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

[Robert Fitzsimons]

Hi Thomas

You email never made it into my mailbox, maybe it got caught as spam.

> 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?

The spike doesn't look like it's from a GSM base station.  What country
are you in?  Have you tried tuning the usrp_fft.py to the 921.6 MHz
signal?

> 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.

Maybe your USRP is picking up some interference, can you try it with a
different computer and with a different power supply?

Robert