Displaying report 1-1 of 1.
Reports until 12:37, Thursday 11 January 2018
H1 SUS (CDS)
filiberto.clara@LIGO.ORG - posted 12:37, Thursday 11 January 2018 - last comment - 14:35, Thursday 11 January 2018(40099)
ITMY M0 (LF RT) / R0 (LF RT) OSEM signal chain

Following up on alog 40014 with reported issues on MO and RO signal chain. Looked at possible grounding issues. Tested cable SUS_ITMY-8 at satellite box and found pin 2 shorted to chamber ground. To eliminate the air-side cable, we tested directly at the feedthru. Same results, pin 2 shorted to ground. The AA/AI/Coil driver driver electronics were also power cycled.

Comments related to this report
jeffrey.kissel@LIGO.ORG - 14:35, Thursday 11 January 2018 (40107)CDS, ISC
Link 

FRS Ticket 9683

Sadly, no change in the R0 V and R transfer function performance (composed of OSEMs LF and RT) after the the shorts were identified (and therefore cables re-seated), nor after the power-cycle of the signal chain. Remember, the SUS_ITMY-8 cable Fil refers to is ITMY's M0 (LF RT) / R0 (LF RT) cable between the satellite amp and the chamber feedthru (see D1100022).

Attached are the results.
Maybe one could argue that the 1.11 1.70 2.82 4.52 5.90 (+/- 0.01) Hz features originally called out in LHO aLOG 40014 have been slightly reduced, but I'm not sure if it's related.
Non-image files attached to this comment
Displaying report 1-1 of 1.