[Discuss-gnuradio] PSK Mod problem? or QT GUI problem?

[Mercado, Alejandra]

Dear GnuRadio folks,

I have a questions about the "PSK Mod" block of GnuRadio. I am following the tutorial found here: https://wiki.gnuradio.org/index.php/Guided_Tutorial_Hardware_Considerations

(the grc is attached)

I followed the instructions to see the output of PSK Mod for 4 constellation points. To my surprise, the constellation graph shows points that are ambiguously between quadrants (see the screenshot).

What causes this? Is it the PSK Mod block that creates output points that do not correspond to one of the four points? Or is it the QT GUI that is not displaying the output correctly? Or both?

Thanks and regards

Screenshot from 2018-11-01 10-14-48.png
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QPSK_TX_b.grc
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