[Hackrf-dev] Static/warbling non reception issue
Karl Koscher
supersat at cs.washington.edu
Sun May 1 16:29:18 EDT 2016
I don't think you sent the screenshot to the mailing list... or at least I
didn't see it? (Does this mailing list even support attachments?)
You don't need anything special to do offset tuning. The DC spike should
not move as you drag the spectrum display left or right. Drag the spectrum
display until the signal you want is free of the DC spike or other noise,
then click on the middle of the signal you want to tune in. It should then
demodulate cleanly.
Here is a screenshot of how it should look:
http://sysnet.ucsd.edu/~supersat/sdrsharpfm.png
Make sure WFM is selected with a bandwidth of 150000.
On Sun, May 1, 2016 at 1:13 PM, davidmarkusgoldstein at gmail.com <
davidmarkusgoldstein at gmail.com> wrote:
> I'd even consider buying studio1, if I can get this to work. I posted the
> basic settings screens...the signals are strong on the spectrum.
> Everything's just so inaudible and static'd.
>
>
> Sent via the Samsung Galaxy Note® II, an AT&T 4G LTE smartphone
>
>
> -------- Original message --------
> From: Cinaed Simson
> Date:05/01/2016 3:49 PM (GMT-05:00)
> To: hackrf-dev at greatscottgadgets.com
> Subject: Re: [Hackrf-dev] Static/warbling non reception issue
>
> On 05/01/2016 06:38 AM, David Goldstein wrote:
> > Maybe someone has an extio that will fix this...?
>
> Yes there is an extio - the poster could supply the list with the
> parameters he's using and his hardware setup.
>
> >
> > On Apr 30, 2016 11:39, "Dominic Spill" <dominicgs at gmail.com
> > <mailto:dominicgs at gmail.com>> wrote:
> >
> > I can't remember how it works in SDR#, but in GQRX you can just click
> > on the display and it will start demodulating that frequency instead
> > of the centre frequency. It's probably the same in SDR#
> >
> > Dominic
> >
> > On 30 April 2016 at 16:36, davidmarkusgoldstein at gmail.com
> > <mailto:davidmarkusgoldstein at gmail.com>
> > <davidmarkusgoldstein at gmail.com
> > <mailto:davidmarkusgoldstein at gmail.com>> wrote:
> > > Hi Dominic,
> > >
> > > Yeah 101.5 and 103.3 are right in town or nearby. I will have to
> > test the
> > > offset features better...I will let you know how this goes.
> > >
> > > David
> > >
> > >
> > > Sent via the Samsung Galaxy Note® II, an AT&T 4G LTE smartphone
> > >
> > >
> > > -------- Original message --------
> > > From: Dominic Spill
> > > Date:04/30/2016 11:23 AM (GMT-05:00)
> > > To: david.goldstein.93 at alumni.vanderbilt.edu
> > <mailto:david.goldstein.93 at alumni.vanderbilt.edu>
> > > Cc: hackrf-dev
> > > Subject: Re: [Hackrf-dev] Static/warbling non reception issue
> > >
> > > On 30 April 2016 at 00:32, David Goldstein
> > > <davidmarkusgoldstein at gmail.com
> > <mailto:davidmarkusgoldstein at gmail.com>> wrote:
> > >> Hi, here's a screenshot of the settings that I can change, plus
> the
> > >> spectrum analysis shot. The audio I get is heavily distorted on
> > the strong
> > >> local FM stations.
> > >
> > > The station at 101.5MHz looks like an excellent signal.
> > >
> > >> So, I have no idea what's wrong, except that it could be the
> > sound driver
> > >> or on-board sound.
