hi Eric, The daughterboard I use is RFX2400 so I set -f 2.45G ( btw my gnuradios have been properly set up since benchmark_tx and receive work fine for gmsk) . I have tried the below stated experiment using two antenna types to see if it is due to the antennas but it is consistent across antennas. 2400-2480 MHz ISM Band PCB Quad Patch, and
2400-2480 MHz ISM Band Vertical Antenna. Also for the above configuration can u kindly also let me know is my observation that 7KHz is the frequency offset due to the oscillators is true? Thanks in advance for ur reply Shyam Eric Blossom wrote: > On Mon, Dec 11, 2006 at 08:30:25PM -0800, Shyamnath wrote: > >> hi, >> I am new to gnuradio architecture and am trying to learn about it. I was >> using the usrp_siggen,py sample code provided with different interpolation >> rates (4, 8,12,16,64) since it has to be a multiple of 4. the observations >> are as follows (which cannot explain) >> >> 1) For interpolation rates set to 4,8,12, at the sender, what I observe on >> the receiver (directly connecting the usrp_source to a file_sink), is just >> noise. >> >> 2) For a interpolation rate set to 64, I almost get the required sinuosoidal >> at the required frequence(100khz), with the difference that the frequency of >> the signal at the receiver for nearly 200 samples at the beginning is >> nearly 7KHZs. To understand this better, I just send a constant signal on >> the sender (using usrp_siggen.py) and received a sinousoidal at the receiver >> with a frequency of 7Khz (which I presume is because of the frequency >> offset). Although I think the above two observations are related I could not >> explain them. >> >> 3) Another interesting case is when the interpolation rate is set to 16. the >> output at the reciver is a signal which has a sinousoidal with the required >> frequency(100khz) spaced with sinousoidals with a frequency of 7khzs. This >> observation is something I cannot understand. >> >> Kindly help me out with this. >> >> Thanks >> Shyam >> > > You didn't mention which daughterboard you are using, but assuming > it's a Basic Tx, be sure to set the -f <freq> option to something like > 10M. Neither the Basic Tx nor Basic Rx will pass signals under about 100kHz. > > Eric > _______________________________________________ Discuss-gnuradio mailing list [email protected] http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
