Jenonnet - 6 minutes ago »
Thank you so much for all your help and suggestions. Unfortunately I don't really understand a lot of it, at 68 years old is a bit confusing to get your head round.
I don't know how to tell which way the aerial should be pointing but it must be ok because when it's connected straight to the TV all the channels work perfectly, it's only when it's connected to the humax box that I have the problems with the BBC channels. So that tells me the aerial is in the correct location and pointing the right way, otherwise the problems would be the same when connected straight to the TV. It's always worked very well when connected straight from the aerial to the TV and all the channels worked perfectly well. That being the case, would I be right in thinking it has to be something to do with the box and not the aerial?
The best clue you have is looking at your neighbours aerials. If they have the elements horizontal they are likely to be pointing at a main power transmitter, if vertical one of the relay transmitters served by the main power transmitter. Your aerial should point the same way and match the vertical/horizontal alignment.
If you know how to grab a copy of window, then best plan is to fill in your postcode and house number and tick the detailed view here Don't forget the detailed view..
At least tell us the colour of the reception boxes (green is best). and name of the transmitter at the top of the list.
In the table at the top of the list alongside the top transmitter it will tell you the distance from the transmitter and the compass bearing (direction), If you can post these as well especially the distance.
This is my result for the Sutton Coldfield Transmitter. Note the green results except for the lower power COM7 and COM 8 mux.
It possible your transmitter has recently changed the frequency of the Multiplex to value your aerial is not suitable to receive. If so you might be able to get it fixed for free if your only source of TV reception is by your aerial.
If you are close to a main power transmitter it's possible the more sensitive tuners in the Humax are being overloaded by too high a signal which the TV tuner can cope with.
In this event a cheap adjustable box connected to the Aerial coax can reduce the level.