Re: [Discuss-gnuradio] Sample recording

[How Chee Hew]

Hi Rob,

If my understanding is correct, with a sampling rate
of 48 kHz (sound card), I will not be able to sample
properly the FM composite signal (left and right +
RDS) which has frequencies up to , if I remembered
correctly, 60-80 kHz region. I guess I would need a
sampling rate of at least 160 kHz when sampling at
baseband (after demodulation) and probably a bit
higher when sampling at IF. (They did not teach
bandpass signal processing back in university, I will
need to check out what sampling frequency is needed
when sampling at IF stage).

If what you say is correct, is it possible for me to
wired up such a setup and decode properly the left and
right channel using software ?

Regards,
HowChee

--- Rob Judd <address@hidden> wrote:
> HowChee,
> 
> The bandwidth required to download such signals
> would be enormous. You
> can do a lot with a simple receiver with a homemade
> IF set to half the
> nyquist frequency, in your case 12kHz.
> 
> Rob
> 
> 
> How Chee Hew wrote:
> > 
> > Hi,
> > 
> > A friend introduce to me the concept of software
> > radio.  I became interested and was trying to
> capture
> > the FM composite signal off my TV/FM tuner card
> using
> > the PC sound card. Since the sound card sampling
> rate
> > is only 48 kHz, I can get only the L+R channel and
> the
> > the pilot tone but not the rest (RDS and L-R) .
> > Getting the GNURadio 20 MHz ADC will be too
> expansive,
> > at least for me.
> > 
> > Does/Can GNURadio provide sample recordings of the
> > signal (e.g FM composite at IF and baseband, AM,
> RTTY,
> > HDTV signal plus whatever signal that can
> received) so
> > it can be used for research and for fun as for my
> > case.
> > If the samples are already available, can someone
> > point me there.
> > 
> > Regards,
> > HowChee
> > 
> 

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