STUDER REVOX C279 Serviceanleitung Seite 112

sruptrR
nd/ox
c279 E
5/5*
5.t+
ALIGNIIIENT INSTRUCTIOTIS
5.4.1
Required measuring instrunents
r
Audio voltmeter
r
AF genenaton
r
Tone
burst
genenator
r
Distortion
meter
5.4.?
Osci
LLator
I
Sepanate
the
mixing console
Jrom
the expansion unit
(Section
5.2.1).
r
Reattach
the
connect'ing cable
to the
CIS socket.
r
Tunn
the selector switch [1] of the osciLtator to 0
dBu
posit
ion.
I
Connect
the
audio
voltneter to
one
o{ the tlJo
osciL-
Laton outputs.
r
Swjtch on the mixing
consoLe.
I trJjth the
trimmer
potentiometer
RA
1
adjust the
output
vottage
of the osciLLator to
775
mv.
a
5.4.3
dbx
TYPE
II
encoder
/
decoder
r Separate the
mixing
consoLe
from
the
expans'ion
unit
(Section
5.2.4).
r
Tunn
the
tnimmen
potentiometers
RA
503,
RA
603,
RA
703,
and
RA
803
to the
cLockHise t
imit position.
r
PLug
the
connecting
cabLe
back
into the
CIS socket.
r
St.,itch on
the mixing
consoLe.
r
Pen{orm
the
aLignment
Hork
in the specified
sequence.
Adiustinq the
asymmetry:
r IndividuatLy
aLign each
encoden
and decoder
channeL.
r llith
the
AF
generaton feed
a
100
Hz.
500
mV
sine
uave
sjgnal to the
channel
to
be measured.
r
Connect the
cathode
ray
osci
LLoscope
via a
measuring
ampLifien
to
TP1
(IC501, pin
7).
r
h,lith
trimmen
potentiometer
RA
502 aLign
the
symmetry
of
the 5
mvpp
ripp[e
s'ignat.
tlith
an optimaL adjustment
the
nesuLting
200 Hz signaL
is nearty
sine-shaped.
Adiustinq the time
base:
r
IndividuaLLy
atign
each encoden and decoder
channeL.
r tJith the
tone
burst
generaton
feed
a signat Hith a
{ne-
quency oJ 1
kHz, 1.4
Vpp
(8
cycLes
on,
128
cycLes
of{)
to the
channel
to
be
measured.
r
Connect
the
cathode
ray osci!loscope
Dc-coupLed
to
TP1
(IC50'l pin
7).
r tdith
trimmen
potentiometer
RA
501
adjust the
steepness
ol the
negative going
edge
of the
saHtooth
voLtage to
750
mV/s.
ALiqnino
the
harmonic
distontion:
r IndjvidualLy at'ign
each encoder
and decoden channeL.
r tnlith the
AF
generaton feed a
500
nV, 1
kHz
sine
uave
signaL
to the
channeL
to
be
measured.
. Connect the distortion meter to the
corresponding
output
and
adjust {or
minimat
distortion
(approx.
0.1%')
h,ith trjmmer potentiorneter
RA 500.
A[iqninq the levet:
r Atign
each
channeL ind'ividuaLLy.
r First aljgn the
encoder and then the
decoder
uith
the
aLigned
encoder.
r li,lith the
AF
generator feed a 1
kHz
sine uave signat,
500 mV,
to the
channel
to
be
measured.
.
connect
the audio vottmeter to the
encoder
output.
r hlith the
trjmmer potentiometen
RA 503
adjust for
an
output
Levet
of
350
mV
(= 3
dB).
t
Connect
the
encoder
output to the
decoder
input.
r
Connect
the audio voltmeten to the
decoder
output.
I
Do
not atten the setting of the
AF
generätot.
r Llith the trjmmen
potentiometer
RA
703
adjust for
a
decoder
output
voLtage
of
500
mV
(=
0
dB).
>@<N
tt ^(
1/,\
Jl
(.,";)
Tav,
o
G@
503
RA
502
RA
5OO
RA
501