F. Clara, R. McCarthy, T. Shaffer

Work corresponding to FRS4559.

Summary: While we did manage to isolate the cameras from their base, the grounding problem still exists.

DetChar noticed a noisy source that turned out to be a grounding issue with the HWS cameras. The above FRS was filed and then T1600449 was created as a solution that LLO had found to isolate the camera. Just as T1600449 outlines, the camera base position was marked with some spare clamps, I then disconnected and removed the camera from the base, and then I laid the Kapton on the base. Reassembling this assembly required the use of a nylon 1/4"x20 0.5" screw to hold it from the bottom, and a removal of all other metal hardware. While I worked on this, Fil connected the shield to the Hirose connector. Once we were done, we plugged everything back in and tested it. No good. We double checked our work and couldn't find a source that might cause the grounding, so we unplugged the camera and made sure that it was actually isolated. It was. The LLO alog30372 said that they only checked it was isolated while it was unplugged. So we went hunting.

Fil poked around some more and then called in some backup from Richard. The three of us taped up the bottom of the power supplies where they contact the metal bars that hold them up inside the table enclosure (see attachments). This also did not work. Some more hunting from Richard found that the photo detectors were also grounding to the table, and possibly other sources. We could choose to find all of these sources and find a way to isolate them all, but for today this was where we ended. Tomorrow we will head to the ends to continue T1600449.

Attachments are: HWSY shown with position clamped and Kapton on, a taped base, and HWSX final.