You shouldn't need to do any tuning.
http://cgit.osmocom.org/rtl-sdr/tree/include/rtl-sdr.h search "test mode" in the file. Once you have enabled the counter, just check the incoming samples to see if you drop any data.
I *think* rtl_test does it when running in async mode, but I'm not so sure. I'd like an official word from the devs on this.


2013/6/27 David Jacobowitz <david.jacobowitz@gmail.com>
One could probably write a program that can tune to a known signal and then test through a range of sample rates to determine which ones generate a data stream that when treated at the expected sample rate gives the expected signal

.... a project for another day.


On Thu, Jun 27, 2013 at 2:16 AM, Sylvain Munaut <246tnt@gmail.com> wrote:
> Thanks, Sylvain. That makes sense. I probably wouldn't have spent so much
> time on it if the lib gave some indication that it wasn't setting those
> rates.

Well, we don't really know exactly what rates are supported by the
hardware or not since there isn't exactly good documentation on it ...
and the lib will just pass that to the hardware as long as the range
fits into the "registers". This way users can  experiment ...

But if you want reliable operation you should stick to "known" working
samples rates like 250k 1M 1.024M 2M 2.048M 2.4M

Cheers

    Sylvain




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