Hugh and I went to HAM3 this morning to see if we could find the cause of the 23 hz line. Finding nothing at the chamber, we decided to start turning stuff off to see if we could get it to go away. Taking the ISI and HEPI down did nothing, but turning the suspension off made the line go away. I then started turning the SUS back on and as soon as I took MC2 to aligned, the 23hz peak showed up. Jeff said that it was likely the sat amplifier needed power cycled, so Hugh is filing an FRS and this is being handed off to Richard. Attached image shows HAM3 GS-13s between 20 and 30 hz. Red is from last night, when everything was on, blue is everything off, green is MC2 aligned (everything else off). HEPI L4Cs and both SUS also saw the peak.
After all the restarts earlier and Richard power cycling MC2, the line is gone. See attached. Red trace is from 8 hours ago, blue is from a couple minutes.
Do we know what power cycling does? how often dows this kind of thing happen?
Richard--The thought/idea is and maybe there is some way we could verify it, that the satellite amplifier goes into oscillation.