Re: [Discuss-gnuradio] trouble with gr_multiply_const_ff

2013-11-30 Thread atools_cook
Hi Marcus, Thanks for your attention. I have upload a bigger size image below. the x axis is sampling point which reflects time and the y axis is margin which reflects the power. I plot the image from the rx block of the gen2_reader project. The signal is transmitted by the tx block of gen2_reader

Re: [Discuss-gnuradio] quadrature_demod losing weak signals

2013-11-30 Thread Alexandru Csete
On Sat, Nov 30, 2013 at 2:50 AM, Kevin Reid wrote: > > This seems like a bug, but I want to check first that I'm not having > unreasonable expectations. I'm using GNU Radio 3.7.2. > > If the amplitude of the input to quadrature_demod_cf is less than about > 10^(-2.23), then the output samples ar

[Discuss-gnuradio] Detecting internal GPSDO.... not found on first connection

2013-11-30 Thread Nasi
Dear All, my device: USRP N200 System: Ubuntu 13.04 1. I always get this on first connections (the next ones are okay): $ uhd_usrp_probe linux; GNU C++ version 4.7.3; Boost_105300; UHD_003.006.000-0-g7788c692 -- Opening a USRP2/N-Series device... -- Current recv frame size: 1472 bytes -- Curren

Re: [Discuss-gnuradio] trouble with gr_multiply_const_ff

2013-11-30 Thread Tom Rondeau
On Sat, Nov 30, 2013 at 5:00 AM, atools_cook wrote: > Hi Marcus, > > Thanks for your attention. > I have upload a bigger size image below. the x axis is sampling point which > reflects time and the y axis is margin which reflects the power. > I plot the image from the rx block of the gen2_reader p

Re: [Discuss-gnuradio] quadrature_demod losing weak signals

2013-11-30 Thread Tom Rondeau
On Sat, Nov 30, 2013 at 5:09 AM, Alexandru Csete wrote: > On Sat, Nov 30, 2013 at 2:50 AM, Kevin Reid wrote: >> >> This seems like a bug, but I want to check first that I'm not having >> unreasonable expectations. I'm using GNU Radio 3.7.2. >> >> If the amplitude of the input to quadrature_demod

Re: [Discuss-gnuradio] quadrature_demod losing weak signals

2013-11-30 Thread Kevin Reid
On Nov 30, 2013, at 2:09, Alexandru Csete wrote: > On Sat, Nov 30, 2013 at 2:50 AM, Kevin Reid wrote: >> >> If the amplitude of the input to quadrature_demod_cf is less than about >> 10^(-2.23), then the output samples are zero instead of the demodulated >> signal. > > I tried your grc file a

Re: [Discuss-gnuradio] quadrature_demod losing weak signals

2013-11-30 Thread Tom Rondeau
On Sat, Nov 30, 2013 at 10:55 AM, Kevin Reid wrote: > On Nov 30, 2013, at 2:09, Alexandru Csete wrote: >> On Sat, Nov 30, 2013 at 2:50 AM, Kevin Reid wrote: >>> >>> If the amplitude of the input to quadrature_demod_cf is less than about >>> 10^(-2.23), then the output samples are zero instead o

Re: [Discuss-gnuradio] Detecting internal GPSDO.... not found on first connection

2013-11-30 Thread Ian Buckley
Whenever I hear of anyone struggling with ethernet ports going up and down unexpectedly on Ubuntu it nearly always comes down to Ubuntu's Network Manager trying to be clever. Go google information on how to disable Ubuntu from automatically managing network interfaces for the version you are usi

Re: [Discuss-gnuradio] quadrature_demod losing weak signals

2013-11-30 Thread Kevin Reid
On Nov 30, 2013, at 8:22, Tom Rondeau wrote: > On Sat, Nov 30, 2013 at 10:55 AM, Kevin Reid wrote: >>/* don't divide by zero! */ >>if((y_abs < 1.5E-5) && (x_abs < 1.5E-5)) >> return 0.0; >> >> Since the preceding multiply_conjugate should square the magnitude, this >> choice of ep