GPS 10 MHz  and  Local 10 MHz
        -------------------------------


                                       Date:  11-Oct-2012

This scope picture shows the 10 MHz signal from the GPS
receiver on channel #1  and  a locally generated 10 MHz
signal from an ovenized quarts oscillator on channel #2.

At the time of this picture the locally generated 10 MHz
quarts oscillator was smoothly running about  0.2 Hz
faster than the GPS 10 MHz signal.  The local 10 MHz was
just used as a reference to trigger the scope and it is
assumed and verified to be rather jitter free.

The point of this scope picture is to see the 5 nsec
adjustments that the GPS receiver makes to the phase
of its 10 MHz reference output signal to keep this
signal locked to "absolute" time.

The intent was to confirm that we correctly understand
the characteristics of the GPS receiver's 10 MHz output
and thus are correctly treating this GPS reference in
the Clock H-Clk card.  Steps in phase like this are
characteristic of numerically controlled oscillators
such as the one used in the GPS receiver.  These steps
in phase are spread out over a couple of msec by the
quarts based voltage controlled oscillator in the phase
locked loop 40 MHz generator in the Clock H-Clk card.