USRP External clocking

GNU Radio
1

Hi All,

Is any modification needed to the USRP board to use an external clock
generator instead of the on board 64MHz one?

Thanks!
[WM]

2

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On Aug 18, 2008, at 10:43 AM, Dan H. wrote:

http://gnuradio.org/trac/wiki/UsrpFAQ/Clocking

And there is another way of clocking if you want to solder on an SMA
connector instead, connect an external clock, and disable the onboard
clock.

http://gnuradio.org/trac/wiki/USRPClockingNotes

  • -Dan
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3

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On Aug 18, 2008, at 9:10 AM, Wireless Monster wrote:

Is any modification needed to the USRP board to use an external
clock generator instead of the on board 64MHz one?

A trivial search of the Wiki, or the mailing list, should be executed
before simple and common queries like this.

wiki search: http://gnuradio.org/trac/search
mailing list via Nabble: http://www.nabble.com/GnuRadio-f1878.html

(the answer is in a FAQ on Wiki and all over the mailing list)

http://gnuradio.org/trac/wiki/UsrpFAQ/Clocking

  • -Dan
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4

Hi Dan,
Thank you for the links. I already did that research, so I could have
written my email differently…

I just wanted the confirmation that all the following modifications are
required to use an external clock source (In the Wiki is on the section
about connecting multiple USRP boards so I just want to be sure…)

  • Solder an SMA connector into J2001. This is the clock input.
  • Move R2029 to R2030. This disables the onboard clock. R2029/R2030
    is a
    0-ohm resistor.
  • Move C925 to C926.
  • Remove C924.

Thank you!
[WM]