We can watch a 4k channel in HD TV using a 4k reciever or 4k STB but resolutions r 1080 p only...the main thing is stb should support H265 4k transmission...then only we get video..in hevc only we get only Audio...At Present None Of Sun Direct HD STBs Doesn't Showing 4K Resolution
Max Is 1080p60
Will Be Interesting To See, How Sun Direct Might Come Up,,,