For ages now the picture on four of these five sets has varied between perfect, through breaking up or freezing to nothing at all. Especially on HD channels and in high winds.
When the system was installed there were huge trees between our aerial array and the transmitter, Winter Hill Nr Bolton in Lancashire. This weakened the signal a great deal, especially in summer when tree leaves aggravated things. This, meanwhile is Winter Hill:
click to make it even taller
Since then, two things have happened - the trees were felled to make way for the apartment block on The Sidings, the roof top of which is considerably lower than were the trees. Secondly, the UK's analogue transmissions were switched off and we went digital. At the same time Winter Hill's output increased greatly in power. These factors each combined to give us a very good signal indeed. TOO good in fact.
Nowadays, signal strength can be displayed among the menu options on screen on the TVs. Each was showing 100%.
The fix? Attenuate (turn down) the signal leaving our mast to 70 or 80% - a simple turn of a screw at the masthead box-of-tricks. Remove two signal-strength-amplifiers which had been installed to enhance our one time too weak signals and Bingo. Perfect HD / 4K TV pictures all round the house.
So, I have discovered that when it comes to TV signals you CAN have too much of a good thing. I have also discovered that Winter Hill is the UK's third highest mast at 1015 feet tall. Impressive:
If that ever pops up in a pub quiz you will thank me for that.