Re: [Discuss-gnuradio] Could this output be a problem with my Hardware or the python codes?

[Eric Blossom]

On Mon, Nov 03, 2008 at 02:55:53PM +0100, Bruhtesfa Ebrahim wrote:
> Hey all,
> 
>  May be my question could be out of topic as it is can be a hardware
> problem, so excuses.
> 
>  The Thing is....I am using USRP with XCVR2450 Tranciever to develop a
> doppler radar(in duplex mode).
>  So, I was checking out my devices.
> 
> When I use USRP_fft.py just to see the environment signals without enabling
> my USRP_siggen.py, I see a certain signal level.
> Then when i start to transmit and recieve in duplex mode running  these
> two python codes simultaneously in different shell scripts; the signal(FFT)
> level
> I am recieving decreases too much. Normally, I should get a more strong
> recieved signal rather since I am transmitting.
> 
> So, does anyone has experience in this stuff ? If so, what do you think is
> the problem? could it be a problem with my Trancievers.
> 
> Thank you!
> Bruhtesfa

You need to run the Tx and Rx in the same graph.  The XCVR2450 shared
resources (e.g., LO) between the Tx and Rx side, and if you run the Tx
and Rx in different processes they don't know about each other and
clobber each other.

Eric