Panasonic RX-CT900 - Tape Deck Alignment Procedures

RX-CT900
Ml PLAYBACK GAIN ALIGNMENT
EQUIPMENT
TEST TAPE
CONNECTION
ELECTRONIC
COUNTER
ADJUSTMENT
(Refer to Fig. 6.)
REMARKS
DECK 1 (Lch)...VR101
: iy
QZZCFM
TP13
ee
(Reh)...VR201
1.
Playback
mode.
(315 Hz, 0 dB) DECK 2 (Lch)...VR102
(Reh)... VR202
2. Adjust VR, for —11 dBV +0.5 dBV.
BGEEY..Rch
li BIAS OSCILLATION ALIGNMENT
EQUIPMENT
TEST
POSITION
CONNECTION
ADJUSTMENT
REMARKS
ELECTRONIC (Refer to Fig. 6.)
COUNTER
A)
...(-+)
1.
Record
mode.
liak...(-)
me
2.
Adjust
VR302,
for
AC
21
V+0.5
V.
N
|
‘i
1.
Record
mode.
ome
2.
Adjust
VR303,
for
AC
13
V+0.5
V.
m@ RECORD/PLAYBACK LEVEL ALIGNMENT
EQUIPMENT
TEST
TAPE
Ce
Fecuic
ADJUSTMENT
REMARKS
eOUNTER (Refer to Fig. 6.)
1. Insert test tape QZZCSZ in DECK 1 anda
blank tape.in DECK 2.
2. Set the unit to the dubbing mode at normal
* speed.
3.
Adjust
VR103
and
VR203
until
the
difference
between
the
playback
level
for
DECK
1
and
the
recording
level
for
DECK
2
is
within
1
dB.
QZZCFM
- (315 Hz, 0 dB)
Leh... VR103
Reh...VR203
. Short-circuit [GX with solder.
. Inserttest tape QZZCSZ in DECK 1 anda
blank tape in DECK 2.
3. Set the unit to the dubbing mode at normal
speed.
4. Adjust VR103 and VR203, for AC
17 mV +0.5 mV.
@ TAPE SPEED ADJUSTMENT
EQUIPMENT CONNECTION
ELECTRONIC
COUNTER
RADIUS
MENT
peMani
Headphones
Jack
(32Q)
Normal
Speed
Adjustment
(
Fabricate
the
plug
as
shown
in
Fig.
1.
1.
Insert
a
test
tape
(QZZCWAT)
in
Deck
1
and
play
it
back.
and
then
connect
the
lead
wires
of
the
i.
.
plug
to
the
measuring
instrument.
2.
aoe
ne
until
the
measured
value
becomes
3.
Check
Deck
2
in
the
same
way
to
make
sure
it
satisfies
the
specification.
Deck
2...-+50
Hz
of the
speed
of
Deck
1.
If it doesn’t repeat steps 1_and 2 above.
Note:
This
set
uses
one
drive
motor,
so
be
sure
to
perform
the
adjustment
in
Deck
1.
High
Speed
Measurement
4.
Insert
the
playback
tape
into
Deck
1
and
the
editing
tape
into
Deck
2.
5.
Set
the
Editing
Mode
Selector
to
the
“HIGH”
position.
6.
Press
the
Deck
2
Pause
button,
then
press
the
Record
Button.
7.
Press
the
Deck
1
Playback
Button.
_ Editing is started by means of the Synchro-Start function.
8.
Check
be
sure
that
the
measured
speed
is
at
least
1.63
times
faster
than
normal
speed.
m@ ALIGNMENT POINT
Please refer to Circuit Board and Wiring Connection Diagram for test point locations.
— ep
—* To Measuring
—e Instrument
7 R=320
oa : Fig. 2 Fig. 3
TEST TAPE
VR501
(Shown in Fig..9.)
QZZCWAT
(3 kHz)
To Headphones
Fig. 1
~19-
RX-CT900
FM ANT FM ANT MWANT
SOMHz IOGMHz 600kHz 459kHz
AM IFT
MW ANT
1400kHz
[es] [et] [Le-r] [73 |
cT2
FM VCO FM 2nd FM
I19kHz+50Hz 1O.7MHz 10.7MHz
Ist Mw OSC
520k Hz
LWANT
27 OkHz
MW OSC
I7IOkHz
De} Cre] [ee] [ee]. [ers]
Fig.
5
Electronic
Headphones jack volt meter
Ss |
Playback “=e =
mode Electronic
volt meter
Fig. 7
Oscilloscope
MECHANISM CONTROL P.C.B.
Tape Speed
ay
Fig. 9
Recore
(Erde)
Record
pecerd pecord
ae
:
Beck
2
‘
Becks
é
pce
ias
eve
eve
aybac!
b
(Norma)
‘TEch)
‘TRem
—GorkeeGy
GarwresK)
Slayers,
Blavback
[vR302]
[vR303] [vrio3} [vr2os)_—[vrio!
FUNCTION OF IC TERMINALS
IC401
(UPD75306G073):
MICROCOMPUTER
Rec bias
oscillator
Keep these cords short.
©In
order
not
to
influence
the
bias
oscillation,
divide
the
voltage
with
1
MQ
and
1
kQ
resistors,
and
measure
the
voltage
across
the
1
kQ
resistor.
Fig. 8
BASIC
INTERVAL
TIMER
INTBT
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MEMORY
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