And now, fun with TEA time:
The newly arrived TA520 time interval analyzer, a dual channel arb, a scope, a lab psu (somewhere in the background), a GPSDO (not visible) and the TXCO radio clock (not visible):
All cobbled together with two external mixer / amplifier circuits
to give me some DMTD (dual mixer time difference) results of the (rather drifty) radio clock vs. the TruePosition GPSDO
The mixer circuits themselves achive about 50ns peak-to-peak jitter when driven from the dual channal arb at 10MHz and 10.0001MHz (100Hz difference).
In the actual configuration, the outputs are set to the same frequency (100Hz above 10MHz) and drive one mixer each. The other mixer inputs are the 10MHz ref out of the GPSDO and the 10MHz output of my (poorest) TCXO radio clock.