40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
  40m Log  Not logged in ELOG logo
Message ID: 687     Entry time: Thu Jul 17 00:59:18 2008
Author: Jenne 
Type: Summary 
Category: General 
Subject: Funny signal coming out of VCO 
While working on calibrating the MC_F signal, Rana and I noticed a funny signal coming out of the VCO. We expect the output to be a nice sine wave at about 80MHz. What we see is the 80MHz signal plus higher harmonics. The reason behind the craziness is to be determined. For now, here's what the signal looks like, in both time and frequency domains.

The first plot is a regular screen capture of a 'scope. The second is the output of the SR spectrum analyzer, as seen on a 'scope screen. The leftmost tall peak is the 80MHz peak, and the others are the harmonics.
Attachment 1: VCOout_time.PNG  9 kB  | Show | Hide all | Show all
Attachment 2: VCOout_freq.PNG  13 kB  | Hide | Hide all | Show all
VCOout_freq.PNG
ELOG V3.1.3-