I'm trying to get a USB TV receiver working under Knoppix 6.2 DVD and I'm hoping some of the more experienced Linux users can put me on the correct path.

I'm in the U.S. I have both an ATI TV Wonder 600 USB receiver and a Happauge WinTV HVR 950Q USB receiver. Both are designed for digital signals. To my pleasant surprise, Knoppix 6.2 seems to detect either of them. In the Sound & Video section of the menu I found Kaffeine. It sees the receivers, knows which one is plugged in. I can go into configure and (under the device tab) set it for over the air ATSC reception. At least I think I'm doing that, I select us-ATSC-center-frequencies-8VSB, although I have no idea what 8VSB stands for. It seems the only ATSC selection I'm offered. Then I can go into the channel scan Here I check the ACTS option in "Filter". I've tried it both also checking the TV box or leaving it unchecked and only checking ATSC (What is the difference?) but in either case the channel scan gets no stations. I've also tried with no filter option checked, since I'm already telling the system that the tuner should be used for ATSC over-the-air reception. It should be getting stations, a scan from Windows with the same receivers and same antennas get plenty of stations.

Can anyone provide insight on what I might be doing wrong?

Are there other tools on the DVD that might help in diagnosing this, even other TV software that I could try (and can you provide any important and non-obvious set-up information)?