I wanted to try adding the "jel" packs that Arnaud and Eyal have been using at LLO (for instance, here ), because it seems to help the low frequency noise. Jason had some left from the oplevs (excess beyond 3IFO needs), so I tried adding some the ETMY BRS, see attached photo. In the process, I must have bumped the "mass adjuster" in the process, because when I checked the BRS status before leaving the end station, it was dead, out of range. So, I set about rebalancing, and found that the rdesktop program (which I had aliased) with the new zotac workstation was laggy and basically useless. After talking to Carlos, I tried using remmina, which was much better, but still laggier than rdesktop was on the old mac/debian workstations. When I left the BRS was still rung up and not ready to use, but was slowly settling down. With the low microseism, this shouldn't interfere with commissioning, so I don't want to risk trying to settle it by hand, yet. If it's still angry tomorrow, I can try soothing it.
The capacitive damper cable from the relay box to the vacuum flange has broken solder joints. There are 3 soldered connections here and the 2 that are actually attached to anything inside the BRS enclosure are both broken. The remaining wire doesn't connect to anything.
Fil resoldered and we re-installed the cable this morning after we figured out the pin-out yesterday afternoon. The cap plates are attached to pins 2 & 5, as you go clockwise around the flange. Filed and close FRS ticket 11638. Attaching my summary here:
After adding insulation to BRS platform, the capacitive damping stopped working, alog https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=44453 and comment. Found that the solder joints on the cable at the vacuum flange were broken. No documentation of the pin-out, there are five pins at the flange, only one is used on this BRS. We measured capacitances between the pins and the vacuum vessel, 3 were ~10pf two were ~60pf. Fil re-soldered the cable and we re-installed. Testing was done by watching the damping, when we had the pins reversed the damping rung the beam up, swapping the leads fixed the damping. BRSY is fixed now, but we should check the cable at EX.