I have been working on assembling 10 grounding plugs for the TEST In connection on the Coil Driver boards, building on work described in https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?.submit=Number&docid=l1200193&version=  These grounding plugs make use of 100 Ohm resistors across pairs of pins and a 0.022 uF capacitor connected between the remaining pin and the DB9 connector metal (see page 16 of the document above for the schematic).  I will next measure the coil driver noise with these ground plugs in place across the TEST Input path.