Re: [Discuss-gnuradio] Testing flex2400

[Eric Blossom]

On Thu, Nov 09, 2006 at 09:56:37PM -0800, Dan Halperin wrote:
> Hi,
> 
> A second question is: With the basic boards as described earlier, I 
> run [usrp_fft.py -f 1M -d 32] and then run the signal generator 
> [usrp_siggen.py -f 1M -i 32]. The spectrum I see has a small peak 
> (but, at 0db) centered at 0 and then a large peak >50db near +0.1MHz. 
> What is going on here?

Try usrp_siggen.py --help

You specified the RF center frequency, but took the default for the
signal generated at baseband (the -w <freq>).  By default it's 100kHz,
thus the peak near +0.1 MHz.

Admittedly this is a somewhat unusual interface for somebody who may
just want a sine wave out.  On the other hand, this code originally
existed to allow us to confirm that the system was working the way we
expected it behind the scenes.

I just checked in an update to usrp_siggen.py that now has the --help
list the default values for additional properties.

Eric