Re: [Discuss-gnuradio] Possible to change RFX400 LO tuning step size?

[Matt Ettus]

Newman, Timothy wrote:
> Is it possible to change the tuning step size on the RFX400 to
> something different than the 2 MHz step size it's on now?  I've been
> looking through db_flexrf.cc and have had no luck.

I assume you mean on the USRP1.  Change the R divider in constructor of 
the db_flexrx_400_{tx,rx}_mimo_b in db_flexrf_mimo.cc

An R divider of 16 (the current setting) make the LO step size 64 MHz/16 
= 4 MHz, but the following stage divides it by 2 again for a step size 
of 2 MHz.  If you want 1 MHz, use 32, if you want 500 kHz use 64.  You 
can also use numbers which aren't a power of 2.  In-band phase noise is 
better for bigger step sizes.

Matt