Technics RS-B14 User manual

Dolby
В»
С
NR-Equipped
ORDER NO. HAD84052768C1
Service Manual
Cassette Deck
RS-B14
Stereo Cassette Deck
DC poer ecc wn]
RS-636 MECHANISM SERIES
Specifications
Deck system:
Track system:
Heads:
REC/PLAY;
Erasing;
Motor:
Recording system:
Bias frequency:
Erasing system
Tape speed:
Frequency response:
Metal;
CrO;;
Normal;
S/N:
Stereo cassette deck
4-track, 2-channel
MX head
Double-gap ferrite head
1 motor system
AC bias
80 kHz
AC bias
4.8 cm/sec.
20 Hz~17 kHz
40 Hz—16 kHz 3 dB
20 Hz~17 kHz
40 Hz~15 kHz X3 dB
20 Hz—16 kHz
40 Hz~14 kHz +3 dB
(Signal level=max recording
level, CrOz type tape)
Dolby C NR in;
Dolby B NR in;
NR out;
75 dB (CCIR)
67 dB(CCIR) :
57 dB (A weighted)
Design and specifications are subject to change without notice.
* Dolby' and the double-D symbol are trademarks of Dolby Laboratories Licensing Corporation.
Technics
Matsushita Engineering and
Service Company
50 Meadowland Parkway,
Secaucus. New Jersey 07094
Color
| (K)...Black Type
(S)...Silver Type
Area
usd U.S.A.
[C]...... Canada.
Wow and flutter:
Fast Forward and
Rewind Time:
Input sensitivity
and impedance:
MIC;
LINE;
Output voltage
and impedance:
LINE;
HEADPHONES;
Power consumption:
Power supply:
Dimensions
(WXHXD):
Weight
Matsushita Electric
Panasonic Hawaii Inc.
91-238 Kauhi St. Ewa Beach
P.O. Box 774
Honolulu, Hawaii 96808-0774
0.0796 (WRMS)
Approx. 110 seconds with C-60 cassette
tape
0.25 mV/4000-—10 КО
70 mV/47 КО
400 mV/1.8 КО
80 mV/8 Q
11W
AC 50 Hz/60 Hz, 120 V
430x108x220 mm
(1629/52" x 48/32" x 92152")
3.1 kg (6 Ibs. 13 02.)
Panasonic Sales Company,
of Puerto Rico, Inc.
Ave, 65 De Infanteria, KM 9.7
Victoria Industrial Park
Carolina, Puerto Rico 00630
of Canada Limited
5770 Ambler Drive, Mississauga,
Ontario, LAW 2T3
Division of Matsushita Electric

Ш CONTENTS
ITEM PAGE
* Location of Controls and Components ......... 2
© Safety Ргесашйіопв5.................................... 3
е Insulation Resistance Test ........................ 3
е Disassembly Instructions ........................... 3
* Measurement and Adjustment Methods ......... 5
е Block Піадгат........................................ 10
• Schematic Diagram ................................. 12
ITEM
* Electrical Parts List .................................
е Circuit Boards and Wiring Connection
Оіадгатї: «susce etium rese Deme sa S eri des
* Mechanical Parts Location
(included Parts List) ...........................
* Cabinet Parts Location (included Cabinet,
Accessories and Packing Parts List) ......
Ш LOCATION OF CONTROLS AND COMPONENTS
(D Power Switch
[power (Ж off • = on)]
Recording Indicator
[rec]
4% Cassette Holder
47 Tape Counter and Reset Button [tape counter - reset]
Input Level Control [input level)
@ Dolby NR Switch [Dolby NR (ЖШ out • = in)]
(5) FL (fluorescent level) Meters
|
e 44 Balance
xl © © | Control
2
Eject
|
ӨТ
[||
[Ба!апсе
Виїїоп — © © © (left «
ecr
A
oat
;
г
center.
