On Tue, Dec 28, 2010 at 12:33 AM, john <sla1nte2...@gmail.com> wrote: > I have migrated to UHD and leaving the rest of the plumbing as is, I > have the attached USRP block which works but when I put the UHD block > attached, it does not without any error diagnostics. > > Sometimes the FFT scope works showing the peaks of local radio stations, > but I never get any audio. > > Anything obvious? I wonder if it is the type of the signal on UHD but > have no more than that hunch. >
John, I suspect the signal strength is too low - I mean the magnitude of the samples. One significant difference between UHD and the old driver is the numerical range of the samples. The old driver used signed integer range with samples between +/- 16000 or so, while UHD uses +/- 1.0. In practice I often see samples far below 0.1. For FM and PM it is no big deal but for AM-type radio this is just too low because the dynamic range of the soundcard is also +/- 1.0. You can use a scope sink connected to the UHD source to see the range of the samples you are getting and put in a "multiply with constant" block to increase the signal to sufficient level. Alex _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
