Nautel XR12, Руководство по установке

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XR12 Installation Manual Audio and IBOC inputs
Issue 3.0 2009-07-15 Page 8-1
Section 8: Audio and IBOC inputs
This section describes requirements associated with audio feeds to the XR12 transmitter. This section
includes the following topics:
• Analog audio
• IBOC input
• Audio configuration - see page 8-2
Analog audio
Modulating audio must be applied from an external source. The RF drive source configuration
determines the audio requirements. The audio source must be balanced, able to drive a 600
Ω
load,
and have a level between 0 and +12 dBm for 100% modulation.
Only one analog input is provided. Program content from the input is applied to either one or both
exciters when they are configured for analog operation.
The transmitter does not have any audio processing capability. Use an external audio processor to
ensure that the audio source material is processed properly. The audio processor adjusts the dynamic
range, loudness, frequency response and symmetry parameters to suit the transmission system.
Carefully control the peak levels.
For monaural applications, the audio may be processed to provide up to 145% positive peak program
modulation, with a 10 kW RF carrier at the nominal ac voltage.
IBOC input
In Band On Channel (IBOC) audio is processed outside the XR12 in the customer’s IBOC
generator – a separate, standalone system that feeds an IBOC signal to the transmitter’s
mag
and
phase
ports.
• Position the IBOC equipment close to the transmitter to minimize cable lengths.
• IBOC audio must be AES-EBU digital. Refer to the NE-IBOC documentation for more
information.