I have been hacking into one of those $20 DVB-T TV Tuner Dongles. To get it to tune to the Freq I want I use the usual method with the ExtIO Drivers. The real problem with this thing, as far as making good use of the valuable E4000, is the RTL2832, even though controlling the Tuner through the USB requires the RTL2832. This clumsy Analog to Digital Converter / USB interface Chip, does not have the Audio dynamic range needed for my purposes. The infuriating predilection it has to crash every time you want to shift frequency is another disadvantage. Since the Owners of the E4000 have gone into Bankruptcy, I am taking the initiative to hack the Tuner. First, I attached a high gain audio amplifier's input directly to the Tuner's output then to a 96K Sample per Second, 24 Bit Audio card to observe a high quality spectral image from the tuner. Next is to hack into and record the I2C sent to the Tuner, so it may be controlled independent of that infuriating RTL2832. If anyone has done this, please share your code and understanding.
Thanks
Jay Salsburg
This clumsy Analog to Digital Converter / USB interface Chip, does not have the Audio dynamic range needed for my purposes.
That's because it's only designed for FM radio. Anything more would have been overkill for the manufacturer's purposes. This is still excellent value for $20 and hasn't been much of a stumbling block for what most people have been doing so far.
The infuriating predilection it has to crash every time you want to shift frequency is another disadvantage.
I'm not sure where you're looking in the docs, but if you're using Balint's USRP ExtIO (as oppposed to the - I think - Osmocom ExtIO) then there are two sets of code for the tuner. The default one offers slightly wider frequency range, but crashes as you have seen. If you add "tuner=e4k" to the device hint then it will switch to the newer code, which doesn't crash, at the expense of having some gaps in the frequency coverage.
First, I attached a high gain audio amplifier's input directly to the Tuner's output then to a 96K Sample per Second, 24 Bit Audio card to observe a high quality spectral image from the tuner.
Presumably this reduces your bandwidth from 3.2MHz to 96kHz, which is 24kHz too low to properly receive wideband/consumer FM radio. Since many people are using the RTLSDR has a kind of glorified RF scanner, I am wondering whether you're trying to do something you really should be doing on a high end device like the USRP?
Next is to hack into and record the I2C sent to the Tuner, so it may be controlled independent of that infuriating RTL2832. If anyone has done this, please share your code and understanding.
Don't quote me on this but AFAIK the RTL just passes the I2C commands through unchanged. This is how the existing E4000 tuner code was able to be adapted to the RTL2832 so quickly.
This list probably isn't the best place to ask about this sort of thing - it's mostly developers focused on improving the hardware rather than getting people started with it. I strongly recommend switching to the ultra-cheap-sdr list[1] instead, which has many more people able to help beginners. Your question about the device crashing is answered quite often, for example. These people can also point you to the many 'getting started' guides, which do explain clearly with screenshots where to put device hints and the like.
Cheers, Adam.
[1] https://groups.google.com/d/forum/ultra-cheap-sdr (you can subscribe via e-mail here if you don't want to use the web interface)
so it is *designed* for FM? That's encouraging because mostly that is all I really need from it, only all my experiments so far have yielded only AM-quality sound, but it's good to hear because it means there's *hope* and so I'll just keep hanging in there until an FM recipe surfaces :)
On Mon, Aug 13, 2012 at 7:58 PM, Adam Nielsen a.nielsen@shikadi.net wrote:
This clumsy Analog to Digital Converter / USB
interface Chip, does not have the Audio dynamic range needed for my purposes.
That's because it's only designed for FM radio. Anything more would have been overkill for the manufacturer's purposes. This is still excellent value for $20 and hasn't been much of a stumbling block for what most people have been doing so far.
The infuriating predilection it has to crash every time you want
to shift frequency is another disadvantage.
I'm not sure where you're looking in the docs, but if you're using Balint's USRP ExtIO (as oppposed to the - I think - Osmocom ExtIO) then there are two sets of code for the tuner. The default one offers slightly wider frequency range, but crashes as you have seen. If you add "tuner=e4k" to the device hint then it will switch to the newer code, which doesn't crash, at the expense of having some gaps in the frequency coverage.
First, I attached a high gain audio amplifier's input directly to the
Tuner's output then to a 96K Sample per Second, 24 Bit Audio card to observe a high quality spectral image from the tuner.
Presumably this reduces your bandwidth from 3.2MHz to 96kHz, which is 24kHz too low to properly receive wideband/consumer FM radio. Since many people are using the RTLSDR has a kind of glorified RF scanner, I am wondering whether you're trying to do something you really should be doing on a high end device like the USRP?
Next is to hack into and record the I2C sent to the Tuner, so it may be
controlled independent of that infuriating RTL2832. If anyone has done this, please share your code and understanding.
Don't quote me on this but AFAIK the RTL just passes the I2C commands through unchanged. This is how the existing E4000 tuner code was able to be adapted to the RTL2832 so quickly.
