View source for DRM trial II in Sottens

[[Image:pylone2.jpg|right|350px]]
===Introduction===
Following the [http://www.coinchon.com/DRM_Sottens_fr.html amateur radio DRM trial on the phased out shortwave antenna in Sottens in 2004], it has been decided to make another amateur radio DRM trial but this time on the 188m MW antenna that has just been phased out on 31.12.2010.


===Transmission schedule===

The tests will happen on 13th February 2011 and 20th February 2011  with 15 minutes periods on the following times (same for both sundays):
*20h-20h15 CET (19h-19h15 UTC) TX on 7.180 MHz
*21h-21h15 CET (20h-20h15 UTC) on 3.780 MHz

We will use the narrowest band so 4.5kHz and high robustness to transmit slides.

Please send your reception reports to [mailto:sottens@hb9mm.com sottens@hb9mm.com]

[http://www.opendigitalradio.org/files/he3om_orig.mp3 Original audio loop transmitted]

===Setup===
[[Image:Setup1.jpg|200px]] 
[[Image:Setup2.jpg|200px]]
[[Image:First stage.jpg|200px]]
[[Image:Final stage.jpg|200px]]
[[Image:Power out.jpg|200px]]
[[Image:Transmission laptop.jpg|200px]]
[[Image:Gnuradio.jpg|200px]]
[[Image:Reception monitor.jpg|200px]]
[[Image:Dream receiver.jpg|200px]]
[[Image:Commercial DRM receiver.jpg|200px]]


*[http://www.drm-sender.de Spark software] (free full license gracefully offered by Michael Feilen)
*[[USRP]] with LFTX daughterboard
*[http://www.minicircuits.com Mini-circuits]  Gali74+ amplifier
*Preamplifier recycled from the bin from Asulab by Yves (HB9DTX)
*Amateur radio linear amplifier.


Mode used: 
*4.5kHz, Mode B, MSC 16QAM, EEP code rate 0.5, AAC audio at 4.8kbit/s
*4.5kHz, Mode B, MSC 64QAM, EEP code rate 0.5, AAC Audio, MOT Slideshow at 2.56 kbits/s

===Report===

To follow...

See also: http://www.drmrx.org/forum/showthread.php?t=2307

===Credits===

Credits to Yves HB9DTX, Stan from Maxxima, the [http://www.hb9mm.com HB9MM amateur radio club] and Swisscom for lending them for a month such a great antenna. At least Sottens will have gone digital before dying. It shows also that DRM transmission can be done with limited equipment (apart from antenna), an interesting thing for local or community radio.
Mathias HB9UFQ

===See also===
*HB9MM special operation in Sottens: http://www.hb9mm.com/sottens
*[http://www.drmrx.org/receiver_mods.html Receiver modification] to catch DRM transmissions using [http://drm.sourceforge.net Dream] or [http://nt.eit.uni-kl.de/static/diorama/index.html Diorama] or [http://www.dsp4swls.de/sodira/sodiraeng.html SODIRA] or any other commercial software radio receiver.