Android app to decode ACARS aircraft transmissions
Apparently, now even the French are taking the fun out of pirate radio – literally. A new intruder to the 43 meter band has been tentatively identified as a French OTHR (Over the Horizon Radar) signal nicknamed Nostradamus. The official name is ONERA, and it is transmitted from a site at Dreux, west of Paris.
It is about 30 to 40 kHz wide. You can see two transmissions of it here (click on the image to view full scale):
The first transmission was using about 6825 to 6845 kHz, then it switched to about 6900 to 6930 kHz, with a stronger signal. These were taken around 2120 UTC.
The signal is quite strong, and capable of obliterating a wide chunk of the 43 meter band. It will switch frequencies every few minutes, so the interference can come and go. When I observed it back on the air at 2225 UTC, the signal was a solid S8.
Thanks to The Hairy Clam for some technical information about Nostradamus.
For completeness, the strong signal you see around 6895, as well as the weaker ones around 6863 and 6938 are PSK utility transmissions. You can also see the carrier on 6860 from Radio Cairo, Egypt.
No word yet on whether Nostradamus sends out real paper QSLs, or worthless eQSLs.