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Entry  Mon May 3 01:16:50 2010, rana, HowTo, Electronics, Marconi phase noise measurement setup pn.png
    Reply  Tue May 4 18:40:27 2010, rana, HowTo, Electronics, Marconi phase noise measurement setup Untitled.pngifrnoise.png
    Reply  Tue May 11 18:58:49 2010, rana, HowTo, Electronics, Marconi phase noise measurement setup Untitled.png
       Reply  Wed May 12 02:21:56 2010, rana, HowTo, Electronics, Marconi phase noise measurement setup pn.png
Message ID: 2913     Entry time: Tue May 11 18:58:49 2010     In reply to: 2869     Reply to this: 2914
Author: rana 
Type: HowTo 
Category: Electronics 
Subject: Marconi phase noise measurement setup 

Just a little while ago, at 2330 UTC on 5/11, I swapped the phase noise setup to use another Marconi - this time its the 3rd one from the top beating with the 4th one from the top (2nd from the bottom).

After a little while, I swapped over to beat the 33 w/ the 199. I now have all the measurements. For the measurement of the last pair, I inserted BALUN 1:1 transformers on the outputs of both signal generators'.

This last pair appears to be the quietest of the 3 and also has less lines. The lines are mainly at high frequency and are harmonics of 120 Hz. Probably from the Sorensen switching supplies in the adjacent rack.

I double checked that the 10 MHz sync cable was NOT plugged in to any of these during this and that the front panel menu was set to use the internal frequency standard. In the closed loop case, the beat frequency between the 33/199 pair changes by less than ~0.01 Hz over minutes (as measured by calibrating the control signal).

 

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