On a Tuesday a couple weeks back I went to HAM8 and looked at connections between the shield pins for all of the single axis seismometers on HAM8, both at the rack and at the feedthru on the chamber. For the H1 seismometer I found that pin 9 (labeled as GS13-2 Sig+ on D1002706) is grounded to pin 5, which is the shield, this would explain why the sensor has a gain of 1/2 compared to the other seismometers. None of the other GS13s show this shield connection to signal. However, 2 of the L4C pairs have multiple wires connected to the shield, I haven't run down what they are yet. All of the wires that are connected to shield are connected at both the rack and the flange, so the issue is somewhere in vacuum. Can't really tell more at this point without opening the chamber. I plan to check HAM7 at some point, but that is a borrow from 3ifo.

Mitch and I did some tests on what spare A+ cables we could find in the staging building, 2 D1000227 pigtails and 2 220(?) 25pin extensions. We couldn't find or cause any connections between the shields and signal wires, but it wasn't an exhaustive test. I'm also huddling some GS13s on the table, I will try to see if there are any wire-shield connections with the cables that are plugged into those sensors.