I get the “no or weak signal message” when helicopters fly close by or large aircraft fly over but yesterday it suddenly came on and stayed on. I changed channel and the picture returned but after about 20 seconds the message returned. I repeated the channel changing several times with the same result. Today I just get the message, even when I change channel. Catch up is working and I can watch already recorded programmes. I have tested the aerial connection with another TV and it works OK. Any suggestions?

Martin