Reports until 16:58, Thursday 09 December 2021
H1 CDS (SUS)
filiberto.clara@LIGO.ORG - posted 16:58, Thursday 09 December 2021 - last comment - 16:30, Friday 10 December 2021(60972)
EX and EY PUM Chassis Modified

WP 10104

PUM Chassis modified per ECR E2100204 and E2100205. Frequency of the input filter to the D070483-v7 circuit modified to allow more dynamic range when in the "State 3" mode.

State 3 Filters:
Input LP filter on
Acquisition filter off

PUM Chassis S1102652 EY
PUM Chassis S1000343 EX

Comments related to this report
jeffrey.kissel@LIGO.ORG - 10:25, Friday 10 December 2021 (60990)ISC, SUS, SYS
Tagging CAL and ISC Groups.

Direct link to ECR and supporting technical note for explanation of changes:
    ECR: E2100204
    Design Study: E2100205

Direct link to DCC file cards for serial numbers:
    EX S1000343
    EY S1102652
Unfortunately, these do not contain raw transfer function data. Will ask Fil if it was saved and if so, if we can get that data posted to these DCC file cards and/or the in to the ^/trunk/Common/Electronics/H1/Data/SUSElectronics corner of the SVN. 

Some historical documentation related to this electronics improvement and/or the PUM drivers:
    LHO:53482 Noise study showing the difference between State 1 and State 3 in terms of use of actuator range.
    LHO:47166 and LHO:47167 The last time we measured the PUM driver's frequency response and updated the compensation in 2019.
    LHO:42662 last time we balanced ETMX's L2 actuator chains.
    LHO:43143 last time we balanced ETMY's L2 actuator chains.

Actions to do well-before O4:
    - need to re-balance coils in State 3 at least, if not all states, and update the https://tinyurl.com/LIGOSUSActuatorTuning Table
    - need to gather new in-situ transfer function data a. la D1900027 if we don't have bench-top testing data (and probably even if we do, since we need all channels, and all states, to such high and low frequencies)
    - fit the data (putting fitting code into new git repo location, https://git.ligo.org/suspensions/ligo/electronics/)
    - Apply updated compensation filters to L2 COILOUTF banks.
filiberto.clara@LIGO.ORG - 16:30, Friday 10 December 2021 (60997)

ITM units have been modified. Transfer function data for all four units is uploaded in DCC.

PUM Chassis S1000346 ITMX
PUM Chassis S1102654 ITMY