The osmocom guys are using a 20$ USB catv tuner as a RF source in
gnuradio. 3.2MS/s !
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.
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
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
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 $50K in engineering costs up front–they sell
thousands and thousands a month. There are already TWO versions of
this dongle, one using the “good” RTL2832U chip, and the other using an
Afatech chip (AF9015 or AF9035). The “magic sauce” that Antti discovered
in the RTL2832U chip to do “raw samples” is peculiar to the RTL2832U
chip, and doesn’t necessarily map on to other DVB-T digital demod chips
on the market.
o The 28.8MHz master oscillator is a very cheap 100PPM
part, which will produce unpleasant frequency offsets, and phase-noise
to match
o Not sure how good the noise figure is, since there’s no
LNA in front of the E4000 tuner chip.
o Don’t know how they implement
re-sampling. If it’s not done right, then there’ll be nasty aliases in
the passband handed to the host
None of these are fatal, but be aware
that the approach of “re-purposing” consumer electronics is fraught with
dangers as described above.
-Marcus
On Thu, 22 Mar 2012 10:53:13
-0400, Tom R. wrote:
Andrew and Sean,
Glad to hear you
both thinking about doing this! Coordinate as you can
and keep us up
to date on the progress.Tom
On Thu, Mar 22, 2012 at 10:45 AM,
Nowlan, Sean
wrote:Funny enough, a coworker mentioned it to me
yesterday morning and then it popped up on discuss-gnuradio. He must
have seen it on Reddit as well. I have one on order too, and I was also
contemplating a GNUradio driver… let me know if you want to
coordinate. Sean -----Original Message----- From:
[email protected]n.invalid [4]
[mailto:[email protected]n.invalid
[5]] On Behalf Of Andrew D. Sent: Wednesday, March 21, 2012 9:34 PM
To: David Kierzkowski; [email protected] [6] Subject: Re:
[Discuss-gnuradio] This is nice Saw it on Reddit a couple days ago,
already have one on order. Then I might work on making a GnuRadio driver
or something for real-time use. On Wed, Mar 21, 2012 at 3:17 AM, David
Kierzkowski wrote:The osmocom guys are using a 20$ USB catv
tuner as a RF source in gnuradio. 3.2MS/s !
http://sdr.osmocom.org/trac/wiki/rtl-sdr [1]
_______________________________________________ Discuss-gnuradio mailing
list [email protected] [2]
https://lists.gnu.org/mailman/listinfo/discuss-gnuradio [3]
_______________________________________________ Discuss-gnuradio mailing
list [email protected] [8]
https://lists.gnu.org/mailman/listinfo/discuss-gnuradio [9]
_______________________________________________ Discuss-gnuradio mailing
list [email protected] [10]
https://lists.gnu.org/mailman/listinfo/discuss-gnuradio [11]
_______________________________________________ Discuss-gnuradio mailing
list [email protected] [13]
https://lists.gnu.org/mailman/listinfo/discuss-gnuradio [14]
Links:
[1] http://sdr.osmocom.org/trac/wiki/rtl-sdr
[2]
mailto:[email protected]
[3]
https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[4]
mailto:[email protected]n.invalid
[5]
mailto:[email protected]n.invalid
[6]
mailto:[email protected]
[7] mailto:[email protected]
[8]
mailto:[email protected]
[9]
https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[10]
mailto:[email protected]
[11]
https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[12]
mailto:[email protected]
[13]
mailto:[email protected]
[14]
https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
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
Worth taking a look for $19 right? The Elonics website claims there’s an
integrated LNA in the e4000 but I can’t find the specs.
http://www.elonics.com/product.do?id=1
Sean
From: [email protected]n.invalid
[mailto:[email protected]n.invalid] On
Behalf Of [email protected]
Sent: Thursday, March 22, 2012 11:06 AM
To: [email protected]
Subject: Re: [Discuss-gnuradio] This is nice
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 R. 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
<[email protected]mailto:[email protected]> 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
entirely agnostic about hardware
I thought that was the point of UHD?
Devices like Funcube and even a sound card with high sampling rates
should be considered when designing this framework as they all should
be selectable from a simple source/sink API. They could have
definitions and return sampling rates and such. I’ll have to
brainstorm a bit for ideas…
~Andrew
Hi
Over on reddit they are reporting that DealExtreme is out of stock "One
of the main sources of tuners is DealExtreme, however they are
apparently out of stock (though they don’t say it) and have very slow
shipping. "
I found another source of compatible devices on Ebay.de
They with ship to North America by DHL if you ask in advance. It is
costing me 26 Euro’s to ship two devices to Canada.
David
On 03/22/2012 11:17 AM, Andrew D. wrote:
Right, but I think the idea here is for $20 why not?
Right, for $20.00, why not indeed! I just didn’t want people making
long-term plans based on something that amounts to
a serendipitous accident.
I really don’t think doing a UHD driver is the right approach, for
reasons of maintenance headaches, and support headaches.
But this does raise a bigger issue of perhaps needing an abstraction
layer for “SDR-like” hardware sinks/sources for flow-graphs
that could reasonably be entirely agnostic about hardware. Myself, I
have a couple of “radio science” applications that try to
be agnostic by supported both UHD devices and gr-fcd–but that
required two separate flow-graphs because there’s no reasonable
way to abstract that stuff away, which I think is a shortcoming.
let me know if you want to coordinate.
Discuss-gnuradio mailing list
Discuss-gnuradio mailing list
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–
Marcus L.
Principal Investigator
Shirleys Bay Radio Astronomy Consortium
http://www.sbrac.org