Complex sentence: Digital signals do not have'grade b' signal areas, and are either'in perfectly' or'not in at all' and since most stations have elected to use UHF rather than older VHF channel allocations, their range is far less than previously.
Split into simpler sentences: Digital signals do not have'grade b' signal areas, and are either'in perfectly' or'not in at all'. Further, since most stations have elected to use UHF rather than older VHF channel allocations, their actual broadcast range is far less than previously.