Panasonic RS-612US-E User manual

ORDER
NO.
ARD-7707065C
Service
Manual
Cassette Deck
10050093 1004988 23
SM=-RS612
RS-612
S-E
SERVICE MANUAL [ J
Front
Loading
Stereo
Cassette
Deck
with
Dolby*
Noise-Reduction
System,
Timer
Stand-By,
and
Bias
and
Equalization
Switches
RS-630U
MECHANISM
SERIES
Specifications
(Catalog
specifications
for
sales)
Power
requirement:
AC;
90~109/110~125/200~219/220
Fast
forward
and
~250V,
50/60Hz
rewind
time:
Approx.
90
seconds
with
C-60
cassette
tape
Power
consumption;
10
W
Input:
MIC;
sensitivity
0.25
mV/applicable
microphone
Motor:
1-electronic
speed
contro!
motor
impedance
4002~20KQ
.
Track
system:
4-track,
2-channel
stereo
recording
and
playback
LINE
;
sensitivity
60
mV/input
impedance
90
KQ
Tape
speed:
4.8cm/s
DIN;
sensitivity
0.25
mV/input
impedance
1.8KQ.
Wow
and
flutter:
0.12%
(WRMS),
+£0.25%
(DIN)
LINE;
output
level
420
mV/load
impedance
,
22
KQ
over
Frequency
response:
CrO2z
tape;
30~15,000Hz
:
40~14,000Hz
(DIN)
Head:
2-head
system
Normal
tape;
30~
13,000Hz
l-super
permalloy
head
for
record/playback
40
~
12.000
Hz
(DIN)
1-double-gap
ferrite
head
for
erasure
Signal-to-noise
ratio:
Dolby
NR
in;
65
dB
(above
5
kHz)
Dimensions:
41.0cm(W)
x
13.6cm(H)
x
24.4cm(D)
Dolby
NR
out;
55dB
Weight:
4kg
(signal level = max. recording level)
Specifications
are
subject
to
change
without
notice.
a
B
a
‘a
a
National
Panasonic
pareeniiy
Cleattic
Medina
Co.
Ue

LOCATION OF CONTROLS
AND COMPONENTS
QDO® ® @ ©)
©
OD ®O®D 1 dU 1913 1
Fig. 1
@ Door open button @ Rewind button @D Recording indication lamp
@ Power switch (® Fast forward button 48) Dolby noise-reduction switch
@ Cassette compartment door a) Playback button (9 Bias selector
@ Tape counter and reset button a2 Stop button @0 Equalizer selector
) Level/VU meter 3) Pause button @) Input selector
© Headphones jack Timer stand-by button @2 Line output jacks
@® Eject button 5) Microphone jacks @3) Record/playback connection socket
Record button d6) Record level adjustment @ Line input jacks
DISASSEMBLY INSTRUCTIONS
Fig. 3
To remove Remove: -—-. : Shown in fig. -—— .
Case cover
Bottom cover
Main P-C.B.
Mechanism

ADJUSTMENTS
Before measuring and adjusting “Overall frequency response’, “Overall distortion” and “Overall S/N ratio”, confirm that the characteris-
tics of 5 items below are within standard which have much relation to or influence on electrical performances above.
1. Head azimuth adjustment. 2. Bias current. 3. Playback gain. 4. Overall gain.
5. Playback frequency response.
I. TEST INSTRUMENTS
1. Prepare test instruments which are equivalent in accuracy to those shown below.
2. The test instruments should be inspected and corrected by specialists once every 6 months, because a long period of use without
maintenance may increase errors in indication.
3. Warm-up the test instruments for 30 minutes and the set to be measured for 10 minutes before taking the measurements. If not,
there may arise an error or difference between the initial value and the stabilized value measured after “aging”.
4. Specifications of test instruments.
(1) Audio frequency oscillator
a. Oscillation froquency: 5Hz~ 500 kHz (5 ranges)
b. Frequency tolerance: +(3% +1Hz)
c. Sine wave
* Output voltage (at 25°C): 5 Vrms + 10% (without load)
2.5Vrms + 10% (with 6002 load)
* Output frequency response: Within £0.2dB, 20Hz~ 20 kHz
Within +0.5dB, 5Hz~ 500 kHz
« Distortion factor: Not more than 0.05%, 200 Hz ~~ 20 kHz
Not more than 0.5%, 5Hz~ 500 kHz
* Output impedance: 6002 unbalanced, within + 15%
* Output attenuator: OdB, 20dB, Error: within +0.2dB
d. Temperature in use of set: Temperature = 0 ~ 40°C, Humidity =90% or less
(2) Automatic-stop distortion meter (with vacuum tube voltmeter)
A. Distortion factor measurement
a. Frequency (fundamental wave): 400Hz, 1kHz +10%
b. Measurement: ; 0.1~ 100% (6 ranges)
c. Input: 50mV ~50V
d. Fundamental wave attenuation: 60dB8 or more
B. Level measurement
a, Measurement: 1mV (—60dB) ~30V (30dB) (9 ranges)
b. Frequency response (1 kHz basis): 20Hz~ 100kHz +0.3dB
c. Input impedance: 1MQ +10%, less than 50 pF
d. Error in indicated value: Within £3% at 1kHz
C. Output terminal
a. Frequency response: 10Hz~100kHz £1dB
100kHz~1MHz +3dB
b. Output voitage: Vrms += 10% (1kHz sine wave)

