Orban OPTIMOD-FM 8700, Operating Manual

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OPTIMOD-FM DIGITAL INSTALLATION
2-29
b) Adjust the 8700i’s C
LIP
L
EVEL
so that on program peaks the input meters in-
dicate no more than approximately –2 dB.
0 dB indicates input clipping on the 8700i. These meters should never
peak as high as 0 dB with program material; always leave a safety margin
of headroom.
C) Calibrate with a Studio Level Control System that has a built-in 100% Calibra-
tion Tone, such as the Orban 6300 Optimod-DAB, 8200ST-Studio Level Con-
troller or 4000 Transmission Limiter:
[Skip this step if you are calibrating in another manner.]
a) Turn on the Studio Level Control System’s 100% Calibration Tone.
On the Orban 4000 Transmission Limiter, press both of the 4000’s front
panel
TONE buttons.
b) Adjust the output level of the Studio Level Control System for 100% modu-
lation of the STL.
c) Adjust the 8700i’s
C
LIP
L
EVEL
to indicate –2 dB on the input meters.
D) Calibrate with an Orban 464A Co-Operator:
[Skip this step if you are calibrating in another manner.]
The 464A does not have a built-in 100% tone. The easiest way to set the
8700i input peak clipping level is to temporarily re-adjust the 464A to
produce clipped waveforms on program material to give a clear indica-
tion of peak clipping level.
a) Record the normal operating settings of the 464A.
b) Set both channels of the 464A controls as follows:
METER CAL 0
HF LIMIT PREEMPHASIS
set to preemphasis of your STL; if no preemphasis,
set to 25

s
OUTPUT ATTEN 0
INPUT ATTEN 10
GATE THRESH 0
RELEASE TIME 0
REL SHAPE SOFT
LEVEL OFF
COMPR OFF
HF LIMIT OPERATE
SYSTEM OPERATE
POWER ON
MODE DUAL
c) Play program material from your studio.
d) Adjust the 464A’s METER CAL controls so that the 0 dB segment on the
464A’s PEAK OUTPUT LEVEL meter just illuminates on program peaks.
e) Adjust the 464A’s OUTPUT ATTEN controls to drive the STL to 100% modu-
lation.