Hi there
Throw indoor aerial out the window, and buy roof-top one.
If you must have an indoor aerial, its a reception issue, I would suggest taking your TV to a neighbour (who has roof-top aerial) and tuning it in there. Then its a matter of playing around by moving your aerial to the best position. Up high near a window is preferred.
More information:
http://www.rica.org.uk/content/indoor-aerials
Cheers
