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Entry  Thu Nov 24 20:22:42 2011, Mirko, Update, IOO, F2A filter for MC UpperCoils.pdfLowerCoils.pdf
    Reply  Fri Nov 25 17:52:28 2011, rana, Update, IOO, F2A filter for MC 
       Reply  Fri Nov 25 23:25:24 2011, Mirko, Update, IOO, F2A filter for MC F2aForMCcomparedToBS.pdf
          Reply  Mon Nov 28 10:54:40 2011, rana, Update, SUS, F2A filter for MC 
Message ID: 6012     Entry time: Fri Nov 25 23:25:24 2011     In reply to: 6006     Reply to this: 6021
Author: Mirko 
Type: Update 
Category: IOO 
Subject: F2A filter for MC 


Woo. Pretty crazy. The numerators should only be ~10% larger than the denominator below 1 Hz. Let's try again.

 [Rana, Mirko]

I redid this calculation. The idea behind it is to get rid on any pitch that is introduced by applying longitudinal feedback to the mirrors. This coupling happens because the center of percussion for pitch , which is identical with the point where the wires lift off of the mirror, is above the center of mass.

With the same values as before, just less faulty math and Q = 2 instead of 10 we end up with the following filters:

For the lower coils (red), compared to corresponding preexisting BS filters (black):


The upper coils' TF is just mirrored at the 0dB magnitude axis, and have a corresponding frequency response.

I switched the F2a filters on for all MC mirrors. For convenience they are split into F2aZeros and F2aPoles. Everything seems fine. The F2a filters seem to be off for ( all ?) other mirrors.

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