Per- > I also have a xcvr2450 that won't lock sometimes. This is at 2.4GHz. > > Also an issue about IQ imbalance: > > I am measuring IQ imbalance. The values are generally quite good. > However, one thing I don't understand is that the mirror frequency > doesn't turn up on exactely "-f" but a few Hertz off. I don't get this. > Are we sure that the down-conversion on the FPGA is completely turned off ?
What size FFT are you using to see the mirror freq? What is the bandwidth of the data into the FFT? From this you could calculate Hz/bin and see if that helps to explain the offset. -Jeff > Ian Holland wrote: >> Hi Matt >> >> >>> Yes, -9 dBm is safe. >>> >> >> Glad to know it was all safe re input levels. >> >> >>> I have not seen the problem locking without trying a lower frequency. >>> What if you try 5 GHz twice in a row? >>> >> >> The problem with the not locking to 5G is very intermittent. A few times >> when it did occur, I tried your suggestion of trying 5G a second time: >> >> 2 out of 3 times, it locked the second time. The other time, it did not, >> but then trying 2.35G followed by 5G did then work. >> >> Regarding the other intermittent issue that appeared as IQ imbalance, I >> have swapped the USRP2/XCVR2450 pair used for transmit with the receive >> one, and haven't observed the issue since. It may still occasionally >> occur for the first pair, but this is a workaround for me. I am still >> confused as to why it occurred to begin with. >> >> Best Regards >> >> Ian. _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
