Akai 1710 Service Manual

1I
IIOW
TO
NIICNSURE
DESIGNATED
VALUES
OF
SPECIFICATIONS
TAI'I] SPDtrD
DEVIATION
:
\{OW
AND
FLUTTER
:
Reco.d
the l,000cps.
sine
curve
of
the tap€
speed
at rating
sp€eds
with
a standa.d
sound
recorder
(AMPEX
351A,
for instance)
which
is little
af-
fccted
by lhe
tape sPecd
deviation
tlrroughout
the
whole
i€ngth
of the
tape.
Put
th;s standard
taPe
on
th€
tapc recorder
unde.
test
for playing
back, and
nreasure
its
outPut
bY a
couDte.,
then
codvert
thc value
into
rating
power
frequeDcy
to cvaluate
the tape speed dcviatior.
Fo.
a rough
measurement,
the
taPe
spe€d deviation
can also
be measured
with a testing
tape for
speed by
astop
Playback
thc 3,000cps
sianda.d
tape
that guarante€s
wo\d and flutter
with-
h 0.07
p€r cent,
aid read
the effect;ve
valuc
otr wow
mere.
Since
the sedsibility
of
wow and flut-
tcr frequency
bclow
2cps
and above
5 cps. d.ops,
the frequency
over 5cps.
is put
to 3db/OCT
circuit,
and
th€
frequency
bclow 2.ps.
is put
to 6db/
OCT circuit
for adjustment
This ad-
justed
value is
called
auditory com-
Connccr
to
thc input
tcdninal of
the
rcco.dcr,
.ccord a sine
curve swecp
f.equency
at 100 cps
-10
db.
from
Audio
frequency Oscillator.
Adjusl toDe
volume
to
flat,
playback
the tape
by .onnectidg
VTVM
tosp€-
aL€r out
put then read
the frequency
response
to adjusl a
maximum
devia'
}.RLqUI]NCY
RESPONSE:
(OVI]RALL
I'REqUENCY
RESPONSE)
TOTAL HARMONIC
DISTORTION
FACTOR:
Provide
the input
terminal
ol the
,ecord.r
with 1.000.ps.
':nF ,
urvF
signals and
.ecord
these signals on
a
recording
tape at
the zero level
on the
recorder's
VU mete.
Then
playback
the siSnals
under the
no.mal recording
condit;on
to meas-
u.c the distortion
factor
by an oscil
lator.
Remove
the recording
tapc
from
the recorder,
then read the
noisc
lcvelon
the oscjllator
to
8ct
the requ;r-
€d dhtortion
factor
by the following
formula:
d0:d-dl d2
d0..required
d...overall
distortion
factor
dl...noise
l€vel
d2...disto.tion
factor of
the oscilla-
to.
uscd
SICNAL
TO
NOISE: Playback
the sine curve,
250 cPS.
tape
rccorded on a
standard recorder
on
th€ reco.der
to measur€
the voltag€
Removc
the taPe, then measure
the
noisc level under
the same condition
Calculate
the ratio between
the two
in d€cibel.
OUTPUT:
I'layback
on the recorder
thc 1,000 cps.
sine
curvc tape
which
was
record€d
at
the zero VU
level on a standard
recorder.
T€rDinatc the
test recorder
with
€ight
ohms.
Square
the voltag€
rcading, then di
vide the figure
by eight ohms
to get
thc r.m.s.
Powcr
output.
CROSS
TALK:
Record 1,000 cps.
signal at
+3VU
on
the
third tack, then playback
this
signal
through a
l,000cps. Band
Pass
Filter.
Compare
the output
of tracks
I
and
3
in decibels.
2-

Akai 1710 Specifications

General

Brand	Akai
Model	1710
Category	Tape Deck
Language	English