I'm using WaveForms 3.8.22's Spectrum Analyzer with Analog Discovery 2.
When I run the analyzer I use FFT with 129 BINs in the 1 Hz to 100 Hz range on both channels.
The magnitude settings of the Spectrum Analyzer are the follows: Vrms, top: 10 mV, bottom: 0 V, reference: 1V, range: 5V.
I selected the exponential dB Average on both channels.
If I run the spectrum analyzer and while it's running I change the top value from 10 mV to let's say 20 mV it instantly changes the chart correctly, but after a new measurement completes the chart changes drastically which is not the expected behavior, I think.
Here is a screenshot of my workspace (just before the change):
And another one just after the change from 10 mV to 20 mV:
As you can see the chart changes significantly while the source signal remained somewhat the same.
Interestingly when I tried to reproduce the problem by connecting the signal generator with the scope while generating a steady sine signal, the problem didn't show.
It did show though when I set the signal generator to sweep mode.
It also work fine if I change the type of the trace from the exponential dB average to sample.
Is there a reason why this could happen? Does the averaging algorithm's buffer get reset when we change any of the parameters of the spectrum analyzer?
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Andras
Hi,
I'm using WaveForms 3.8.22's Spectrum Analyzer with Analog Discovery 2.
When I run the analyzer I use FFT with 129 BINs in the 1 Hz to 100 Hz range on both channels.
The magnitude settings of the Spectrum Analyzer are the follows: Vrms, top: 10 mV, bottom: 0 V, reference: 1V, range: 5V.
I selected the exponential dB Average on both channels.
If I run the spectrum analyzer and while it's running I change the top value from 10 mV to let's say 20 mV it instantly changes the chart correctly, but after a new measurement completes the chart changes drastically which is not the expected behavior, I think.
Here is a screenshot of my workspace (just before the change):
And another one just after the change from 10 mV to 20 mV:
As you can see the chart changes significantly while the source signal remained somewhat the same.
Interestingly when I tried to reproduce the problem by connecting the signal generator with the scope while generating a steady sine signal, the problem didn't show.
It did show though when I set the signal generator to sweep mode.
It also work fine if I change the type of the trace from the exponential dB average to sample.
Is there a reason why this could happen? Does the averaging algorithm's buffer get reset when we change any of the parameters of the spectrum analyzer?
Thank you,
Andras
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