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PC-5 L/LB
|
Adjustments
1.
Adjustment Procedure of Cassette Mechanism
(Adjust the mechanism or confirm that it is in normal operating condition prior to the adjustment of the electrical circuit.)
. Connect
an electronic voltmeter to
the LINE OUT terminals.
. Play back the VTT-658 test tape.
. Adjust
the
head
angle
with
the
screw (A) until the reading of the
electronic voltmeter becomes maxi-
mum for both channels.
4. After adjusting, set the screw with
screw bond.
Adjusting
record/playback
head position
WRN
Screw (A) | Maximum | If the head is worn, disconnected or
exceedingly
magnetized
so as not to
provide the necessary characteristics,
replace it with a new one.
After replacement, the head position
adjustment
as well
as the playback
level adjustment, the bias current ad-
justment and the recording level ad-
justment are all necessary.
lf the output difference between the
left and right channels exceeds
3 —
4 dB, the head is defective.
Replace it with a new one.
Screw ©
Employ
a special
cassette ' (C-120)
from which parts of the casing, where
the erase head, record/playback head
and
capstan
engage,
has
been
cut
away. Perform tape transport with the
cassette
tape.
Adjust
the
screw
until the tape runs in the center of the
erase head tape guide.
Adjusting erase
head height
Incorrect
Correct
Tape guide
Tape guide
ia
Er
Tape guide
i Tape
Connect a speed meter (an electronic
counter) to the LINE OUT terminals.
Play back the VTT-656 test tape.
Adjust the semi-fixed
resistor in the
motor
until the reading of the speed
meter is 3000 Hz.
Semi-
fixed
resistor
in the
Adjusting motor
speed
Employ
a torque testing cassette tape
for the checking.
Checking play-
back torque
Checking fast
forward torque
Measure the torque in the fast forward
mode
in the same
manner
as in the
above.
Checking rewind
torque
Measure
the
torque
in the
rewind
mode
in the same
manner
as in the
above.
Connect
a wow
and flutter meter to
LINE OUT terminals.
Play back the VTT-656 test tape.
Check
to see
if the
reading
of the
meter is within 0.04% (WRMS).
Checking wow
and flutter
No. 1443
3000 Hz
—70
- cm
80 gr-cm
80 gr-cm
More than
More than
Be sure to perform this adjustment
after replacing the erase head.
If the
speed
meter
functions
as a
wow
and flutter meter, also, connect
the deck to the INPUT terminals of
the meter.
If the
standard
torque
is not
ob-
tained,
replace
the
take-up
disc
assembly.
If the
standard
torque
is not
ob-
tained, perform the following.
1. Clean
the capstan
belt, the idler
circumference,
the motor
pulley,
the take-up
reel disc
circumfer-
ence, the flywheel circumference,
etc.
2. Replace the belt and idler.
If the
standard
torque
is not
ob-
tained, clean the capstan
belt, idler,
motor
pulley,
flywheel
circum-
ference,
rewinding
idler
circum-
ference, left reel disc circumference,
etc.
If the reading becomes moving value
even if conforming to the standard, a
re-claim
may
be raised. Repairs are
necessary.
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