Last week we tested both the new and old flanges with the GAGG housing set up described in the previous ELog entry.

Performance of the new flange was excellent, with clear signal and low noise contribution. We didn't take any photos of this as it was so textbook.

The old flange we identified as performing poorly in June was installed and we carried out the same pulser tests.
This flange clearly creates a different noise environment and initially showed noise comparable/exceeding the 500mV pulser we were inputting.
A photo of the scope signal from one of the pad detectors is shown in Attachment 1.

We thought this could be due to the separate ground planes the MPR and MSI modules are on on the flange PCB so connected these ground planes together. 
This did not really improve the very noisy signal, but made the MSI-8 slightly worse. All-in-all, no significant improvement.

We noted an electrical connection between the D-Sub connector housings and the L-brackets on the flange, connecting the D-Subs, their signal and grounds directly to the ring.
Isolating them from the flange was as simple as applying some tape to the inside of the bracket.
I installed the old flange in the ESR with the GAGG housing and the noise is dramatically improved. There remains some significant wobble in the signal baseline