Forum: GNU Radio spurious spikes in FFT

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Kutik (Guest)
on 2009-06-03 20:10
(Received via mailing list)
My HW configuration: USRP1 with DBSRX, no input signal.

Using the script to plot FFT -f 1003.25M -d 8 -g 72 I see
spurious spikes at 1000 MHz and 1004 MHz (the next one is at 1008 MHz).

Where does these spurious signals come from? In the thread "Spurious
Seen with"
one of the explanations is the 64MHz clock, but then the spikes should
be in
64MHz intervals.

On the picture below with 0dBm CW input signal at 1015 MHz you can see
spurious spike is significantly strong. Reducing the gain removes the
signals - the CW and the spurious.

Does anyone have experience how to remove/suppress the spurious signals?
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