Hi Marcus,

The external 10MHz did the trick. I have another related question which I
think we can address here without opening a new ticket. The USRP B210 has a
1PPS port. However, I was not able to poll the status of the time source,
"pps_locked". When I searched for a list of all onboard sensors, the only
visible sensor was "ref_locked". Am I missing something? How can I use and
poll the status of 1PPS?

Regards, Moses


On Wed, May 15, 2024 at 6:04 PM <discuss-gnuradio-requ...@gnu.org> wrote:

> Send Discuss-gnuradio mailing list submissions to
>         discuss-gnuradio@gnu.org
>
> To subscribe or unsubscribe via the World Wide Web, visit
>         https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
> or, via email, send a message with subject or body 'help' to
>         discuss-gnuradio-requ...@gnu.org
>
> You can reach the person managing the list at
>         discuss-gnuradio-ow...@gnu.org
>
> When replying, please edit your Subject line so it is more specific
> than "Re: Contents of Discuss-gnuradio digest..."
>
>
> Today's Topics:
>
>    1. USRP B210 Frequency Offset (Moses Browne Mwakyanjala)
>    2. Re: USRP B210 Frequency Offset (Marcus D. Leech)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Wed, 15 May 2024 11:52:27 +0200
> From: Moses Browne Mwakyanjala <mbkit...@gmail.com>
> To: GNURadio Discussion List <discuss-gnuradio@gnu.org>
> Subject: USRP B210 Frequency Offset
> Message-ID:
>         <
> cabysgdmphq54warsy--5-7renj3pfrahtowuce_rss8ypq-...@mail.gmail.com>
> Content-Type: text/plain; charset="utf-8"
>
> I've encountered a consistent frequency offset of around 2ppm with my new
> B210. Operating at a sample rate of 4 MSPS with the "internal" clock, all
> calibrations were performed using a sine wave from an Agilent signal
> generator.
>
> Though seemingly minor, the 800Hz offset at UHF poses challenges in
> receiving low-rate data from orbiting satellites. Is there an automated
> method to approximate and mitigate this offset? Currently, I manually
> adjust the frequency by subtracting the offset in ppm. However, I'm curious
> if there are more sophisticated solutions available, excluding reliance on
> GPS or a 10MHz reference.
>
> Best regards,
> Moses
>
> [image: image.png]
> -------------- next part --------------
> An HTML attachment was scrubbed...
> URL: <
> https://lists.gnu.org/archive/html/discuss-gnuradio/attachments/20240515/3082954d/attachment.htm
> >
> -------------- next part --------------
> A non-text attachment was scrubbed...
> Name: image.png
> Type: image/png
> Size: 33653 bytes
> Desc: not available
> URL: <
> https://lists.gnu.org/archive/html/discuss-gnuradio/attachments/20240515/3082954d/attachment.png
> >
>
> ------------------------------
>
> Message: 2
> Date: Wed, 15 May 2024 09:10:13 -0400
> From: "Marcus D. Leech" <patchvonbr...@gmail.com>
> To: discuss-gnuradio@gnu.org
> Subject: Re: USRP B210 Frequency Offset
> Message-ID: <ec4c50e0-0e19-494a-b25b-f273464fe...@gmail.com>
> Content-Type: text/plain; charset="utf-8"; Format="flowed"
>
> On 15/05/2024 05:52, Moses Browne Mwakyanjala wrote:
> > I've encountered a consistent frequency offset of around 2ppm with my
> > new B210. Operating at a sample rate of 4 MSPS with the "internal"
> > clock, all calibrations were performed using a sine wave from an
> > Agilent signal generator.
> >
> > Though seemingly minor, the 800Hz offset at UHF poses challenges in
> > receiving low-rate data from orbiting satellites. Is there an
> > automated method to approximate and mitigate this offset? Currently, I
> > manually adjust the frequency by subtracting the offset in ppm.
> > However, I'm curious if there are more sophisticated solutions
> > available, excluding reliance on GPS or a 10MHz reference.
> >
> > Best regards,
> > Moses
> The on-board clock on a B210 is good to about 2.5PPM.  So, it's working
> as you would expect.
>
> There's nothing built in to the UHD API for this, because normally, if
> you care about clock accuracy beyond what the internal clock
>    can supply, you use an external, better, clock.   GPSDOs are not very
> expensive these days, and you can pick up used
>    10MHz OCXO units fairly cheaply as well...
>
>
> >
> > image.png
> -------------- next part --------------
> An HTML attachment was scrubbed...
> URL: <
> https://lists.gnu.org/archive/html/discuss-gnuradio/attachments/20240515/db078ea5/attachment.htm
> >
> -------------- next part --------------
> A non-text attachment was scrubbed...
> Name: image.png
> Type: image/png
> Size: 33653 bytes
> Desc: not available
> URL: <
> https://lists.gnu.org/archive/html/discuss-gnuradio/attachments/20240515/db078ea5/attachment.png
> >
>
> ------------------------------
>
> Subject: Digest Footer
>
> _______________________________________________
> Discuss-gnuradio mailing list
> Discuss-gnuradio@gnu.org
> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
>
>
> ------------------------------
>
> End of Discuss-gnuradio Digest, Vol 259, Issue 8
> ************************************************
>

Reply via email to