PSK31 with GNU Radio

Hi all,

Is anyone using GNURadio to modulate or demodulate PSK31? According to
the archives, Chuck Swiger did have this working, but the page with his
code on is gone and it isn’t archived on the wayback machine.

Thanks,

Dan

Dan MD1CLV wrote:

Hi all,

Is anyone using GNURadio to modulate or demodulate PSK31? According to
the archives, Chuck Swiger did have this working, but the page with his
code on is gone and it isn’t archived on the wayback machine.
Chuck has put up a new webpage at
http://www.swigerco.com/

The GnuRadio stuff is under
http://www.swigerco.com/gnuradio/index.html

But I can’t find the PSK31 stuff.
On his old page it was at:
http://webpages.charter.net/cswiger/psk_experiment.html

(I am very happy though that his GnuRadio vector analyzer info is back
online)

I have successfully decoded PSK31 in the past using the following.
Capture using Gnuradio to file.
convert the file to a wav file using sox
decode the file using some other opensource PSK31 program.

You can do all this in realtime if you use Pipes in stead of files.
in pseudocode it would look something like this:
mkfifo psk.raw
mkfifo psk.wav
usrp_rx_cfile.py [commandline options here] -s psk.raw
sox [commandline options here] psk.raw -o psk.wav
pskprogram psk.wav

It’s a while ago, so I don’t remember all settings I used.
I think I captured to file in the short format (not in the float format)

Of course, much better is to implement PSK31 in the gnuradio framework.

Greetings,
Martin