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CT-7R/6R
ELECTRICAL
ADJUSTMENTS
Precaution
HEAD
AZIMUTH
ADJUSTMENT
1.
Mechanical
adjustment
should
be completed.
2. Clean
the
following
parts with
an
alcohol
Setting:
moistened swab; Record/Playback head, Pinch
Mode
..........ecee-
Playback
roller, Erase head, Rubber belts and Capstan.
(FWD and REV)
3. Demagnetize record/playback head with a head
Test tape
............
STD-341A, 10kHz
demagnetizer.
portion
4.
Do not use magnetized screwdriver for adjust-
AC mV meter.........
OUTPUT terminals
ments.
VR501, VR502
.......
Max.
5.
Adjustment and measurements should be per-
formed
for both
L-ch
and
R-ch with rated
PB HEAD
power supply voltage.
Se:
ei
6.
Adjustments should be performed in the order
given in this service manual. Altering the order
:
can hinder proper adjustments, resulting in loss
Fe asa|
of performance.
7.
Level
during
measurements
are
based
on
OdBv=1V.
Connect
a 50kQ
dummy
resistor
across the OUTPUT terminals.
5
9.
Set the DOLBY
NR switch OFF unless direct-
ed otherwise.
REV
FWD
YS
3
A's =n
i
{-) Screwdriver
Test Equipment/Tools Required;
1.
Test tape
STD-331A
......
for general playback pur-
Fig. 2 Azimuth preadjustment
pose
STD-341A
......
for playback
adjustment
Procedure:
STD-608A
......
NORMAL blank tape
Play a tape in both forward and reverse direc-
STD-603........ *CrO, blank tape
tions. Adjust the head azimuth screw to the posi-
STD-604........
METAL blank tape
tion of maximum
output level.
2.
Audio oscillator
3.
AC millivoltmeter (AC mV)
4.
Attenuator
TAPE
TRANSPORT
ADJUSTMENT
5.
Oscilloscope
1.
Load a mirror-equipped cassette half.
6.
Resistor 50kQ (1/4W)
2.
Set the DIRECTION switch to FORWARD and
then the mode to PLAY.
LEVEL (dB)
3. Adjust the adjust nut @ so that no curling
takes place on REC/PB
head guide and erase
head guide as shown in Fig. 3.
Set the DIRECTION switch to REVERSE.
Adjust the adjust nut @ so that no curling
occurs
on
REC/PB
head
guide
and
erase
Fig. 1 Contents of the test tape STD-341A
head guide.
6.
Play atape in both FORWARD and REVERSE
directions and check that no curling on tape is
found.
—204
333Hz
100 sec
100 sec 50sec 100 sec
Sie
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