First, an update regarding HVR-1600 support. I'm using Debian Etch, but knoppmyth is so close you shouldn't have too many surprises. Going to http://ivtvdriver.org/index.php/Cx18 and downloading the archive is a good start. Be sure kernel headers and kernel-tree(?) packages are installed. Instead of "make menuconfig" just do make. When it's done, make install. To finish installation, you'll need the firmware.

I'm a Time Warner _Basic_ subscriber (TWC) in the Los Angeles area. (no cable box! at $12/month.)

Setting up the NTSC tuner is no problem. I set it to cable-hrc and it enters all the unencrypted+encrypted channels. Hint, you want those encrypted channels because they go on promotional binges for weeks at a time year-round where they make a wide variety of encrypted channels available.

After testing all band/broadcast combinations, I've come to the conclusion that TWC in the Westchester (Part of L.A.) area transmits NO HD over the bare wire.

I am considering taking the issue up with the municipality, as they are the only leverage point that seems to exist. If anyone has any experience working through local government on a cable franchise issues please let me know on this thread.

Generally speaking, USA HD cable is sent over QAM which many tuner cards don't support. I haven't peeked lately but doubt that the cx18 driver supports QAM even if the HVR-1600 does. (And I'm not sure if it does in the first place.)

When I've had the chance to play with a generic QAM tuner (standalone or TV-integrated, not PC-based) on a basic cable wire I've only been able to get a couple of actual HD stations (local station rebroadcasts), sometimes some raw pay-per-view (that someone else is watching and controlling) in SD format, but even the basic HD channels and a couple local channels were encrypted. So basically I've only seen what I could see better with an antenna plus on one cable system I got to watch someone else fast forward, pause, rewind and change the movie on user-controlled pay-per-view feeds.