[Hackrf-dev] Static/warbling non reception issue
Dominic Spill
dominicgs at gmail.com
Mon May 2 09:37:29 EDT 2016
David,
Did you try the suggestion below from Karl? I'm fairly sure this will
solve your problem.
Thanks,
Dominic
On 1 May 2016 at 21:29, Karl Koscher <supersat at cs.washington.edu> wrote:
> 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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>
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