I’ve suggested this to you before. Start with a pure some way at your target frequency—what does your spectrum analyzer say about power. Now Modulate it to produce a bandwidth of 1khz—what does your spectrum analyzer say about the power in each bin? Now what about with 10khz of modulation bandwidth, what of 100khz?
Sent from my iPhone > On Mar 16, 2021, at 1:52 PM, AKINYELE ITAMAKINDE <[email protected]> > wrote: > > > connected the antenna to the good channel Rx/TxThanks, I have been checking > out your suggestions. > What i meant by "negative Tx power" is that the Tx power is giving negative > value (-30dbm) > 1. I have upgraded to GNURadio >=3.8 but it is giving this warning message > after trying to import QT GUI sink > Block paths: > /home/elect/gnuradio/share/gnuradio/grc/blocks > Warning: restarting the docstring loader (crashed while loading > 'qtgui_bercurve_sink') > Warning: restarting the docstring loader (crashed while loading > 'qtgui_const_sink_x') > Warning: restarting the docstring loader (crashed while loading > 'qtgui_edit_box_msg') > Warning: restarting the docstring loader (crashed while loading > 'qtgui_freq_sink_x') > Warning: restarting the docstring loader (crashed while loading > 'qtgui_histogram_sink_x') > Warning: docstring loader crashed too often > Pls, can you help to solve this problem? > 2. For QT GUI Sink bandwidth, I will do that when the above problem is solved. > 3. Yes I measured the signal power using a spectrum analyzer. > 4. Did you check your signal amplitude at USRP bloc input? i don't know how > to do this but check it when i solve the problem > 5. yes, i connected the antenna to the good channel Rx/Tx. > > >> On Fri, Mar 12, 2021 at 3:30 PM Christophe Seguinot >> <[email protected]> wrote: >> Hi >> >> - What does "negative Tx power" means ? >> >> A few suggestions: >> >> move to GNURadio >=3.8 (most of us uses GR 3.8 or 3.9 so it's difficult to >> help for outdated GR 3.7) >> QT GUI Sink : Bandwith should be equal to sample rate of the block incoming >> signal, i.e. samp_rate at the RRC Filter output (the FFT Sink does not work >> as a real spectrum analyzer) >> Did you measure the signal power using a spectrum analyzer ? When do so, the >> receiving antennna being close to the emitter antenna, you should get the >> -20 to -30 dB as compared to the emitted power (frequency close to 1GHz and >> 6dBi antennas (Indoor panel), this is depending on frequency and antenna >> gain). If your emitted power is +20 dBm, you should measure something in the >> range 0 dBm to -20 dBm. If not, there is something wrong in the transmission >> chain. >> Did you check your signal amplitude at USRP bloc input (The maximum value >> should be 1 Volt to get maximum RF power which also depend on USRP settings >> Did you connected the antenna to the good channel Rx/Tx ? >> Sincerely, Christophe >> >> On 12/03/2021 15:08, AKINYELE ITAMAKINDE wrote: >>> Good day to all community members. >>> Please, I need you to help correct this flow graph configuration. The Tx >>> power radiating is too minimal. I have adjusted and also added some other >>> blocks to boost the signal but all to no avail. The flow graph is been used >>> for propagation channel measurement. I will like someone to take me through >>> or send video and other link on how to solve this problem. The flow graph >>> is attached. >>> Thank you. >>> Akinyele.
