Graham
The problem I have happens not only on the Avant but on an older Beovision as well.
What happens is the picture on the UHF station starts off perfectly but after about 3 mins it starts to deterioate until it finally disappears.
This happens on all uhf channels.
It is not the antenna as it has happened in another house, and I have tried numerous ones.
It seems to work through outside tuning devices such as video (not as clear but picture stays on) and digital set top box.
Any ideas would be grateful
Thanks for the reply Graham