Jim, Dhruva, Evan (WP10981)

We removed the two beam clamps attaching the upper portion of the NCAL assembly to the side of BSC9 (see D1900145 for the assembly drawing; the assembly remains attached to the BSC pier). Jim inserted two folded-up squares of natural rubber between the NCAL and the BSC. We spun NCAL up to 30 Hz and did not observe a noticeable change in its level of vibration or audible noise, either with or without the rubber. The BSC9 accelerometer in the X direction showed an essentially identical level of noise in comparison to the previous situation when the assembly was clamped (67207).