[Discuss-gnuradio] Audio spectrum inversion - easy & fun

[cswiger]

Gang - Here's a simple script that demonstrates spectrum inversion
using the multiply by [1,-1] method (mixing with Nyquist frequency).
Requires nothing but a sound card, and sounds just like listening
to a SSB signal on the wrong sideband.

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fron gnuradio import gr
from gnuradio import audio

def build_graph ():

        gr = gr.flow_graph ()
        sample_rate = 8000

        src = audio.source (sample_rate)
        out = audio.sink (sample_rate)

        vec1 = [1, -1]
        vsource = gr.vector_source_f (vec1, 1)
        multiply = gr.multiply_ff ()

        fg.connect (src, (multiply, 0))
        fg.connect (vsource, (multiply, 1))
        fg.connect (multiply, out)

        return fg

def main ():
        fg = build_graph()
        fg.start ()
        raw_input ('Press Enter to quit')
        fg.stop()

if __name__ == '__main__':
        main ()



Good luck

--Chuck