On Tue, Jul 30, 2013 at 10:35 PM, Bruno Cardoso <bpcard...@gmail.com> wrote: > Hi Tom, > > I tried to follow your tips but the FM transmitter is not working yet. Here > is the file: WBFM_transmitter_Bruno2.grc > <http://gnuradio.4.n7.nabble.com/file/n42845/WBFM_transmitter_Bruno2.grc> > > I'm matching the sample rates all the way through my flowgraph. > > I'm also using the USRP1 through the ¨UHD: USRP Sink¨ block with a 250k > sample rate, which is a rate that's supported both by N2XX family and > USRP1/B100 family. > > There is something missing yet. > > Thanks for your help. > > Bruno
Bruno, 1. You don't need a throttle block. A throttle is only necessary when running without any hardware. You have both an audio sink (running at 44.1 kHz) and a USRP sink (running at 250 kHz). These are your rate-limiting blocks and the throttle is just getting in the way. 2. You are massively overloading the signal into the USRP sink. That signal level should be +/- 1 at the very most. But you'll want to back off from that for linearity reasons. Instead of setting the gain of the LPF to 40, create a slider for that that goes from 0 - 1 with 100 steps. Default it to 0.5. The signal looked very clean that way. -- Tom Visit us at GRCon13 Oct. 1 - 4 http://www.trondeau.com/grcon13 _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
