HD channels for Bay Area Comcast

It sounds like you're asking the same question as in this thread.

 

This sounds like a totally different problem. This sounds like a clear QAM problem.

The TiVo doesn't know about what channel the cable company calls a digital channel unless you have cable cards. So the cable company may broadcast channel 2 digitally on 87.4, but TiVo doesn't know that. They also broadcast the HD versions on some random channel as well, and the cable company calls the HD version of channel 2 702, I've no idea what channel the cable comapny sends it on, its broadcast over the air (OTA) as 2.1 (actually carried on 56.1).

With a cable card your TiVo would know that the HD version of 2 was on channel 702, without it it doesn't. If you had an antenna it'd know that channel 2.1 (broadcast on 56.1) was really the HD version of channel 2.

Without a cable card though it sees that programming information ("PSIP" data) broadcast with the channel, the cable company passes this information down the wire as well. (I think they're required to do that.) So the TiVo sees the PSIP data and says the channel is actually 2.1.

The really dumb part is that it doesn't connect this with the over the air 2.1, for which it has channel data, it doesn't know about cable 2.1, only cable 702 and OTA 2.1. TiVo could supply data for these channels, but seem to be blind to this idea.

If you got cable cards, they'd show up as 702, 705, 707 etc.

 

Usual suggestion for trying OTA is to see what Antennaweb has to say you'll need for an antenna. The bay area is a bit of a tricky place for OTA reception, but if the tuner in the HD is as good as the one in the S3, it should work great.