There's nothing wrong with your new TV. The signal dropouts are most likely just to do with the shared aerial etc. The fact that the new TV works means that the problem is with your old Hitachi TV and/or the Logik receiver you have. Take your new TV and plug it into the aerial socket where your Hitachi is at the moment. Check that you get reception on it. If you do then there's no problem with the aerial connection in your Lounge. Then try plugging the Logik into the new TV. Then we'll know if the Logik is faulty. Let me know what happens and I'l advise further