Show 297: data radio, pt.4 by Johannes Raggam

johannes raggam for radio helsinki

data radio, pt.4 is an experiment to transmit encoded digital data over a civil FM radio network. the sounds received can be decoded using special, freely available software or – if available – hardware devices. with the process of encoding digital data, transmitting it over terrestrial radio networks and decoding at endpoints an simple alternative to the network called internet is created.

in fact, such guerrilla networks were successfully created by different parties in crisis/war situations. for example, the serbian radio b92 used CB radio transmission for exchanging information with isolated parts of former yugoslavia.

listeners of radia.fm are encouraged to decode or record (for later decoding) the  data or just listen to the stream of fax noise.

for decoding, follow these instructions:

* install the software to decode the encoded data and configure it according to the settings explained below.

* connect the line-out of your stereo with the line-in of your computer.
alternatively, but trickier, redirect an internet audio stream to the decoding software.

“data radio” – in german “datenradio” – started as a project for the “netart community convention 2009″ in graz by johannes raggam in collaboration with christian pointner. for more information (in german) see [1][2].

Settings for HamFax on linux
—————————-
carrier     800Hz
deviation   400Hz
modulation  FM
filter      middle
lpm         200
color mode

Software for decoding
———————
linux
””’
HamFax: http://hamfax.sourceforge.net/

windows (untested)
”””””””””
MultiPSK: http://f6cte.free.fr/index_anglais.htm
MultiFAX: http://www.qsl.net/n2zde/index.html

OSX (untested)
”””””””
MultiMode: http://www.blackcatsystems.com/software/multimode.html

References
[1] https://wiki.mur.at/ncc09/DatenRadio
[2] http://ncc09.mur.at/doku/media.html