said by Jerm :

Yeah the problem for better or worse is if you want to watch an HD *signal* on a 19" TV you'd be hard pressed to notice any benefit really. And realistically it would be even harder to see stuff unless you were sitting really close vs watching standard def.

I have a 50" Plasma and a 19" standard def CRT. From a normal viewing distance I couldn't imagine watching HD on the 19" as it would make things too small!