GPS Clock to DOM Hub Clock Distribution 2005
At the south pole, the clock fan-out configuration is more complex than
the ones used in test laboratories, or DOM Freezer Labs at Wisconsin, Zeuthen, or
Uppsala. Unequal cables must be used to achieve
the -8ns
delay between 1 Hz _↑‾ to 10 MHz
_↑‾ timing, as measured at the monitor test point on the
end panel of
the DSB card. i.e. the 10 MHz signal rises 8ns before the 1
Hz signal. This timing has an 11ns safety margin with respect to
the forbidden timings noted below. (-8ns timing is the same as
+92ns, which is within a safe operating region)