USRP2 external reference clock


Could someone please help me with a quick question?

I am trying to sync up the clocks on two USRP2 boards. How do I use the
external reference clock “REF CLOCK” input? What does this input take?
My understanding is that it takes a 10 MHz sine wave, 1 volt

And how do I enable this input? Do I need to set anything in my

Thanks a lot!!

Steve McMahon