Today, Manu and Eric changed the cavity valves pressure system to open and close them.

during the lock of the OneFive+Amp or of the Koheras, we saw a very noisy PZT signal at 30Hz with increasing/decreasing amplitude very slowly.
this noisy signal was not seen at the begining of the experiment.
as it is independant of the laser source, we guess it should come from the cavity.
at this moment, one only see these valves (which tend to close by themself when there is some leakage) as a source of frequency noise.
we will see if, with this cabling change, the noise on the PZT signal changes also.