On Thu, 2011-01-20 at 12:48 +0100, Paco Quiñoy wrote: > > Hi all, > > Making some tests I have found that my system (USRP + RFX900) > transmits an important signal (it seems a tone) without any > application running, just when I plug the power source it transmits > this unwanted signal. I'm working at the GSM900 downlink frequency > band (between 935 and 960 MHz) and the signal appears close to the > upper side of this band, around 959,6 Mhz. > > My system makes an spectrum sensing for that band and it locates the > present signals, so it produces an error because it detects this > undesired signal generated by itself. Any idea of the problem? Any > solution?
Paco, This is likely to be the 15th harmonic of the USRP's 64MHz sample clock (64e6*15=960e6). It may get better after the USRP is initialized (run uhd_usrp_probe or any other application after power-up). The AD9862 tends to come up in a weird state. --n > > Thanks! > _______________________________________________ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio