I recently got some 21" CRTs and now my tv officially pales in comparison. my tv at my desktop is 13" and i got to wondering if i could watch tv on my monitor. it has two inputs, vga and bnc rgb with a button to change between the two. so on to my question... anyone know any reasons why i shouldnt do this, and where can i find a schematic on how to accomplish this? i spent a good deal googling but not much luck.. only commercial adapters
the tricky part with that is that tv is much lower bandwidth than VGA, most monitors don't support horizontal refresh rates that low. Googling for how to connect a console to a VGA monitor should yield some useful results, http://atarilabs.com/meat/2000/1201_rgbprimer.shtml explains some of the difficulties. Bottom line is it would take way more work, and probably more expensive parts, to take any kind of cable tv input and turn it into VGA, you're better off buying a device that does it for you, in my two seconds of googling i found this - http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=1208335&CatId=1430 but that is still more expensive than the cheapo TV cards.
Getting from composite to RGB is very complex. It involves some pretty involved signal processing, at frequencies beyond the range of normal hobbyists. You pretty much have to buy an adapter. That's why you didn't find any circuits.
