I uh what? I don't see why that would be the case. The whole reason U103 exists is to switch between a GPSDO (if present) and an external reference.
You might wait for the official Ettus response for this if you don't want to take responsibility for blowing it up, but I drew the schematic and I say you're fine. Incidentally, very early prototypes of the B200 used a neat PIN diode switch ring which would allow outputting the GPSDO signal as well as using either the reference port or GPSDO as a clock input. I can't remember why it didn't make it into production, but one side effect would be that if misconfigured, you could damage hardware. Maybe that was it. ;) Nick On Fri, Mar 9, 2018 at 8:48 PM Marcus D. Leech <mle...@ripnet.com> wrote: > On 03/09/2018 11:44 PM, Sailor Jerry wrote: > > Thanks. Shall I ignore that sentence from USRP B2x0 Series manual "The > B200 and B210 cannot support an external 10 MHz reference if a GPSDO is > already present on the motherboard. If an external 10 MHz is to be used, > the GPSDO needs to be physically removed from the device beforehand."? > > I think that advice is still correct, but I cannot remember why. Nick? > > > > > On Fri, Mar 9, 2018 at 8:32 PM Marcus D. Leech <mle...@ripnet.com> wrote: > >> On 03/09/2018 11:25 PM, Sailor Jerry wrote: >> >> Would be happy to restore it to original condition :-) >> >> I'm using the uhd_rx_cfile to capture the data. How do I control U103 >> from this app? I don't see any command line arguments for that? Do I need >> to rebuild it? >> >> You'd have to add that, inserting a call to set_clock_source() at an >> appropriate place. >> >> The example apps (and this is one) don't necessarily expose all available >> features. >> >> >> >> >> >> On Fri, Mar 9, 2018 at 8:08 PM Marcus D. Leech via USRP-users < >> usrp-users@lists.ettus.com> wrote: >> >>> On 03/09/2018 08:11 PM, Nick Foster wrote: >>> >>> It's a slick mod though. See the zero-ohm resistor bridging U103 pins 1 >>> and 3? Remove it, and you'll return the B210 to factory standard. >>> >>> Assuming no other modifications have also been made. =) >>> >>> Nick >>> >>> Your eyes are much better than mine.... >>> >>> >>> >>> On Fri, Mar 9, 2018 at 4:31 PM Marcus D. Leech via USRP-users < >>> usrp-users@lists.ettus.com> wrote: >>> >>>> On 03/09/2018 07:22 PM, Sailor Jerry via USRP-users wrote: >>>> >>>> HI Marcus, I see your point and also saw the schematic. The previous >>>> owner told me that this particular board was modified to have 10 MHz be >>>> brought out to the outside connector. I did verify it with the scope and >>>> indeed saw the 10 MHz coming out. I don't know if it's one of the standard >>>> factory options or just some custom modifications (the board has >>>> Olifantasia label on it). Will take a closer look at pins 3 and 1 of U103 >>>> as you suggest. If they are bridged indeed then I guess simple removal of >>>> GPSDO would do the trick. >>>> >>>> >>>> That is NOT a factory-standard option. >>>> >>>> >>>> >>>> >>>> On Fri, Mar 9, 2018 at 4:10 PM Marcus Müller <marcus.muel...@ettus.com> >>>> wrote: >>>> >>>>> Dear Sailor Jerry, >>>>> >>>>> I'm not sure I'm following here: The 10 MHz connector is hardware-wise >>>>> connected only to inputs, not to anything that can output anything; >>>>> compare the schematic[1] on page 1. So, I'm pretty certain your device >>>>> can't be condigured to have the 10 MHz connector be an output for >>>>> anything. >>>>> >>>>> Can you maybe describe the problem you're having? >>>>> >>>>> Best regards, >>>>> Marcus >>>>> >>>>> [1] https://files.ettus.com/schematics/b200/b210.pdf >>>>> On Fri, 2018-03-09 at 23:51 +0000, Sailor Jerry via USRP-users wrote: >>>>> > I inherited the B210 board that has the 10 MHz connector configured >>>>> > as an output. I wonder if anyone is aware of this configuration and >>>>> > if it's possible to reconfigure it to accept the external 10 MHz >>>>> > input. >>>>> > >>>>> > My current plan is simply remove GPSDO and hope for the best. >>>>> > >>>>> > Attached are two pictures of my board. One is with GPSDO inserted and >>>>> > another one with GPSDO removed. >>>>> > >>>>> > Thanks a lot! >>>>> > >>>>> > >>>>> > >>>>> > _______________________________________________ >>>>> > USRP-users mailing list >>>>> > USRP-users@lists.ettus.com >>>>> > http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com >>>>> >>>> >>>> >>>> _______________________________________________ >>>> USRP-users mailing >>>> listUSRP-users@lists.ettus.comhttp://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com >>>> >>>> >>>> _______________________________________________ >>>> USRP-users mailing list >>>> USRP-users@lists.ettus.com >>>> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com >>>> >>> >>> _______________________________________________ >>> USRP-users mailing list >>> USRP-users@lists.ettus.com >>> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com >>> >> >> >
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