I performed ringdowns on the most recent batch of hole cantilevers (see CRYO:2004). This is the first set of ringdowns done with the newer clamp design (i.e., the ones that go into the main experiment) and with the precise clamp alignment procedure.
Both cantilevers had a frequency of 94 Hz. I made two ringdown measurments on each one, with a full removal and reclamp between trials.
Sample "2/27/2018 #1A1" exhibited a Q of 83k on the first trial, and again 83k on the second trial. This is near the thermoelastic limit for this specimen, and the reproducibility is very nice.
Sample "2/27/2018 #1A2" exhibited a Q of 88k on the first trial, but only 74k on the second trial.
Therefore, it seems that while the new clamps are capable of being very robust, it is still possible for clamping effects to come into play.
Also, I found the odd triangular-connector breakout cable that I need to interface with the feedthrough on the smaller cryostat! After tearing the Cryo Lab up looking for it, I found it in the EE Shop :-)