Also, for comparison purposes, here is my 2000 bit/s modem running through a Yaesu FT60 handheld radio: https://www.youtube.com/watch?v=bsmGYWxjfjU The filter in Gqrx is adjusted for wide deviation (5 kHz) but the signal is only really about 3 kHz wide.
Please note how the signal is 15-16 dB smack on above the noise floor. If I were to run your modem, it would probably decode even where my SDR falls over. This is probably because the RTL-SDR has a much lower noise figure than my USRP, although I will trade that any day for the 12 bit ADC. 73, Adrian On 3/16/16, Adrian Musceac <kanto...@gmail.com> wrote: > Hi David, > > Is it possible to get our hands on the Gnuradio code? I've been trying > to optimize modems running at 1200 bits/second and the best I could do > was 100% copy at 8 dB above analog FM for DBPSK and 12 dB above for > GMSK. Your modem seems to be 16-20 dB better than that! If I could see > the Gnuradio graph maybe I could figure out what I'm doing wrong. > > Thanks, > Adrian > > On 3/16/16, Steve <coupaydevi...@gmail.com> wrote: >> Ha, I wish it was through a radio! >> >> I'm trying to think what I have laying around here that might make a good >> transmitter for it. >> >> On Wed, Mar 16, 2016 at 4:02 AM, glen english <g...@cortexrf.com.au> >> wrote: >> >>> ah. good stuff. nice progress. >>> >>> >>> On 16/03/2016 7:50 PM, Steve wrote: >>> >>> Just using the script: >>> >>> freedv_tx 2400A ve9qrp_10s.raw modem.raw >>> >>> Which produces a RAW audio file sampled at 48 kHz and importing that >>> into >>> audacity. >>> >>> On Wed, Mar 16, 2016 at 3:46 AM, glen english <g...@cortexrf.com.au> >>> wrote: >>> >>>> Hi Steve >>>> >>>> Nice >>>> >>>> is that through a PA- if so, linear or linear in say 3dB compression? >>>> >>>> >>>> On 16/03/2016 7:42 PM, Steve wrote: >>>> >>>> Thought I'd upload a spectrum snapshot. You can't really see the >>>> carriers >>>> until you drop the number of samples to about 256, but this shows how >>>> wide >>>> it is. >>>> >>>> I noticed that the freedv_tx was outputting +/- 1.0 signals and a >>>> couple >>>> of clips going on. Maybe need to knock it down to +/- .5 like the old >>>> FDM >>>> modes. >>>> >>>> FYI >>>> >>>> Steve >>>> >>>> >>>> >>>> ------------------------------------------------------------------------------ >>>> Transform Data into Opportunity. >>>> Accelerate data analysis in your applications with >>>> Intel Data Analytics Acceleration Library. >>>> Click to learn >>>> more.http://pubads.g.doubleclick.net/gampad/clk?id=278785231&iu=/4140 >>>> >>>> >>>> >>>> _______________________________________________ >>>> Freetel-codec2 mailing >>>> listFreetel-codec2@lists.sourceforge.nethttps://lists.sourceforge.net/lists/listinfo/freetel-codec2 >>>> >>>> >>>> >>>> >>>> ------------------------------------------------------------------------------ >>>> Transform Data into Opportunity. >>>> Accelerate data analysis in your applications with >>>> Intel Data Analytics Acceleration Library. >>>> Click to learn more. >>>> http://pubads.g.doubleclick.net/gampad/clk?id=278785231&iu=/4140 >>>> _______________________________________________ >>>> Freetel-codec2 mailing list >>>> Freetel-codec2@lists.sourceforge.net >>>> https://lists.sourceforge.net/lists/listinfo/freetel-codec2 >>>> >>>> >>> >>> >>> ------------------------------------------------------------------------------ >>> Transform Data into Opportunity. >>> Accelerate data analysis in your applications with >>> Intel Data Analytics Acceleration Library. >>> Click to learn >>> more.http://pubads.g.doubleclick.net/gampad/clk?id=278785231&iu=/4140 >>> >>> >>> >>> _______________________________________________ >>> Freetel-codec2 mailing >>> listFreetel-codec2@lists.sourceforge.nethttps://lists.sourceforge.net/lists/listinfo/freetel-codec2 >>> >>> >>> >>> >>> ------------------------------------------------------------------------------ >>> Transform Data into Opportunity. >>> Accelerate data analysis in your applications with >>> Intel Data Analytics Acceleration Library. >>> Click to learn more. >>> http://pubads.g.doubleclick.net/gampad/clk?id=278785231&iu=/4140 >>> _______________________________________________ >>> Freetel-codec2 mailing list >>> Freetel-codec2@lists.sourceforge.net >>> https://lists.sourceforge.net/lists/listinfo/freetel-codec2 >>> >>> >> > ------------------------------------------------------------------------------ Transform Data into Opportunity. Accelerate data analysis in your applications with Intel Data Analytics Acceleration Library. Click to learn more. http://pubads.g.doubleclick.net/gampad/clk?id=278785231&iu=/4140 _______________________________________________ Freetel-codec2 mailing list Freetel-codec2@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freetel-codec2
