Hi all, I updated my multi-channel, narrow-band FM recorder, tested with B200 and N210, and put it on GitHub. https://github.com/madengr/nbfm_rec Features: Parallel demodulation and recording of NBFM radio channels Up to N channels limited by CPU and bandwidth of SDR (tested to 25 MHz) Squelched audio blocked from recording Mixed audio for real-time monitoring Channels recorded to individual *.wav files Tested with: GNU Radio 3.7 Ettus N210 + WBX Ettus B200 Lou KD4HSO -- View this message in context: http://gnuradio.4.n7.nabble.com/Updated-NBFM-Recor... Sent from the GnuRadio mailing list archive at Nabble.com.
on 2014-06-15 02:25
on 2014-06-15 17:12
On Sat, Jun 14, 2014 at 8:23 PM, madengr <email@example.com> wrote: > Up to N channels limited by CPU and bandwidth of SDR (tested to 25 MHz) > Lou > KD4HSO > Nice work. I recommend seeing if you can replace the bank for xlating_fir_filters with a pfb_channelizer_ccf block. This should be more computationally efficient than all of the xlating filters, so I'd really like to see if that's true for you app. Tom
on 2014-06-15 18:29
I actually started with that, but the US 2 meter "suggested" channels are either 15 kHz or 20 kHz spacing depending on location. It's interesting to dump all the 2 meter repeater traffic in my city to disk for several days. Even the busy ones are only active about 2 hours/day. Unfortunately the 800 MHz public saftey band is so wide it's difficult to capture many channels, and they are P25 anyway. I patched in the DSD P25 decoder, but it can only handle two channels simultaneously. The public safety channel spacing may work well with the pfb_channelizer. Thanks, Lou KD4SHO Tom Rondeau-2 wrote > _______________________________________________ > Discuss-gnuradio mailing list > Discuss-gnuradio@ > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio -- View this message in context: http://gnuradio.4.n7.nabble.com/Updated-NBFM-Recor... Sent from the GnuRadio mailing list archive at Nabble.com.
on 2014-06-17 18:12
On Sun, Jun 15, 2014 at 12:28 PM, madengr <firstname.lastname@example.org> wrote: > Thanks, > Lou > KD4SHO > Gotcha. That makes sense. Thanks for the explanation. There are ways to handle this situation of non-equal bandwidths, but I'd wonder if it's more complicated for this project than it's worth (using the concept of the reconstruction filters). Could be a good testing ground, though, to build a system that channelizes the entire band, does some signal detection for those channels that are active, figures out their channel bandwidth, and pulls them out or reconstructs them as necessary. It's a pretty advanced use of the PFB channelizers, though, so it's not a trivial experiment to just run. Nice work! Tom