Just to rule out interferers: * the stripes go away when you turn of the USRPs? * Also, the stripes aren't there, either, when you use the Lime on the same 1.011 GHz frequency, exactly?
My suspicion is that this is mostly USB3 emissions (those could be, but not necessarily are, happening through the USRP itself, or through cables, or through your host computer. If your sampling rates allow it (they do, I think you're using 500 kHz only¹), try to use a USB2-only cable or port and see whether these disappear. Also, are you using an external power supply for your USRPs? If this is actually an interferer, it might as well be some periodic behaviour of the power supply. Best regards, Marcus ¹That's a sampling rate that should work on B200 and B20xmini, but it's uncomfortably low – try with 1 MHz and host-side resampling, maybe? On Wed, 2019-12-18 at 21:28 +0300, Геннадий Казачёк via USRP-users wrote: > Hello, Sam! > No, I use two devices as transmitter and receiver and third board I > use just to observe sonogram. > Pulsations exist on both b205 and b210 devices if I use them as a > transmitter and not exist if I use as transmitter another vendor's > device - LimeSDR. > > All 3 USRP devices are industrial with metal case, and LimeSDR is > not. > > On Wed, 18 Dec 2019 at 21:26, Геннадий Казачёк < > gena.kazac...@gmail.com> wrote: > > All 3 USRP devices are industrial with metal case, and LimeSDR is > > not. > > > > On Wed, 18 Dec 2019 at 21:25, Геннадий Казачёк < > > gena.kazac...@gmail.com> wrote: > > > Hello, Sam! > > > No, I use two devices as transmitter and receiver and third board > > > I use just to observe sonogram. > > > Pulsations exist on both b205 and b210 devices if I use them as a > > > transmitter and not exist if I use as transmitter another > > > vendor's device - LimeSDR. > > > > > > On Wed, 18 Dec 2019 at 18:49, Sam Reiter <sam.rei...@ettus.com> > > > wrote: > > > > Just to be clear, you see these pulsations when transmitting > > > > with a b205mini, but not with the b210? > > > > > > > > Is the b205mini a bare board or an industrial model with a case > > > > and aluminum heat sync? > > > > > > > > Sam Reiter > > > > Ettus Research > > > > > > > > > > > > On Wed, Dec 11, 2019 at 11:48 PM Геннадий Казачёк via USRP- > > > > users <usrp-users@lists.ettus.com> wrote: > > > > > Hello! > > > > > I'm trying to build QPSK based system on GNURadio. > > > > > I'm using two USRP B205-mini boards as transmitter and > > > > > receiver, also I got B210 board that I run gqrx on to watch > > > > > what is really going on. > > > > > I noticed a strange behaviour on my tests, so I began to > > > > > investigate it and ended to a very simple graph, that is in > > > > > attachment. On a frequencies that are multiple of 10Mhz, like > > > > > 1020Mhz all works like expected and sonogram looks good. If I > > > > > tune to any other frequency, even 1Hz more or less, the > > > > > sonogram is full of pulsations and frequency of that > > > > > pulsation is depends of exact tune frequency. I attached some > > > > > screenshots of that pulsations. > > > > > On receiving part that pulsations cause many errors while > > > > > decoding. > > > > > I got another board, LimeSDR-Mini, and no such behaviour > > > > > observed while running graph on it. > > > > > I wonder what is going on, and how can I fix this problem. > > > > > Thank you. > > > > > _______________________________________________ > > > > > USRP-users mailing list > > > > > USRP-users@lists.ettus.com > > > > > http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com > > > > > > > > > -- > > > Геннадий Казачёк > > > > > > -- > > Геннадий Казачёк > > > _______________________________________________ > USRP-users mailing list > USRP-users@lists.ettus.com > http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com _______________________________________________ USRP-users mailing list USRP-users@lists.ettus.com http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
