[Discuss-gnuradio] Spurious Spikes Seen with usrp_fft.py

[Thomas]

Hi everyone,

I am using a USRP with only a DBSRX daughterboard installed. The image at the following link is a screen capture I took.

http://img340.imageshack.us/img340/3570/screenshotusrpfftfy8.jpg

Does anyone know why the spike at 921.6 MHz is there? I have observed many of these spikes in other parts of the spectrum using usrp_fft.py. I looked for them using a real spectrum analyzer connected to an antenna and did not observe them.

I used the same parameters in usrp_fft.py that were used in the first image at the following link.

http://273k.net/gsm/find-a-gsm-base-station-manually-using-a-usrp/

This spike does not exist in their plot.

I appreciate your responses.

Thanks,

Thomas

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