I'm updating my sky to HD soon.Am I right in thinking I need two cables through wall to box not one as for the standard box.I want to be ready when they arrive to set up HD box.
The diameter of the two cables is almost exactly that of your one current cable. I too had the same concerns, but didn't have any problem when my HD installation came.
(P.S. You're in for a treat. World Cup in HD has been superb)