Hi Guys,
I want to upgrade my standard sky system to sky plus. I know I have to change the box and LNB but what spec cable should I use?
CT100 a.k.a. "Satellite cable". It's not hard to find. I doubt you'd need to go very far down the list of B&Q,
Screwfix before you found a roll of it.
If you currently have Sky (not +) you will likely have one cable. You will need a total of two cables for Sky+, so you will likely need to run one more cable at a minimum. (Though, there is nothing stopping you running two fresh cables --- at least this way they will match in appearance and performance, and you will then be running on fresh cable on both inputs rather than one new cable and one daggy old cable.)
Technically, CT100 is in a class of similar cables. There are thinner ones (like CT67) and thicker ones (like CT125), the difference being that thicker cables lose less of the signal per unit length, so the thicker the cable, the longer the run you can have, but CT100 is your basic bread-and-butter satellite cable that will work well in most ordinary houses.
I seem to recall a kind of cable which was like two satellite cables joined together side-by-side, probably CT67 grade, and in theory this meant an installer could just run one of these cables and save time.
But if you're bothered enough to do it yourself, you might as well have two proper full CT100 cables and get a good signal to your box.