Recordings cutting audio, video blurred

I noticed that several of my recordings are coming with blurred video, cutting audio, really bad image in some parts and impossible to watch/hear. In the beginning I thought it would related to an specific channel, as some videos recorded fine, but it does not to seem the case because different shows, from different channels, are also showing the same behavior.

Questions are:

  • what is the issue?
  • antenna? i live less than 15mi to every major broadcaster
  • HD? I am using an old 500Mb Seagate GoFlex

Thanks a lot for any help.

What are you using for playback? Same issue if you try something different?

Mostly ROKU 4 but the same issue from yesterday’s recording came up on my iPhone 6S Plus