Re: [Discuss-gnuradio] RFX 900 200mW

[Matt Ettus]

Vincenzo Pellegrini wrote:
> Hi everybody,
> just a simple question:
> does the RFX900 provide 200mW just out of the box? Do I have to take 
> care of something in particular in order to obtain them?
>
> Actually, what are the appropriate gain values that I should pass to 
> subdev.set_gain() n order to maximize correctly the output power?
>
> Sorry for bthering the list with such questions but I was unable to 
> have them answered in the RFX900 section of the wiki.. maybe I'll add 
> them myself once I'll have fully understood the issue..


That is a saturated power level.  For any linear signal you will need to 
back off a bit.  In any case, you control the output power by 
controlling the amplitude of the signal you send to the USRP.  +/-32767 
will be the max power but will result in RF clipping.  You will need to 
find the max power you can get with your particular signal and still 
maintain enough linearity.  If you need a dB or 2 more, you can bypass 
the ISM band filter with a cap of about 100pF and then cut the traces to 
the filter.

Matt