Hi Adam,

> > > The bandwidth of the I/Q pair is too large to be transmitted
> > > over USB for the reception of TV signals. After demodulation
> > > the bandwidth is lower so it would (marginally) fit an USB
> > > interface if we talk about traditional analogue TV. For digital
> > > TV the bandwidth reduction by the decoder is much larger.
>
> Is that correct?  From what I can find, an analogue TV signal has a
> bandwidth of around 6-8MHz.

Yes.

> The HackRF is an SDR that works over
> USB2.0 and can capture a chunk of RF spectrum up to 20MHz, which
> should be ample for one analogue (or even digital) TV signal, perhaps
> even two if the channels are close enough together.

I was under the impression that the USB channel was the reason that
the highest sampling rate I was aware of in continous mode is 4 MHz
(QS1R) Now, I did not think of the fact that for the dongle we need
only 8 bit while normal SDRs use 16 bit so with my assumption the
maximum sampling speed would be 8 MHz. To receive 6-8 MHz bandwidth
one would need to sample quite a bit higher. Surely one could apply
digital filters but even so a, substantial amount of oversampling
is needed.

Are you sure HackRF really can send 20 MHz of bandwidth over USB 2.0
continously? Where did you find that info? (Seems I should try to
push SDR manufacturers who use USB 2.0 to supply modes with higher
sampling rates...)

73

Leif