We have tried all of that. Antenna is turned off, Tvs are set to cable and scan is done. None of the Tv's gets anything. The RV shop has done a test on the wire running from the exterior of the RV to the antenna/cable panel in the RV and they get a tone showing the wire was fine. Then they hooked the cable up through the cable box in their shop and it worked. They have a specific brand of cable like Comcast. I agree, the cable should work with no cable box. It works on everyone elses motorhomes. But on my RV, I never get any cable in any campgrounds, including Disneyworld Campground.
So then the question becomes, is there a universal box I can buy that will allow me to receive/convert cable in the campgrounds?