I have a Twinhan 7240 USB tuner dongle that is unsupported for linuxtv, and I'd like to offer my efforts if anyone wants to help make it supported. I don't have a ton of experience with this work, but I can follow instructions and send back results. Please be in touch if you're interested, or if I missed somewhere that it's actually supported already. Thanks! ~$ lsusb -s 1:3 Bus 001 Device 003: ID 13d3:3215 IMC Networks DTV-DVB UDAT7240 - ATSC/NTSC/PAL Driver(PCM4)