Turn up the transmit gain on the USRP sink. Start with ~40dB and transmit amplitude 0.3.
Nick On Tue, Jun 18, 2019 at 9:40 AM Simona Sibio <[email protected]> wrote: > Thank you for the assistance. > I tried to change the amplitude but the amplitude and frequency are not > accurate in the oscilloscope yet. > If I lower the amplitude, the S/N is lowered then it is worst. > > Best Regards, > > Simona > > > Il giorno mar 18 giu 2019 alle ore 18:33 Nick Foster <[email protected]> > ha scritto: > >> Waveform source amplitude is too high. Turn it down to <0.4. >> >> On Tue, Jun 18, 2019 at 9:31 AM Simona Sibio via USRP-users < >> [email protected]> wrote: >> >>> Hi Michael, >>> >>> thank you for your interest. >>> >>> I have two N200 and each one have two daughterboard UBX-40; the >>> transmitters are connected by coaxial cable to an oscilloscope >>> (Rhode&Schwarz RTO2064) to check the waveform. >>> The version of UHD is 3.13.0. >>> >>> I tried to send a constant signal using the flowgraph (Screenshot from >>> 2019-06-18 14-56-57) in attachment on GNU radio Companion 3.7.13.4, and on >>> the oscilloscope I saw this "IMG_6586". >>> Also, I tried to generate a constant signal in Simulink model (16-42-17 >>> & 16-14-04) on Matlab R2019a but, on the oscilloscope, I saw this >>> "IMG_6584". >>> >>> I tried to send a sine signal with the Simulink model in attachment >>> (16-46-10) and, on the oscilloscope, I saw this "IMG_6583". >>> Also I tried to generate the sine signal with GNU radio (17-08-58) and I >>> saw this "IMG_6588". >>> >>> It is possible to see how the amplitude and frequency change in every >>> case, I need to obtain an accurate signal because I have to measure the >>> amplitude and phase in a particular point in the circuit. >>> And in the previous email, I added that the problem increases when I >>> lower the carrier frequency. All these measures were taken with a carrier >>> frequency at 3 GHz, but if I change the fc at 1 GHz the shape is worst, >>> e.g. IMG_6589. >>> >>> Thank you in advance. >>> >>> Best Regards, >>> >>> Simona >>> >>> >>> Il giorno mar 18 giu 2019 alle ore 15:34 Michael Dickens < >>> [email protected]> ha scritto: >>> >>>> Hi Simona - Can you please educate us as to a few items? >>>> >>>> * your setup: you have an N200 + some daughterboard (which one) + some >>>> spectrum analyzer (which one), connected ?somehow? -> are you doing actual >>>> wireless Tx -> Rx, or do you have a cable hooked up between the N200 & >>>> spectrum analyzer? >>>> >>>> * what waveform you're trying to generate, and what is the actual >>>> flowgraph you're using for GNU Radio? how are you generating the waveform >>>> in MATLAB? >>>> >>>> * which version of GNU Radio and UHD are you trying to use? >>>> >>>> * which version of MATLAB and it's UHD are you trying to use? >>>> >>>> The above might help someone to diagnose your issue ... without it, we >>>> can make some guesses but not much in the way of specifics. >>>> >>>> Please remember to "reply all", so that others can see your response >>>> and be able to chime in to provide help. - MLD >>>> >>>> On Tue, Jun 18, 2019, at 8:42 AM, Simona Sibio via USRP-users wrote: >>>> >>>> Dear Sir/Madam, >>>> >>>> I am Simona Sibio, a student in Heriot Watt University. >>>> I am working with USRPs both on Matlab and on Gnuradio, and with both >>>> softwares I have the same problem: the shape (generated by >>>> N200+daughterboard 10 MHz to 6 GHz) is not accurate, in attacched some >>>> photos. >>>> At 1 GHz, the shape is worst than when the carrier frequency is 3GHz. >>>> It is not possible to measure the amplitude and frequency because, also >>>> at 3 GHz, it is not stable. >>>> Could you help me? >>>> >>>> Thank you in advance. >>>> >>>> Best Regards, >>>> >>>> Simona >>>> >>>> >>>> _______________________________________________ >>> USRP-users mailing list >>> [email protected] >>> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com >>> >>
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