Back on 23 December, Keita found the need to tilt the HEPI to pitch the TMS. Attached is a plot showing the T240 signal going back 30 days from now. The time keita tilted the HEPI is pretty obvious in the middle of the trends when tilted axes of the T240s are affected. Much of the period since 23 Dec has the ISI off (tripped from T240 saturations) and so not the source of the increase in these T240 signals.
As I've logged before, the ETMX ISI has not managed to stay engaged for more than a few hours since this time. Notice too on these trends, the signals with the largest amplification has a regular hit of the rail. The second plot I've attached is a single channel of 15 days. Notice the rail hit every 24 hours; this is to the minute as best I can tell from a 15 day dv trend. I am suspicious that this is real given the periodicity.
Finally, the last plot zooms in to 8 days of this channel and I've added a channel indicating the HEPI tilt. Notice in the middle of the plot where on 2 & 3 Jan I'm mucking about with tilts and ISI. The noise of the T240 is reduced when there is no tilt applied.
Duplicated this situation at ITMY. We removed the HEPI position loops and took the ISI to damping only and then tilted the HEPI -12000 counts in the same method as the ETMX. Attached is the nominally affected channels. Upper right trace is the offset. There is no large difference between the periods of offset and no offset; certainly not to the extent it is seen on the ETM. Fabrice is currently repeating this measurement at ETMX while ISC has relenquished control.
