Hd Digital Radio - Orban OPTIMOD 5750 Operating Manual

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Orban 5750 Technical Manual Operation

HD DIGITAL RADIO

HD HF SHELF EQ (Pre/Post) determines whether the HD HF shelving equalizer will be placed before or after the look-
ahead limiter that feeds the HD output.
HD POLARITY sets the polarity of the output of the HD processing to Positive or Negative. The switch allows you to
match the polarity (sometimes informally called "phase") of the audio through the analog FM and HD transmission
channels, regardless of how your facility is configured. It is important to match polarity to avoid a momentary
decrease in loudness during analog/digital receiver crossfades.
BS.1770 SAFETY LIMITER ON/OFF activates or defeats the BS.1770 Safety Limiter, which is applied only to the digital
radio processing. This control affects the behavior of the digital output receiving the HD feed
BS.1770 LOUDNESS CONTROL THRESHOLD sets the threshold of the BS.1770 Safety Limiter and the calibration of
the BS.1770 loudness meter.
When the BS.1770 Safety Limiter is OFF, the BS.1770 Loudness Control Threshold sets the calibration of the BS.1770
Loudness Meter, such that "0" LK/LU on the meter corresponds to the loudness appearing at the Digital Output
assigned to "HD." This calibration is only correct if the Digital Output 100% Peak Level control is set to 0 dBFS.