ -50 Hz).
Stereo Separation
9.
10.
11.
12.
13,
Switch the selector of stereo modulator to left channel
modulation.
Adjust VR102 so that the output of right channel is
minimized.
Switch the selector of the modulator to right channel
modulation.
Adjust VR102 so that the left channel is minimized.
Set VR102 to a average, if the separation of left and
right is different. R-S77
No.2520

Muting Level
Note: No adjustment is necessary. However, if the check-
up is required, take the following steps.
1. Release the MONO/FM MUTE OFF pushbutton during
this adjustment procedures.
2. Connect a VTVM and an Oscilloscope to the Rec. out
jacks on the rear panel.
3. Set the RF generator to 108 MHz, a modulation of
1 kHz and a deviation of 75 kHz, to provide an input
of 8uV.
4. Turn VR101 clockwise and remember the point (or
position) at which the muting ceases operating.
5. Turn VR101 counterclockwise slightly so that the out-
put level drops by 1 dB.
6. Attenuate the output of the RF generator to 2 dB from
8 uV of step 2 and check that the muting is still oper-
ating.
8-(2) AM Section
Tracking and Sensitivity
Low Frequency
1. Press to AM position
2. Connect the RF generator to the antenna terminals on
the rear panel, set this to 600kHz (603 kHz) with
30 %modulation at 400 Hz.
3. Connect an AC VTVM and an Oscilloscope to the Rec.
Out jacks on the rear panel.
4. Set the frequency display of the unit to 600 kHz
(603 kHz).
5. Adjust T201, T202, T203 and the ferrite bar antenna
adjusting the coil to maximize the output signal.
High Frequency
6. Set the RF generator to 1400 kHz (1404 kHz) with
30 %modulation at 400 Hz.
7. Set the frequency display of the unit to 1400 kHz
(1404 kHz).
8. Adjust the trimmers TC201, TC202 in the tuning
_ gang so that the output signal is maximized.
9. Repeat these high and low frequencies adjustment
procedures alternately until maximum sensitivity is
obtained.
9. Power Amplifier Idling Current Adjustment
Procedure
R738
Right
channel
Adjustment Location of TX X-267 [_]-1 Main Amp. P.C. Board Ass’y
Precaution:
(1) Allow the set to warm up at least 5 minutes before
connecting aDC VTVM.
(2) Must keep the heatsinks cooling to prevent overheating
and consequent destruction of the semiconductor
junction and set the volume control to minimum
during these adjustment procedures.
(_): for Right channel Adjustment
R-S77
No.2520
Fig. 14
Procedures:
1. Turn R737 and (R738) fully counterclockwise before
the power switch on.
2. Connect a DC VTVM to the Test Point L-CH and L-E
(R-CH and R-E).
3. Adjust R737 (R738) for DC VTVM reading of 5 mV.