Without an external reference, the onboard 40MHz VCTCXO will handle creating a decent reference without the benefit of the PLL locking it to a 10MHz reference. Wouldn't be much use otherwise.
On Fri, Mar 9, 2018, 9:46 PM Sailor Jerry <sailorje...@scmarinetech.com> wrote: > Guys, thank you so much for your support, you are awesome! > > Now I feel myself as complete idiot. I removed GPSDO. Disconnected the > 10MHz clock, by USRP is still working and it seems to be on more or less > correct correct frequency. I clearly can see the input tone on fft utility. > > Is there some other clock source I'm unaware off? Can I see the ADF4001 > lock status? Here is the output I'm getting: > linux; GNU C++ version 5.3.1 20151219; Boost_105800; > UHD_003.009.002-0-unknown > > -- Loading firmware image: /usr/share/uhd/images/usrp_b200_fw.hex... > -- Detected Device: B210 > -- Loading FPGA image: /usr/share/uhd/images/usrp_b210_fpga.bin... > -- Operating over USB 3. > -- Detecting internal GPSDO.... No GPSDO found > -- Initialize CODEC control... > -- Initialize Radio control... > -- Performing register loopback test... pass > -- Performing register loopback test... pass > -- Performing CODEC loopback test... pass > -- Performing CODEC loopback test... pass > -- Asking for clock rate 16.000000 MHz... > -- Actually got clock rate 16.000000 MHz. > -- Performing timer loopback test... pass > -- Performing timer loopback test... pass > -- Setting master clock rate selection to 'automatic'. > -- Asking for clock rate 32.000000 MHz... > -- Actually got clock rate 32.000000 MHz. > -- Performing timer loopback test... pass > -- Performing timer loopback test... pass > > > > > On Fri, Mar 9, 2018 at 9:09 PM Sailor Jerry <sailorje...@scmarinetech.com> > wrote: > >> That would explain it , thanks :-) >> >> On Fri, Mar 9, 2018 at 9:07 PM Nick Foster <bistrom...@gmail.com> wrote: >> >>> 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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