The telephone companies used unbalanced double shielded 110 ohm coax for video (television). Nice stuff. I can't find a number on the coax. Its about the size of RG 8 with two insulated wires inside one blue and one white with a double shield around it. I have a couple short pieces of about 50 foot or more left I plan on trying to use them on a low noise recving ant,. jim WØNFL