[eject
(4)]
[eTel
ше
right)]
@ Record Button
[rec- © (9)]
(4) Play Button [play-
(8)
Stop
Button
[stop
"uM
5
(>))
(6) Rewind/Review Button
[rew/rev (44))
@ Tape Selector
13 Microphone Jacks
[tape
select
[mic
(left
»
right)]
(Normal
•
CrO;-
(2
Headphones
Jack
[phones]
Metal)]
17
Input
Selector
Pause
Button
[input
select
(Ж
line-
=
mic)]
[pause
(11)]
Dolby
NR
Select
Switch
“-(7)
Fast
Forward/Cue
[Dolby
NR
(IR
[E]
«
—
(hj
Button [ff/cue (PP )]
7/09 Line Input Jacks [LINE IN (L-R)]
7 À Line Output Jacks [LINE OUT (L -R)]

Ш SAFETY PRECAUTIONS (For U.S.A.)
. Before servicing, unplug the power cord to prevent an electric shock.
.
When
replacing
parts,
use
only
manufacturer's
recommended
components
for
safety.
. Check the condition of the power cord. Replace if wear or damage is evident.
. After servicing, be sure to restore the lead dress, insulation barriers, insulation papers, shields,
etc.
Aa WPM —
5. Before returning the serviced equipment to the customer, be sure to make the following insulation
resistance test to prevent the customer from being exposed to a shock hazard.
Ш INSULATION RESISTANCE TEST (For U.S.A.)
1. Unplug the power cord and short the two prongs of the plug with a jumper wire.
2. Turn on the power switch.
3. Measure the resistance value with ohmmeter between the jumpered AC plug and each exposed
metal cabinet part, such as screwheads, antenna, control shafts, handle brackets, etc. Equipment
with antenna terminals should read between 3MQ and 5.2M to all exposed parts. (Fig. 1)
Equipment without antenna terminals should read approximately infinity to all exposed parts.
(Fig. 2)
* Note: Some exposed parts may be isolated from the chassis by design. These will read infinity.
Antenna
terminal
Exposed Exposed
metal metal
part part
Ohmmeter d jussis
Fig. 1 Fig. 2
Resistance = 3M2—5.2M& Resistance = Approx оо
4. If the measurement is outside the specified limits, there is a possibility of a shock hazard. The
equipment should be repaired and rechecked before it is returned to the customer.
Ш DISASSEMBLY INSTRUCTIONS
The head azimuth can be
adjusted by removing the
cassette lid.

AC power transformer Main circuit Record/playback
circuit board (о) board changing wire
| \ 0 (К)
(0) How їо remove flat cable
Flat cable White line Open the lid of connector in the
direction of the arrow as shown
left-hand, and extract the flat
cable to disconnect.
Connector
(Flat cable connector)
FL meter
circuit board
Power switch circuit board (C)
Fig. 3
I
1
(9 1-Clamper (N)
|
1
Motor assembly
Volume circuit board
Fig. 6 Fig. 7
Shown in
Ref. No. Procedure To remove —. Remove —. fig. —
Case cover SB SCIOWS uestis ener ento sa P ue ER due (A) 1
* As shown in fig. 6, raise the clampers in
PDF the direction of arrow @ and remove
2 LED «аин баата the LED circuit board іп the direction S
of arrow® .
9 38СТӨМе eux dan exti иии ушу залы eda қада юшде da ag (B) 2
3 1-2-3 а ie e Pull out the connectors [А] [B]. ............... (С) 3
* How to remove flat cable [C] [D] F] ......... (D) | 3
--4--

| RS-B14 |
Іш 2 Procedure To remove —. Remove —. ps in
* Push the eject button ........................... (E) 1
9.2 о СТУС езара Yon once i ep NU uS rd (F) 2
92 SCIOWS: aus sis teria cie vel; 2 oi ware es one adie арқар (G) 5
қ ; Remove the counter Беії........................ (H) 5
4 1-4 M :
echamsm umit * Pull out the connectors [A] [B] ............... (C) 3
* As shown in fig. 3, remove the record/
playback changing wire in the direction 3
of arrow (3).
Г ST STEW еа Г ЛУГ ГКК Г Г mae and (J) 3
©“ SGEOW аы ал нен дббн дублі а qu (К) 3
* As shown in fig. 3, remove the record/
playback changing wire in the direction 3
5 1-2-5 Main circuit board * of arrow (8) .
