Greetings from the Florida Panhandle
You need to tell us a little more about your television. Is it the one that came with your Airstream? If your television was made in 2003, it is most likely not capable of receiving a digital signal without a converter box. As far as cable goes, you have to make sure that the antenna connection is turned off, and that the television is set to receive a cable signal.
SuEllyn & Brian McCabe
WBCCI #3628 -- AIR #14872 -- TAC #FL-7
2015 FC 25' FB (Lucy) with HAHA
2005 Suburban 2500 Quadrasteer (Olivia) & 2011 Silverado 3500 (Fred) with Outfitter Truck Camper (Ethel)