After some prompting, I have put together three high-quality signal captures for your enjoyment. The captures were made using the commandline: ./usrp_rx_cfile.py -o filename.dat -d8
Signal generator is a lab-grade HP8657B, recently calibrated, with output level set at -10dBm, and with a 20dB attenuator at the USRP (-30dBm signal, theoretically). The four frequencies used were 100kHz, 500kHz, 1MHz, and 2MHz. The DDC was set to zero. Filenames are: 1MHz-sin-usrp-hp8657b-20050421.dat.bz2 2MHz-sin-usrp-hp8657b-20050421.dat.bz2 100KHz-sin-usrp-hp8657b-20050421.dat.bz2 500KHz-sin-usrp-hp8657b-20050421.dat.bz2 All are available at http://www.lamarowen.net/files/ They average 1.5-2.5MB bzip compressed; uncompressed they are roughly ten times that size. USRP serial# 179 was used to make these captures, using a BasicRX module. The results are encouraging. Previously, I had used my cheap Elenco function generator; come to find out that its output is horrible and shouldn't be used for basically anything. Probably a bad output coupling cap or something. The HP8657B is only rated to go down to 0.1MHz, but it does go up to 2060MHz, which is the range in which it gets used at PARI (we calibrate using it at 1420MHz and -122dBm). By comparing output levels one could look at frequency response to a degree. If desired, I can use our noise source as well; it's calibrated flat from about 1MHz to over 100MHz. -- Lamar Owen Director of Information Technology Pisgah Astronomical Research Institute 1 PARI Drive Rosman, NC 28772 (828)862-5554 www.pari.edu _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
