Re: [Discuss-gnuradio] fft sink x-axis units

[Eric Blossom]

On Fri, Dec 01, 2006 at 03:53:36PM -0500, Eric Hill Matlis wrote:
> I'm trying to figure out how the x-axis units work on the fftsinks.  In 
> the application "am_rcv.py", the first plot shows the incoming data 
> plotted as an fft, however the units are centered about 0 kHz.  In another 
> application, say usrp_wfm_rcv_pll.py the units are centered about the 
> actual frequency of the carrier.  Why is this?  The fft sink in both cases 
> is plotting the fft of the source, so I don't see why there should be a 
> difference.
> 
> thanks,
> 
> eric

It depends on who coded them when.  Originally there was no interface
for telling the FFT sink what RF frequency corresponded to DC in the
FFT output.  Now there is.  Feel free to submit a patch for am_rcv.py.

Eric