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Entry  Tue Aug 24 18:44:03 2021, Koji, Update, CDS, FB is writing the frames with a year old date Screen_Shot_2021-08-24_at_18.46.24.png
    Reply  Wed Aug 25 17:31:30 2021, Paco, Update, CDS, FB is writing the frames with a year old date TRX_noise_2021-08-25_17-40-55.pngTRX_TRY_power_spectra.pdf
       Reply  Thu Aug 26 10:10:44 2021, Paco, Update, CDS, FB is writing the frames with a year old date Screenshot_from_2021-08-26_10-09-50.pngTRXTRY_Spectra.pdf
    Reply  Wed Aug 25 18:20:21 2021, Jamie, Update, CDS, GPS time on fb1 fixed, dadq writing correct frames again 
Message ID: 16298     Entry time: Wed Aug 25 17:31:30 2021     In reply to: 16294     Reply to this: 16300
Author: Paco 
Type: Update 
Category: CDS 
Subject: FB is writing the frames with a year old date 

[paco, tega, koji]

After invaluable assistance from Jamie in fixing this yearly offset in the gps time reported by cat /proc/gps, we managed to restart the real time system correctly (while still manually synchronizing the front end machine times). After this, we recovered the mode cleaner and were able to lock the arms with not much fuss.

Nevertheless, tega and I noticed some weird noise in the C1:LSC-TRX_OUT which was not present in the YARM transmission, and that is present even in the absence of light (we unlocked the arms and just saw it on the ndscope as shown in Attachment #1). It seems to affect the XARM and in general the lock acquisition...

We took some quick spectrum with diaggui (Attachment #2) but it doesn't look normal; there seems to be broadband excess noise with a remarkable 1 kHz component. We will probably look into it in more detail.

Attachment 1: TRX_noise_2021-08-25_17-40-55.png  80 kB  Uploaded Wed Aug 25 18:43:08 2021  | Hide | Hide all
TRX_noise_2021-08-25_17-40-55.png
Attachment 2: TRX_TRY_power_spectra.pdf  29 kB  Uploaded Wed Aug 25 18:43:58 2021  | Hide | Hide all
TRX_TRY_power_spectra.pdf
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