Scope
This document applies to Omnia.9 audio processors running in FM + HD mode and discusses issues with HD blending.
Description
A customer reports that the station runs HD, and is having issues with HD Blending. An HD modulation monitor is running, and using the display was able to obtain correct alignment, however, it is still drifting, and I am unsure why this is happening.
Solution
The solution here is to run the HD off the FM processing core instead of its own. This will help to stabilize the timing.
To do this;
Turn on Output Delays
Navigate to System
System Configuration
Processing Paths
Turn on "Output Delays"
Click "Apply Config"
Reboot
Set "Crossfeed" option
Navigate to HD1
Then Processing
Then Bypass
Set the "Crossfeed;" to "Use FM Audio
Turn off previously set diversity delay
Go to System
I/O Options
Diversity Delay
Turn off the diversity delay set here
Finally
Go to System
I/O Options
Output Delay
Set your diversity delay here
The HD will still have its own limiter (instead of the pre-emphasis and clipper in the FM channel) as well as a control to reduce the treble. That along with the HD Limiter Drive control and a switch to enable the HD Limiter Meters can be found in FM / Processing / HD Crossfeed.
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