On Wed, Jan 28, 2009 at 04:09:54PM -0800, Yong J. Chang wrote: > > Hi all, > > Now I'm confusing intermediate frequency of RFX2400. I cannot find any > references about that. > As I know so far, RFX2400 converts carrier frequency(we selected it on > python script) band freq to 10Mhz intermediate freq. This 10Mhz signal is > passed to FPGA. Therefore, DDC frequency is fixed on 10Mhz. Is it right? > > Any help is appreciated. > > Y.C
The RFX boards are quadrature direct conversion. We feed them complex basebase within a few MHz of DC. The DDC/DUC are used for fine tuning since the VCO on the daughterboards have a non-zero step size. You can see what's happening by examining the result from u.tune(). I highly recommend the USRP FAQ: http://gnuradio.org/trac/wiki/UsrpFAQ http://gnuradio.org/trac/attachment/wiki/UsrpFAQ/USRP_Documentation.pdf?format=raw See also the nice diagrams on this page: http://gnuradio.org/trac/wiki/UsrpRfxDiagrams Eric _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
