Yeah I saw those in maplin, I can't see a thread but I can't see inside very easily either. Looking at it again my description was pretty poor, a standard uk tv socket has a pin surrounded by a circular ground piece, this actually looks more like a miniature phono socket, theres a metal surround which contacts on the outside. The inside is nylon with a small hole in the middle.
The manual & website are no help unfortuantely.
I might pick up one of the F type connectors tomorrow and see it it fits.
EDIT: just noticed theres a satelite connector on the wall next to me, it looks alot like that, I thought the threads would be on the socket surround, not on the actual outer bit of the phono bit (theres a terrible description and a half). I'll get one tomorrow and try it, I assume it just wires up to a piece of coax like a normal PAL plug would?
Cheers for the help