[time-nuts] Hydrogen maser frequency jumps

[Jim Palfreyman]

Hi all,

Has anyone here who is familiar with hydrogen masers ever experienced a
sudden jump in phase of the 5MHz output?

We have found they occur semi-regularly (few times a week) and are trying
to find a culprit.

The weird thing is that the jump is ~0.7ns and that 1/0.7E-9 is close-ish
to 1420.4MHz which is the hydrogen line. Too much of a coincidence for me.

These seem to be appearing at three different locations with the same model
of maser at each location. I won't mention the model publicly.

We're still investigating various potential causes (e.g. power spikes,
cables being moved), but this 0.7ns figure is niggling me.

Has anyone here ever seen such a thing before?


Jim