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gnuradiognuradio-companion

GNURadio - WX FFT Plot not showing frequency on the x axis

I'm using WX GUI FFT to display a specific frequency range (38Hz for IR). I can't seem to get the plot to show the frequency range on the x axis. I have it set up like follows:

enter image description here

And here's what it looks like when it runs:

enter image description here

As can be seen there's no frequency range on the x axis.

Any idea what I'm doing wrong?

Solution

  • The display is absolutely correct.

    You set the sampling rate, and hence the bandwidth to be displayed, to be nominally 10 MHz, so each of the ten divisions of the x-Axis should be 1 MHz wide.

    Now, your center frequency is in fact of course not 0 MHz, but 38 kHz, but WX GUI rounds the numbers for display – it's really not that useful to see "0.038 MHz" as an axis label.

    More importantly, you seem to be confused about what the sampling rate and what the center frequency are supposed to be; my gut feeling is that you want to observe an 38 kHz wide channel around 10 MHz. What you do is observe 10 MHz around 38 kHz (which, physically, doesn't make much sense, and you should see very clear warnings about that in the console).

    Furthermore, WX is going away with the next release of GNU Radio. Use the Qt GUI instead.