Attachment 2299 is US digital broadcast TV network that has been broadcasting on a limited number of OTA channels and on C-band satellite (Galaxy 19) for several years now. AMGTV is also available for free on the internet. AMGTV's content is mostly movies - 16 hours a day on weekdays. It broadcasts in 480i. I always hoped some local station would pick it up as a sub channel. But...
As of today AMGTV has been added to the Roku channel store as a live stream: You can also add it to your listings.
Here's a link to the TV stations broadcasting AMGTV from
Here's a link to their schedules in PDF format:
I can report that the image quality is fairly good for SD on Roku, quite reliable and stable, but unfortunately it's in 4x3 format.