Clocks checklist:
                                                          
                                                                       DSN  GBT

Obtain the record of the discrepancy between 1 PPS signal and GPS or
NIST over the past few days.  (DSN has yet to implement this)

Set the PFS sampling frequency to 5 MHz.  

Make sure that all synthesizers are locked to a frequency standard.  
Please double-check and use an oscilloscope if in doubt.

Record 1 PPS signals from both clock clusters with the data-taking
system at 5 MHz sampling frequency.  Use 6 dB attenuator pads and
connect to PFS.  Record for ten minutes or so.  Check that the rising
edge of the clock appears after 5 digital delays at the beginning of
each file.

During the magic receive cycle at DSN, read the frequency from the
sampling clock synthesizer display and record it in the log notes at
the beginning, middle, and end of the run.