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Entry  Fri Nov 26 13:00:20 2010, Zach, Laser, GYRO, Gyro OLTFs and current noise spectrum oltfs_11_23_10.pnggnoise_11_23_10.png
    Reply  Fri Nov 26 19:43:34 2010, Koji, Laser, GYRO, Gyro OLTFs and current noise spectrum 
Message ID: 1178     Entry time: Fri Nov 26 19:43:34 2010     In reply to: 1177
Author: Koji 
Type: Laser 
Category: GYRO 
Subject: Gyro OLTFs and current noise spectrum 

It seems that the gyro noise level looks much better than that in entry 1150. Can you overlay the improvement of the gyro signal?

Note that your latest gyro signal is not valid above 1kHz considering you only have OLG of less than 10 above 1kHz.
(i.e. error in the noise level estimation is more than 10% above 1kHz unless you conpensate the effect of the control.)

- I wonder how I can obtain 0.67 (rad/s)/V from this formula... (In other word, I like to know the freq stability measured by the VCO.)

- How do we characterize / reduce the low frequency noise? Does going to vacuum really improve this noise? What is expected?

- Where is the VCO phase noise level now?

- We definitely need to have better PHD circuit. Probably we can use the box but should replace the board.

- We should start to look at the beat signal.

Quote:

500 kHz/V (VCO gain) x (c * 3.15 m) / (4 * 0.62 m2) ~ 0.67 (rad/s)/V

 

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