When the master clock on a USRP2 is locked to a reference (external source or another USRP2), are the oscillators on the RFX or XCVR boards locked as well? Or do they generate their own clock? I have an application that is very sensitive to clock mismatch (both sampling clock and up/downconversion clock) between transmitter and receiver, and I would like to synchronize the clocks on two USRP2s.