TV Picture keeps freezing/breaking up

[doinmummy]

This is driving me mad!
I have had a new aerial fitted which they assured me was all ok for the digital switch over.
I have a Sony tv with built in digibox.
Why does it keep breaking up or the screen goes black and says 'programme not tuned'?

Both the tv's in our house have done this for the past few days. Not a clue why, must be something in the air!

It seems to happen in fits and starts. It can goes weeks and weeks with a lovely picture but this week has been awful. It seems to know exactly what bit of a programme is the crucial bit and freezes right at that moment !

Digital runs in straight lines, if something gets in the way of the signal like a van or a plane it cuts out, Digital terrestrial has all ways been like that, I often have to move my aerial around to get channels and get them working again when workmen are near by and the like.