This was a common problem when on digital first came out it all depended how good an area you were in for reception.We were told we were in a good catchment area and we would have no problems.I got on digital when it first came out but couldn't get all the channels we wanted we were told we would need an aerial upgrade this means for �40 someone from on digital comes out and replaces your aerial. We never bothered It does sound as if you need a stronger aerial so you can get the other channels you are missing.Try your local paper there will be someone there that fits aerials at a good price.