Thought I would compare the 1 PPS outputs from the three GPSDO's I have here.
The blue trace is the Nortel NTGS50AA which is the trigger channel
The yellow trace is the cheapie Trimble 57964-15 with 63090 OCXO
The purple trace is the HP 58540A
The scope has been running on infinite persistence for a few hours.
You can see the jitter on the HP is probably double what it is on either of the others(I have triggered on the Trimble with similar results).
I have changed the antenna delay to get them to be reasonably close on the scope so it is easier to see. By default the Nortel leads the Trimble by roughly 500ns which leads the HP by 100ns. So even with 3 GPSDO's I have no idea when the pulse really occurs