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Entry  Sun Jun 10 03:46:38 2018, Koji, Update, IOO, WFS HEAD SW confusion C1IOO_WFS_HEADS.png
    Reply  Mon Jun 11 22:46:24 2018, Koji, Update, IOO, WFS HEAD SW confusion 180611_IMC_WFS1.pdf180611_IMC_WFS2.pdf
       Reply  Thu Jun 14 00:46:09 2018, rana, Update, IOO, WFS HEAD SW confusion 
Message ID: 13960     Entry time: Thu Jun 14 00:46:09 2018     In reply to: 13946
Author: rana 
Type: Update 
Category: IOO 
Subject: WFS HEAD SW confusion 

its painful, but you and I should probably take these out, bypass the switches and use them with fixed gain; the 'Reed Relay' attenuators are not a good part for this app.

The historical problem is that they tend to self oscillate with full gain because they had 2 MAX4106 in series which couple to each other in the bad way --- need to remove one of them and set the gain of the other one to 10.

Quote:

The unfortunate discovery today was that the attenuator switches on the IMC WFS heads are actually assigned to individual segments, and they are active. That means that we have been running the WFS with an uneven gain setting.

 

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