According to FCC Sec 76.630 and CFR Title 47, Sec 76.901(a), a cable provider who chooses to “rebroadcast” local Over-the-Air (“OTA”) channels, must do so in what is known as clear QAM. Clear QAM is still an encrypted signal, but a new television set with an ATSC tuner will be able to decrypt and display it without renting a “cable box” from your subscriber.
Time Warner Cable follows this regulation, but they have figured out a way to discourage cable theft by moving their re-broadcast OTA channels around periodically. To the end user with a standard ATSC tuner, this means that some HD channels (i.e. SoCal 2-1, 4-1, 5-1, 7-1, 9-1, 11-1, etc) may stop working until a channel scan is performed on the TV. The thing is that this also affects HDHR users adversely. If you use a DVR that utilizes a Silicon Dust HDHR digital tuner and capture device, those channels the cable company moved around won’t record the shows you may have scheduled to record anymore. Recording content on stations or channels that were moved by the cable company will require you to perform a new channel scan using the configuration utility. Otherwise the HDHR device will record an hour of blank screen or give you a failure to capture notice (in SageTV).
Although performing a channel scan within the Silicon Dust HDHR utility is straight forward(see screen shot below),
the real issue is that you won’t necessarily know when or how often it will need to be done. Really our only indication is some failed recordings on a channel that we know to be working previously. Unfortunately by that time it’s usually too late to perform a channel scan. So if anyone has advance knowledge of when Time Warner will be moving OTA HD channels and can provide an update or schedule of when this will happen, I’d greatly appreciate it and I’ll gladly post it as well.
UPDATE: I know that recently (as in Sept. 29th or so), Time Warner Cable moved channel 7-1 and a few others.
