Nic, Evan

We have gotten DRMI to lock on the 3f signals using the new, modified BBPD serving as REFLAIR_B.

Some good UTC times for 3f locking: 2014-11-09 0:56:50, 01:13:10, 02:41:00

Judging by POPAIR_B_RF18_I_ERR, the lock is kind of ratty both on 1f and 3f.

I think the reason Alexa and I couldn't lock yesterday is that we had the wrong relative gain for RF135Q/RF45Q. Nic and I remeasured it today and got 2.0. It is still true, however, that the ramping matrix doesn't give the expected behavior; it seeems to approach the requested value almost asymptotically, taking far longer than the specified ramp time.

We then adjusted the gains in the 3f input matrix to reduce gain peaking in the demodulated spectra of RF27 and RF135. We have written the following matrix elements into the lscparams guardian file:

• RF27I → PRCL = −4.0
• RF135Q → MICH = 2.0
• RF27I → SRCL = −0.6
• RF135I → SRCL = 1.7

Attached are our measured OLTFs of PRCL, MICH, and SRCL while locked on 3f. The DTT files are in my directory under Public/2014/11/DRMI3f.