Forum: GNU Radio Stuttered processing with OsmoSDR and DVB-T Stick

Hello,

I run gnuradio latest stable installation on a 64bit Ubuntu Installation 
with Pentium 977 + 8GB RAM. I use the DVB-T Hama Nano DVB-T-Stick which 
is one of the RTL-Chip derivates. I tried to create a FM-Radio reception 
which only consists of the OsmoSDR-Srouce, A WBFM Receive PLL and the 
Audio Sink (see attached png)

What I get is a stuttered signal processing of the recepition. I can 
here the radio signal, but it is interrupted at a rate of approximately 
3 Hz. I checked the CPU load but it is well below 100%. Does anyone have 
an idea what I did wrong? I would appreciate any sort of suggestions. 
Thanks!

Additional experiment: when I make a chain of sine-wave -> 
WBFM-Transmitter -> WBFM-Receiver -> Audio Sink, with the sample rates 
as shown in the original fm receiver, there is continuous playback. 
Therefore I expect that it has something to do with the OsmoSDR, libusb, 
rtl-driver, rtl-chip.

Any suggestions?

Regards,

Markus
================================
m48/m48+ by Markus Gonser

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E-Mail:  m48@mksg.de

On 24/11/12 06:55 AM, Markus Gonser wrote:
> approximately 3 Hz. I checked the CPU load but it is well below 100%.
>
>
> Discuss-gnuradio@gnu.org
> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
705.6k is likely not a supported sample rate on the RTLSDR.

It's fairly rare that sample rates on any SDR are exactly multiples of
audio rates, so you have to use
  rational resamplers, or fractional interpolators to match rates.

Hey Marcus,

thank you for your feedback. That must have been it! I also tried the 
simple_fm_rcv exmample on http://sdr.osmocom.org/trac/wiki/rtl-sdr and 
it actually works wonderfully. Sorry for this premature queastion.
Regards,

Markus

Am 24.11.2012 um 14:32 schrieb "Marcus D. Leech" <mleech@ripnet.com>: