TV used as a Oscilloscope
I am just leading you to some resources in the web. A Scope can never perform well on TV. It would be better you go for a USB PC Scope that are not only practical but professional too.
“so I’ve decided I want to make it into a fully-functional scope that I can use in my lab. I was pleasantly suprised when I came across the one built in ’86, it suits all my needs, it was very generous of them to make the design public domain.”