Below is a duplicate of my SEI ELOG.  Talking with Calum this morning, seems we should have replacement for these in about a month.  Is it likely we'd be doing low noise experiments where this ground loop problem might appear?


SEI ELOG id 1970:
The BSC Trillium Cable D1100152 is unique in the BSC ISI In-vacuum cables in that it is one piece. All other cables, GS-13s L4-Cs and Actuators, are two piece and one of these two has one end where the peek connector has been metalized. Since the metal backshell has been shorted to the shield & pin1, the metalized connector is too now tied back into the rack ground. This is just fine for the two part cables as the metalized peek connector (with ears) are mounted to the Cable Bracket D1001347 isolating the ground connection.
The problem with the Trillium Cable is the cabling company got sloppy and put the metalized connector with ears on when it should not have. Now the metalized connector mates up to the Trillium and shorts the grounded shield & Pin1 to the Trillium pod, Stage1 etc etc. I understand this is not desirable.

Corey and I looked closely at one of these Trilliums to confirm and yes the backshell is shorted to pin1 and therefore likely to ground back at the rack. That connection continues to the metalized connector and to the front of the connector where it would contact the Trillium pod. We took the backshell back as far as comfortable and could not see where the Pin1/Shield/backshell connection was made so I'm not sure we can address it there.

Solution? Could we not just get another connector that wasn't metalized and exchange it? Needs to be classA'd, probably need a fancy gizmo to install it, and have to test the cable again.  [BenA has proposed cutting a groove around the metalized connector through the metalization to break the contact to the front of the connector--seems dirty, ugly, non-LIGO]
Maybe we'll actually get some cables that were made correctly soon and we can exchange it?