I've got one in my hands right now (I went though all the drawers to find it !)
It has the 3 connectors as above, and a coax plug on the other end; and also a power adaptor joined to it too (I used it a while ago, on my old tv and worked perfectly.
Written on the data plug is "RF-Unit Auto switch VHF/UHF"
They must exist somewhere on the web (try Ebay or Google) Mind you I don't even want mine !