Thanks for some informative responses. It sounds that I may have kept the amplifier button pressed.
My TT is a 2015 Nash 23D, and the manual had no information on either satellite, OTA or cable. I bought my Samsung TV from Costco right before the trip, so it's maybe a month old.
The exterior of the TT there are two coaxial connections (one of which was marked satellite). The output end (near the TV) had both a satellite and a cable/OTA connection - but I probably had the the amplifier turned on. I did try going through both the satellite and cable connections, incase it was a loose connection.
When scanning through the TV it allowed both OTA or cable scanning, either independently or combined (I tried both), and it picked up both types. But as I said, I was only able to get the OTA.
It sounds like I should try it with the amplifier turned off.
Paul