Ooops, that tboltjit.gif plot was actually from a Trimble Resolution-T SMT timing receiver running with an indoor antenna, not a Thunderbolt. The Thunderbolt with an outdoor antenna is about twice as good. I just added the ability to feed the timing jitter value to Lady Heather's real time ADEV calculation code. I doing a run with a Z3801A at the moment... (at 500 tau it's down to 9E-4)