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1. Generate a 476MHz RF reference in Sector-2 to use with XTCAV.  The RF reference will have similar jitter characteristics as the LCLS-II Master Oscillator.
2. Transmit a 476MHz RF reference to Sector-10 to replace the LCLS-I Master Oscillator.  The new RF reference will have similar jitter characteristics as the existing LCLS-I Master Oscillator.
3. Align the triggerring of the Super-Conducting (SC) & Normal-Conducting (NC) timing systems for XTCAV to operate at 120Hz.
4. Merge the NC event timing onto the SC event timing. 

LCLS-I Timing System Description

The In LCLS-I, the 476MHz MO provides an RF source to the timing system.  This signal is combined with a 360Hz signal derived from the a sequencer chassis (i.e. derives a 360Hz signal coincident with the zero crossings from the 3-phase AC power line).  The 476MHz and the 360Hz signals are routed to the inputs of the VME-based Master Trigger Generator (VMTG).  The VMTG output is thus synchronized with the 476MHz MO --via a 71kHz RF signal-- and it triggers the fiducial generator at 360Hz.  The 360Hz output of the fiducial generator is amplitude-modulated onto the original 476MHz signal (hence 2.78ms between peaks and with a 476MHz frequency) and is propagated down the Main Drive Line (MDL).  The aforementioned trigger generation occurs in Sector-10 in its entirety and then gets propagated to other sectors and buildings.

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