* When measuring and adjusting, set the
main P.C.B. as shown in Fig. 4. 4
Then, connect the ground of main P.C.B.
and the bottom case with a wire.
6 1-6 EL meter circuit board * How to remove flat cable [D] .................. (D) 3
% 2156ГЕ: mens mue cec scia anus ur m à sae DR dd (P) 5
* How to remove flat cable [C] .................. (D)
* As shown in fig. 6, raise the clampers іп
7 1-6-7 Volume circuit board the direction of arrow (1) and remove 6
the volume circuit board in the direction
of arrow (2).
8 1—8 Power supply circuit € DISGEOIMS.- : Haies hassan жай arius кке жеміне (L) 3
board * How to remove flat cable [E] fF] ............... (D) 3
9 1-9 Power switch circuit © 2:ISGIOWS. sam eme dr eas Soe uae ісігін quos mse à (M) 3
board * How to remove flat cable [F] .................. (D) 3
OISCIBWS. Sans зы ес ыс ылы ына (М) 7
10 1-4- й
| 18 Maier assembly е 2'SGIOWS: ulis suu tke ааа адас teet à (O) 7
ж When adjusting in record mode, fix the rec/play switch (51) on the main P.C.B. at “гес” by use of a clip or the like.
Ш MEASUREMENT AND ADJUSTMENT METHODS
NOTES:
e Before making the adjustment and measurement, be sure to read
“Ref. No. 4: to remove main circuit board” of “DISASSEMBLY INSTRUCTION”.
Tape speed adjustment VR
Jumper wire for
erase current adjustment (J118)
A = ELE
VR10 Ф CLEA
|
mi
уво
22}
тра
**7—TP3
2 c VR2—qG&
ibs Е aie
| d |
Fig. 1

RS-B14
NOTES:
Set
switches
and
controls
in
the
following
positions,
unless
otherwise
specified.
*
Make
sure
heads
are
clean
*
Tape
selector:
Normal
*
Make
sure
capstan
and
pinch
roller
are
clean
*
Input
selector:
Line
in
e
Judgeable
room
temperature
20+5°C
(68+9°F)
*
Input
level
controls:
Maximum
*
NR
switch:
OUT
*
Balance
control:
Center
Q Head azimuth Condition: Equipment:
adjustment * Playback mode • VTVM
е Normal tape mode * Oscilloscope
* Test tape (azimuth)...QZZCFM
L-CH/R-CH
output
balance
adjustment
терта
1.
Make
connections
as
shown
іп
fig.
2.
Reon
/
са
a
қаулай
ый
EA
[c
Ro
“ker
Playback mode VTVM Oscilloscope
. Playback the 8kHz signal from the test tape (QZZCFM). Fig. 2
Adjust screw (B) in fig. 3 for maximum output L-CH and R-CH levels. Ig.
When the output levels of L-CH and R-CH are not at maximum at the c Record/playback
same point adjust as follows. ee ngad
. Turn screw (B) shown in fig. 3 to find angles A and C (points where /
peak output levels for left and right channels are obtained). Then, A
locate angle B between angles A and C, i.e., point where L-CH and Screw (8)
R-CH outputs are balanced. (Refer to figs. 3 and 4.) Fig. 3
L-ch peak level R-ch peak level
1 Ж
ГА
L-CH/R-CH
phase
adjustment
LEVEL
|
4. Make connections as shown in fig. 5.
5. Playback the 8kHz signal from the test tape (QZZCFM).
Adjust screw (B) shown in fig. 3 so that pointers of the two VTVMs
swing to maximum and a lissajous waveform as illustrated in fig. 6 is
obtained on the oscilloscope.
Record/ Oscilloscope
playback head
Playback
D
mode LINE OUT
Vertical Horizontal
Fig. 6
Fig. 5 g
Ө Tape speed Condition: Equipment:
* Playback mode * Digital frequency counter
* Test tape... QZZCWAT
Tape
speed
accuracy
Record/
playback
LINE
OUT
head
.
Test
equipment
connection
is
shown
in
fig.
7.
о
.
Playback
test
tape
(QZZCWAT
3,000Н2),
and
supply
playback
signal
о
at
to
the
digital
frequency
counter.
