When I canned the airwaves using a Hauppauge HVR-900H USB tuner, I found a channel called TV3 (AC-3).
From my testing so far it appears that the TV3 signal has AC-3 audio on all the time, usually 2.0 but 5.1 for those shows which are also in HD.
I am using a PCH to view the broadcasts. If I try to view TV1 say, there is no audio which I can understand given they are likely to be using AAC-HE LATM.
Just wondering why TV3 has chosen to broadcast AC-3 audio all the time (not that I am complaining!)