Hi Marcus, Thanks. That explains it. Will try 5 MHz with our N200.
Cheers, Dan On Jun 30, 2015, at 4:56 PM, Marcus Müller wrote: > Hi Daniel, > that README refers to things of the past (when you specified a decimation > rather than the sampling rate you want), and "USRP" refered to what we > nowadays call the USRP1. > > In the version of the usrp_rx_hrpt.grc, from which the .py gets generated, > the USRP source is just configured to 4MS/s. > > The question is whether 4MS/s is really the optimum rate; I haven't studied > the HRPT signal enough to answer this. In principle, for the 100MHz devices > (N210/N200), 4MS/s is a suboptimal rate, since the decimation (25) is odd, > and I'd try with something less strange, like 5MS/s. > > Best regards, > Marcus > > On 06/30/2015 10:49 PM, Daniel Marlow wrote: >> Hello, >> >> In the gnuradio/gr-noaa/README file under usrp_rx_hrpt.py, there is a >> comment that >> reads as follows: >> >> "The present HRPT demodulator is only tested at decimation 16. The only >> other >> valid decimation rates are 24 and 32, which may work, but with more bit >> errors. No >> other decimation rates will work." >> >> My (perhaps naive) question is whether the important parameter is the >> decimation >> rate, or the sampling rate. For example, with 64 MHz USRP, a decimation of >> 16 would >> give 4 MHz sampling, whereas with a higher rate USRP, the same decimation >> would >> yield a higher sampling rate. >> >> I would appreciate it if someone could clarify this point for me. >> >> Sincerely, >> Dan Marlow >> >> >> >> >> >> _______________________________________________ >> Discuss-gnuradio mailing list >> Discuss-gnuradio@gnu.org >> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > _______________________________________________ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
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