[jonifen]

I found that if you can get the portable aerial up high enough near the outside wall pointing in the same direction as the other aerials in the area, it might work. We've got a £6 basic aerial from Wilkos in one of the kids' rooms (the front box bedroom) near the outside wall on the wardrobe - works perfectly, she gets all channels fine.

In the back room we bought a One4All 40dB booster aerial for about £18 from Argos which works well (but not as well as the cheap-un in the front room!)

The cable you need can be picked up from your local Tesco for about a quid.