Playpack
те
на
тТаШЕНЕ
conni
. Measure this frequency.
.
On
the
basis
of
3,000Hz,
determine
value
by
following
formula:
Fig.
7
Tape speed accuracy = TOO 100(%) where, f = measured value
. Take measurement at middle section of tape.
Standard value: «1.596
. If measured value is not within the standard value, adjust it by using the tape speed adjustment VR shown in
fig. 1.
Note: Please use non metal type screwdriver when you adjust tape speed accuracy on this unit.
Tape speed fluctuation
Make
measurements
in
same
manner
as
above
(beginning,
middle
and
end
of
tape),
and
determine
the
difference between maximum and minimum values and calculate as follows:
f,-f
Tape
speed
fluctuation
=
3.000
х100(%)
fi
=
maximum
value,
f,
=
minimum
value
Standard value: Less than 1%

RS-B14
©
Playback
frequency
Condition:
Equipment:
response
*
Playback
mode
*
VTVM
*
Normal
tape
mode
*
Oscilloscope
* Test tape...QZZCFM
1. Test equipment connection is shown in fig. 2.
2.
Playback
the
frequency
response
portion
of
test
tape
|
Playback
frequency
response
chart
(022СЕМ):
3.
Measure
output
level
at
315Hz,
12.5kHz,
8kHz,
4kHz,
1kHz,
amt
ШЕШІНЕ
ne
250Hz,
125Hz
and
63Hz,
and
compare
each
output
level
ІШ;
ИСЕН
9%
ul
with the standard frequency 315Hz, at LINE OUT.
4.
Make
measurements
for
both
channels.
ИН
СШ
5.
Make
sure
that
the
measured
values
are
within
the
range
|
-
=
=
ag
specified
in
the
frequency
response
chart.
(Shown
in
fig.
8).
ШІ
ao
ІШ
Sat
=
63H H н: H2 н: н: z
Fig. 8
© Playback gain Condition: Equipment:
* Playback mode * VTVM
* Normal tape mode * Oscilloscope
* Test tape...QZZCFM
1. Test equipment connection is shown in fig. 2.
2. Playback standard recording level portion on test tape (QZZCFM 315Hz) and, using VTVM, measure the
output level at LINE OUT.
3. Make measurements for both channels.
[ Standard value: 0.4V+1dB |
гар.
.
If
the
measured
value
is
not
within
the
standard,
adjust
VR1
(L-CH)
or
VR2
(R-CH)
(See
fig.
1).
B After
adjustment,
check
"Playback
frequency
response"
again.
@ Erase current Condition: Equipment:
* Record mode • VTVM
* Metal tape mode * Oscilloscope
Erase head
. Test equipment connection is shown in fig. 9.
. Place UNIT into metal tape mode.
. Press the record and pause buttons.
. Read voltage on VTVM and calculate erase current by following
formula:
AON-
Record mode
R84 (12
Voltage across resistor R84 Fe
1 (Q)
Standard value: 155+15mA (Metal)
Erase current (A) =
5. If the measured value is not within the standard value adjust it by
following the adjustment instructions.
Adjustment
* |f the erase current is more than 170mA, cut the jumper wire (See fig. 1).

@ Overall frequency Condition: Equipment:
response
*
Record/playback
mode
*
VTVM
*
Test
tape
*
Normal
tape
mode
*
ATT
(reference
blank
tape)
e
CrO,
tape
mode
*
AF
oscillator
...
QZZCRA
for
Normal
*
Metal
tape
mode
*
Oscilloscope
...QZZCRX
for
CrO,
* Input level controls... MAX • Resistor (6009) ...QZZCRZ for Metal
Note:
Before measuring and adjusting, the overall frequency
response make sure of the playback frequency response (For
the method of measurement, please refer to the playback fre-
quency response).
Overall frequency response chart (Normal)
(Recording equalizer is fixed)
1. Make connections as shown in fig. 11.
2. Place UNIT into normal tape mode and insert the normal
reference
blank
test
tape
(QZZCRA).
SO
үм
Жш 5ш
кш
Ж
We
100?
