Alexa, Daniel, Evan

In order to use the new REFLAIR_B, we have made the following changes:

• The whitening gains are now 30 dB and 18 dB for RF27 and RF135, respectively.
• The dark offsets for RF27 and RF135 have been measured and nulled.
• The demod phases have been adjusted to 115.5° and 20° for RF27 and RF135, respectively. By driving PR2 at 131 Hz and SR2 at 184 Hz, we find that the PRCL and SRCL signals can now be made to appear in the correct quadratures (see first attachment).
• By driving a 5.75 Hz line in PRCL (and subsequently SRCL and MICH), we have measured the relative gains between the 1f and 3f signals:

  	PRCL	SRCL	MICH
  RF27I/RF9I	−0.49	−3.9
  RF135I/RF45I		2.4
  RF135Q/RF45Q			0.46 2.0

  The RF27I/RF9I measurement for SRCL is low SNR for some reason. [Edit, 2014-11-05: I think I must have taken the RF135Q/RF45Q measurement upside-down. I retook it today and got a magnitude of 2.0.]

By using these gain measurements to adjust the DRMI 1f matrix elements, we have tried to transition from DRMI 1f to DRMI 3f. Howver, so far it keeps dropping lock.

The demodulated 1f and 3f spectra (taken while DRMI is 1f locked) are attached (units are cts/rtHz).