I need to test the noise on power supplies for clock oscillators. The typical method is to use a spectrum analyzer at the lowest frequency base with AC inputs and get a spectrum of the noise using average and log X axis.
The problem with R5 is that while you can do this and for low frequencies (0-73Hz) the problem is the software does not show anything below -110dB.
With a 12 bit signal analyzer like the HP 356X series they usually go to -130dB and -150dB for 14 bit.
I tried using the ADC-216 which does allow up to -150dB on R5 but it has it's own set of problems.
With the 3224 and R5 I can first do a shorted probe measurement to get a baseline for noise. Then merge that with the UUT and get a better result. Unless the noise floor is below -110 for which then it just dies.
Another problem which I noticed yesterday is that everytime the R5 software does an average it opens a new window. I could not understand why R5 kept crashing until I realized this. I expected it to keep averaging over the same window.
Anyways... I am trying to get some pretty low measurements as I have some new discrete regulators in the 33nV-100nV range. So if anyone can tell me how to use the 3224 to accomplish better testing I would appreciate it.