I assume this TV of yours has a cable port? If so, you need an RF to coax adapter:



Screw one end into the cable port, and stick the RF cable fromt he Atari into the other end. It replaces the RF switchbox. If you need more help, go here:

www.atariage.com


and ask the same question. They'll be able to give you more "How do I hook up my Atari" info than you can imagine.