Re: [Discuss-gnuradio] This is nice

[Andrew Davis]

Right, but I think the idea here is for $20 why not?

As far as a driver goes what they have now is a program that starts
the thing and tunes it, then reads samples, all of this is already
build into the UHD framework. I'm not sure but I would like to make
this a UHD compatible USB device. ( Much like the USRP1 )

~Andrew

On Thu, Mar 22, 2012 at 11:06 AM,  <address@hidden> wrote:
> I also have a trio on order.  The issues I can see surrounding this approach
> are:
>
>    o Consumer electronics parts lineups are capricious and unreliable--the
> target device may use the "SDR-capable chip" this month, and next month,
> they've found that they can shave $0.35 of off the B.O.M. by going with a
> totally different parts line-up they will, even though it will cost them
> $50K in engineering costs up front--they sell thousands and thousands a
> month.  There are already *TWO* versions of this dongle, one using the
> "good" RTL2832U chip, and the other using an Afatech chip (AF9015 or
> AF9035). The "magic sauce" that Antti discovered in the RTL2832U chip to do
> "raw samples" is peculiar to the RTL2832U chip, and doesn't necessarily map
> on to other DVB-T digital demod chips on the market.
>
>
>
>   o The 28.8MHz master oscillator is a very cheap 100PPM part, which will
> produce unpleasant frequency offsets, and phase-noise to match
>
>
>
>   o Not sure how good the noise figure is, since there's no LNA in front of
> the E4000 tuner chip.
>
>
>
>   o Don't know how they implement re-sampling.  If it's not done right, then
> there'll be nasty aliases in the passband handed to the host
>
>
>
> None of these are fatal, but be aware that the approach of "re-purposing"
> consumer electronics is fraught with dangers as described above.
>
>
>
> -Marcus
>
>
>
> On Thu, 22 Mar 2012 10:53:13 -0400, Tom Rondeau wrote:
>
> Andrew and Sean,
>
> Glad to hear you both thinking about doing this! Coordinate as you can
> and keep us up to date on the progress.
>
> Tom
>
>
> On Thu, Mar 22, 2012 at 10:45 AM, Nowlan, Sean
> <address@hidden> wrote:
>
> Funny enough, a coworker mentioned it to me yesterday morning and then it
> popped up on discuss-gnuradio. He must have seen it on Reddit as well.
>
> I have one on order too, and I was also contemplating a GNUradio driver...
> let me know if you want to coordinate.
>
> Sean
>
> -----Original Message-----
> From: address@hidden
> [mailto:address@hidden On
> Behalf Of Andrew Davis
> Sent: Wednesday, March 21, 2012 9:34 PM
> To: David Kierzkowski; address@hidden
> Subject: Re: [Discuss-gnuradio] This is nice
>
> Saw it on Reddit a couple days ago, already have one on order. Then I might
> work on making a GnuRadio driver or something for real-time use.
>
> On Wed, Mar 21, 2012 at 3:17 AM, David Kierzkowski <address@hidden>
> wrote:
>
> The osmocom guys are using a 20$ USB catv tuner as a RF source in gnuradio.
> 3.2MS/s !
>
> http://sdr.osmocom.org/trac/wiki/rtl-sdr
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