Wednesday 19 July, 2006, 15:56 - Amateur RadioTuning around the amateur bands during recent sporadic-E openings, I regularly stumbled across voice traffic in a slavic language on 29612.0 kHz USB (upper side band). The format of the traffic was clearly not amateur, and given this, and the fact that it is right in the middle of the relatively active 10 metre FM section of the band but was not FM made me wonder what it might be. Enjoying a mystery I managed to make a short recording of some of the traffic [304kB windows media file] at around 14:15 GMT on 17 July 2006.
Not speaking whatever language it is I posted a message on the Utility DXers Forum message board. What a great set of individuals! Within half a day I'd received a response that the most likely culprit of the signal I heard was the Russian Air Defence (the Protivovozdushnoy Oborony or PVO) who track all aircraft through their airspace giving a continuous read-out (quite literally!) of the sector quadrant and the corresponding coordinates of each aircraft.
It turns out that the PVO also run a morse code based variant of this service which has been given the designator 'M21' by Enigma 2000, the group who monitor 'number stations' such as the Lincolshire Poacher. Looking back through their records shows that a station called 'V21' was active on 30220 kHz in the past. I don't know whether V21 is the voice equivalent of M21 or not, but if it is, presumably they have now moved to 29612 kHz for the time being in a random attempt not to be intercepted. Bit of a silly exercise really given where they've plopped themselves. It makes you wonder whether military radio operators have any idea what goes on around them. To change frequency in order to maintain some kind of covertness is vaguely clever, but to have changed into the middle of a fairly active section of an amateur band is just a bit daft.
I also dropped a note to the UK representative of the IARU Region 1 Monitoring Service, who record and monitor all 'intruders' into the amateur bands. Don't know whether this will make their offender list or not, but it's nice to be on the discovery end of something rather than just following the lead of others!