PCTVSystems QuatroStick-nano 520e
The device also comes with an analog input, but the analog part is not supported by the linux driver yet(?). The analog input provides composite and s-video connectors using an included adapter cable.
See the external product page for more information.
Support for the DVB-C and DVB-T part of the tuner has been added to kernel, and include since 3.4 in all stable kernel releases. 
Log from initialization on kernel 3.3.1 with latest linux media drivers built from source, and firmware extracted from Windows driver:
[ 6138.750171] usb 1-4: new high-speed USB device number 5 using ehci_hcd [ 6138.865854] usb 1-4: New USB device found, idVendor=2013, idProduct=0251 [ 6138.865866] usb 1-4: New USB device strings: Mfr=1, Product=2, SerialNumber=3 [ 6138.865877] usb 1-4: Product: PCTV 520e [ 6138.865884] usb 1-4: Manufacturer: PCTV Systems [ 6138.865892] usb 1-4: SerialNumber: 000000107NYD [ 6138.866623] em28xx: New device PCTV Systems PCTV 520e @ 480 Mbps (2013:0251, interface 0, class 0) [ 6138.866633] em28xx: Audio Vendor Class interface 0 found [ 6138.866640] em28xx: Video interface 0 found [ 6138.866645] em28xx: DVB interface 0 found [ 6138.866721] em28xx #0: chip ID is em2884 [ 6139.162325] em28xx #0: Identified as PCTV QuatroStick nano (520e) (card=86) [ 6139.162686] Registered IR keymap rc-pinnacle-pctv-hd [ 6139.162975] input: em28xx IR (em28xx #0) as /devices/pci0000:00/0000:00:1d.7/usb1/1-4/rc/rc3/input11 [ 6139.163396] rc3: em28xx IR (em28xx #0) as /devices/pci0000:00/0000:00:1d.7/usb1/1-4/rc/rc3 [ 6139.164187] em28xx #0: Config register raw data: 0xac [ 6139.164195] em28xx #0: I2S Audio (3 sample rates) [ 6139.164201] em28xx #0: No AC97 audio processor [ 6139.181061] em28xx #0: v4l2 driver version 0.1.3 [ 6139.202893] em28xx #0: V4L2 video device registered as video0 [ 6139.222688] drxk: status = 0x639260d9 [ 6139.222702] drxk: detected a drx-3926k, spin A3, xtal 20.250 MHz [ 6140.635363] DRXK driver version 0.9.4300 [ 6140.650978] drxk: frontend initialized. [ 6140.651003] tda18271 15-0060: creating new instance [ 6140.660604] TDA18271HD/C2 detected @ 15-0060 [ 6140.998550] DVB: registering new adapter (em28xx #0) [ 6140.998563] DVB: registering adapter 0 frontend 0 (DRXK DVB-C DVB-T)... [ 6141.000971] em28xx #0: Successfully loaded em28xx-dvb [ 6141.000991] em28xx-audio.c: probing for em28xx Audio Vendor Class [ 6141.000998] em28xx-audio.c: Copyright (C) 2006 Markus Rechberger [ 6141.001038] em28xx-audio.c: Copyright (C) 2007-2011 Mauro Carvalho Chehab [ 6141.002243] Em28xx: Initialized (Em28xx Audio Extension) extension
The DRX-K demodulator requires a firmware file that must be uploaded by the driver: dvb-demod-drxk-pctv.fw
This file can either be downloaded by the get_dvb_firmware script available in kernel source.
Alternatively, you can download the extracted firmware directly from this link
Target directory: /lib/firmware
The 520e uses a shared frontend for both DVB-T and DVB-C.
In the Windows software "TVCenter" (available from PCTVSystems), there is a option to disable the amplifier. This option is currently not available(?) in the linux driver. This might be the reason why the device has problems locking on some DVB-C frequencies .
Latest ACG (Automatic Gain Control) changes in the TDA18271 driver.