A seperate cable from the lnb is the only sensible option you should have two spare outputs if you only have one sky sky hd box.
Sky hd satellite cable splitter.
If you are looking at extending the wires from your satellite dish to your sky box then a sky extension cable is what you need to get the job done quickly and easily.
Search no more for an awesome satellite tv splitter as this brilliant satellite tv splitter supports a number of different hdcp inputs such as 1 2 1 1 and 1 0 plus it also supports hdmi 1 3 making it truly exquisite and exceptional in transferring a number of different video formats such as 1080p 1080i 720p 576p 480p 576i and 480i.
Many sky customers want to move or extend their sky boxes to another place in the house but to do this you will need a longer length of satellite cable.
Quick and to the point on how to make a screw on f connector for sky satellite and numerous aerial connections including tolls that are needed.
Another answer and a method relatively overlooked here in the uk this could be done would be using a smart splitter and an scr single cable router compatible lnb or satellite multi switch amplifier and scr enables satellite receiver the majority of new sky hd boxes come equipped with this facility accessed within the hidden installer menu.
A switch will connect one or the other and not both at once.