3. Supply а 1kHz signal from the AF oscillator through ATT to
LINE
IN.
-
i
K
4. Adjust АТТ so that input level is -20dB below standard Р | i
5
recording level (standard recording level =0 VU).
. Adjust the AF oscillator frequency to 1kHz, 50Hz, 100Hz,
200 Hz, 500Hz, 4kHz, 8kHz and 10kHz signals, and record ув? (L-CH) |
these signals on the test tape. VRB (R-CH) 0 lj
. Playback the signals recorded in step 5, and check if the = Ó
frequency response curve is within the limits shown in the
overall frequency response chart for normal tapes (fig. 10).
(If the curve is within the charted specifications, proceed to
steps 7, 8 and 9.)
If the curve is not within the charted specifications, adjust p ella Утум. pM d
as follows; v б For overal frequency
VTVM Oscilloscope response measurement
For bias voltage
measurement
Fig. 11
Adjustment (A): Adjustment (B): b
When the curve exceeds the TD When the curve falis below
overall specified frequency : Le the overall specified fre-
response chart (fig. 10) as Hi quency response chart (fig.
shown in fig. 12. == ® 10) as shown in fig. 13.
1) Increase bias current by = р | 1) Reduce bias current by
turning VR7 (L-CH) and turning VR7 (L-CH) and ==
VR8 (R-CH). 7 УВВ (R-CH). а ЕЗИ
(See fig. 1 оп page 6.) pe QUK Repeat steps 5 and 6 for EE WM
2) Repeat steps 5 and 6 for SkHz 7kHz 8kHz confirmation (Proceed to 6 kHz 7ана ван:
confirmation (Proceed to Fig. 12 steps 7, 8 and 9 if the Fig. 13
steps 7, 8 and 9 if the curve is now within the | ;
curve is now within the charted specifications (
charted specifications as shown fig. 10.) as shown fig. 10.)
3) If the curve still exceeds the specifications (fig. If the curve still falls below the charted specifica-
10), increase bias current further and repeat tions (fig. 10), reduce bias current further and
steps 5 and 6. repeat steps 5 and 6.
7. Place UNIT into CrO, tape mode.
8. Change test tape to CrO, reference blank test tape} Overall frequency response chart (CrO,, Metal)
(QZZCRX), and record 1kHz, 50Hz, 100Hz, 200Hz, 500Hz,
4kHz, 8kHz, 10kHz and 12.5kHz signals. Then, playback
the signals and check if the curve is within the limits shown
in the overall frequency response chart for CrO, tapes (fig.
14).
. Place UNIT into metal tape mode and change test tape to
metal reference blank test tape (QZZCRZ), and record
1kHz, 50Hz, 100 Hz, 200Hz, 500Hz, 4kHz, 8kHz, 10kHz and
12.5kHz signals. Then, playback the signals and check if
the curve is within the limits shown in the overall frequency
response chart for metal tapes (fig. 14).
. Confirm that bias voltage are approximately as follows
when the UNIT is set at different tape mode.
* Measure the voltage across the head using a VTVM.
50H: 100H2 2008: 500Hz ]KHz 2кн2 ані
around 6.2V (Normal position)
Reference value: around 8.9V (CrO, position)
around 15.7V (Metal position)

i
|
RS-B14
|
©
Overall
gain
Condition:
Equipment:
е
Record/playback
mode
*
VTVM
*
AF
oscillator
*
Normal
tape
mode
*
ATT
*
Oscilloscope
*
Input
level
controls...
MAX
*
Resistor
(6009)
J
*
Standard
input
level;
*
Test
tape
МІС
...............
-72%3ав
(reference
blank
tape)
... QZZCRA for Normal
.
Test
equipment
connection
is
shown
іп
fig.
15.
Record/playback
1
2.
Insert
the
normal
reference
blank
tape
(QZZCRA).
ғи
3.
Place
UNIT
into
record
mode.
а
Bx:
4.
Supply
а
1kHz
signal
through
ATT
(-24dB)
from
AF
oscillator,
to
LINE
RE
TT
TS
IN.
oscillator
(BEER
Record
mode
5.
