Orban OPTIMOD-FM 8500S, Руководство по эксплуатации

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OPTIMOD-FM DIGITAL INSTALLATION
2-21
Do not use the Digital Output level control to match the loudness of the
FM analog and HD audio at the radio.
Instead, use the
HD L
IMITER
D
RIVE
control in the active Processing Preset to do this as the last step after you
have customized to preset to your liking. Using the
HD L
IMITER
D
RIVE
con-
trol prevents unnecessary gain reduction from occurring in the HD proc-
essing’s peak limiters.
BS.1770 Loudness Control: Some countries now require the integrated
loudness of digital radio transmissions to be equal to a “target loudness”
set by the regulatory authority of the country in question. The 8500S/HD
provides a “BS.1770 Safety Limiter” for this purpose. The BS.1770 Safety
Limiter should be defeated in HD Radio installations.
Note that when the BS.1770 Safety Limiter is active and D
IGITAL
O
UTPUT
#1
is set as the “BS.1770 reference output,” the
D
IGITAL
O
UTPUT
#1
level con-
trol does not affect loudness, but only sets the peak headroom. For ex-
ample, if the
D
IGITAL
O
UTPUT
#1 control is set to –2 dBFS, peaks will not
exceed –2 dBFS but the BS.1770 loudness will remain calibrated to the
value of
D
IALNORM
that you specify in I/O Setup. Quick Setup does not in-
clude setup of the BS.1770 safety limiter; see step 12on page 2-35 for
setup instructions.
E) Set the analog output level.
a) Press the Next button.
b) [Skip this step if you are not using the analog output.]
Turn the knob to set the desired analog output level corresponding to
100% modulation, in units of dBu (0 dBu = 0.775 Vrms).
The most accurate way to set this control is by observing a modulation
monitor or analyzer connected to your transmitter.
c) Press the
Next
button.
If you activated the modulation setup tone in step (A)a) on page 2-19,
the tone will turn off automatically.
F) Press the Next button.
You have now completed the guided Quick Setup procedure and are in
the normal
Recall P
RESET
screen. However, if your country requires you
to comply with the multiplex power ceiling specified in ITU-R BS412-9,
you will also need to set up the 8500S’s Multiplex Power Controller by
following the instructions in step 1 on page 2-22.
13. Choose a processing preset.
[If you are setting up the 8500S for use as a stand-alone stereo encoder, skip this
step.]
A) Turn the knob until your desired preset is visible in the lower line of the dis-
play.
B) Press the Recall Next button to put your desired preset on-air.
This step selects the processing to complement the program format of