my point Ethel was that cable is only found in conurbations with a largish population. if the OP was on the edges of one then chances are they'd have a phone signal as well because the networks look after the population in these areas.. My nearest conurbation has a population in excess of 10,000. They don't have cable there but they do have phone masts and coverage for all the networks.
When a phone network says they have 99% coverage, what they actually mean is that they cover 99% of the population not the land mass. There are still vast areas of this country that have no phone signal at all. I would doubt, though I can't prove it obviously, that there is anywhere in this country that has cable without a phone signal on one of the networks