See D1400363 for overall scheme and cable details.

The 71 MHz sine is ported to D1400155 in TCS-X1-R2-27 SE of BSC1.  From there sync signals go to the three BSCs corners 1 & 3 satellite racks.  At each BSC, the corner 1 signal is passed on to corner 2 with a local cable.

Attached are three plots with the three BSCs showing reference traces from early this morning before the big EQ.  Current traces are from later today.  There are no combs popping up suggesting there are no cross talking sync signals.  There is variablilty between the reference and current noise floors.  Some are lower a few are slightly higher but nothing standing out affecting an entire corner (see ITMX ST2 H2.)  I suspect when the middle of the night comparison is done with similar conditions, they will look even better and that cables are okay.