Ted Sandler

Does anyone have suggestions for a converter to connect an old Atari 800 computer to a modern flat screen television? I've attached a cable coaxial converter to the RF cable and plugged it into the flatscreen, but the picture looks very dim. Suggestions welcomed!

Are Stackpole keyboards okay? I hear the plungers get brittle and break after this many years. Also is mylar a good or bad thing? Thanks!

I need to buy a new keyboard for my Atari 800 and I've been told that Mitsumi holds up better than Stackpole or Hi-Tek. I am wondering if this keyboard is a Mitsumi: https://www.ebay.com/itm/124062095130?ul_noapp=true I contacted the seller and he was not sure without opening the package. Anyone have any idea what brand this keyboard is? Thanks Ted