I have taken the transfer function of the coil A, B, C, and D inputs to outputs on the Satellite Box (D0901284).
The measurement was taken with an SR785 sourcing the input through a Coil Driver Chassis to turn the input into a differential, and then fed through the Satellite Box.
We expected the Satellite Box to be have flat phase response and gain.  We have confirmed that to a tenth of a percent. (0.1%)
The Reference TF was taken of the Coil Driver Chassis by itself, and the residual calculation took our response from the Satellite Box Coil A over Reference TF.
The following was calculated using Satellite_Box_TF_Plotter.m located in /ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/PreER8/H1/Measurements/Satellite_Box/2015-08-17/.