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Co-Operator
MAINTENANCE
4-7
g)
Turn
both
GATE THRESH
controls
fully
clockwise,
and
turn
both
INPUT
ATTEN
controls
fully
counterclockwise.
h) Verify that
both
GATE THRESH
indicators
light.
i)
Set
the
audio
oscillator's
output
level to
OdBu.
j)
Slowly
turn the
L
INPUT
ATTEN
control
clockwise
until
the
L
GATE THRESH
indicator
goes
out
k) Set the
MODE
button
to
STEREO,
verify that the
R GATE THRESH
indicator
goes
out.
l)
Set
the
MODE
button
to
DUAL,
and
turn
both
GATE THRESH
controls
fully
coun-
terclockwise.
m)
Check
the
right
channel
gate control
circuit
by
repeating the
above
for the right
channel.
Use
the right
channel
controls,
LED,
and
terminals instead
of
the
left,
and
substitute
TP10
for
TP7.
n)
Disconnect
the
audio
oscillator
from
the
Co-Operator.
7)
Check
VCA
control
circuits
and
gain
reduction meters.
a)
Connect
the
audio
oscillator to
the
LEFT
IN HI
terminal,
and ground
the
left
IN
LO
terminal.
Set the
oscillator's
frequency
to
1kHz
and
its
output
level to
OdBu.
b) Set the controls as follows:
L
INPUT
ATTEN
L
GATE THRESH
L
RELEASE
TIME
L
LEVEL
L
COMPR
MODE
FULLY
CLOCKWISE
FULLY
COUNTERCLOCKWISE
FULLY
COUNTERCLOCKWISE
ON
ON
DUAL
c)
Verify
that
all
LED
segments of
the
L GAIN
REDUCTION
meter
light.
d)
Set
the
L REL SHAPE
button
to
HARD.
e)
Mute
the
oscillator,
verify that the
L GAIN
REDUCTION
meter
reading
decays
to
"OdB"
in
7
seconds
±2
seconds, then
restore
the
signal.
f)
Turn
the
L
RELEASE TIME
control
fully
clockwise.
g)
Mute
the
oscillator,
verify that the
L GAIN
reduction
meter
reading
decays
to
"0"
in
28 seconds
±5
seconds, then
restore the signal.
h)
Turn
the
L
RELEASE TIME
control
fully
counterclockwise,
and
set
the
MODE
button
to
STEREO.
i)
Mute
the
oscillator,
verify
that
both
GAIN REDUCTION
meters' readings decay,
and
that the
meters
track
each
other
closely.
Restore
the
signal.
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