Here is a little PDF of what I plan to do to both of the transmission QPD whitening boards later today. The idea is to take away the remote gain slider inputs, and force the gains to always be at +30dB.
The red and blue notes are from Koji's elog 9854, and the green are my plans for today.
I will cut the traces from the gain slider inputs, and pull the negative input of the AD620 to ground. The positive input will be connected to the +5 voltage line, with a divider so that the positive input to the AD620 is about 666mV.
The AD602 will be maxed out at +30dB with anything over 625mV.
Unless there are objections, I will start these modifications in an hour or so. I will also make the Xarm whitening always-on, just like Koji has already done for the Yend.
EDIT, JCD, 12Dec2014: These are not the modifications that were made. Please see ____ for actual modifications.