I am a ComCast subscriber in Elizabethtown, KY and have a digital LCD HD TV that I receive all the channels I want without a cable box.
However, the channels show on my set with multipe sub-channels on each channel. For example 2-1, 2-2, 30-1, 30-2, etc. Is there any published listing of channels in this digital form or am I going to have to make my own? Where might I be able to find a listing like this if it exists?
Your television has a QAM tuner that can tune a limited number of cable channels that are transmitted by Comcast in non-encrypted QAM - also referred to as "Clear QAM". (QAM is Quadrature Amplitude Modulation, the transmission system used by cable companies in the U.S.).
FYI the vast majority of cable channels are encrypted, meaning you cannot view them without having them decoded by an authorized device such as a cable box. The non-encrypted channels are the limited basic service tier, i.e. local broadcast channels and public, educational and government channels.
Comcast does not provide support for subscribers who view their programming using a QAM tuner. It's not illegal to use a QAM tuner to view non-encrypted programming, but Comcast expects you to rent one of their cable boxes to view their channels.
If you do not rent a cable box, you may find that Comcast frequently changes the QAM station numbers without notice to subscribers, making it hard to know where your favorite stations are. You will need to regularly re-scan the stations using the QAM tuning scan system.
The closest place to find a list, and is might not be totally accurate is HERE. Since this list is uploaded from owners of their TV tuners, it is not guaranteed to have much accuracy. If no one in Etown has one of their tuners, then the data might bounce to another system semi-close to the area. Most people end up making their own list on a spreadsheet.
These channels can and do get shuffled around at times without notice, so if you lose any channels, do a re-scan on the TV.