Recently, a Cuban numbers station has been heard transmitting on 8992. The choice of this frequency is peculiar since 8992 is a nighttime frequency for the USAF's Global High Frequency System (GHFS). It's unknown whether or not this frequency is used in order to try to jam the USAF communications on that freq or if it was just an oversight. At any rate, I don't believe the Cubans would care that they're causing interference whether or not they're aware of it. Cuban numbers stations aren't any stranger to this frequency, however, since they tend to pop up here every so often, probably with their usual sked change every few months. So far a sked has been appearing here every Tuesday at 0400 UTC.
Another interesting thing about this sked is that the numbers transmissions are being sent in USB instead of the Cubans' usual choice of AM. And if that weren't enough, before the transmissions have been heard Spanish language radio programming. Radio Havana? Unfortunately I don't speak Spanish, but the audio can be found at http://www.ute-monitor.org/mfa/8992_Numbers_voice.wav. Also, a "siren" sound was heard before a broadcast, presumably to warm up the transmitter before a broadcast. A recording can be heard at http://www.ute-monitor.org/mfa/8992_Numbers_siren.wav. The "siren" was heard at 0354, then at 0400 was a distorted numbers broadcast.
I have heard Radio Havana programming preceding what we've always suspected to be Cuban numbers stations before. I have no doubt that they're sharing transmitting facilities with Radio Havana. The R. Havana programming on numbers station frequencies is most likely due to mixing at the transmitter site. Either that or else the technicians are using a bit of the audio to test the transmitter shortly before the broadcast. It has been noted with a few of the "Russian Woman" transmissions that a few numbers are read several minutes before the actual broadcast. Here, too, it is suspected that this is to test the audio of the transmitter. However, in the case of the Cuban stations, some of the Spanish language programming is clear while the numbers transmissions are distorted. Sometimes, both the programming and the numbers are distorted, leading one to think that it's due more to technical difficulties than an equipment test. It's worth monitoring Radio Havana at the top of the hour to see if any numbers station audio gets mixed in. As far as I know, no numbers broadcast has ever been heard on R. Havana audio.
The bottom line is that with the current economic situation in Cuba, it's not always easy maintaining transmitting facilities. Thus the level of quality of the numbers transmissions tends to suffer.
Many thanks to Jeff Haverla for his observations.
Numbers loggings:
4635//5812 - E5 in AM at 0200 rptg 711 Count 95 (JM)
4505 - Cuban 5F CW cut # stn w/ 5F msg. (TS)
5325 - Scrambled speech comms in USB at 0358. (TS)
6840//9130 - E10 in USB at 0100 rpting EZI2 (JM)
7887 - Cuban YL/SS in AM at 0213. (TS)
8300 - "New Star" YL/CC in AM w/ 4F msg. (TS)
11545//12603//13375 - E3 at 1500 in USB rptg 95292 (JM)
Contributors: JM - John Maky, AR; TS - Tom Sevart, KS.
That's all for now. Catch you next month.