Akai 1710W Service Manual

ll.
MEASURING
METHOD
TAPE
SPEED
DEVIATION
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Method
involving
use
of
pre-recorded
tape
Playback
on
the
tape
recorder
to
be
tested
tape
pre-
recorded
at
1,000
Hz
+
0.1%
for
measuring
tape
speed
deviation.
Connect
the
appropriate
output
to
a
frequency
counter
meter
in
order
to
measure
the
tape
speed
deviation
from
the
resulting
deviation
of
the
measured
frequency.
2.
Method
involving
use
of
timing
tape
(designed
for
tape
speed
measurement)
This
method
utilizes
a
timing
tape
marked
at
intervals
of
7-1/2.
The
running
time
of
the
tape
over
60
marked
section
is
measured
in
order
to
calculate
the
deviation
of
the
tape
speed.
In
applying
this
method,
however,
it
should
be
born
in
mind
that
the
timing
tape
stretch
or
contract,
measurement
error
is
inevitable,
so
that
it
is
necessary
to
measure
the
total
length
of
the
tape
in
advance.
WOW AND FLUTTER
Playback
the
3,000
Hz
pre-recorded
tape
whose
wow
and
flutter
level
is
guaranteed
to
be
smaller
than
0.07%
for
measurement
by
means
of
a
wow
meter.
It
is
also
possible
for
a
3,000
Hz
sine
wave
to
be
recorded
and
played
for
measurement
by
means
of
the
wow
meter.
In
this
case,
however,
the
wow
meter
indicates
a
value
as
much
as
twice
the
value
given
in
the
specification
on
the
first
page.
SIGNAL
TO
NOISE
RATIO
1710W
ee
Set
the
Equalizer
Switch
on
“7.1/2
ips”
position
and
playback
a
tape
containing
a
1,000
Hz
sine
wave
record-
ed
at
“0”
VU
level
on
a
standard
recorder.
Connect
a
V.T.V.M.
to
the
line
output
jack
of
the
recorder
and
measure
its
output.
Then
remove
the
tape
and
measure
the
noise
level
under
the
same
condition.
Convert
each
of
the
measured
values into decibles.
TOTAL
HARMONIC
DISTORTION
FACTOR
1K Hz
Audio
Distortion
Oscillator
meter
Connect
the
measuring
instrument
as
shown
above,
and
record
the
1,000
Hz
sine
wave
at
“0”
VU.
Playback
the
resultant
signal
and
measure
the
overall
distortion
factor.
Measure
the
noise
level
of
the
tape
recorder
with
the
tape
removed;
connect
the
audio
oscillator
directly
to
the
distortion
meter
for
measurement
of
the
distortion
factor
of
the
oscillator.
The
required
distortion
factor
may
be
obtained
from
the
results
of
the
above
measurement
by
the
following
formula.
dy = d—d, —d,
where, dy = Required
d
=
Overall
distortion
factor
d, = Noise level
d,
=
Distortion
factor
of
the
oscillator
(Note:
New
tape
of
particularly
good
quality
should
be
used
for
measurment
of
the
distortion
factor).
POWER OUTPUT
Palyback
a
tape
containing
a
sine
wave
of
1,000
Hz
recorded
at
0
VU
on
a
standard
recorder.
Connect
a
V.T.VM.
to
the
line
output
jack
of
the
re-
corder
and
measure
the
voltage
at
the
output
of
the
recorder
to
be
tested.

Akai 1710W Specifications

General

Brand	Akai
Model	1710W
Category	Measuring Instruments
Language	English