Following Jeff's log last week, we wanted to try a different blend filter on HAM3 to see if we could get any improvement. Arnaud suggest a 500 mhz blend that is installed on the Livingston HAMs, shown as the the green traces in the first attached image (01_28 blend is shown in blue, 250mhz blend is in red) . I copied the filters over this morning, and turned the new filter on in the RY dof. It didn't do anything good, shown second and third images. Current confguration is shown in solid lines ( normal 01_28 blends everywhere), dashed lines are with 500 mhz blend on RY only. The .6hz peak disappeared, but a new one at 1.14hz appeared, there's some more junk just below 2 hz, and it looks like a bunch of CPS noise is being reinjected above 1hz. I've returned the ISI to the nominal config.