Re: [Discuss-gnuradio] Frequency Offset

[Josh Blum]

Eric Blossom wrote:
> On Wed, Sep 02, 2009 at 09:14:52AM +0800, fangming he wrote:
> > Hi, all
> >
> > I set the frequency of USRP to be 910MHz, but I noticed that
> > the central frequency of the signal is 914MHz. Why there is 4Mhz frequency 
> > offset.
> > I also found that there is also a signal comeing up in 896Mhz. The amplitude of
> > the signal in 914MHz is 20dB higher than the amplitude of the signal in 896Mhz.
>
> Did you call u.tune(..., 910e6, ...) to set the frequency?

Thats news to me! The grc generated code here just calls set lo.

The temporary solution would be to create a gui control for the 
frequency and to change the frequency at runtime. This will cause 
u.tune(...) to be called.

-Josh