It works now, although with some U's on the console, they were there before anyways. I forgot to run systctl -w net.core.rmem_max=50000000 and net.corewmem_max=1048576. As soon as I ran it the harmonics went away.
On Wed, Jan 8, 2014 at 4:26 AM, Ralph A. Schmid, dk5ras <[email protected]>wrote: > May it be just some lost packet or smth. like that? It looks very similar > when USB does not catch up when using my USRP1 and BladeRF... Missing > samples can create funny signals. > > > > Ralph. > > > > > > *From:* [email protected] [mailto: > [email protected]] *On Behalf Of *Matt > Ettus > *Sent:* Wednesday, January 08, 2014 2:25 AM > *To:* Jonathan Fox > *Cc:* GNURadio Discussion List > *Subject:* Re: [Discuss-gnuradio] [USRP-users] USRP N210 Signal Phase > Issue > > > > > > It could be the usrp digitally clipping, not the analyzer. > > > > Matt > > > > On Tue, Jan 7, 2014 at 5:17 PM, Jonathan Fox <[email protected]> > wrote: > > On Tue, Jan 7, 2014 at 7:11 PM, Marcus D. Leech <[email protected]> wrote: > > > > Try reducing the amplitude to 0.7. Another possibility is that your > computer can't keep up. If you are using one of the standard programs, are > there U's printing in the terminal? > > > > Matt > > > > Also, what RF gain are you setting? Does it exceed the maximum input > level of the spectrum analyser? > > Are you connected directly, or with an antenna? > > > > > > On Tue, Jan 7, 2014 at 3:03 PM, Jonathan Fox <[email protected]> > wrote: > > A colleague and I are sending a simple signal in GNU Radio (sine wave, 1 > MHz, amplitude of 1) to the USRP sink and have the center frequency at 500 > MHz. The N210 USRP is hooked up to an Agilent spectrum analyzer. On the > analyzer we are seeing a weird phenomena every two seconds. At first we see > the carrier frequency and two sidebands from the sine wave (see attached > normal.gif). Then after two seconds we get two bursts of multiple harmonics > (see odd.gif). > > > > The question is, why is this happening? Does the phase of the 1 KHz signal > become discontinuous before or after being sent to the USRP? > > > > Thanks, > > > > Jon Fox > > > _______________________________________________ > USRP-users mailing list > [email protected] > http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com > > > > > > _______________________________________________ > > Discuss-gnuradio mailing list > > [email protected] > > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > > > > -- > > Marcus Leech > > Principal Investigator > > Shirleys Bay Radio Astronomy Consortium > > http://www.sbrac.org > > > _______________________________________________ > Discuss-gnuradio mailing list > [email protected] > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > > > I don't recall seeing any U's but I can recheck tomorrow. The gain on the > USRP was set to -2. The USRP was connected directly with an SMA cable. The > analyzer is an Agilent E4440A, the Analyzer is rated for at least 1 Watt on > average, 100 Watt on a peak pulse (with the built-in attenuator in use). > While I am not ruling out the maximum input I thought the N210 tops out at > 0.5 Watts due to FCC regulations. > > > > Thanks > > Jon > > > _______________________________________________ > Discuss-gnuradio mailing list > [email protected] > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > >
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