Comment Re:DVB Tuners (Score 1) 81
That is a newer generation of the same thing, but if you notice they decode DVB-T2, which is High-Definition. The cheap RTL dongles decode about 3 MHz of spectrum space which is enough for a Standard-Definition DVB signal, but not enough for HD. The newer ones that do DVB-T2 have a wider chunk of spectrum space they translate, wide enough for an HD signal. In the US, an ATSC or "digital TV" High-Definition signal is about 6 MHz wide, for reference.
These newer generation dongles must have internal improvements that allows them to grab a bigger hunk of RF spectrum. The professional SDR devices that cost upward of $1000 can grab much larger chunks of spectrum, some can do 20 MHz wide swaths of RF.
What utter bullshit.
DVB-T occupies 5/6/7/8 MHz (depending on country). The transmission is COFDM spread-spectrum, the data is interleaved across all subcarriers, and (ignoring hierarchical transmissions, which are rare) the whole ensemble needs to be retrieved to demux a single channel. So, regardless of whether the content is SD or HD, DVB-T dongles always have received the whole 5/6/7/8 MHz wide channel to work (decoding is done in software).
DVB-T2 occupies 1.7/5/6/7/8/10 MHz (depending on purpose & country - e.g. 1.7MHz is meant for mobile, while afaik 10MHz isn't in use anywhere yet). The transmission is an extended version of DVB-T's COFDM spread-spectrum, the data is likewise interleaved across all subcarriers, and (ignoring hierarchical transmissions, which are rare) similarly the whole ensemble needs to be retrieved to demux a single channel. So, regardless of whether the content is SD or HD, any DVB-T2 dongle needs to receive the whole 1.7/5/6/7/8/10 MHz wide channel to work. I don't know of any offhand, but presumably decoding is similarly done in software.
Raw mode - typically used by SDR software when using chep DVB-T dongles - is different. That has limitations, but it's got nothing to do with the channel bandwidth when using the dongles for DVB-T/DVB-T2.