Looking for a DVB-C tuner

The most common reason why I would ask for help (online) is lack of work force to investigate and fix issues in the VLC media player bug tracker, of which I have been the triager for the past few years. Like most other VLC developers, I do that on my free time. That means we have rather limited time and motivation to address other people's issues and so I ask for help. Sometimes, I might also be looking for help testing some new code. This time however, I need with something completely different.

At some point last year, I finally gave in, bought a TV set and registered myself as a licensee for TV reception. Finally? If you must know, the yearly license fee exceeds 200€, so it took some thinking before making the investment. In fact, in 15 months, I will have spent more for licensing than for the 24-inches HDTV set. But lets get to the point.

As a core VLC developer, I had been intending to improve our Linux DVB input code. While it is working, it is one of the oldest input plugin in the VLC and there is much room for improvements. In particular, we need to implement the Linux DVB API version 5. This is also known as the S2API because it introduces support for the second generation satellite DVB standard, DVB-S2. But it also supports a number of other standards, and will also soon support DVB-T2, the newer European standard for digital terrestrial TV.

I also meant to improve hardware autodetection with udev, fix cable TV modulation scan, improve integration with the VLC threading subsystem... and probably a few other things that might crop up.

So I went to the LinuxTV hardware compatibility list and bought a "supported" tuner. On the hardware side, it looked perfect:

Things were too good to be true: I got a new revision of the model, while Linux currently (March 2011) only supports older ones. In fact, it was so new that it came with officially "beta" software on Windows, that would not render any TV channel, though scanning did work.

Then I exchanged the device for a much less ideal model. That one is larger, relies on an external power supply and lacks the RF loop. But anyway, for reasons as yet unknown to me, that device fails to find my cable TV channels (even on Windows: I suspect a country-specific tuning frequency problem). The terrestrial tuner is officially not supported on Linux (it works fine on Windows).

So now, I am about to give up. I need a USB DVB-C tuner with Linux drivers that do work. Technically, I need QAM-64, QAM-128 and QAM-256 modulations, and frequencies on multiple of 4MHz.

Any help is welcome and might foster further VLC development.
Thanks in advance. (I can be contacted privately here)