Hi Christian, No, what you need is a good external clock. The internal clock will drift with temperature and age etc and is not deterministic. Depending on your price point, there are multiple options, from cheap GPSDO's do the highest-end Fugro Atomichron ones (Sparkfun GNSSDO for example).
Kind regards, John -----Original Message----- From: Christian Zäske <[email protected]> Sent: Friday, June 12, 2026 10:50 AM To: Rognskog, John-Harry <[email protected]>; usrp-users <[email protected]> Subject: Re: [USRP-users] B200 frequency shifted Hi John, yes we are using the internal clock. It is just a bit weird that the exact same setup worked in the past. We then had the SDR deployed in another project and now wanted to try the setup again and it stopped working because of the shift. But if it is technically within spec and we can't really do anything to fix this, I guess we just need a new SDR On 6/12/26 10:42, Rognskog, John-Harry wrote: > Hi, > I assume you are using internal clock? 5kHz is within its spec (barely). My > units vary in that range, although not as much individually. > Kind regards, > John > > -----Original Message----- > From: Christian Zäske via USRP-users <[email protected]> > Sent: Friday, June 12, 2026 10:35 AM > To: usrp-users <[email protected]> > Subject: [USRP-users] B200 frequency shifted > > Hello, > > (Sorry if this is a duplicate, I think there went something wrong with my > last email to the mailing list) > > In the past, we used a B200 and srsRAN to build our own LTE cell, which > always worked flawlessly. After some time, we wanted to build this setup > again but we ran into an issue: The phone never found the cell. > > After looking into the problem I noticed, that the output frequency of the > B200 is shifted around +5 kHz at around 2.6 GHz (Verified it with another > SDR). Too much for the phone to get the signal properly. When I manually > adjust the frequency in srsRAN to compensate for the 5 kHz shift, the phone > immediately detects the cell. > > At lower frequencies, the shift also gets lower. > > Is there something we can do to revive the B200? Because this exact setup > worked in the past, I think something happened to the b200 that causes this > shift. > > Thanks in advance, > Christian > -- Christian Zäske IT-Security Consultant ______________________________________________________________ SySS GmbH Schaffhausenstraße 77, 72072 Tübingen, Germany Tel: +49 (0)7071 - 40 78 56-6211 Mobil: +49 (0)151 - 43 15 76 17 E-Mail: [email protected] Web: https://urldefense.com/v3/__https://syss.de__;!!Iu2wxiM!wwprKEyDucVwOpSfDbCwl9MEQsITTk_vz8bLTXTDUu3hKozc1aJL7iIzbj7F3damEkAQfLnSqNMQkzzzTQBtZVvhYVAYZw$ PGP-Fingerprint: 51D4 6E9B 3C29 7347 AC01 0F5A 7B00 D164 A32F 9AC9 Geschäftsführer: Sebastian Schreiber, Sebastian Nerz Registergericht: Amtsgericht Stuttgart / HRB 382420 Steuernummer: 86118 / 55809 _______________________________________________ USRP-users mailing list -- [email protected] To unsubscribe send an email to [email protected]