Adjust
ATT
until
monitor
level
at
LINE
OUT
becomes
0.4V+1
dB.
Қайы
6.
Playback
recorded
tape,
and
make
sure
that
the
output
level
at
LINE
—
*"«/Patex
OUT
becomes
0.4V+1dB.
=]
|
7.
If
measured
value
is
not
0.4V+1dB,
adjust
it
by
using
VR5
(L-CH)
or
S
E|
>
i
VR6
(R-CH).
Playback
mode
—
VIVM
Oscilloscope
8.
Repeat
from
step
(2).
Test
tape
Fig. 15
Q
Fluorescent
meter
Condition:
Equipment:
*
Record
mode
e
VTVM
*
AF
oscillator
*
Input
level
controls...MAX
*
ATT
*
Oscilloscope
*
Resistor
(6009)
. Make connections as shown (See fig. 16).
. In the recording pause mode, apply 1kHz (-24dB) to LINE
IN.
.
Adjust
АТТ
so
that
output
level
LNE
OUT
is
0.4V+1dB.
AF
oscilator
АТТ
мелу
Record
mode
УТУМ
—
Oscilloscope
.
At
this
time,
check
that
OdB
indicator
is
lighted
halfway
Fig.
16
(intermediate
brightness
between
full
brightness
and
light-
out:
See
fig.
17).
-:3
Г
ТОРЕК
10
+
$
3
4
(|
*
005
3]
+08
5.
It
the
indicator
is
not
lighted
halfway
as
described
in
step
4,
|
ТІЛЕДІ
£O № +
adjust
VR9
(L-CH),
VR10
(R-CH).
Шш
ШШШ
uibs
gx
6.
Repeat
adjustments
and
checks
at
steps
3,
4
and
5
two
or
three
times.
Fig.
17
ш ш шшшшшшшшшш
Ф
Dolby
NR
circuit
Condition:
Equipment:
*
Record
mode
*
VTVM
*
AF
oscillator
*
Dolby
NR
switch...IN/OUT
*
ATT
*
Oscilloscope
*
Dolby
NR
select
*
Resistor
(6009)
switch...B/C
Balance
control...Center
* input level controls... MAX
Record side
*
Check
of
the
Dolby-B
type
encoder
characteristics
.
Make
connections
as
shown
in
fig.
18.
.
Set
the
unit
to
the
record
mode.
(NR
select
switch
is
OUT.)
.
Apply
a
1kHz
signal
to
LINE
IN.
.
Adjust
the
ATT
so
that
the
output
level
at
TP3
(L-CH)
and
TP4
(R-CH)
is
12.3mV.
.
The
output
level
at
pin
21
should
be
OdB.
.
Set
the
NR
select
switch
to
B,
and
make
sure
that
the
output
signal
level
at
pin
21
of
IC5
(L-CH)
and
IC6
(R-CH)
is
+6dB+2.5dB.
.
Set
the
NR
select
switch
to
OUT,
and
adjust
the
frequency
to5kHz.
The
output
signal
level
at
pin
21
should
be
OdB.
.
Set
the
NR
select
switch
to
B
and
make
sure
that
the
TP3
(L-CH)
output
signal
level
at
pin
21
of
IC5
(L-CH)
and
IC6
(R-CH)
is
ТРА
(R-CH)
+
8dB+2.5dB.
*
Check
of
the
Dolby-C
type
encoder
characteristics
9.
Repeat
steps
1-5
above.
10.
Set
the
NR
select
switch
to
C
and
make
sure
that
the
output
signal
level
at
pin
21
of
IC5
(L-CH)
and
IC6
(R-CH)
is
+
11.5dB«2.5dB.
AF
oscillator
ATT
"me
11.
Set
the
NR
select
switch
to
OUT
and
adjust
the
frequency
16
(R-CH)
VIE.
оваа
to
5kHz.
The
output
signal
at
pin
21
should
be
OdB.
.
12.
Set
the
NR
select
switch
to
C
and
make
sure
that
the
Fig.
18
output
signal
level
at
pin
21
of
IC5
(L-CH)
and
ІС6
(R-CH)
is
T
8.5dB+2.5dB.
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