Continuing the coil balancing work that Jeff and Arnauld did yesterday. I have redone here M3 stage of SR2 and improve on the one done yesterday, so the balancing done here will be final.
I am following the notes on aLog entry 13203.

1.- Verifyed that all required lock-in processing filters were ON.
2.- Locking output channels are on the same range.
3.- 	3.1.- Set SR2 M3 Control State Request to -2 so that I can do the next step.
	3.2.- Turned off all compensation filters in COILOUTF.
4.- Both Oscillators on
5.- LKIN EXC On at stage M3 of SR2 and then set the matrix to achieve proper feedback to magnets for balancing purposes.
6.- Tuning the demo-phase for Y and P by minimizing abs(Q):
	Original Phases: Phase_Y=162.5; Phase_P=346.2
	Tuned Phases: Phase_Y=177.5; Phase_P=101.2
7.- Now fine tuning: After averaging for 100 seconds I get with the above tuned demo-phase:
	
	Channel					Mean		Std
	H1:SUS-SR2_LKIN_P_DEMOD_I_OUTPUT    0.354412932551    0.264863588971
	H1:SUS-SR2_LKIN_P_DEMOD_Q_OUTPUT    -0.163124796397    0.259760509422
	H1:SUS-SR2_LKIN_Y_DEMOD_I_OUTPUT    2.51550842896    0.253143227116
	H1:SUS-SR2_LKIN_Y_DEMOD_Q_OUTPUT    0.320404387696    0.314157503514

8.- Perturbed coil balance by 5% in Pitch:

	Channel					Mean		Std
	H1:SUS-SR2_LKIN_P_DEMOD_I_OUTPUT    0.851457980145    0.470590672751
	H1:SUS-SR2_LKIN_P_DEMOD_Q_OUTPUT    1.20609980375    0.430006270327
	H1:SUS-SR2_LKIN_Y_DEMOD_I_OUTPUT    -33.8241021085    0.233048919653
	H1:SUS-SR2_LKIN_Y_DEMOD_Q_OUTPUT    10.5780652899    0.384469670781

9.- Comparing above results as before and after the big pitch perturbation we obtain dPhi_YAW = -15.76, this gives a New YAW Phase = 161.74
10.- After setting the new YAW Phase as per previous calculation we return coil balance gains to +/-1 and then perturbe coil balance by 5% in Yaw, I notice that the output of Q-phase on Yaw did not change with the perturbation as expected:
	Channel					Mean		Std
	H1:SUS-SR2_LKIN_P_DEMOD_I_OUTPUT    12.233386665    0.49093307219
	H1:SUS-SR2_LKIN_P_DEMOD_Q_OUTPUT    23.0653030109    0.403437476115
	H1:SUS-SR2_LKIN_Y_DEMOD_I_OUTPUT    -15.9078921098    0.414784263366
	H1:SUS-SR2_LKIN_Y_DEMOD_Q_OUTPUT    0.977137203924    0.329209454431

	Comparing above results as 'before' and 'afte'r the big yaw perturbation we obtain dPhi_PITCH = 62.91, this gives a New PITCH Phase = 161.74

11.- After changing the PITCH demo-phase as above and restoring the COILOUTF gains to +/-1 we capture final numbers:
	Channel					Mean		Std
	H1:SUS-SR2_LKIN_P_DEMOD_I_OUTPUT    -28.3204587579    0.447526860178
	H1:SUS-SR2_LKIN_P_DEMOD_Q_OUTPUT    -0.0284926997822    0.529445025268
	H1:SUS-SR2_LKIN_Y_DEMOD_I_OUTPUT    -14.0667103422    0.302460075544
	H1:SUS-SR2_LKIN_Y_DEMOD_Q_OUTPUT    1.04279550266    0.500395875968

12.- After careful tuning of the coil balance gains these are the final values:
	H1:SUS-SR2_M3_COILOUTF_UL_GAIN 0.976
	H1:SUS-SR2_M3_COILOUTF_LL_GAIN -1.1
	H1:SUS-SR2_M3_COILOUTF_UR_GAIN -1.005
	H1:SUS-SR2_M3_COILOUTF_LR_GAIN 0.963

13.- The improvement in balance is quantified on the attached plot below. The reduction in the 4Hz injection signal is given next:
	                P         Y
	Not Balanced   0.72      0.355
	With Balance   0.0061     0.0266
	ratio          118.033     13.346