[time-nuts] Lady Heather Data Explained?

Mark Sims holrum at hotmail.com
Wed Aug 17 21:29:36 EDT 2016

Well,  what now gets shown / plotted depends upon the receiver type.

For Thunderbolts the standard plots are the DAC (EFC) volatge,  temperature sensor reading,  and the PPS and OSC offset values from the primary timing message (the OSC plot defaults to OFF since it generally looks like a lot of annoying noise).  If you cozy up with a copy of the Thunderbolt manual, you should be able to figure out that the various values shown mean.

Lady Heather calculates and displays plots of the ADEV values of the PPS and OSC readings.  These don't have a whole lot of correlation to true ADEV values since they are not referenced to an independent reference (the idea for including the ADEV stuff was to eventually interface to an external time interval counter).  Despite that,  the ADEV values can give you and idea of how well the unit is working (particularly when the unit is configured with disciplining turned off).   

More information about the time-nuts mailing list