(3) Attenuator
a. Input impedance: 6002 unbalanced
b. Maximum attenuation: 121dB
c. Minimum attenuation: 0.1dB
servis
(4) Oscilloscope
a. Cathode ray tube: Effective ranges 8 x 8cm
b. Vertical axis
* Input sensitivity : 30 mV ~ 30 V/cm
* Frequency band: DC ~2MHz
* Transient time: 180ns.
* Input impedance: 1MQ, 35 pF
c. Horizontal axis
« Tuning range: 30Hz ~ 2 MHz
* Sweep time: lus~100ms/cm
* External sweep: 1Vp-p/cm or more
(5) Digital electronic counter
a. Number of figure: 4 (decimal system)
b. Input sensitivity: 100 mVrms
c. Input impedance: 1MQ, 40 pF
d. Frequency measurement range: 10 Hz ~ 100 kHz
e. Counting time: 0.1, 1, 10s
(6) Wow meter
a. Measured center frequency range: 3kHz 4%
b. Input level range: 30mV~3V
c. Input impedance: About 50 KQ unbalanced
d. Measurement: 0.01~3% (5 ranges)
e. Indicator error: Maximum error in indicated value +5% in
each range.
f. Frequency response: Conforming to weighting curve characteristics
(WRMS), JIS C5551.
Flat characteristics (RMS)
0.5~200Hz, within —3dB (4Hz basis)
g. Meter indication system: Effective value indication, conforming to
JIS C5551.
h. Meter response characteristic: About 5~ 7 sec.
i. Oscillation frequency : 3 frequencies (3kHz, 3kKHz +3%)
J. Temperature range: O0~40°C

ll.
MEASUREMENT
CONDITIONS
1. Standard measurement conditions
«
Ambient
temperature:
10~30°C
(50~86*)
*
Ambient
humidity
:
30~90%
RH
* Power voltage accuracy: +3%
2. Position of tape recorder
+
When
measuring,
place
the
unit
under
test
in
a
horizontal
position.
3. Oscillator output voltage adjustment
*
Connect
the
equipments
as
shown
in
the
following
and
adjust
the
oscillator
output
control
knob
for
1V
(f=1kHz)
through
the
attenuator
while
keeping
the
attenuator
at
OdB.
+
When
supplying
a
signal
to
the
tape
recorder
amplifier,
adjust
the
input
level
using
the
attenuator.
Output control knob
Resistor 600Q
Audio
frequency
oscillator
j
Attenuator
i
Vacuum
tube
voltmeter
Oscilloscope
lil. TEST TAPE
Test tape life
The
more
frequently
the
test
tape
is
used,
the
more
the
tape
characteristics
will
deteriorate
(e.g.
lowering
of
recorded
level,
worsening
of
frequency
response
particularly
in
high-frequency
range,
and
an
increase
in
wow
due
to
tape
elongation)
until
meas-
ured
values
become
unreliable.
Even
in
such
a
case
when
a
tape
is
not
used,
but
stored,
for
a
long
period
of
time,
tape
shows
deterioration
in
performance
because
of
self
damagenetization
due
to
storage
conditions,
etc.
Please
refer
to
the
tape
life
specification
and
use
care
not
to
use
a
tape
longer
than
its
rated
life
when
servicing
Frequence
of
use:
Not
more
than
20
times
for
each
tape
length.
Storage period: Not more than 6 months.
* Test tape
PARTS
NO.
PARTS
NAME
|
SPECIFICATIONS
REMARKS
STANDARD
REC.
5
TIMES
REPETITIVE
RECORDING
LEVEL
&
FREQ.
|
TAPE
SPEED:
1-7/8IPS.
(4.8CM/S),
RESPONSE
TAPE
#
FULL
TRACK
(10
MIN.)
OdB: STANDARD REC. LEVEL (160pWb/mm)
—10dB
WOW & TAPE TAPE SPEED: 1-7/8IPS. (4.8CM/S),
SPEED
TAPE
3kHz
|
FULL
TRACK
(45MIN)
OdB: 250pWb/mm
-10 dB
|
TAPE
SPEED:
1-7/8IPS.
(48CM/S).
AZIMUTH
TAPE
6.3kHz
FULL
TRACK
(15MIN)
0d8: 250pWb/mm
REFERENCE BLANK
TAPE
(NORMAL)
UNRECORDED
TAPE
(20MIN.)
!
REFERENCE BLANK
ESO
|
|
UNRECORDED
TAPE
(20MIN.)