You're right in that I need more than GR. The audio of a pocsag broadcast is very distinct. It's also clearly visible on a waterfall. The problem is that I have too much static in there. Way too much noise. I can't get the gqrx module (where I tune and see the waterfall) set right so the reception is fine. I think the Wikipedia article had a soundbite of a pocsag encoding. If you listen to it you'll notice it's very distinct.i just have 90% noise and I can hear the broadcast in the very background. On Jun 1, 2015 5:25 PM, "Marcus Müller" <marcus.muel...@ettus.com> wrote:
> Hi again, > > Ok, I'm not familiar with the standard POCSAG, but if you got a signal > that you still need to decode with something else, how do you know you > don't get clear reception? What is your measure for "good reception"? > > As far as I read the English wikipedia, POCSAC uses a 4.5kHz binary FSK, > so can you see the two alternating frequency e.g. in a waterfall plot of > your RX signal? > Ideally, you'd directly be able to see the 512, 1200 or 2400 baud. > > To explain a bit more: > GNU Radio is not a decoder for any specific standard; think of it as the > LEGO of SDR. You can build amazing things with it, in fact, there's a lot > of examples that come with GNU Radio, and useful and complex standard > implementations (FM receiver, DTV transmission!), but if you need to have > something that's not there, you might need to a) use someone else's > Out-Of-Tree module or b) implement that functionality yourself. So I must > admit that I don't have the slightest idea which settings you're referring > to :) Maybe you're interested in a quick&dirty introduction to GNU Radio > [1]. > > In the case of POCSAG, I remember gr-pocsag being a thing (search for > pocsag on cgran.org); I can't remember the original author, and I presume > it's pretty much dead -- but I'd love to be proven wrong. > Also, pyboms has pocsag-mrt package, but that seems to rely on GNU Radio > 3.6.2, if the Readme is correct, so that's pretty dead, too. > > > Best regards, > Marcus > > [1] https://github.com/iZsh/pocsag-mrt > On 06/01/2015 10:18 PM, Stephan van Beerschoten wrote: > > It is. I plan on running the output through a utility that can decode it. > However, before that can happen I need to find out how I can get a clear > reception of the broadcast. > On Jun 1, 2015 4:15 PM, "Marcus Müller" <marcus.muel...@ettus.com> wrote: > >> I'm a bit confused, I though POCSAG was a text pager system? >> >> On 06/01/2015 10:04 PM, Stephan van Beerschoten wrote: >> > Hi Guys, >> > >> > I compiled gnuradio for my ODROID ARM platform, and I can listen to >> > regular wideband radio just fine. I am using a Generic RTL2832U with >> > Rafael Micro R820T tuner. >> > >> > The radio quality is fine, and even when using the rtl_fm tool >> > directly (off topic for this list), it works. >> > >> > However, when I switch channels to 155.520 to capture POCSAG >> > broadcasts I cannot get a clear reception. I can't find any decent >> > documentation on GR to tell me what each setting is, and I am not a >> > HAM radio operator so some of the basics evade me. >> > >> > I can't get decent POCSAG reception with the rtl_fm tool either, so >> > this is probably a setting thing somewhere. >> > >> > Why can't I get clear reception? Any pointers? >> > >> > Stephan >> > >> > _______________________________________________ >> > 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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