> > >
> > > Are you demodulating the signal at the centre frequency? Or at an
> > > offset? The spike in the middle is the DC offset, so if you're
> > > demodulating there you're going to see bad data. It's explained in
> > > more detail here:
> > >
> >
> https://github.com/mossmann/hackrf/wiki/FAQ#what-is-this-big-spike-in-the-center-of-my-received-spectrum
> > >
> > > Thanks,
> > > Dominic
> > >
> > >> -----Original Message-----
> > >> From: Dominic Spill [mailto:dominicgs at gmail.com
> > <mailto:dominicgs at gmail.com>]
> > >> Sent: Friday, April 29, 2016 5:40 PM
> > >> To: davidmarkusgoldstein at gmail.com
> > <mailto:davidmarkusgoldstein at gmail.com>
> > >> Cc: hackrf-dev
> > >> Subject: Re: [Hackrf-dev] Static/warbling non reception issue
> > >>
> > >> On 29 April 2016 at 17:31, davidmarkusgoldstein at gmail.com
> > <mailto:davidmarkusgoldstein at gmail.com>
> > >> <davidmarkusgoldstein at gmail.com
> > <mailto:davidmarkusgoldstein at gmail.com>> wrote:
> > >>> Hi, how can I test the hackrf to see if it's damaged? I have
> sound
> > >>> card issues, it seems, on my i7-2600 win7 64 bit system, so I
> > tried it
> > >>> on a Vista laptop and experienced the same: static and
> > choppiness and
> > >>> some distorted voice on local fm. So perhaps the radio is
> damaged.
> > >>
> > >> This doesn't necessarily mean that the radio is damaged, although
> > we can
> > >> help to test whether it is, but it may be something not quite
> > right in your
> > >> settings. Telling us which settings you are using for sample
> > rate, gain,
> > >> filter, etc would really help us to diagnose the problem.
> > >>
> > >> Thanks,
> > >> Dominic
> > >>
> > >>> -------- Original message --------
> > >>> From: Dominic Spill
> > >>> Date:04/28/2016 7:31 PM (GMT-05:00)
> > >>> To: davidmarkusgoldstein at gmail.com
> > <mailto:davidmarkusgoldstein at gmail.com>
> > >>> Cc: hackrf-dev
> > >>> Subject: Re: [Hackrf-dev] Static/warbling non reception issue
> > >>>
> > >>> On 28 April 2016 at 20:28, davidmarkusgoldstein at gmail.com
> > <mailto:davidmarkusgoldstein at gmail.com>
> > >>> <davidmarkusgoldstein at gmail.com
> > <mailto:davidmarkusgoldstein at gmail.com>> wrote:
> > >>>>
> > >>>> Hi, this might not be a tech support list but I don't know what
> > to do
> > >>>
> > >>> Hi David,
> > >>>
> > >>> We're happy to provide tech support through this mailing list;
> I'm
> > >>> sure we'll be able to help you.
> > >>>
> > >>>> ...everything seems set up properly but I get static and broken
> up
> > >>>> voice broadcast on local fm. I think it's the alc889 Realtek
> sound
> > >>>> card doing this...I had this issue with a winradio g 315
> > because I'm
> > >>>> running win 7 64bit.
> > >>>
> > >>> Are you using SDR# on your Win7 install? Could you give us some
> > >>> examples of the settings you are using? If it's easier, you can
> > >>> attach a screenshot of the setting panel in SDR# (or whichever
> tool
> > >>> you're using). You could also attach a screenshot of the tool
> > so that
> > >>> we can see how strong the signal is compared to the background
> > noise.
> > >>>
> > >>>> They tweaked a driver for me and I got the winradio running
> but I
> > >>>> don't know what to do now with the hackrf I have, if it is the
> > sound
> > >>>> card at all. Any tips?
> > >>>
> > >>> One option would be to try not using realtime processing.
> > Capture ~20
> > >>> seconds FM station to a file, then demodulate it from the file
> > >>> afterwards. Finally, you should be able to play back the file as
> > >>> audio. If it's a problem with the quality of the signal being
> > >>> received, the output will still be choppy, but if the output is
> > smooth
> > >>> we can look at where else things may be going wrong.
> > >>>
> > >>> It certainly looks like you have enough CPU power and RAM to
> support
> > >>> the task that you're trying to do, so we'll have to narrow down
> > where
> > >>> the problem could be.
> > >>>
> > >>> Thanks,
> > >>> Dominic
> >
> >
> >
> > _______________________________________________
> > HackRF-dev mailing list
> > HackRF-dev at greatscottgadgets.com
> > https://pairlist9.pair.net/mailman/listinfo/hackrf-dev
> >
>
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