On 01/19/2017 01:28 AM, Marc Pàmies Massip wrote: > Oh, really? I was using a HackRF-One and sampling at 10MHz.
I was betting on a RTL dongle. And I'm guessing SDR# is running on Windows. You should also try a WBFM channel - between 88-108 MHz. There could be Windows USB driver issues - or the version of the HackRF One libraries and utilities doesn't match the firmware. Try hackrf_transfer -r NUL -s 8000000 The two columns should be equal in magnitude - otherwise the USB/computer are to slow for 8 MHz sampling - which is minimum requirement. Don't use a USB hub. And post hackrf_info on the above information on the mailing list [email protected] - someone on the list may have seen the problem before. I know next to nothing about Windows. > > Now I've tried with different sample rates (8MHz, 10MHz, 12.5MHz and > 16MHz) and the peaks are always there. Maybe it's true that they appear > more often for higher sample rates, but I am not able to make them > disappear. > > Marc. >> >> On 19/01/2017 9:38:34, Cinaed Simson <[email protected]> wrote: >> >> On 01/18/2017 01:31 PM, Marc Pàmies Massip wrote: >> > Hi, >> > >> > Maybe this is a stupid question for experts in SDR, but I haven't >> find a >> > clear explanation yet. I know it is normal to have a DC offset in the >> > center of the spectrum, but I am surprised by the amount of static >> peaks >> > that I see sometimes in specific bands (you can find attached some >> > images to better understand what am I talking about). It is obvious >> that >> > those are not "real" signals, in fact when I re-tune the SDR peripheral >> > they don't move according to the frequency displacement. I want to >> > understand if it is due to a software problem (the screenshots were >> > taken from SDR#) or if it has something to do with the hardware (maybe >> > those are just harmonics from some kind of square signal, i.e clock). I >> > am worried because they are extremely strong and because of this I >> could >> > have trouble detecting weaker signals nearby. >> > >> > Summarising, my questions are: >> > >> > - What causes those peaks? >> > - Is it necessary to remove them for a proper signal detection? >> > >> > Thanks in advance, >> > >> > Marc. >> >> You haven't indicated what hardware you used or the sampling rate. >> >> Try reducing the sampling rate - the sampling rate used may be unstable. >> >> > >> > >> > _______________________________________________ >> > Discuss-gnuradio mailing list >> > [email protected] >> > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio >> > >> >> >> _______________________________________________ >> Discuss-gnuradio mailing list >> [email protected] >> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio _______________________________________________ Discuss-gnuradio mailing list [email protected] https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
