If you have a RCA (yellow/red/white) output on the cable box, you can get a converter. I did it with Dish network. Had a sd output but only had a HD tv with zero rca inputs. So had to convert that signal to get it in the tv via HDMI. This is the box I got to do it with. https://www.amazon.com/gp/product/B003NS0UUQ/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1