This list probably isn't the best place to ask about this sort of thing - it's mostly developers focused on improving the hardware rather than getting people started with it. I strongly recommend switching to the ultra-cheap-sdr list[1] instead, which has many more people able to help beginners. Your question about the device crashing is answered quite often, for example. These people can also point you to the many 'getting started' guides, which do explain clearly with screenshots where to put device hints and the like.
Cheers, Adam.
[1] https://groups.google.com/d/**forum/ultra-cheap-sdrhttps://groups.google.com/d/forum/ultra-cheap-sdr(you can subscribe via e-mail here if you don't want to use the web interface)
so it is /designed/ for FM? That's encouraging because mostly that is all I really need from it, only all my experiments so far have yielded only AM-quality sound, but it's good to hear because it means there's /hope/ and so I'll just keep hanging in there until an FM recipe surfaces :)
Yes, because the dongles provide digital TV (via hardware) and as an extra selling point, analogue FM radio (provided via the SDR.)
I don't know what platform you're on or what your goals are, but I hear the SDR# program for Windows offers excellent stereo FM support, as it's one of the few programs that can deal with the ~120kHz bandwidth needed for a WBFM signal.
Cheers, Adam.
From what I understand, the digital TV standard here in Canada is different from DVB-T (I am a complete neophyte at all of this) and so that particular feature of the device won't be of much use to me, but as for the FM, I'm on the Ubuntu/Linux GNU platform, so I'm awaiting on the kindness of strangers to perfect the kernel drivers enough to match the Windows kit performance. But that's okay, because I'm learning a lot in the process :)
The DVB-T option isn't much use to anyone, because we all bought the device for SDR purposes :-) No disrespect, but wanting to use the device just for FM radio is a bit of a waste - you have the Swiss Army Knife of radio receivers, but you only want to use the corkscrew?
Just for the record, there are no kernel drivers for the SDR side of things, it's all done in userspace. This userspace code, developed by people on this list, is designed to operate under Linux and it then gets ported to Windows. So luckily for you, running Linux means you'll always have easy access to the latest userspace driver code, before it gets to Windows.
Unfortunately so much SDR software is Windows only, especially the packages aimed at beginners like myself, who don't know enough about RF yet to get any GNURadio flow graphs working.
Personally the best I have done so far is to run HDSDR under Wine, and use the Linux BorIP server to pass data (via loopback TCP) between Wine and the RTL device. This allows HDSDR to run pretty much the same as it does under Windows.
But of course HDSDR can't quite do FM radio (since it only goes up to 96kHz), but it does work really well for receiving other NBFM and AM broadcasts (police, aircraft, etc.)
Cheers, Adam.
heh ... well it may be a waste, but it was an honest waste: it was the cheapest PC-USB FM radio offered on an ebay auction ($14 shipping included) and I'd already tried several USB-cable FM radios that turned out to be completely useless for various reasons, and even wal-mart can't sell a decent FM radio these days for even twice that price, so it seemed like a reasonable gamble, and as it is, I've now (a) discovered the whole SDR phenomenon and (b) learned that I might someday get FM, CB, police and weather all from this one device that as it turns out, I didn't really need because pulseaudio can do what I originally needed.
so I'm not complaining, I'm just looking in on wide-eyed naivity bewildered by the great vistas that now open before me :)
and now you'll have to excuse me, I'm off to google HDSDR :)
On Tue, Aug 14, 2012 at 9:13 PM, Adam Nielsen a.nielsen@shikadi.net wrote:
From what I understand, the digital TV standard here in Canada is
different from DVB-T (I am a complete neophyte at all of this) and so that particular feature of the device won't be of much use to me, but as for the FM, I'm on the Ubuntu/Linux GNU platform, so I'm awaiting on the kindness of strangers to perfect the kernel drivers enough to match the Windows kit performance. But that's okay, because I'm learning a lot in the process :)
The DVB-T option isn't much use to anyone, because we all bought the device for SDR purposes :-) No disrespect, but wanting to use the device just for FM radio is a bit of a waste - you have the Swiss Army Knife of radio receivers, but you only want to use the corkscrew?
Just for the record, there are no kernel drivers for the SDR side of things, it's all done in userspace. This userspace code, developed by people on this list, is designed to operate under Linux and it then gets ported to Windows. So luckily for you, running Linux means you'll always have easy access to the latest userspace driver code, before it gets to Windows.
Unfortunately so much SDR software is Windows only, especially the packages aimed at beginners like myself, who don't know enough about RF yet to get any GNURadio flow graphs working.
Personally the best I have done so far is to run HDSDR under Wine, and use the Linux BorIP server to pass data (via loopback TCP) between Wine and the RTL device. This allows HDSDR to run pretty much the same as it does under Windows.
But of course HDSDR can't quite do FM radio (since it only goes up to 96kHz), but it does work really well for receiving other NBFM and AM broadcasts (police, aircraft, etc.)
Cheers, Adam.
-
Adam Nielsen -
Gary Lawrence Murphy -
Jay Salsburg