40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
  Cryo Lab eLog  Not logged in ELOG logo
 List  |  Find  |  Login  |  Help 
Entry  Mon Nov 3 15:16:28 2014, Dmass, Noise Hunting, Noise Budget, New beat spectrum: ErrSigs.pngBeatNz.png
    Reply  Mon Nov 3 16:15:21 2014, Dmass, Noise Hunting, Noise Budget, Beat spectrum not ltd by  
       Reply  Mon Nov 3 20:27:28 2014, Dmass, Noise Hunting, Noise Budget, ISS servo fail? 
          Reply  Wed Nov 19 14:54:36 2014, nicolas, Noise Hunting, Noise Budget, ISS servo fail?  
       Reply  Tue Dec 2 22:51:52 2014, Dmass, Noise Hunting, Noise Budget, Beat spectrum not ltd by  PDH_demod_chain.png
          Reply  Sat Sep 12 14:25:05 2015, Dmass, Noise Hunting, Noise Budget, Beat spectrum not ltd by  
    Reply  Mon Nov 3 20:36:14 2014, Dmass, Noise Hunting, Noise Budget, New beat spectrum: 
       Reply  Tue Nov 25 22:45:43 2014, Dmass, Noise Hunting, Noise Budget, New beat spectrum: 
          Reply  Wed Dec 3 17:02:31 2014, Dmass, Noise Hunting, Noise Budget, Noise budget cleaning up 
             Reply  Thu Dec 4 02:45:49 2014, Dmass, Noise Hunting, Noise Budget, Noise budget cleaning up PDH_sensing_nz.pngLB1005inputNoise.png
                Reply  Sun Dec 7 12:42:55 2014, rana, Noise Hunting, Noise Budget, Scatter Noise hump is RAM 
Message ID: 1168     Entry time: Tue Nov 25 22:45:43 2014     In reply to: 1165     Reply to this: 1174
Author: Dmass 
Type: Noise Hunting 
Category: Noise Budget 
Subject: New beat spectrum: 

I was artificially limiting my PLL range by directly driving the Marconi with the IF output of the mixer - this restricted it to ~500mV range.

The input range of the Marconi is (measured to be) +/- 2V (~ 8x higher than the mixer output I was using. Free-ish lunch here.

 

We might have to wait until we're cold to have low enough drift to use the Marconi in any truly low noise way, but I believe it's no longer limiting at even room temperatures. Beat noise spectra tomorrow.

ELOG V3.1.3-