What device do I need to get a good picture on 2nd tv without it being connected to main ariel?

I have a second TV in my bedroom that is not connected to the main ariel and the picture is very poor using rabbit ears with amplifier. I have been told that I can purchase a device that gets the signal from the main TV downstairs. Neither of my TV's are digital. I have had a look on ebay and now I am totally confused!