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 > ************************************************ >
