no sound on PBS programs on AMC3

[globalwave]

I have a ADTH satellite reciver from IPTV.I get most of the chennels from T-5 and I try to point another 3 LNB to different satellites...G3..G4 and AMC 3. Every programs that the receiver pick up is in good quality but Why I can not get the sound on the PBS programs from AMC 3 even the picture quality is very good.????? please help..
Thank you..

 

[Mr Tony]

AC-3 audio so you need a satellite receiver and a home receiver that does AC-3