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I have been reading and doing the steps on this webpage of GNURadio : https://wiki.gnuradio.org/index.php/Guided_Tutorial_PSK_Demodulation

In the middle of the page, there is a section: "Using the Polyphase Clock Sync Block in Our Receiver". It has a flowgraph to showcase the usage of polyphase clock synch block. I made a flowgraph by copying every single block shown in the flowgraph (I think so). I ran the simulation, but the result I get is completely different from the result the section shows.

I have attached my flowgraph and the flowgraph of the tutorial plus my result and the tutorial's result, respectively.

**my flowgraph: enter image description here

**The tutorial's flowgraph: enter image description here

**my result (output of the polyphase sync with the same parameters values as the tutorial's): enter image description here

**The result of the tutorial's flowgraph: enter image description here

Why isn't my result similar to the result of the tutorial? I just took the parameters from the tutorial one by one. I can't understand why mine doesn't work. The polyphase synch block has altered the constellation in amplitude while has not recovered the timing. Pure corruption?!?

Thank you.

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    $\begingroup$ Welcome to the Amateur Radio Stack! First, I'd point out that if you look at your results, you can discern the four clusters, so what you have must be close. I'll be glad to fire this up and have a closer look, but I'm wondering if this is really an amateur radio question. How are you using GnuRadio? $\endgroup$
    – David Hoelzer
    Oct 4 at 12:15
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    $\begingroup$ Thank you. Yes, but the blur around each symbol is the same as that of before the channel! The polyphase synch is doing nothing here but reducing the amplitude of the symbols dramatically. I am using GNURadio version 3.8.2 on windows 10. $\endgroup$
    – A.Aalipour
    Oct 4 at 13:58
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    $\begingroup$ My question is that while I have copied each and every parameter in my flowgraph from those of the tutorial, why am I getting different results. This is really on my nerves. $\endgroup$
    – A.Aalipour
    Oct 4 at 14:02
  • $\begingroup$ "I have attached my flowgraph and the flowgraph of the tutorial plus my result and the tutorial's result respectively." It might help if you edited your question and labeled each one of these images. $\endgroup$
    – Mike Waters
    Oct 4 at 15:25
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    $\begingroup$ @MikeWaters I wrote, at the top of each picture, what it shows. Thank you. $\endgroup$
    – A.Aalipour
    Oct 4 at 15:55

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