Re: Sample Rate & Hardware Considerations Tutorial: GNURadio.org

Ray,

Thank you for that information. It will help me in revising the tutorial.

Cheers!
--
Barry Duggan KV4FV

On 5/2/20 11:51 AM, Ray Roberge wrote:
> Barry,
>
> I believe I know why the example sample rate was set that way in the past.
>
> Many users use a RTL-SDR (RTL2832U chip with a R820T or E4000 tuner typically).
> It works correctly over two groups of sample range: 225,001 -> 300,000 Hz and 900,00 -> 3,200,000 (or less).
> If you choose a sample rate not in those ranges, the chip will "choose" a sample rate that it will work with and a message is sent to STDIO to inform the user.
>
> So, you will see a lot of 250 KHz, 1 Msps and 2 Msps rate examples.
>
> Thanks for updating the Tutorials!
>
> Regards,
> Ray Roberge
> WACYB
>
> ----------------------------------------------------------------------------------------------
>
> Message: 1
> Date: Fri, 1 May 2020 12:24:49 -0500
> From: Barry Duggan <barry@dcsmail.net>
> To: james.hayek@gmail.com
> Cc: Discuss Gnuradio <discuss-gnuradio@gnu.org>
> Subject: Re: Sample Rate & Hardware Considerations Tutorial:
>     GNURadio.org
> Message-ID: <272447af-b0a4-048b-5a1c-a48e7ad93c18@dcsmail.net>
> Content-Type: text/plain; charset=utf-8; format=flowed
>
> James,
>
> Thank you for your comments on our documentation! I started working on
> the docs last year including adding flowgraphs to the block docs and
> updating the tutorials to rel 3.8. The
> https://wiki.gnuradio.org/index.php/Guided_Tutorial_Hardware_Considerations
> is one which has been updated recently, but I didn't have the hardware
> to test it. (I will next week).
>
> So, for question 1: that tutorial was written several years ago. I don't
> know why that sample rate was chosen, but some older computers have
> trouble with high sample rates......
>
> message truncated
>