Main results of the HAM-ISI tests

- Position sensors
    o The two satellite boxes are now synchronized – No crosstalk 
    o Measured sensor sensitivity = 840counts/mil
- Measured vertical spring constant =  2.491e5N/m (2.62% from nominal value)
- Measurement of the Local to Local transfer functions. No particular issues except on V1 geophone transfer function. Below 1 Hz, magnitude is about 25% higher than the other transfer functions and the Q at 1Hz is also lower. We didn’t notice any difference on CPS transfer function. V1 Geophone might be guilty. Note: No electronic correction on plots presented (1 zero @ 10 Hz - 1 pole @ 50 Hz in the new GS13 interface chassis).
- Measurement of the Modal to Modal transfer functions. 
   o RY geophone transfer function is not clean in the section between 500mHz and 5Hz. We messed up when we defined the magnitude of the excitation. The drive was too strong. The saturation counter indicates that RY Geophone signal saturates. We haven’t redone that measurement (HAM is unplugged now – New floor next week).
   o We can also notice that signals on position sensors in the Cartesian basis are out of Phase. Adding a sign in DISP2CEN matrix in make_HAMX1_projections_100709 will fix that. CONT2ACT and GEO2CEN look good.
- We installed the damping loops using HAM6 filters. No problem of instability. Check out power spectrums when all damping loops are engaged.