QA401 Trouble reproducing Manual page 50

QA401
1

Ok, I’m brain dead. I am trying to duplicate the testing on page 50 of the manual.

  1. What is the trick with zoom. I can’t reliably zoom. I can try over random places of the main waveform and sometime it works, most times not. Are their certain criteria I need to adhere to before it works? Have to do with FFT or averaging? I can’t manage to get the zoom view on page 50. Is the Axis settings, Default key the return normal view or is there another key?
  2. I don’t get less than 1 Hz resolution with 32K FFT, I get 1.46 Hz.
  3. I can’t seem to get the X axis to look like the one on page 50. That looks compressed compared to my best attempt.
  4. What are the x/y cursor lines in green? They don’t always follow the cursor.
2

Hi @bklein,

  1. You should be able to zoom by dragging a rectangle around the region you want to zoom, and then press XLOG or XLINEAR to zoom back out. so, yes, the Axis button is the correct way to reset your zoom

  2. What is your expectation for resolution at 32K with 48K sample rate?

  3. Which version of the manual are you looking at? The graph on page 50 looks to have a pretty typical graph. Can you try file->Reset Startup Defaults to see if that clears things up?

  4. Can you shown an example of the XY cursor lines?

Thanks, Matt

3
  1. Something changed - now the zoom is working 100%. Before it would only work about 10% of the time and never on peaks. Something jinxed it and then something fixed it.
  2. First off I’m new at this stuff so I was just trying to duplicate what I see in the manual. On page 50, FFT is 32768, SR is 48000, Res is 732 mHz.
    I see Res is SR/FFT size, 48000/32768=1.46 but the photo shows 732mHz which is half that. This kind of thing is in several places in the manual. The manual came with the 1.908 software load, which is the latest, although there are two prerelease versions above it. Do they have this fixed?
  3. As above, my manual is 1.908 May 2020 and came with this version software.
    IMG_8619
    IMG_86191920×1440 294 KB

    See I have Log Axis set to 1 Hz to 20 kHz. Freq. start 20 Hz stop 20kHz. The manual shows X freq. below 1 Hz and that won’t fit on my screen. Is there an X axis compression trick?
    IMG_8616
    IMG_8616480×640 99.1 KB
  4. Green cursor lines in photo.
4

I just checked 1.924 and the Res thing is fixed. I’ll just move to this level of software and see how things are.

Barry