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Co-Operator
INSTALLATION
2-11
b)
Set
the controls as follows:
L
METER
CAL
0
L
HF
LIMIT
PRE-EMPHASIS
75us*
L
OUTPUT
ATTEN
0
L
INPUT
ATTEN
0
L
GATE THRESH
0
L
RELEASE
TIME
5
L
REL
SHAPE
SOFT
L
LEVEL
OFF
L
COMPR
ON
L
HF
LIMIT
OPERATE
L
SYSTEM
OPERATE
POWER
ON
MODE
DUAL
*
Or
to
match
the
pre-emphasis
of
the transmission
system.
c)
Advance
the
L
INPUT
ATTEN
control
until
the
L GAIN reduction
meter
indicates
5dB
gain
reduction.
d)
Set the
L
COMPR
button
to
OFF.
e)
Turn on
the
transmitter.
f)
Advance
the
L
output ATTEN
control
until
your modulation monitor
indicates
100%
modulation.
If
a modulation monitor
is
not
available,
observe
the transmitter's input
with an audio
voltmeter,
and
adjust the
L OUTPUT ATTEN
control
to
a
level
equivalent
to
100%
modulation.
g)
Advance
the
L
meter cal
control
until
the red
+3
segment
of
the
L
peak
output LEVEL
meter
just
lights.
The
L
PEAK OUTPUT LEVEL
meter
is
now
calibrated
so
that
+3
corre-
sponds
to
100%
modulation
of
the
transmitter.
h)
Turn
the transmitter
off.
1
1
)
Calibrate clipping
level.
a)
Advance
the
L INPUT ATTEN
until
the
L
HF
LIMIT
indicator just
lights,
then
back
off
slightly
so
that the
L
HF
LIMIT
indicator
is
no
longer
lit.
The
Co-Operator
is
now
producing
a clipped
400Hz
sine
wave.
The
peak
level
of
this
wave
corresponds
to
100%
modulation.
b)
Adjust
the
L
OUTPUT ATTEN
control so
that
the red
+3 segment
of
the
L
PEAK
OUTPUT LEVEL
meter
just
barely
lights.
The L
OUTPUT ATTEN
is
now
correctly calibrated to the
transmitter.
Provided
that
no
significant
overshoot occurs
in
the
transmitter,
the
L
PEAK OUTPUT
LEVEL
meter
will
give an accurate
indication
of
peak
modulation.
With
the
L LEVEL
switch
set to
OFF, and
the
L
COMPR
switch
set to
ON,
an
undistorted
sine
wave
peaking
at
between
23%
and
29%
modulation
should
be
produced.
With
the
L LEVEL
switch
set to
ON,
the
level
should
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