Normally Amtrak doesn't talk much. The only time you will hear Amtrak if the train is approaching a signal that is less than clear (green), or UP has a reason to talk to them, such as slow orders, or passing another train that is parked in a passing track, with the Conductor performing a rollby.
The Sedalia Sub uses 160.47 for its trains and though I'm not 100% sure on the actual segments I think it runs from Rock Creek Jct to River Jct or Cole Jct in Jeff City, though these might be the same junction. I hear them referenced by other units along the line but don't hear to much from them. From KC to Rock Creek its either BNSF on 161.085 or KCT 161.010. I cannot remember which controls it.