The short answer is they aren't retailed. They are only sold to cable companies, and they are set up to work with their propitiatory system. The best you can get from a retail outlet is a clear QAM tuner which will only decode the most basic channels. Their has been some talk of a "generic" DTA that will work with both Motorola and Cisco cable systems, but as far as I know none has been produce as of yet. Even if such an animal existed that doesn't mean that it would be made available to the general public. Also, cable companies are trying to get the rules changed so that they can encrypt all the channels, which would make clear QAM tuners (including the ones in digital TVs) useless.