I hope that this is the appropriate place to ask this question about our new-to-us big screen television. It's a used Samsung. For reception all we have and likely all we will ever have is an antenna in the attic and coaxial outlets in the walls. Plugged it in and it says "No Signal". Will newer UHDTV's work off the attic antenna or do they need to be hooked up to a cable box or something else?