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Reports until 14:38, Friday 24 February 2017
H1 ISC
heather.fong@LIGO.ORG - posted 14:38, Friday 24 February 2017 (34387)
Changes to OAF BLRMS filter and violin mode MEDM labels

Heather, Keita, Sheila

We noticed that whenever H1 regains lock status, the OAF BLRMS range contributions channel 5 takes several hours to stabilize (see first plot). We attributed this behaviour to the fact that the BLRMS filter, whose frequency range corresponds approximately to the violin modes, was not wide enough, leading to leakage. We broadened the frequency range and loaded it while H1 was in commissioning mode, and a plot of the adjusted filter is attached. No changes were made to SDF.

In addition, we noticed a few frequency labels in SUS_CUST_VIOLIN_OVERVIEW.adl (in particular, ITMX mode 1 and ETMX mode 4) did not match the actual frequency values being filtered, so we edited MEDM to fix the discrepancies. ITMX mode 2's filter name was also incorrectly labelled, and this has been fixed. These changes were cosmetic and do not affect the violin mode filters themselves.

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