[Fil Arnaud]
Few days ago I realized SRM top mass dials were moving more than usually, so I took a spectra this morning which shows noise at around 1700Hz for LF RT SD and T3 osems signals. Those four osems are using the same quadrupus cable from the flange to the sat box. The spectra compares those four osems with SR3 RT SR3 SD SRM T1 and T2, which shows a peak at 1700Hz but much less higher.
We tried powering down the AI chassis and the coil drivers several times, which didn't fix the issue. I don't recall we powered down the AA chassis, so that might be the next thing to try.
To be fixed.
Similar issue as this
Richard, Fil, Sheila, Jeff
We looked into this noise a bit more this morning. Richard tried several tests, swapping the satelite amplifier box, power cycling the coil driver ect. The problem follows the cable from the chamber. Something inside the chamber is grouding the sheild of the cable. Fil tried installing a break out with pin 13 (for the sheild) cut at the input to the satelite box, but the noise is still there.
The second attached screenshot shows the elevated noise in LF, RT, SD, and T3. These are the channels that share a satilite amp (and cable for the chamber) while T1+T2 are on a different cable, and have fine noise.
The low frequency osem noise seems similar to the noise of SR3. (first screenshot) So for now we can just move on.
