I have just purchased a freeview box- £60 argos. I have set it all up but i can only get 4 channels, and they are all unwatchable as the picture freezes/sound drops etc. I assume it is a problem with the reception? Analog tv is ok and i can get all channels fine. I live in the CV postcode area (warwickshire). Does anyone think an ariel signal booster will help my situation??? Many thanks.