loss of picture/signal at same time every night

A friend of mine tells me that in recent weeks her two televisions lose picture and sound at 7.30 in the evening and then it returns at 7 in the morning. She has a rooftop aerial adn is left with only RTE, UTV, BBC1 (living in NW). Her other TV on "rabbit's ears" is not affected. Any ideas out there as to what could be the cause?

So what channels does she actually loose, and how are they delivered (cable, sattelite, mmds, local deflector system etc).
Wexfordman

If she is using a dish or cable TV that is connected to a decoder/skybox thing, is the power to this box being disconnected for any reason -the box being plugged out to use another item or the box is plugged into a socket that's on a timer?

Could someone be disconnecting her cable and borrowing her connection for their own viewing for the evenings?

As I said in OP.... it's not cable....rooftop aerial...no dish ....not on Sky, just terrestrial stations. Could it be machinery or something operating these hours in a local hospital or something that interferes with the signal?

Welfarite,

Anywhere near army base? I know their equipment or something about their premises (whatever it may be) can affect reception - happened to us with boring regularity in a rental house some years back.