Hi

I am quite fresh on GNU Radio so please exscuse me if ask stupid

questions.

I simlpy want to view the fft of two sines.

Code:

"

self.src0 = gr.sig_source_f (sampling_freq, gr.GR_SIN_WAVE, 350, ampl)

self.src1 = gr.sig_source_f (sampling_freq, gr.GR_SIN_WAVE, 440, ampl)

self.src = gr.add_ff ()

self.connect(self.src0, (self.src, 0))

self.connect(self.src1, (self.src, 1))

self.scope = fftsink.fft_sink_f (self, panel, 512,

sampling_freq, fft_rate = 1)

self.connect (self.src, self.scope)

vbox.Add (self.scope.win, 1, wx.EXPAND)

"

when the window opens there seems to be a sensible spectrum for a very

short period of time, then it flats out and doesnt make much sense.

I have tried changing the fft_rate, sampling_freq and various other

parameters, but the same problem occurs. I have also tried using

fftsink.make_fft_sink_f, but also then a similar problem occurs. After

a very short time the blue line drawing the spectrum disappears.

–

Erlend Barstad Strand