Omnia Omnia-6EX / EXi, Инструкция по установке и эксплуатации, Страница: 41 / 125

Omnia-6ex Use and Operation Manual – V: 1.20
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SRC (Sample Rate Converter) board (see Pg. 60). AES-2 can also be locked to whatever the AES-1 Output is set to,
as well as synchronized to AES-1 if it is being synchronized by an external AES/EBU source.
Outputs
Think of this as a simple router. It enables either the FM or HD/DAB output signals to be routed to whichever
physical output is desired: the Analog, AES-1, or AES-2 connectors. The analog output (including the Headphones)
can be assigned to either the conventional FM, or the HD/DAB output for monitoring purposes.
FM Outputs Submenu (FM Mode Only)
Diversity Delay: (Ex i Only)
The four controls in this box are used to adjust the built-in conventional FM channel diversity delay time to
precisely match the delay of the HD channel’s audio. The diversity delay is engaged or defeated using the “Delay”
On or Off settings. The delay time can be adjusted using “Coarse”, “Medium” and “Fine” controls. The “Coarse”
control adjusts the delay time from 0 to 10 seconds in 0.1 second (100 ms) increments. The “Medium” control more
finely adjusts the delay time from the “Coarse” control over the range of +/- 50 ms in 1ms increments and the
“Fine” control even more finely adjusts the delay time from the previous two controls over the range of +/- 500us
in very precise 10.4us increments.
Pre-Emphasis
For the transmission side of conventional FM broadcasting, some form of high-frequency boost, or pre-emphasis is
used. The most commonly used values of pre-emphasis are 50 and 75 µs (microseconds). For North and South
America, 75 µs is used. In Europe, Australia and New Zealand, 50 µs is employed. The factory default pre-emphasis
setting is 75 µs. The pre-emphasis selection affects the operation of the audio processing and is applied to the
composite, discrete, and digital outputs. The pre-emphasized signal at the Left/Right and digital outputs can be
restored to flat, if needed, by the De-Emphasis parameter selection.
To set the Pre-Emphasis, rotate the jog-wheel to highlight one of the three choices: Off, 50 µs or 75 µs. Click the
jog-wheel to set the pre-emphasis selection.
Note: Normally, the Off selection under the Pre-emphasis options would not be used in conventional FM
transmission applications, but is provided in instances where processing of a flat signal is desired. One example
would be when preprocessing prior to a satellite uplink in distributed radio networks.
De-Emphasis
The Left/Right FM mode outputs are pre-emphasized under normal circumstances, such as when feeding an
outboard stereo generator or discrete microwave studio-transmitter link. The same applies when feeding a digital
exciter from the AES/EBU output. These outputs can also be de-emphasized for installations that require a flat
frequency response, as is the case when feeding other types of studio to transmitter links or for monitoring.
To change the De-Emphasis setting, rotate the jog-wheel to highlight one of the three choices: Off, 50 µs or
75 µs. Click the jog-wheel to set the de-emphasis selection. If choosing a de-emphasis time constant, it should match
the pre-emphasis time constant. Bear in mind that if Pre-Emphasis is turned on, selecting De-Emphasis Off means
that the outputs will be pre-emphasized.
Note 1: The De-Emphasis setting does not affect the composite MPX outputs, which always follow the Pre-
Emphasis setting.