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Message ID: 1840     Entry time: Thu Dec 12 16:48:39 2019
Author: Duo 
Type: DailyProgress 
Subject: Modifying the board changes the transfer function 

The noisemon board has been modified according to 1835. We do not expect any change in the transfer function but we see an increase in the gain above 20Hz.

Attachment 1 shows the comparison between modified board transfer function and the original board transfer function.

Attachment 3 shows the difference of the transfer functions in attachment 1. There is about 8-10dB increase at 100Hz after the modifications.

Attachment 4 is a comparison of LISO simulations. I calculated the transfer functions of the whole noisemon circuits before and after the modifications. I substracted them and found the difference.

Without putting attachment 3 and 4 in the same picture we can see that they are very different. LISO basically says there will not be any significant change in the transfer function but actually our measurement shows that there is.

Attachment 1: ModifiedVsIntact.pdf  84 kB  | Hide | Hide all
Attachment 2: ModifedVsIntact.xml.gz  2.906 MB
Attachment 3: gainDiff.pdf  36 kB  | Hide | Hide all
Attachment 4: lisocomparison.pdf  12 kB  | Hide | Hide all
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