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Entry  Fri Jul 16 14:19:02 2010, Megan, DailyProgress, VCO, Busby box NewBusbyNoise.pngBusbyModelNoise.pngPhaseNoiseCompared.png
    Reply  Fri Jul 16 15:18:55 2010, Frank, DailyProgress, VCO, Busby box 
       Reply  Fri Jul 16 15:34:51 2010, Megan, DailyProgress, VCO, Busby box PhaseNoiseCompared.png
Message ID: 229     Entry time: Fri Jul 16 15:34:51 2010     In reply to: 228
Author: Megan 
Type: DailyProgress 
Category: VCO 
Subject: Busby box 


there are 0 Ohm resistors, but you can also make a simple short between those two pads

i don't understand the third graph.  Looks like the blue data is the frequency noise calculated from the electronic noise with your 680KHz/V coefficient. The green one looks like phase noise, so i think you have to convert one of those into other units


I replaced the batteries of the Busby box today to see if that reduced noise. It did not. Measuring the instrument noise and TP7 noise gave exactly what I got yesterday with the old batteries. I subtracted the instrument noise to plot against the model again and got basically the same graph as yesterday.

I also tried comparing the phase noise coming from the electronic noise against the total noise of the VCO. The total noise of the VCO was apparently below that of the electronic noise. I'm wondering if it could have been the fault of all the ground loops, since removing almost every cable changed the graph of the electronic noise so much. So at some point soon I would like to re-connect the entire VCO and measure the phase noise again, making sure I remove every unnecessary cable. This part confuses me though - all the schematics label the connecting resistor as 0, so I'm not sure if there is a 0 resistor or if it's a value that I don't know?


 Looks like I made the third graph without really thinking about what I was doing. The y-axis is labeled completely incorrectly, the blue data is frequency noise calculated from the electronic noise, and the green data is the phase noise from the VCO. So, after thinking about what I was doing, I converted the electronic noise into phase noise and graphed them together (with correct axis labels). They look more similar now, but I would still like to measure the VCO without the extra cables. I'll try connecting the VCO and measure again.

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